Saturday, January 16, 2016



EQUIPMENT :  General — Wireless Sets — Radio Relay — Cable —Exchanges & Telephones — Line Equipment — Teleprinters & Fuller Phones — Power Equipment & Batteries — Crypto Equipment — Specialist Vehicles. STATIC COMMUNICATIONS : Wireless — Line Communications — Signal Centre Procedure — Communication Boards & Committees — Amateur Activities. TACTICAL COMMUNICATIONS : Tactical Communications Committee — Line Communications — Signal Despatch Service — Plan AREN — Electronic Data Processing Systems (EDPS). CONCLUSION.

From the time of its inception in 1911 up to 1947 and even for a few years thereafter, the equipment and communication policy concepts of Indian Signal Corps were based those of the Royal Signals in UK. This was perhaps unavoidable since the Corps was officered entirely by Royal Signals which also provided a large share of the technical personnel. Also, since the equipment in service in India was produced in the UK or one of the Commonwealth countries based on British designs, it was natural that the policy for its exploitation be similar to that prevalent in UK.
During World War II several shortcomings were noticed in the existing equipment in service with signal units in the corps and divisional signal units. A comprehensive review was carried out in 1944 and the following changes were recommended in the organisation and equipment of divisional signals, which then had only two companies:-1
No 1 Company
  • In Wireless Sections A & B, the 22 set was to be replaced by 19HP. For rearward links to corps, the SCR 399 would replace SCR 177B.
  • The Cable Section (C) would hold 50 miles of D8 and 30 miles of D3 cable.
  • The Despatch Rider Section (D) would be given motor cycles as well as jeeps.
  • The Operating Section (O) would be capable of establishing two light and two heavy signal offices. This would cater for advance or step up offices for the main and rear divisional headquarters. 
  • In the H Section, for the Commander Royal Artillery (CRA), the 22 sets would be replaced by two 19HP sets, one for the forward net and the other for the rear link to Commander Corps Royal Artillery (CRRA).  Artillery lines would be laid by C Section.
  • The artillery, anti-air craft and anti-tank regiment signal sections would use the 19HP instead of the 22 set for rearward communications. 
No 2 Company
  • Since the 19HP could not be mule packed, brigade signal sections would use the 22 set with the 76 set as an alternative.  The battalion detachments would use the 22 set.
  • The N Section for Commander Royal Engineers and the R Section for the divisional reconnaissance regiment would use the 19HP set.
  • For infantry tank cooperation, the 38 set would be used.
A new war establishment of the divisional signals was issued in 1946, superseding the one that had been in existence since 1926 with several amendments (Ind/WE/I/26/8).  Shortly after Independence, the War Office Policy Statement No 25 of 30 April 1948 was issued in UK. Though this policy statement was applicable only to Royal Signals, it is of interest to us because the equipment policy in India was then dependent on UK for supply of all signal equipment, including wireless sets.
In 1949 a Signal Equipment Policy Statement was drawn up by Signals Directorate under two heads i.e. ‘Short Term’ and ‘Long Term’.  The Short Term Policy was to be applicable a maximum period of five years.  It was based on the following factors:-
  • During the next five years existing stocks of American and British types of obsolescent equipment will continue to be used for reasons of economy.
  • New items of equipment will be introduced only when stocks of existing types of equipment waste out. 
  • The substitution of existing equipment when wasted out would depend upon stocks of new equipment received from the UK and also on indigenous production and development. 
            The Long Term Policy was intended to follow the Short Term Policy, for which no firm date was given. It was based on the available information of the War Office Policy and its stability would depend on the supply of equipment ex-UK and the results of trials of this equipment in India.
The General Staff Policy Statement No 76 Issue No 2, a basic policy document on signal equipment, was approved by the General Staff Equipment Policy Committee in April 1955, in order to guide the development and production of the first series of indigenous equipment with the aim of achieving self-reliance and in order to inject an orderly family of equipment conforming to the then tactical doctrine. The salient features of GSPS No. 76 of 1955 in respect of signal equipment are given below:-2
  • Regimental communications would be based on line telephony on field cable and direct link radio telephony. Wireless sets would be a mix of HF (mobile) and VHF (manpack).
  • In infantry units, battalion to company nets would use a VHF manpack set with a range of 5 miles. Company to platoon nets would be based on a light weight VHF pouch set having six pre-set channels and a range of 1.5 miles. HF sets would be used if use of VHF was precluded due to terrain or long ranges (jungle, desert etc).
  • In armoured units, regimental nets would be based on HF sets with a range of 15-20 miles. Communications within troops and with infantry would be on VHF sets. Sets would cater for intercommunication between crew and re-broadcast facilities between HF and VHF sets.
  • Wireless sets in field artillery and anti-tank units would be similar to those in armoured units.
  • Communications in coastal batteries, light anti-aircraft and heavy anti-aircraft units would be based on two types of wireless sets, with ranges of 15-20 and 100 miles respectively.
  • For line telephony, magneto telephones with facility to work on central battery (CB) and magneto switchboards of 12 lines would be used.
  • Existing assault and D class cables would be replaced by general purpose twisted field cable weighing less than 50 lbs per mile with speech range of 8-10 miles, capable of being laid from dispenser packs or drums.
  • Charging sets of 150 watt (manpack) and 500 watt (vehicle mounted or capable of being carried on a mule) would be authorised.    
In addition to regimental communications, GSPS No 25 of 1955 laid down the requirements for wireless and line communications in corps and divisions that were to be provided by Signals. This included the types of wireless sets, exchanges, cable, telephones, carrier equipment, voice frequency telegraphy equipment and so on. In brief, the requirements were as given below:-
·         Wireless communications would be on HF, using three different types of sets, having ranges of 15-20 miles, 30 miles and over 100 miles respectively, the last two using separate sets for transmission and reception.
·         A simple man transportable radio relay of range 15 miles capable of working with 1+4 carrier telephony and voice frequency telegraphy equipment would be provided.
·         In addition to light field cable of range of 8-10 miles, D8 cable of range 15 miles would be provided. Quad cable would be suitable for use with carrier equipment such ACT (1+4). A 10 pair multi core cable would be used in place of the 7 pair VIR.
·         Switchboards would cater for 40 lines, capable of being built up to 200 lines.
·         Multi channel equipment such as (1+1) and (1+4) would be provided, the latter catering for expansion up to (1+12).
·         Single and multi channel voice frequency telegraphy (VFT) equipment would be provided, for use with fuller phone.
·         On line cipher machines with page printer would be catered for.
The next major change in equipment policy occurred in 1961 with the issue of General Staff Policy Statement No 76 (Revised). The reasons that necessitated the revision of the existing policy were the advent of nuclear weapons, enhancement in ranges and lethality of tactical weaponry and greater mobility of fighting formations and units which were likely to be widely dispersed and communications would have to be provided over longer ranges. The emphasis on electronic warfare and the additional requirement of circuits for surveillance and warning systems also had to be taken into account. Due to congestion in the available frequency bands, there was a need to exploit higher frequencies and reduce the transmission bandwidth by use of new techniques. 3
GSPS No. 76 (Revised) was issued on 22 May 1961, superseding GSPS No. 76 of 1955. It was decided that the short term policy issued earlier vide GSPS No. 61 would continue and be reviewed from time to time within the framework of the new long term policy statement. Since the development of the new equipment was likely to take considerable time, it was also decided that an interim policy would be formulated to bridge the gap between the equipment under development and the final requirement as visualised in the long term policy. 
An important feature of the new policy was with regard to the nomenclature of wireless sets. It was felt that the existing system did not convey any information about the equipment, necessitating frequent reference to data books. The new system would consist of alphabets and figures that would indicate the frequency band (HF, VHF, UHF or SHF); type of carriage (manpack, vehicular or static) and the range in kilometres. In addition, an ‘A’ would be used to indicate an amplifier used with a basic wireless set. As an example, a HF manpack set having a range of 8 kilometres would be called HM8. If this was associated with an amplifier unit that was also man-transportable increasing the range to 25 kilometres, the nomenclature of the complete station would be HM8AM25.
Another notable feature was to standardize the various types of signal equipment thus reducing the size of the inventory and giving greater flexibility in their employment. For regimental communications three types of VHF and comparable HF counterpart wireless sets were to be developed. The first of the series would be crystal controlled with a ground range of 3 kilometres; the second in the series would be continuously tuneable with a ground range of 10-12 kilometres; while the third would have a ground range of 25 -35 kilometres. For use at higher echelons, wireless sets would have ground ranges of 80, 150 and 800 kilometres. In the immediate future the sets would be in the HF band but would be shifted to the VHF band as VHF technique progressed. Sets for ground to air communication would use frequencies in the UHF band. 
The salient features of the long term policy enunciated by GSPS No. 76 (Revised) of 1961 are given below:-
  • For regimental communications, the first family of HF sets would be used if VHF could not be used due to terrain. HM-10 would be used between battalion and company and HM-30 for rearward links.
  • In case VHF sets could be used, the sets used would be VM-3/VV-3, VM-10/VV-10 and VM-30/VV-30. All sets in the VHF family would be inter-workable, with frequency coverage of 30-70 Mc/s.
  • Formation wireless sets from brigade upwards and operated by Signals would use the second family of HF sets, with frequency coverage of 1.5 – 30 Mc/s. The sets in this family were the wireless senders HV-80, HV-150 and HV-800 and receivers HR-1and HR-2.
  • Radio relay equipment would comprise two types of sets. The forward area radio relay set (RR1A, RR1B and so on) would have a range of 30-35 kilometres per hop and be capable of handling up to 12 carrier channels. The rear area radio relay set (RR2A, RR2B and so on) would have a range of 45-55 kilometres and be capable of handling up to 16 carrier channels. 
  • Scatter sets (RR3, RR3A and so on) would have a range of 200-300 kilometres. They would be integrated with radio relay sets of the RR2 system.
  • Wireless sets for other applications were the HM-800 for CW only; UV-1 for tanks; UM150/UV 150 for ground to air communication; and the general purpose VHF receiver VR-1.
  • Regimental field exchanges would have 12 lines while formation exchanges would have 40/160 lines. A general purpose field telephone would be used at all levels. For mortar and anti-tank platoons and artillery sub units sound powered telephones would be provided.
  • For clearance of message traffic, fuller phones would be used in brigades and divisions. Upwards of division, teleprinters would be used. Other equipment such as facsimile, tape relay equipment, teleprinter exchange and automatic data corrector would also be used at higher headquarters.
  • Apparatus carrier telephone (ACT) 1+1 would be used at division and brigade. At higher headquarters, ACT 4/16 channels would be provided.
  • Apparatus voice frequency telegraph (VFT) speech plus duplex (S+Dx) would be used at corps, division and brigade. Apparatus voice frequency telegraph 4/16 channel would be used at corps and division.
  • Two types of speech secrecy equipment would be developed. The lighter version for use in brigade and battalion would work off batteries, while the heavier version for use in formation headquarters would work off AC mains. 
  • An off line cipher machine would replace the existing Type ‘X’ Machine Mk II. In addition, an on line cipher machine would be designed.
  • Carrier quad capable of providing 95 kilometres range with ACT (1+4) and carrying 16 carrier channels over short line tails would be used. For forward troops, field cable providing range of 30-40 kilometres between telephones would be provided. For local lines and line tails, 10 pair cable would be used. 
Soon after the issue of the   GSPS No. 76 (Revised) of 1961, the Sino-Indian conflict of 1962 took place. A large quantity of signal equipment was received from the USA, for use in formations facing the Chinese. In addition, considerable quantity of equipment was purchased from foreign countries. This upset the planned induction of equipment as envisaged in GSPS of 1961. Another factor was the formation of the Tactical Communications Committee (TCC), which recommended several changes in the communications set up of the Army. Two important changes were the decisions to go over largely from HF to VHF radio communications, and the introduction of radio relay in the divisions. This necessitated the development of various types of new equipment. Due to shortage of time, much of this equipment was acquired from foreign countries.
Wireless Sets
            At the time of Independence, almost all wireless sets in service with the Indian Signals Corps were of British, American or Canadian origin. Most of these sets had been developed during World War II and given to India through the Lend-Lease scheme, under which war material being produced by all Allied nations was pooled and allocated to theatres that needed it most. This proved to be a boon for countries such as India that produced hardly any equipment of their own. In addition to imports under the Lend Lease scheme, some equipment was obtained after the war from ex-US Army surpluses.  The wireless sets that were in service at that time were as under:-
·                     Wireless Set 22 A general purpose HF set that could be used in vehicle, animal or manpack role, with an output of 8 watts on CW and 3 watts on RT. It had a range of 25-30 miles and was used for forward communications in divisions and brigades. Was subsequently replaced by WS 62.
·                     Wireless Set 19 Low Power/High Power         A versatile HF set used in armoured formations and also for communication between corps and division. With a power output of 9 watts it gave a range of 20-30 miles, which could be doubled by converting the set to high power using Amplifier RF No. 2. Versions ‘B’ and ‘C’ were used for intra squadron communications and communications within the tank, respectively
·                     Radio Set SCR 399    This was a medium power set used for communication rearwards of division. It was used in conjunction with generator PE 75/PE 95.
·                     Wireless Set 53  This was a general purpose HF medium power set that could be used in mobile as well as static roles. With a power output of 250 watts, it gave a range of 100 miles on rod aerial which was mounted on the roof of the vehicle when working on the move.
·                     Wireless Set 62  A general purpose HF set that could be used in vehicle, animal or manpack role,  with an output of 1.1 watts on CW and 0.8 watts on RT. It gave a range of 25 miles on CW and 15 miles on RT when stationary using a 14 foot rod aerial. The set was not hermetically sealed but splash, rain and immersion proof. It could be remote controlled from half a mile on D3 cable.
·                     Wireless Set Burndept BE201/CN348  The CN348  was used for air to ground communication. It had a power output of 3 watts and a range of 60 miles with aircraft at a minimum height of 5000 ft. The BE201 was a crystal controlled set and an improved version of CN348. It had a wider frequency coverage, slightly higher power output and better performance.
·                     Wireless Sender Marconi SWB8X This was a high power sender for long distance CW, RT, RTT and SSB transmission in the HF band. The power output was between 2 to 4 kilowatts depending on the mode and the range was 2500 miles depending on frequency and aerial used.
·                     Receiver R201 A diversity receiver used for reception of high speed telegraph signals over long distances. It had automatic frequency control (AFC) and used three rhombic aerials connected to the receiver by 75 ohms impedance feeders.
·                     Wireless Set 76/R209  The crystal control sender (76) could work off mains or batteries giving ranges of up to 500 miles on wireless telegraphy. The receiver (R209) was a general purpose field receiver with a built in vibrator power supply unit and loudspeaker. It replaced R 106, R107 and R109 receivers.
·                     Wireless Sets 48/18/46   These were very low power wireless sets used by units of Artillery, Engineers, Signals and Military Police.
Soon after Independence, it was decided to import WS 88 from UK for regimental communications. Two models of the set, known as Type A and B, were approved. WS 88 Type A had four spot frequencies viz. 40.2, 40.9, 41.4 and 42.15 Mcs. It was meant for use primarily between infantry company and platoon.  WS 88 Type B also had four spot frequencies (38.01, 38.60, 38.30 and 39.70 Mcs) and was intended for use in mortar and artillery roles. The first 100 pieces of WS 88 Type A were received in early 1948.  Type B was then still in the development stage and was received a little later. It was used for communication in mortar platoons and by Engineers during bridging operation. 
Along with the 88 set, WS 31 was also imported in 1948 for regimental communications. It was a light weight manpack set used for RT communication between battalion and company.  With frequency coverage of 40-48 Mcs and power output of 0.3 watts, it had a range of 2-4 miles.  Being dust and waterproof, it was suitable for infantry during assault landings. Shortly afterwards, it was discovered that it was an exact replica of the American SCR 300.  It was then decided to take over all available stocks of radio set SCR 300 at the US Army Surplus Stores Depot in Calcutta. (The words wireless and radio are interchangeable. The British used ‘wireless’ while the Americans used ‘radio’. In India, ‘wireless’ continued to be used until 1965, when it was replaced by ‘radio’ in all forms of military writing vide Army Order 583/65. Similarly, cycles per second or c/s was replaced by Hertz or Hz).  
             In 1949 a new policy regarding the employment of very low power wireless sets viz. 46/48/18 being used by units of Artillery, Engineers, Signals and Military Police was issued. It was decided that instead of all units using all three types of sets, each would use one or at the most two types. Accordingly, WS 48/18 was earmarked for Artillery and Engineers; WS 46 for Infantry and WS 48 for Military Police. Only Indian Signals units were permitted to use all three types. These sets had actually been superseded by WS 31 but were still being used because only limited stocks of the latter were available. Once sufficient stocks of WS 31 were received, WS 48/18/46 were phased out.4
            Indigenous research and development and the electronic industry in India was in a stage of infancy in 1947 and remained in this state up to the 1960’s. Most of the radio sets which had been in service for over a decade were approaching obsolescence in their country of origin and needed constant attention due to ageing.  Communication concepts were essentially governed by the necessity of conforming to the equipment available rather than on an integrated system tailored to meet the tactical requirements of command and control.   Most of the radio sets operating in the HF band, rear of the unit or equivalent level, had a very restricted part of this band available for usage.  Radio frequency congestion and attendant interference coupled with the susceptibility of the HF to the vagaries of natural and manmade disturbances and seasonal/diurnal propagation constraints set the thought process of switching over to the VHF for most of the short-haul radio links forward of the main divisional headquarters, range and terrain conditions permitting.
            During the late 1950’s some new equipment of post-war origin such as the radio sets C11/R210, C42 and C13, which had been introduced in the British Army, were tried out with a view to make up the deficiencies of comparable equipment supplies of which had virtually dried up due to their obsolescence in their country of origin.  For regimental communications, the 6-channel VHF crystal controlled radio set ‘P’ had been under development by M/s Bharat Electronics Ltd (BEL) since 1954, to replace WS 88.  It was then expected that production would commence in 1956.  However, certain defects were noticed in the proto-type trials during October 1955 and the sets were returned to the designer for modifications.  User trials on RS P Type ‘A’ were again carried out in April 1958 and certain defects were brought out.  In October 1959, four prototypes of RS P Type ‘A’ (for infantry company to platoon communications) and two prototypes of Type ‘C’ (used for infantry-tank communications) were sent to 50 Independent Parachute Brigade Signal Company for short trials.  A considerable amount of interference between channels was experienced and the sets were returned to BEL for aligning them on a new set of frequencies.  The Electronics Research and Development Establishment (LRDE) completed technical trials on RS P Types ‘A’ and ‘B’ in July 1961.  Short user trials revealed that the battery life of the set was low and it was not omni-directional.  In October 1962, technical trials on the AFV version of the set were completed by LRDE.  1 Armoured Divisional Signal Regiment was ear-marked to carry out user trials in the first quarter of 1963.  Meanwhile, orders for limited quantities of the equipment had been placed on BEL, much against the wishes of the Signals Directorate.  During October 1964, it came to notice that inter-channel interference was prevalent in the sets of the first production batch.  Stability of the set below -20ºC was also found unacceptable.
            In early 1963 it was learned that the RS DA/PRC 261, a 12 channel crystal controlled low power VHF set had been developed by M/s Philips (Holland) for the Dutch Army.  Six pieces of the equipment were procured immediately for assessing their suitability for introduction into the service to replace RS 88, instead of the RS P, which had still not been accepted.  The Dutch sets were subjected to user trials in Ladakh and their performance was found to be vastly superior to that of RS 88 or RS P.  An indent for quantity 900 of RS DA/PRC 261 was floated for immediate procurement in January 1964 and the supply was expected to commence from September 1964.  A letter of intent was also given to M/s Philips (India) for assembling 3,500 sets during the last quarter of 1964. It is pertinent to note that RS DA/PRC 261 was the first transistorized equipment to be introduced in service in India.
            From 1948 onwards, the wireless set used for communications between a battalion and company headquarters was WS 31, and that between company and platoon was WS 88. After the Sino Indian conflict in 1962, a considerable amount of equipment was received from the USA. This included 500 pieces of RS AN/PRC 10, which were to be issued to units facing the Chinese. It was decided to use the set for communications between a battalion and company headquarters, replacing the WS 31. In January 1963 the first lot of RS AN/PRC 10 sets was issued to 20, 17 and 27 Divisions. The WS 31 sets rendered surplus in these formations were utilized to make up deficiencies of Eastern and Western Commands.
By this time, the US Army had switched over to the RS AN/PRC 25, a new generation equipment which was the first set using the principle of frequency synthesis.  In October 1963, a formal request was made to the United States Indian Supply Mission (USISM) to provide two sets for trials, as replacement of RS 31 and AN/PRC 10.  The two sets arrived in India during April 1964 and were put through successful user trials.  Subsequently, in October 1964, trials conducted in 4 Mountain Divisional Signal Regiment re-affirmed the suitability of the set.  An indent for six sets was initiated which on arrival were put through trials in a number of units including 6 Mountain Divisional Signal Regiment.  As in the case of RS DA/PRC 261, besides procuring some initial quantity by direct import, a contract was signed between M/s BEL and M/s RCA, the manufacturers in USA, to produce the set under collaboration in India.  Subsequently, a booster unit was developed for the set indigenously by BEL, which later started producing a fully transistorized version of RS AN/PRC 25 as well as the booster.
            Till the development of the booster unit of RS AN/PRC 25, the only VHF set available with 15 watts of radiated power for obtaining longer communication range was the C42, being used in the British Army.  Four sets were procured from UK in October 1955 and issued to Technical Development Establishment (Electronics), Bangalore (it later became the LRDE) for technical trials and subsequently to 1 Armoured Divisional Signal Regiment for user trials. The trial report from the unit received in July 1961 recommended introduction of the set in the Army. A case was initiated for procurement of quantity 2,000 of this set from BEL, which was to manufacture the same under licence. Subsequently, BEL incorporated an improvement in the set for operation from 12 volt DC (for use in B vehicles) and with 50 KHz channel separation as against the original 100 KHz.  Production of the RS C42 was later stopped when it was decided to replace the equipment by RS AN/PRC 25 with booster (transistorized). 
            After it was decided to switch over command links from HF to VHF in 1963, the RS 62, a low power HF set used for regimental communications needed replacement by an indigenous set both as a backup set to VHF communication as well as for issue in lieu of the VHF set pending adequate production in the country.  In 1963 the LRDE developed RS HM 30 which was suitable for operation by a hand/pedal generator in order to cut down logistical problems in the high altitude areas.  Trials were carried out in ‘R’ Communication Zone Signal Regiment in January 1964.  The set was not recommended for acceptance. However, to make up the acute deficiencies of RS 62, it was decided to procure 2,000 pieces of this set from BEL.  The set was later declared obsolete and replaced by ‘one time’ imported GR345 and TRA922, both of UK origin, and the indigenously produced LHP202 and subsequently by RS HB, a Plan AREN era equipment.
Another wireless set that was introduced in armoured units as the companion set of RS C42 was RS C13, an HF set with phase modulation which gave longer range. Twelve pieces of RS C13 were procured from M/s British Communication Corporation (UK) in January 1958 for use in A vehicles. 
Divisional Signals is responsible for provision of communications rearward from units up to brigade and divisional headquarters. The wireless set in general use for formation level communications was the RS 19 LP/HP. This set had been in use for several years and needed replacement by a more efficient and reliable set. The set indentified for this purpose was the RS C11/R210, then in use by the British Army.  In July 1955 a statement of case for procurement of six pieces of RS C11/R210 was initiated along with an FSK (frequency shift keying) appliqué unit for radio teleprinter working. In January 1958, information was received that trials conducted in UK on FSK operation with RS C11/R210 had not proved satisfactory.  The idea of FSK working on the set was dropped and the indent was accordingly amended.
            The RS C11/R210 was found suitable after trials conducted in January 1961, and a case for bulk procurement of this set was initiated to replace RS 19 HP and C52.  The set was subsequently formally introduced in service in July 1963 and an indent for quantity 500 was placed on BEL, which was to produce the set in the country under collaboration.  By October 1963, the total quantity under indent on BEL was 2,475.   However, the production was later halted when several defects were noticed. A major shortcoming was the very high battery drain of 23 amperes on ‘send’, which resulted in the requirement of bigger and a greater number of secondary batteries.  In 1972, the RS HC, a Plan AREN era equipment with better power efficiency and higher power output was developed and began to replace RS C11/R210.
            Till 1963, a variety of radio stations had been procured from UK and USA as medium power sets for use in divisions and corps.  The two main sets in this category were the RS 53 ex-UK and SCR 399 ex- USA.  Both sets were available in two versions – mobile and static.  The American RS SCR 399 was more popular because of its ruggedness and low fault liability.  RS D11/R230, quantity 25 of which had been received as aid from UK in 1963, was not found satisfactory due to its high fault liability. 
            The large variety of equipment posed problems for procurement and positioning of their spares.  To reduce the variety and to minimize the logistics by dove-tailing the basic design of medium and high power sets, a search was on for suitable basic equipment in 1962/63. The 400 watt set developed by M/s Siemens of West Germany was tried in 1963 and was adjudged as better than RS D11/R230.  The firm was also willing to grant licence for indigenous production within the country.  The set had a number of advantages over the older types of wireless sets in this category. It provided both simplex and duplex operation; in addition to RT and CW, it provided RT-SSB, FSK and FSK with RT-AM; it had better frequency stability because of frequency synthesis; there was quick change-over from one class of emission to another and there was a facility of space diversity reception.
            In 1965 it was decided to manufacture RS 400 Watt (Siemens) under licence at BEL.  Subsequent development was the complete transistorisation of the transmitter except for the power amplifier valves and incorporation of RT-ISB emission in the transmitter.  After the introduction of Plan AREN equipment, the 400 Watt (Siemens) was ultimately replaced by RS HD.
            High Power transmitters BC 339L and ET 4331 (RCA) were procured during World War II from USA for providing long range HF communications.  These sets did not have the teleprinter and single side band facilities and were used on Static Wireless Army Network (SWAN).  They had to be phased out after the International Telecommunication Union (ITU) decreed that all static networks were required to work on SSB.  Some pieces of RS-63 procured from the UK during late 1940’s were also held by the RTT sections.  This set was extremely bulky and had restricted mobility.  A search was made to find a suitable set to replace these older types of sets.  RS D 13 (Marconi, UK), AN/TRC 115 (Collins, USA) and AN/GRC 108 (General Dynamics, USA) were considered.  The RS D13 was already developed and two sets were ordered in 1964 for ascertaining their suitability.
            At the same time, M/s Siemens of West Germany had designed a booster unit for the 400 watt medium power radio station capable of giving 1 KW power output.  Since it had already decided to go in for the 400 watt set based on Siemens design, it was decided to procure the 1 KW transmitter as well of Siemens design.  The production commenced in 1965 at BEL and by 1972 about 80 static sets had been inducted.
            Mobile high power stations were authorized to corps signal regiments and some communication zone signal regiments to bridge communication gaps which could not be covered by medium power radio stations.  Attempts were made to convert the 1 KW Transmitter (Siemens), which is basically a static station, into mobile role. However, two major problems were encountered.  Firstly, the station had to be accommodated in one vehicle which was not possible due to the weight and dimensions of the equipment and its accessories.  Secondly, the transmitter was designed to operate off three-phase power supply which is not always available in the field.  M/s BEL re-designed the equipment to work on single-phase AC mains.  However, the proposition to use only one vehicle was technically not found feasible and it was agreed to have the entire station in two vehicles – one 3-ton vehicle for installing the transmitter and another 1-ton vehicle to accommodate the receiver segment.  Two mobile stations were procured, but the performance of the equipment was not found acceptable.  The design of the equipment was also out-dated. 
            Transmitters 5 KW are required for communications over distances beyond the ranges obtained with 1 KW transmitters.  The older versions of such equipment in service were SWB8X, SWB11E and HS31.  These transmitters were imported from UK to provide RTT and SSB circuits in static role.  A few of these sets were still in service in 1972, but it was difficult to maintain them for want of spares. In order to have only one family of radio equipment with the Siemens 400 watt as the basic set, it was decided to induct Transmitter 5 KW developed by Siemens (West Germany) which would be indigenously produced by BEL under licence.   Quantity 14 sets had been inducted by 1972. Subsequently, BEL offered an improved 4 KW transmitter designed by them instead of the Siemens equipment.
            After the approval of Plan AREN by the Government in 1971, orders were placed on BEL, Bangalore for development and production of the complete range of radio equipment that would ultimately replace the existing sets. Details of the new radio equipment are given below:-5
VHF Radio Sets
VA (platoon sets) to replace VM2 1A, VM2 5A.
VB (company sets) to replace AN/PRC 25.
VC (battalion sets) to replace AN/PRC 25 with booster.
HF Radio Sets
HB to replace HM30 or equivalent.
HC to replace C11/R210.
HD to replace Siemens 400W (Mobile).
HE to replace Siemens 1KW (Mobile).
HX-special purpose trans-receiver.
Radio Relay Sets
RR (light weight) to replace AN/PRC 25 (radio relay).
RRA to replace C41/R222.
RRB to replace FM200.
HRA   - medium grade HF receiver
HRB    - high grade HF receiver
Ground to Air sets
UA to replace GU 734
UB (UA with high power).
Radio Relay
            Radio relay came to India only in the early sixties, though it had been in use in USA and UK for several years. During World War II and for several years thereafter all equipment used in India was imported. Also, many signal officers were sent abroad for training. As a result, developments in Europe and America were generally known to the Signals Directorate, which tried to obtain the latest equipment for use in India
            In 1955 it was learned that M/s Siemens and Halske had produced a transportable six channel radio link system with pulse modulation (PPM6/400) with frequency coverage 335-420 Mcs.  The use of pulse width modulation gave a very favourable signal-to-noise radio and low cross-talk values.  The system operated with six channels and thus provided up to six simultaneous telephone conversations each covering a band of .300 to 3.400 Kcs.  Distances of about 30 miles were covered in a single hop in reasonably flat country.  With relay stations the range could be increased.  The equipment was divided into portable cases, with no case weighing more than 154 lbs.  It could be fitted in a 3 ton vehicle for mobile use. It was decided to procure the radio link system with two relay stations for trials to ascertain its suitability for introduction in India. 6 
            Shortly afterwards it was decided to conduct trials on the SPO 50-50, a multi-channel radio relay system then being used by the British Post Office in UK. To conduct the trials an independent unit - 1 Medium Radio Relay Section - was raised in Delhi in 1959 under the command of Captain A.S. Kahlon.  However, the SPO 50-50, being designed for civilian use, could not meet the stringent requirements of terrain and climate.
 In 1960 eight pieces of RS C41/R222 were imported from UK. This was developed by ATE Bridgeworth for the British Army. It was a multi-channel, FM- VHF set with frequency coverage of 50-100 Mcs and power output of 50 watts. It was used for communicating over visual or quasi-visual distances of 25-30 miles using a high gain yagi aerial mounted on a 36 feet high mast. The range could be increased with the help of relay stations. The equipment could work as a ground station or mounted in vehicles. It was also capable of being transported by animals. The complete station could work as a terminal station or a relay station, with facilities to drop channels at relay stations.  The equipment was compatible with indigenous multi channel carrier equipment such as ACT (1+1) and ACT (1+4), as well as voice frequency telegraph equipment such as S+Dx and 3 Channel Duplex.  The system was found suitable and accepted for induction in the Indian Army.  Additional sets were ordered and received during 1961.  Some of these were used during the Goa operations in 1961 and proved their worth.     
In 1963 another radio relay equipment FM 12/800 manufactured by M/s Siemens and Halske of West Germany was procured for trials.  During preliminary examination the equipment worked successfully between Delhi and Karnal with relay stations at Sonepat and Panipat. However, during detailed user trials by 1 Medium Radio Relay Section it was not found suitable for use in the field on account of its weight.  Subsequently, a considerably lighter equipment, FM 12/400, operating in the 400 – 470 Mcs band, which provided 12 voice channels, was obtained. During trials, it was found that the ‘line of sight’ range was as good as that obtained with WS C41; with the squelch system provided in the receiver the background noise was  less; tuning and operation was easier; front-to-back ratio of radiation was low and aerial alignment was not critical.
The RS FM 12/400 was also tried out in Jammu & Kashmir, where it was found that although it was lighter than the C41 and was fully transistorized, it suffered from certain defects. Being crystal controlled, it could only be used for single channel operation. There was a high back fire of the aerial, which was conspicuous and could be easily detected from air. In 1966 comparative trials of FM 12/400, C41/R222 and AN/PRC 25 (in radio relay role) were conducted in 4 Mountain Divisional Signal Regiment.
            In 1968 multi channel radio relay equipment THC618 offered by a foreign firm was evaluated by Special Signal Regiment.  The equipment operated in the frequency range of 70 – 150 Mcs and provided 640 channels.  Trials carried out in Special Signal Regiment brought out that the set was comparable to RS C41/R222 and offered no distinct advantage over it except that the aerial mast provided with the equipment being of pneumatic type was easier to install.  The aerial was a three element yagi with transmitting and receiving arrays mounted at right angles to each other on the same mast. 
            In 1968 M/s BEL produced a lighter version of RS C41/R222. The light weight set known as RS C41/R222 (Modified) was smaller in size by about 50% and in weight by about 80%. It was housed only in two cases viz. transmitter and receiver which carried their own power supply units. The power consumption was also less.
            In 1968 another radio relay set FM 200 was received for trials from Siemens. The set was an improved and transistorized version of FM 12/800, developed for multi channel radio relay communication for use in rear areas. The frequency coverage was from 225 to 480 Mcs and 810 to 900 Mcs continuously tuneable with channel spacing of 125 Kcs. It provided 4/12/24 channels plus one service channel on FDM and PCM/TDM. With power output of 12-20 watts, it gave a range of 35 kilometres. The power supply used was 110/220 volts AC single phase or 24 volts DC with automatic change over from mains to battery supply. The set was tried out by Special Signal Regiment and two corps signal regiments and was found to be much superior to RS FM 12/800.  Since it fully met our requirements it was decided to purchase 24 sets immediately from West Germany. A case was also taken up for indigenous manufacture of the sets by BEL in collaboration with M/s Siemens. 7
In 1947, the types of cable in service were the same as those that had been used during World War II. At the Field Force level, the lines were based on field cables like D3 and D8, Assault No. 2, 7-pair VIR and carrier quad. Multi air line cable using cadmium copper wires was authorized for higher formations. The cable was laid using various types of cable laying equipment from vehicles, animals or manpack.
            In 1950 trials were carried out with three types of manpack cable layers with the intention of selecting the most suitable type for the Army’s requirements. These were the Manpack Cable Layer (German); the Packboard Cable Layer No. 4 developed by Technical Development Establishment (Instruments & Electronics), Dehradun and the American cable laying apparatus known as Reel Equipment CE-11. The German type cable layer was found to be the most suitable, being lighter, easier to handle and faster. It also had the facility for intercommunication between the layer and the originating end during the period of laying.
In 1951 it was decided to discontinue the use of obsolete types of cable layers and standardize the cable laying apparatus in the Army. The various types of apparatus cable laying (ACL) that was approved were the ACL No.10, ACL No. 6 (to replace ACL No. 2), ACL No. 6A (for snow covered regions only), ACL No. 11 (to replace ACL No. 3) and ACL No. 8 (for troops equipped with mules).
Till that time, cable on manpack basis was laid from drums and the process was very slow and strenuous.  In 1949 a lighter version of the cable was developed in UK which could be laid from a dispenser pack, resulting in greater speed and less fatigue.  The Cable Electric D10 was a light weight general purpose field cable intended to replace existing D3, D8 and Assault No. 2 cables, for use mainly at divisional headquarters or lower levels.  The cable consisted of three strands steel and four strands copper, all strands being 0.011 inches in diameter and provided in the form of a twisted pair only. It was insulated with polythene and sheathed with nylon and was to be supplied in half mile lengths in dispenser coils, capable of being laid at speeds up to 100 miles per hour.  The coils were packed in canvas to withstand free dropping from air. It was decided to import the D10 cable to replace the existing types of field cable D3 and D-8. The TDE (I&E), Dehra Dun was asked to design winding machines to enable the coils to be wound in the field.8
After the 1962 war, considerable amount of cable was procured from foreign countries. This included JWD1/TT from Japan, WD1/TT from USA and D10 from UK.  During preliminary trials they were found suitable in electrical and mechanical performance, except for some minor defects. In hot weather the cables became so hot that it was difficult to hold them in a naked hand; due to their smooth   surface and the cables being thinner than the existing cables, they slipped when pulled for tying back; except for D10, all other cables had a shining surface which gave a shine up to a distance of 200 to 300 yards in bright daylight.  All these cables had generally the same electrical and mechanical properties. The cables were subjected to detailed user trials by 26 Infantry Divisional Signal Regiment. All cables were found suitable.  The range obtained with existing field telephones was 15 to 16 miles. Speed when laid by hand was 2 miles per hour and when laid from a vehicle with ACL No. 11 was 3 to 4 miles per hour.
Indigenous manufacture of WD1 and D10 cable was subsequently taken up at the Ordnance Cable Factory, Chandigarh. By 1965 the position of field cable had improved and it was decided decontrol field cable D3, D8 and assault cable and use the existing holdings of these cables for training.  The hard scales in respect of cable were removed and additional issue of up to 50 percent of authorisation in respect of WD1 and D10 cable was also approved for training to all units.
In 1967 it was decided to rationalise the authorization and holding of the four types of carrier quad cable viz. P Mk I, P Mk 2, P Mk 3 and heavy duty Bulgarian P 270. The Bulgarian heavy duty cable was considered most suitable for corps arteries and was authorised to brick type line sections. It was also issued to medium radio relay sections and command signal regiments. P Mk 3 was suitable for divisional arteries and issued to divisional signal regiments. The P Mk 1 and 2 being old and unreliable were utilised for providing carrier tails at division, corps and communication zone headquarters.9
 Cable Carrier Quad Type ‘P’ Mk 3 also began to be manufactured at the Ordnance Cable Factory, Chandigarh from 1969 onwards.  Another cable that was introduced at the same time was light weight communication quad cable. This was tried out in Special Signal Regiment along with couplers and loading pots and found satisfactory.  The cable had four copper and three steel strands. About 400 metres of cable were bound on one drum. The cable had excellent electric characteristics with very low attenuation, high insulation resistance and a cut off frequency of 30 KHz when loaded. 
           Before the commencement of the 1971 war, action was taken to make up the deficiencies of cable and also cater for the likely operations in East Pakistan where additional lines would have to be laid behind the advancing troops.  Cable Carrier Quad P 270 was imported from Bulgaria in 1971. In addition large quantities of cable were ordered from indigenous sources.  This included an order of 44,000 kilometres of cable WD1 and 1400 kilometres of cable carrier quad 1A on Ordnance Cable Factory, Chandigarh. In addition, an order for 500 kilometres of Cable 10 pairs plastic was placed on M/s Indian Cable Company.
Exchanges & Telephones
In 1947 the various types of exchanges and telephones in service were as under:-
  • Switchboard Command 200 Line  This was a magneto type switchboard with conference facilities for use at larger headquarters. It could accommodate 20 junctions and 180 extensions, the former being able to work to any type of exchange e.g. magneto, CB and auto.
·         Switchboard (F & F) 20, 40 and 60 Line This was a general purpose magneto switchboard for use in the field.   The capacity could be 20, 40 or 60 lines according to the requirement. It had the facility for conference calls and the junctions could work to magneto, CB and auto exchanges.
·         Switchboard Magneto 10 Line (WD)  A portable magneto switchboard for use in units and smaller headquarters. It was very rugged and could be used in any climate or weather. It was used with a telephone set L or equivalent.
·         Exchange Magneto (WD) Unit Type N Positions A magneto exchange that provided 50 magneto extensions and 10 universal exchange lines per position. It could be built up to a maximum of 300 magneto extensions and 60 universal exchange lines.
·         Exchange CB Multiple (WD) Unit Type N Positions A central battery exchange for use at large headquarters; it was capable of providing 50 extensions and 10 junction lines. The maximum capacity of the exchange was 900 extensions and 50 junction lines.
·         Telephone Set J  A light weight tropicalised field telephone for use with magneto or CB exchanges or  point to point circuits. It gave a range of 18-20 miles on D8 and 13-15 miles on D3 cable. It was housed in a sheet metal case and was designed to be immersion proof.
·         Telephone Set L  A portable set for use in forward areas and by linemen. Ranges obtained were slightly less than those from Telephone Set J, which replaced it. 
·         Telephone Set TP-6  This was designed for use on common battery lines of corps and army headquarters. It was similar to a commercial telephone but was treated for tropical use. It could operate over a 30 db net loss circuit.
·         Telephone Set EE8, EE8A and EE8B This was a compact, rugged and portable American field telephone that could work on CB and magneto. It was carried in a leather/nylon/canvas case with straps and could work on a line with 30 db loss.
·          Telephone Set F A portable telephone that could be used with magneto or CB switchboards. It gave ranges of 14-16 miles on D8 and 8-10 miles on D3 cable. A buzzer or magneto generator was used for calling.
·         Telephone Set F (HP) The telephone was provided with an amplifier unit which increased its range two and a half times.   
Tele Set ‘F’ Mk-II TMC
There was almost no change in switchboards and telephones until the early sixties, when some equipment was procured from abroad. This included the 40 lines switchboard manufactured by M/s Ericsson of Sweden. Known as the AMB 1012, this exchange used the latest technology such as spring loaded cords and had a very low insertion loss of .25 db. It was housed in slip-in type units complete with speaking, ringing and clearing circuits. Another switchboard produced by Ericsson was the 12 line AEM 1022 which had similar facilities.  Two switchboards imported from UK were the 30-60 line SB 86 and 12 line SB 22. 
Indigenous manufacture was also started at the same time. The Switchboard Field 1A, a 40 line single position switchboard that was to replace the F & F, was fabricated by the P&T Workshop, Jabalpur. It was rather bulky (132 Kg.) compared to the Ericsson 40 line whose weight was only 57 Kg. However, in view of the shortages of switchboards it was decided to induct the equipment in service. By 1967 over 400 pieces of Switchboard Field 1A had been procured. A 12 line magneto switchboard designed by the Electronics Research and Development Establishment (LRDE) was also tried and found acceptable.
The Telephone TA/PT-1 (Sound Power) was procured from the UK. A field telephone was developed by ITI to replace the existing field telephones. Trials carried out by Special Signal Regiment and 26 Infantry Divisional Signal Regiment in 1964 found that the telephone apart from being comparatively heavier did not give adequate range. Hence it was not accepted. However, the field telephone manufactured by Bell of Belgium was found suitable. Switchboards TU 11 (10 lines) and TU 21 (20 lines) were imported from Czechoslovakia and the M194-M (40 lines) from the USSR for trials in 1965. TU 11 was not found suitable and rejected. However, the TU 21 and M194-M were found acceptable.
The transistorized Repeater Field Telephone No 1 was designed by LRDE in 1966 based on the design of the equipment received earlier for trials from UK. An order was placed for 200 pieces to make up the deficiency of Telephones F (HP) and Amplifiers Field Telephone, which would be replaced by this equipment.  The utility of this equipment was however different from those it was replacing.  Whereas Telephones F(HP) and Amplifiers Field Telephone were individual subscriber equipments, the Repeater Field Telephone No. 1 could  only be used between exchanges and was thus a common subscriber equipment. 10
            In 1967 the Indian telephone Industries (ITI) developed a new telephone set that gave a range of 30-40 kilometres on all types of cable. The telephone was subjected to trials in two infantry divisional signals regiments and found acceptable. A manual 40 line switchboard developed by ITI was also subjected to intensive trials in an infantry divisional signal regiment, but its performance was found to be inferior to that of the switchboard F&F and switchboard Field 1A. Hence it was not recommended for introduction into service. In 1968 a 15 line switchboard developed by LRDE Bangalore was made available for trials. It had a low insertion loss of .3 db and its capacity could be increased to 30 lines. However, its performance as not found to be satisfactory.
            In 1970 it was decided to authorize the ITI field telephone and the magneto telephone to all units. An order of 8340 field telephones was placed to cater for the requirements during the next five years. Meanwhile the indigenous Switchboard Magneto 50 lines (Ericsson) had been cleared for production in 1971. Deliveries of this exchange started in 1972. Simultaneously, orders were placed on M/s Ericsson for 1000 pieces of their 15 line exchange. A 15 line cordless exchange developed by LRDE was also accepted, though it had certain limitations for use in the field and could be used in vehicular role only.
Telephone exchange in Calcutta, July 1971
Line Equipment
            Other than exchanges, telephones and teleprinters, various types of equipment were in use for deriving additional telephone and telegraph circuits on trunk lines. Some of the equipment in use in 1947 was as given below:-
  • Apparatus Selective Carrier No. 1  This provided a point to point circuit on a open wire route. It used 28 spot frequencies and 14 circuits could be set up simultaneously on the same route without mutual interference. The range was 100 miles at lower frequencies and 20 miles at higher frequencies. The ACT (1+4) could be used simultaneously on the same pair of wires.
  • Apparatus Carrier Telephone (1+1)   This provided an additional speech circuit on open wire lines, unloaded or lightly loaded cables with cut off frequency above 9 Kcs. It had an output of +18 db and a range of 5 db for the carrier circuit over line with attenuation of 46 db at 9 Kcs. 
  • Apparatus Carrier Telephone (1+4) This provided one audio and four carrier channels over two or four wire lines. The output was + 5 db and the range was 3 db on carrier circuit over two wire line of attenuation 40 db at 40 Kcs or four wire line with attenuation 42 db at 16 Kcs.
  • Apparatus Carrier Telephone 3-Channel Types SAS & SAT  These provided high grade permanent long distance communications giving one audio and three carrier circuits over a two wire physical line. The output was +17 db and the range was 0 db over a line with uniform attenuation of 34 db at 30 Kcs.
  • Apparatus Voice Frequency Telegraph (S+Dx) This provided simultaneous telephone and telegraph duplex channel over a physical or carrier telephone circuit. It could be used over a line of 50 db attenuation at 1.9 Kcs.
In 1949 a new version of the ACT 3-Channel SAS/SAT system known as SUS/SUT was subjected to bench trials at Eastern Court, Central Telegraph Office, New Delhi, under supervision of the manufacturers Automatic Telephones Equipment (ATE), Liverpool. The equipment was identical in purpose to SAS/SAT, and the same carrier frequencies had been used for the 3 channels in each case. However, the equipment had been reduced in size to one 10 ft. 6 in. high bay instead of three 8 ft. 6 in. bays that were used for SAS/SAT.  The bench trials were successful. However, the P & T Department preferred Standard Telephones and Cable Limited equipment to that of ATE, because the former had been found more reliable and its supply of spares was more regular. Manufacturers of ATE offered to mount SUS/SUT equipment in two or three bays of smaller size in lorries for use by the Army. 
Another piece of equipment evaluated at this time was the Two Tone Voice Frequency Carrier Telegraph System of Standard Telephones and Cables Limited. This system converted double current telegraph signals into voice frequency tones suitable for modulating a radio carrier wave and similarly converted tones from the output of a radio receiver into double current signals which could be associated with a teleprinter or with any other telegraph instrument up to a maximum speed of 75 bauds. A maximum of 18 carrier frequencies were available spaced 120 cycles apart, the lowest being 420 cycles  and the highest 2460 cycles.  These corresponded to the 18-channel VFT system that was in extensive use in this country.  Thus a maximum of nine 2-tone channels could be obtained for working over radio links, or a suitable combination of 2 and 4-tone channels could be worked, e.g. five 2-tone channels and two 4-tone channels.11
In January 1963 channelling equipment for radio relay working Carrier Telephone Terminal ACT (1+4) was received from M/s Radio Engineering Products, Canada. The equipment comprised Telephone Carrier Terminal TA 5006; Group Modem F 35700 and Communication Patching Panel SB 611/MRC.   The equipment was capable of providing up to 24 channels in frequency range of .3 to 116 Kcs and had a range of approx 40 miles on spiral four cable on 4-channel working.   Accelerated trials carried out revealed that the equipment was lighter and more compact than any of the carrier equipments in use.  It was recommended that 250 pieces of the equipment be procured from Canada for the medium radio relay sections.
The Telegraph Regenerative Repeater DE- 229000/1 to remove distortion effects of land lines and wireless links was developed by ITI at this time. The equipment was designed for insertion in telegraph circuits to correct distortion and send out fresh distortion-less signals at the correct speed.  A case for the procurement of the equipment for trials to assess its suitability for Army was initiated. 
The General Staff Policy Statement of 76 (Issue No 2) of 1961 specified that carrier equipment such as ACT (1+4) and ACT (1+1) and voice frequency telegraph equipment such as S+Dx would be used at formation headquarters down to brigade level. Within two years the  requirement of the number of channels visualized to be provided by Apparatus VFT and ACT, vide GSPS No 76 (Issue No 2)  had to be revised to cater for 6/12 and 2/24 channels respectively, instead of 4/16 channels in both cases.  This became necessary because the Apparatus VFT as visualized in the GSPS was required to work at speeds up to 100 bauds for rapid clearance of traffic.  To work the telegraph equipment at this speed, the bandwidth required as per CCITT recommendations was such that it was possible to obtain only 12 and 6 interference free channels on 4 wire and 2 wire basis respectively. As for the ACT, the amendment aimed at bringing future carrier equipment in line with other telephone carrier equipments developed and manufactured by technologically advanced countries and the equipment of P&T pattern.  These equipments, with the help of group modulation units, could build up to 12 or 24 channels and multiples of 12 channels.  The revised GSPS was amended to guide development of future carrier equipment which should be capable of providing 4/12/24 channels. 12
In 1964 the Tactical Communications Committee recommended that radio relay with associated carrier equipment be authorised to all mountain divisions. A year later this was authorised to infantry divisions as well. These decisions gave a fillip to the design and production of line equipment in the country. The ITI and LRDE, which were mainly responsible for the design of line equipment, were also given the task of producing lighter and more rugged versions of the equipment already in use by the Army.
            By 1965 both LRDE and ITI had designed and fabricated transistorized versions of Apparatus VFT (S+Dx) against the General Staff requirement for the existing equipment to be replaced by really light and compact equipment. Preliminary examination of the equipments carried out by Special Signal Regiment revealed that both equipments were likely to meet our requirements. Simultaneous Phase 1 trials were conducted by IV Corps Signal Regiment, followed by Phase 2 trials at the School of Signals.  The equipment was found acceptable and cleared for introduction into service.
            In 1966 orders were placed for the supply of ACTT (1+4+4) quantity 56; group modem quantity 50 and VF attachments quantity 304.  The components for the ACTT (1+4+4) were already available in the country and the equipment was being assembled in 509 Central EME Workshop Agra while the group modems and VF attachments were being imported from Canada.  The VF attachments were for use with the ACTT 1+4+4 which provided one physical speech channel of reduced band width,  four carrier speech channels and four VFT channels.  The output at the terminals of the four VFT channels was available in the form of VF tones, and not DC.  These VF tones were converted by the VF attachment into DC Signals for the teleprinter.  In turn the DC signals from the teleprinter were converted into VF tones by the VF attachment. 
            In 1967 production models of transistorized ACT (1+1) and ACT (1+4) were made available by ITI for troop trials.  Phase I trials were conducted in Special Signal Regiment and Phase II and Phase III trials in two corps signal regiments and selected divisional signal regiments.  The equipment performed well during troop trials and was cleared for introduction into service. Production of these equipments commenced in 1968 but it was only in 1970-71 that they began to reach the units.
In 1968 prototypes of group modem developed by ITI were made available for trials, which were conducted in Special Signal Regiment.  The equipment provided 3+12+12 channels on radio relay path or carrier quad cable in conjunction with three each of ACT (1+4) 3A and Apparatus 4 channel Telegraph (ITI). 
            During the troops trials of ACT (1+4) 3A some discrepancies were noticed in the performance of the equipment while working on radio relay system C41/R222. The reasons for these were investigated by a team of engineers from ITI attached to Special Signal Regiment. As a result of this, a suggested procedure for lining up the radio relay system while mounting ACT (1+4) 3A was issued by Army HQ in February 1970. This was also issued as an Appendix to the User Hand Book on ACT (1+4) 3A.  Proving trials of the equipment on radio relay were conducted in Special Signal Regiment, I Corps Signal Regiment and XI Corps Signal Regiment to assess the performance of the equipment in light of lining up procedures issued by ITI.
By 1971 the transistorised versions of ACT (1+4) 3A, ACT (1+1)1A and App VFT (S+Dx) 4A had reached the units but the quantities were small. For example, the authorised/held quantities of the three equipments in divisional signal regiments were 50/8, 75/6 and 100/8. The situation in corps signal regiments was slightly better, where the figures of authorised/held quantities were 50/18-24, 50/12 and 60/12-14 respectively. However, it was ensured that each field unit would have a minimum of two pieces of each equipment.13
Teleprinters & Fuller Phones
At the time of Independence, there were basically two pieces of equipment that were used for transmission of telegraph signals - the fuller phone and the teleprinter. The Fuller Phone Mk 4 was a portable direct current telegraph instrument for use in forward areas that was practically immune from interception. It was highly sensitive and provided reliable communications at extremely low currents of 2-5 micro amperes. It could be used over twin lines or a single line and earth return. It could also be used on a simple series superposed circuit or superposed phantom circuit. Under field conditions it gave a range of 15-20 miles which could be increased many times over PL. Several models of the instrument were available, with additional facilities. The Mk 4* was fitted with radio suppression to reduce the possibility of radio interception. The Mk 5 had a tropical finish and was fitted with a crash limiter which reduced acoustic shock from ringing currents when a telephone was used in series. The Mk 6 was fitted in a metal case and was immersion proof and tropicalised. In addition to Signals, fuller phones were authorized to Infantry and Artillery units. 
The Teleprinter 7B (WD) provided a means for rapid and accurate transmission of intelligence over land line and wireless. It was an automatic telegraph machine that used the start-stop principle and employed the Murray code.  It could be used on single wire and earth, 2-wire or 2-wire and earth return circuits. The Teleprinter 7B (WD) used a power supply of 24 volts DC for the motor and 12+12 or 80+80 volts (depending on the line condition)  for telegraph signalling. The speed was 50 bauds or 66 words per minute.  It had a keyboard similar to that of a typewriter and could be operated by a typist. The teleprinter was used by Signals and authorized to almost all signal units from brigade upwards.
Teleprinter 7B (WD)
In 1950, a new teleprinter was offered by M/s Creed, a British firm. Two versions of the Teleprinter Creed Type 50 were offered, one for base use and the other for relatively forward areas.  Both sought to overcome errors due to omission from the transmission of ‘line feed’ or ‘carriage return’ signals.  They were to be smaller and lighter than earlier models.  The specifications required them to operate for 1000 hours without adjustment and 5000 hours without major overhaul.  The project was then still in the early stages and it was not known when the teleprinters would be produced.
In 1956 The Government decided to establish a teleprinter factory in India.  The proposed factory would also satisfy the requirements of Army in respect of teleprinters and ancillaries. In order to find out the latest techniques used in the manufacture of such machines so as to produce a suitable qualitative requirement (QR) on teleprinters and other five unit code machines, it was decided to import a few pieces of equipment for trials. Accordingly, two models of teleprinters were obtained from Siemens and Halske, West Germany. These were the Tape Teleprinter Type 68 and Page Teleprinter Type 37, along with a Tape Transmitter.
  Another equipment obtained from Creed for user/technical trials was the perforator typewriter which has been developed in UK.  With the existing perforators it was not possible to obtain local record copy and as such correctness or otherwise of punched tape could not be ascertained at the time of punching.  With a perforated typewriter a local copy simultaneously with the punched tape was obtained. The typewriter keyboard was simpler than the teleprinter keyboard.  Its operation would also be easier with the result that the traffic clearance capacity of an operator would increase.  The machine would be useful in static signal offices where the traffic load was heavy.
  Along with the Creed perforator typewriter the Cocoqulet teleprinter produced by Ateliers de Construction Electriquits, Charleroi, Belgium was also requisitioned for trials from the British concessionaires, Pye Telecommunications, Cambridge. The teleprinter used a 32 character system similar to the Murray Code.  The speed of transmission was 50 bauds. The special advantages of the system were reduced distortion, better immunity to interference, slow fading and selective fading.
            Though the decision to establish a teleprinter factory in India had been taken in 1956, it was only in 1962 that it bore fruit. The two firms in contention were Siemens of Germany and Olivetti of Italy. There is an interesting story of how the matter was decided. The SO-in-C, Major General R.N. Batra gave a presentation to the then Defence Minister, Mr. V.K. Krishna Menon, on the various types of equipment to be purchased for the Army. Also in attendance were the Army Chief, the Defence Secretary and the Financial Advisor. Since teleprinters were needed by Defence as well as the Department of Posts and Telegraphs, the SO-in-C recommended that both departments should procure the same model, for the sake of standardization He gave a number of reasons to support his view, such as economy in production, repairs and training. After hearing him out the Defence Minister said, “I will not have the teleprinter in Defence that the ‘Postman’ is going to have. If they go in for Siemens, we will have Olivetti, and vice versa.”
Fortunately, the 1962 war erupted soon afterwards and Krishna Menon had to resign. Wiser counsels prevailed and Olivetti was selected for Defence as well as the Department of Posts and Telegraphs. The new factory of Hindustan Teleprinters Ltd. was set up at Madras in collaboration with Olivetti and started production in 1963. The first model produced was the Teleprinter T2CN (Olivetti). Shortly afterwards, a ruggedized version known as Teleprinter T2CNF (Olivetti) was produced for use in field units of the Army.
Teleprinter T2 BCNF
The Teleprinter 3A (T2B-CN) and Teleprinter 4A (T2B-CNF) began to be issued to units in 1966. Shortly afterwards, two new models known as the T2BSN and T2BSNF were designed for exclusive use of the Army. The Teleprinter 5A (T2BSN) began to be issued to units in 1969, while the first batch of Teleprinter 6A (T2BSNF) was issued a year later in 1970. However, the rate of production was very slow.  The supply of field teleprinters was about 500 every year, while that of static teleprinters was only 100 each year. It was estimated that the complete requirement of teleprinters would be met only by 1975. Accordingly, units were advised to continue using the older Teleprinters 7B (WD) and GPO Mains until they became unserviceable and beyond economic repair. 14
Power Equipment & Batteries
            All electronic devices need electrical power. Depending on the size and complexity of the equipment, the power can be supplied by primary cells, secondary batteries or generators. In addition, charging sets are needed for charging secondary batteries. Some of the power equipments in use in 1947 were as under:-
·                     Charging Set 60 W No. 1  This was pedal driven charging set with an output of 4 amperes at 15 volts. It was used with WS 22, 62 and 76.
·                     Charging Set 80 W  A light weight charging set that used petrol as fuel and gave an output of 18 volts DC. It was used with WS 62 and 76/R209.
·                     Charging Set 300 W Johnson Chorehouse CHI 395.5  A petrol driven air-cooled charging set that gave an output of 15 volts DC.
·                     Charging Set 550 W No. 1 A petrol driven air-cooled charging set that gave an output of 18 volts DC. The No. 2 model also had a switchboard. The Charging Set 550 W SCR 169 was smaller in size and lighter, with the output voltage being 32 volts DC.
·                     Charging Set 1260 W No. 1   A petrol driven air-cooled charging set with 35 volts DC output and a switchboard. The No. 2 model had the same characteristics except that the voltage that could be varied from 18 to 36 volts.
·                     Charging Set 4 KW Lister A petrol driven air-cooled charging set that delivered 80-125 volts DC.
·                     Generating Set 2 KVA Onan A petrol driven air-cooled generator that delivered 230 volts AC at 60 cycles. It was used with WS 36.
·                     Generating Set 3 KVA Onan This was a petrol driven water-cooled generator that delivered 230 volts AC at 60 cycles. It formed part of WS 10 and WS 53 stations.
·                     Generating Set EDC 3.5 KVA This was a petrol driven water-cooled generator that delivered 230 volts AC at 50 cycles. It was used with WS 53.
·                     Generating Set 15 KVA Lister A diesel driven water-cooled generator that delivered 230 volts AC at 50/60 cycles. It was carried in a two wheeled 1 ton trailer and used with WS 63.
·                     Generating Set PE-75 This was a 2.5 KVA petrol driven air-cooled generator of American origin that delivered 115 volts AC at 60 cycles. It had to be started by hand and was used with a large number of American radio sets of the AN/TRC and SCR series.
·                     Generating Set PE-95 A to D  These 5 KVA petrol driven air-cooled generators delivered 115 volts AC at 60 cycles. They had electric starters and were used with the SCR 299, 696 and 698. The G and H models had an output of 5-10 KVA at 115-230 volts. They were used with SCR 299, 399 and 499.
Secondary batteries of various types were used for wireless sets. There was an acute shortage of ‘battle batteries’ used with WS 38 and 48 in the early years and it was decided to declare this item as rationed.  Under the rationing scheme, a bulk allotment was made to commands every quarter at the scale of 12 batteries per set on operational tasks and three batteries per set under training. Indigenous production was started in December 1947 and 4,000 each of battle batteries for WS 38 and 48 were produced.
During the war the ‘Ruben Mallory’ type dry battery had been designed in USA and used with the VCR 300 set which was similar to the British WS 18 and 38. The War Office in UK had adopted this design in 1946 and started making dry batteries that were sent to all theatres for trials.  60 batteries were sent to India by air and 60 were despatched by sea in March 1947.  Trials were conducted on the batteries that arrived by air at the ISC School, Mhow with WS 38 under normal working conditions.  It was noticed that the shelf life of these batteries was very low. The time lag between the date of manufacture and their arrival at Ordnance Depot in India needed to be greatly reduced, to prevent deterioration ‘on the shelf’.
Out of the 60 batteries sent to India by sea, 39 were found to be unserviceable on arrival (their life then being 8 to 10 months) and others were rapidly deteriorating.  When this was reported to the War Office it was learned that the batteries sent were the first of this type produced in Britain and were not expected to be perfect in the first instance. A fresh lot was despatched to India in December 1947.  These were sent directly to units with a questionnaire for their comments and feedback.
            By 1949 the position of battle batteries had improved considerably and instructions were issued to make full use of these battle batteries both for operational and training purposes.  However, due to their shelf life being 9 - 12 months, it was noticed that large quantities of battle batteries were becoming unserviceable whilst in storage.  Within six months approximately 17,000 batteries became unserviceable while lying in storage, involving financial loss to the extent of Rs. 3,54,000. 
The indigenous production of dry batteries in India also started around 1950. The firms in India could produce only ‘Can’ type batteries and not the ‘Layer’ type, which were more compact, lighter and had greater shelf life.  The two firms which had been meeting service requirements of dry batteries were M/s Estrella Batteries Limited and National Carbon Company.  They were approached to produce ‘Layer’ type batteries but expressed their inability to do so.  Meanwhile TDE (I & E) Dehradun succeeded in producing a ‘Layer’ type battery and arrangements were made for the manufacture of such batteries in the Ordnance Factory.  The rate of production of batteries 162/3 volts was expected to be 1000 per month.  The Ordnance Factory also undertook to manufacture batteries 90/1.5 volts used with WS 88.  Production of these batteries was expected to commence towards the end of the year 1951.  The number of dry batteries, which could be produced in the Ordnance Factory, Dehradun was limited, due to shortage of accommodation.  In view of the very large number of dry batteries of various types needed, it was recommended that an Ordnance factory be established to produce dry batteries only.
            There were not many changes in the charging sets and generators being used during the 1950s. As in the case of other equipment, it was only in the early sixties that several new models were developed. The 150 watt constant current petrol/kerosene charging set was intended to be used for charging secondary batteries of low power wireless stations in forward areas. It would replace the Charging Set 80 watt. The Charging Set 500 watt was also developed for charging secondary batteries of low power wireless sets and was to replace the Charging Set 300 watt. The Charging Set 2 KW was to replace the Charging Set 1260 watt. The Charging Set 5.4 KW was developed as an interim replacement for the Charging Set 6 KW. In the category of generators, the Generating Set 3.5 KVA was developed as a replacement of all existing generating sets in the power output range of 2 to 3.5 KVA.15  
            In 1963 two portable charging sets were received from the USA for trials. The Generating Set Tiny Tiger No 302 was a small portable manpack generator/charging set, with an output of 0.6 amperes at 250 volts AC or 12.2 amperes at 12 volts DC. Out of the 12 sets examined by the Signals Trials and Demonstration Unit, two failed after 50 hours running due to heavy carbonization. The Charging Set 150 watt (USA) was tried by the same unit and also failed due to the same reason.
            At that time the batteries being used with WS VM50 were the 12 volt, 20 ampere-hour silver zinc type, at the scale of one battery per set. The silver zinc batteries were non-spillable and came in a foam case provided with a shoulder strap attached to a cane basket for easy carriage. The battery was extremely sensitive as regards the charging rate and specific gravity and was frequently damaged due to negligence. The problem was overcome in 1964 with the introduction of the Battery Secondary 12 volt, 20 ampere-hour of indigenous manufacture, which replaced the existing batteries 12 volt, 14 ampere-hour and 12 volt, 22 ampere-hour.  However, since the rate of supply was very slow, these batteries were issued only to units holding WS VM50 and WS 62 in the first instance.
            After the authorization of radio relay equipment to divisions the issue of suitable power equipment for the WS C41/R222 had to be decided. Since the Power Unit PE-75 was lighter as compared to Generating Set 3 KVA/3.5 KVA and could be broken up into mule loads, it was decided that radio relay sections forming part of mountain divisional signal regiments would be issued PE-75 while  medium radio relay sections would use the Generating Set 3 KVA/ 3.5 KVA . Subsequently, the holdings of Generating Sets 3 KVA/ 3.5 KVA were rationalised within commands. The bulky and a heavy generating sets such as the 3.5 KVA Lister/Coventry Climax were issued to command, corps and communication zone signal regiments, while the lighter generating sets in this category were issued to divisional signal regiments. 
In 1967 a new policy was issued   regarding the various types of charging sets to be used with low power radio stations in the interim period and at the final. The salient points were as given below:-
Type of Radio Station                                                Type of Charging Set
Interim                        Final 
·                     RS 62 (Manpack)                                            80 W                                       150 W 

·                     RS HM 30, 62 (TPSU), R105D                      80 W/150 W                150 W
AN/PRC-25 with booster, VM-50,
GG 733 and GR 345 

·                     S76/R209, BE 201, CN 348,                                      150 W/300 W              150 W
62 (Rotary) and AN/GRC-9 

·                     RS 19, C11/R210, C42, C52,                         300 W                         500W
      C-13, R112, R113 and GR 345

It was also decided that the project for development of Charging Set 8 KW as visualized in GSPS No 81 would be closed, since the requirement could be met by Charging Set 6 KW that was under production.  It was also felt that the various types of heavier generating sets in the range of 10-18 KVA could be rationalised. Since the Generating Set 12.5 KVA could meet the power supply needs of all field signal units, it was proposed that this should be standardized, as a replacement for the Generating Set 15 KVA, 17 KVA (or 18.75 KVA) in addition to Generating Sets PE-95 and 9 KVA.
            In 1968 the policy regarding Generating Sets 3.5 KVA had to be reviewed after it was brought out during trials of 400 Watt Mobile station that a power source of 3.5 KVA is not quite adequate.  Further for radio relay station a generating set of 2 KVA capacity was adequate both from the point of view of power rating as well as of weight and size.  The development of the 3.5 KVA generator was not making headway due to non availability of an indigenously produced prime mover, where as feasibility of the indigenous production of 2 KVA existed. Hence, it was decided to amend the GSPS No 81 so as to change the requirement of generating set 3.5 KVA to one of 4 KVA and include the requirement of generating set 2 KVA.16 
In order to diversify the sources of production/supply of the Charging Set 150 Watt (Indigenous) and to complete existing deficiencies expeditiously, letters of intent for the supply of 500 pieces were placed on three different firms in 1968. These were M/s J. Stone & Co, Calcutta, M/s Aviquipo, Calcutta and M/s Beni, Calcutta. The first two firms would use the indigenous Villiers engine while M/s Beni would use the indigenous Veegal engine. 
At this time M/s Kirloskar Electric Co. Ltd. developed a lighter and much improved version of the Generating set 5.5 KW installed on a 1-Ton, 2-wheeled GS Trailer.  The complete set including engine, alternator, control and charging cubical, accessories and tool box were mounted on a common slid base, making it one compact unit. The set gave an AC output of 8 KVA at 230 volts single phase and DC output of 5.5 KW at 15-110 volts, in three different circuits.  The control and rectifier units could also be used as a static charger from AC mains where available. 
            In 1970 the prototype Generating Set 11.25 KVA developed by LRDE was received for trials. The generating set had been designed as a power source for both ground and trailer mounted roles for supplying single phase AC power to radio sets, field equipment and lighting of divisional and corps headquarters. During preliminary trials in Special Signal Regiment the performance of the set was found generally satisfactory. The equipment was then sent to a field unit where it performed well and was accepted.
By the end of 1972, various types of power equipment were being produced by a number of Indian companies. The Charging Set 150 Watt was being made by M/s Intercontinental Agencies, M/s Beni and M/s Dasani Engineers (P) Ltd.  The Charging Set 500 Watt was being supplied by M/s Aviquipo and M/s Beni.  Orders for Charging Sets 2 KW had been placed on the Viman Engineering Co as well as Beni. Charging Set 5.5 KW was being manufactured by Kirloskars.  Generating Sets 4 KVA were being produced by M/s Beni, Viman and Siemens.  The Generating Set 11.25 KVA developed by LRDE in collaboration with M/s Parrys was being manufactured by the latter and M/s Greaves Cotton, who were also supplying the Generating Set 18.75 KVA. 
Crypto Equipment
Up to the end of World War, the only crypto equipment in use in India was the Machine Type ‘X’, though several countries had made rapid strides in the use of mechanical and electrical machines for on line encryption and decryption of classified messages. The story of Enigma, developed by Germany has been described by F.W. Winterbotham’s in his book Ultra Secret and in Peter Calvocoressi’s Top Secret Ultra, both published in 1974. Britain had broken the code being used on Enigma, and was able to get advance information of German plans throughout the war.
At the time of Independence, Indians were handling all types of equipment in use in the Corps with the exception of cryptographic devices, which were the exclusive preserve of British personnel. It was only after 1947 that Indian cipher operators started operating the Machine Type ‘X’, which was used for mechanical enciphering and deciphering of classified messages. These were used at divisional headquarters and above only.  At brigade headquarters and below, messages were enciphered in book cipher.  It was only in 1955 that action was initiated to procure Hagelin Cryptographer Type C52B and CX52B machines for trials to replace low grade cipher (Linex).  These machines were electrically operated but could also be hand operated. The major advantages of this machine over the low grade cipher in use were that it was less tedious and easier to operate; was quicker in enciphering/deciphering (200 groups per hour could be enciphered and 250 groups per hour could be deciphered as compared to Linex where only 120 groups per hour could be enciphered and 150 groups deciphered); and that it was portable, being lighter in weight and smaller in size.17
Another machine that was obtained for trials was the Portex Literal Cipher Machine. This was a small hand operated off-line, tape printing cipher machine, with alphabet wheel input, designed for use at lower headquarters.  It had an electrical permuting maze operated from a self-contained 45-volt dry battery good for over 100,000 operations.   The speed was 10 words per minute.  The cryptographic unit consisted of an eight 26-point rotor maze with a crossover at the cipher end.  Each rotor consisted of an insert and a housing. The insert was selected from a set of sixteen and could be fitted in the housing in any one of twenty-six possible angular positions; the housing was fitted with a rotatable alphabet type. 
In 1956 the Machine Type ‘X’ Modified 80+80 Signalling was  subjected to trials by 1 Army HQ Signal Regiment.  Subsequently a statement of case for modification of ‘On the Line Cipher Machine’ to incorporate the facility of tape relay working was submitted to the Modification Sub Committee and approved in 1957.
 In 1962 infantry brigade signal sections were authorised one Machine Type ‘X’ each. However, due to shortage of this equipment, it could not be issued to all infantry brigade signal sections. A year later the EME demonstrated the first ‘On Line Cipher Machine’ at the Army HQ signal centre.  The existing Machine Type ‘X’ was modified for ‘On Line’ working by using the existing auto-head and punching unit. This increased its traffic clearance capacity. It also had the facility of getting the crypt and punched tape simultaneously for multi address messages and obtaining corrections during transmission, thereby avoiding check and repeat messages and subsequent delays.  
In 1963 the Air Force demonstrated a machine Type X Mk 2, modified as Mk 22, using the available cross over units.  These were tried out along with the original Machines Type X Mk 22 imported from the UK. It was found that the performance of the modified machines was quite good. Shortly afterwards 300 pieces of Machine Type X Mk 22 were received from the UK under the ‘Aid Programme’. These could be issued to ‘aided’ units only, the requirement of ‘non-aided’ units being met by conversion of Mk II machines to Mk 22 at the 509 Central EME Workshop, Agra. It was expected that by end of 1965 all units would be issued with the new machines. However, it was only in 1967 that Machine Type ‘X’ Mk 22 was introduced into service.
   In 1966 Model 1 of Equipment ‘X’ (On Line Cipher Machine) was developed by Defence Electronics Research Laboratory (DLRL) Hyderabad and issued to units for trials. The first ten electronic cipher machines ex DLRL Defence known as Equipment Cipher Line 1A were distributed to Army HQ Signals and command signal regiments in early 1968. Two months later, another ten pieces were received and issued to command and corps signal regiments in addition to MCTE.18
           In 1968 two prototypes of the Equipment Cipher Line Mk II developed by DLRL were made available for trials.  This machine was smaller, lighter, more compact and had many new features for improved reliability and maintainability.  It had better and cheaper switches than those used in Mk 1 version of the machine.  The machine was fully compatible with the older Mk I version in regard to the performance in electrical circuit design.  After trials carried out in Army HQ Signal Regiment, certain improvements/modifications were recommended in the production model of the machine. The ECL Mk II was introduced shortly afterwards, followed by the ECL Mk III. By 1972 a more sophisticated version of the machine (ECL Mk IV) was being developed by DLRL. These had in-built cryptogram and were expected to be issued during 1973/74.
            In 1970 two prototypes of Equipment ‘CADDIS’ developed by LRDE has were received in Special Signal Regiment for preliminary examination and trials. This equipment was intended for forward area speech security role for use with RS AN/PRC-25. It was claimed to have the facility of secure voice communication for durations of 6 to 8 hours, over the simplex radio link set up by means of the terminal radio sets. 
Specialist Vehicles
            A large variety of signal specialist vehicles had been developed in UK during World War II. Some of these vehicles were held by units at the time of Independence in 1947. With import of vehicles having ceased after the end of the war, there was an acute shortage of signal specialist vehicles in India in the initial years. In 1950 efforts were made to obtain some vehicles from trade in UK, after the War Office expressed their inability to provide any from their own stocks. However, it was not certain that the required number and types of specialist vehicles could be obtained from UK.
It was learned that approximately 165 Lorries 3-Ton 4 x 4 with box type bodies were held in Vehicle Depot, Dehu.  It was decided to utilize these for conversion to suitable signal specialist vehicles.  The EME commenced work in October 1950 for conversion of two types of vehicles viz. Command Low Power and Terminal Equipment Vehicle Type D.  The responsibility for conversion of Lorry 3-Ton 4x4 Command LP was given to  512 Command Workshop, Kirkee while that of Lorry 3-Ton 4x4 TEV Type D  was entrusted to 505 Command Workshop, Delhi Cantt. Deficiencies in respect of other specialist vehicles such Lorries Wireless High Power G 53 were being met by mounting WS SCR 399 in cabins on Lorries 3 Ton GS.  In lieu of Trucks 15-cwt 4x4 Wireless, Trucks 15-cwt 4x4 GS with Conversion Kit No 16 were to be issued.  Simultaneous action was also be taken to install fittings in 152 Trucks 15-cwt 4x4 with box type bodies held in vehicle depots to convert them into Trucks 15-cwt 4x4 wireless.   
             By 1951 the prototype Lorry 3-Ton 4x4 TEV Type D converted in 505 Command Workshop had undergone user trials with 4 Divisional Signal Regiment. The vehicle provided facilities for easy installation and working of the major items of equipment such as one 20/40/60 line switchboard; one teleprinter 7B(WD) complete station; one ACT 1+1 No. 2; one Apparatus VFT S+Dx No. 2, up to eight fuller phones and two telephone sets. When fully staffed, four of the personnel had to be accommodated in an adjoining collapsible shelter, carried in the vehicle on the move.  The vehicle carried a 550 watt charging set and its own secondary batteries adequate for equipment power requirements, lighting and fans.  When fully or partially unequipped, the table space available was suitable for the use of the signal office staff.  
 The Lorry 3-Ton 4x4 Command LP converted in 512 Command Workshop had also undergone user trials with 5 Divisional Signal Regiment. It had the staff compartment in front and the equipment compartment in the rear in contrast to the Bedford Command LP produced during the war.  It carried the same wireless sets (WS 19HP and WS 19) but provided additional control facilities.  The vehicle was self-sufficient for power requirements and carried a 1260 watt charging set and adequate secondary batteries for the purpose.  The vehicle was slightly overloaded, but it was hoped that this could be adequately rectified by strengthening of the rear springs or reduction in the weight carried. 
Meanwhile, work on the prototype Truck 15- cwt 4x4 Wireless had also commenced in 505 Command Workshop. The vehicle was designed to accommodate up to two wireless sets, which could be a combination of WS 19, WS 19(HP), WS 22, WS 62, WS 76/R 109/R 209 or WS CN348. Alternately, it could carry one WS 62/CN348 or one WS 52 Canadian. There was provision for carriage of charging sets and batteries corresponding to the above sets and for an additional light field set in exceptional cases. However, it was found that the prototype using the Chevrolet 8444 chassis when fitted with the WS 52 Canadian or WS 19(HP), if carried as complete truck/ground stations, would overload the vehicle. For the carriage of these sets it was decided to use the Dodge 1 ton Power Wagons.  For all other sets corresponding to WS 19 truck/ground station in bulk, the Chevrolet 8444 chassis would be suitable.  The existing bodywork of the house type body was also bulky.  As such the prototype had to be redesigned with lighter furniture and fittings so that adequate load carrying capacity was left for the signal equipment, the crew and their kit.  
At this time General Staff Policy Statement No 35 was issued which gave out the design of the basic house type body for the 3-Ton vehicle to meet the long term requirements of Signals. A team consisting of one signal officer and three OR was attached to the Technical Development Establishment (Vehicles), Ahmednagar to oversee the progress on the design of the vehicles.
In 1963 the General Staff Policy Statement No 90 in respect of signal specialist vehicles was issued.  Based on this, priorities for the development of various signal specialist vehicles were worked out. Higher priority was given to vehicles required for the mountain divisions, prototypes of which were expected to be ready by December 1963.  Prototypes of the other vehicles required urgently, were expected to be ready by December 1964.  The vehicles were as under:- 19
Prototypes to be ready by December 1963 
Truck 1 Ton 4x4 Wireless (HP) 
Truck 1 Ton 4x4 Wireless 
Truck 1 Ton 4x4 Command Vehicle (LP) 
Truck 1 Ton 4x4 Signal Centre (Light) 
Truck 1 Ton 4x4 TEV (Light) 
Truck 1 Ton 4x4 Cipher Office (Light) 
Truck 1 Ton 4x4 Air Support Tentacle 
Truck 1 Ton 4x4 Radio Relay (Light) 
Truck 1 Ton 4x4 Wireless Reception 
Truck 1 Ton 4x4 Mobile Signal Workshop 
Lorry 3 Ton 4x4 Command Vehicle (HP) 
Lorry 3 Ton 4x4 TEV (Medium) 
Prototypes to be ready by December 1964 
Truck 1 Ton 4x4 Line Construction & Maintenance 
Lorry 3 Ton 4x4 Cipher Office (Medium) 
Lorry 3 Ton 4x4 Signal Centre (Medium) 
Lorry 3 Ton 4x4 TEV (HP Basic) 
Lorry 3 Ton 4x4 Teleprinter Office 
Lorry 3 Ton 4x4 Mobile Signal Workshop
In 1964 it was decided that all future development of specialist bodies will be based on Trucks 1 Ton Nissan and Lorries 3 Ton Shaktiman.  While development action already in hand for building of specialist bodies on other types of vehicles would not be discontinued, no fresh development of specialist bodies on other chassis was to be undertaken without the specific approval of the Government.  
Since the requirement of signal specialist vehicles was unlikely to be met soon, units were permitted to modify GS vehicles on their own. Funds for this purpose were sanctioned by the Government but these were woefully inadequate. Units resorted to various types of innovations and improvisations to modify vehicles in accordance with their needs. Since these modifications were of a temporary nature, units were advised not to improvise hard plywood roofs and retain the canvas canopies for the interim period. Some units managed within the allotted funds by making full use of timber and other expendable items authorized on WET.  The restriction imposed on issue of GS vehicles (75 percent of WE) was not applicable to the GS vehicles issued in lieu of signal specialist vehicles. 
 After the authorization of radio relay to mountain divisions it became necessary to design a suitable vehicle to house the radio relay station. 509 Central EME workshop started work in 1965 to modify Truck 1 Ton 4x4 Dodge bodies for the installation of WS C41/R222.  The first lot of 21 modified vehicles was issued to the seven divisions deployed in the East, at the scale of three per unit. Subsequent issues were made to divisions in the West and medium radio relay sections. 
During World War II, fairly extensive wireless networks were established in India, which then included Burma and Ceylon, where South East Asia Command was located. High speed wireless links existed between Delhi and London, in addition to several overseas stations such as Melbourne and Colombo.  Wireless links also existed to all commands and operational theatres. Transmitter stations had been established at Lodi Road in Delhi and at Bagjola in Calcutta from where operations of the Eastern Army were controlled. After the end of the War, a large number of wireless links became redundant and were closed. According to the new general staff policy for static communications formulated in 1946, the scale of wireless circuits was one RT and one WT circuit down the chain of command from Army HQ to sub area headquarters. This formed the basis of the Static Wireless Army Network (SWAN) that existed at Independence. Apart from internal links, SWAN also included links to foreign stations such as London. After Independence, several others such as Saigon, Rawalpindi, Kathmandu etc. were added to SWAN. The link to Rawalpindi was subsequently closed in April 1948.
In 1948 it was decided to establish speech communications on wireless to Mhow. The Delhi – Mhow RT Duplex link was opened and Mhow became the third station on the Command RT net that existed between Delhi, Ranchi and Poona. Shortly afterwards, due to frequent breakdown of line communications between Delhi and Ranchi, it was considered necessary to split the above RT net in November 1948. The Command RT net H21A would now work to Poona and Mhow, while the H21B would be exclusively for Ranchi.
In 1949 wireless links were established between SrinagarJammuRawalpindi and Naushera – Kotli for the use of the United Nations Commission for India and Pakistan (UNCIP). The Srinagar, Jammu and Naushera terminals were manned by Indian Signals personnel while the Rawalpindi and Kotli terminals were manned by Pakistan Signals. 
It was observed at this time that each command was following a different system of nomenclature for wireless circuits. The sequence of various circuits was not uniform and consecutive, and different prefixes were used within the same command. It was decided that suffixes used in wireless diagrams would be standardized. Links at Army HQ would be affixed by the letter A, Southern Command with S, Eastern Command with E and Western Command with W. In September 1949, Ahmednagar and Deolali were added to the RT link working to Mhow. The three RT links working from Delhi were re-grouped as given below:-
·         DelhiPoona                                          A5
·         DelhiRanchi                                         A8
·         Delhi-Ahmednagar-Deolali-Mhow         A16
            On the move of Officers Central Record Office from Jhansi to Delhi in 1949, it was decided to close the Jhansi terminal on A13, the Delhi-Simla-Jhansi CW net.  Since the advance party of HQ 1 Armoured Division had moved to Jhansi, it was decided to retain this terminal for some time for schedule working on A13 (Delhi-Simla) and E3 (Ranchi-Lucknow) nets. Subsequently, the Jhansi terminal on A13 was closed and replaced by one at Meerut, manned by 1 Armoured Division. In view of the fact that wireless link between Delhi – Gangtok existed and Calcutta had no direct interest in Gangtok, the Calcutta – Gangtok wireless link was closed down in 1950.
            In 1950 a new policy for Post Emergency Static Intercommunications was issued. It laid down that Army fixed wireless networks will be installed providing radio telephony and hand speed Morse/radio teleprinter signalling facilities in the normal chain of command down to and including sub area headquarters and for field formations down to brigade headquarters. In exceptional cases fixed wireless links would also be provided to certain important depots/installations such as Defence Services Staff College, Wellington and Central Ordnance Depot, Agra. Rear link sets at field formation headquarters would be provided from within the resources of field formation signal units.
            The hand speed Morse wireless links from Army HQ to command headquarters as also wireless links from command headquarters to area headquarters would progressively be converted to radio teleprinter signalling.  Eventually all wireless links from Army HQ to command headquarters would be converted to combined radio teleprinter signalling and radio telephony working (single side band).  As a long term policy it was hoped to convert these hand speed Morse links to radio teleprinter signalling.  If additional wireless communications were warranted from static formation headquarters to units, these would be provided by from within the working sets at the formation headquarters and the units concerned. The above fixed wireless network entailed the provision of permanent transmitter and receiver sites in the normal chain of command down to area headquarters.  Only transmitter sites would be provided at sub area headquarters and independent sub area headquarters where receiver stations would be established in respective signal offices.20
A wireless link with Korea was established in 1953 for the Custodian Force India that was sent there under the aegis of the United Nations. Wireless communications were also established with the International Commissions in Indo China. These consisted of one RTT and one CW hand speed link between New Delhi and Saigon and one standby CW hand speed link between Ranchi and Saigon and subsequently between Calcutta and Hanoi. Details of communications with Korea and Indo China have been given in Chapter 8.
An interesting development was with regard to the Hindi Morse Code. In accordance with AO 6/S/51, it had been laid down that the common language of the Army will be Hindi and the common script will be Devnagri with effect from 1 October 1956.  Since Hindi was to replace English as the official language of the Army at a later date, it was visualized that this would affect the Corps of Signals in several ways. The three main areas requiring attention were the preparation of Hindi codes for use on Army telegraph circuits; modification/manufacture of telecommunication equipment such as teleprinter and automatic telegraphy equipment for transmission/reception of Hindi codes; and preparation of ciphers and codes in Hindi. To prepare personnel for use of the Hindi Morse Code training was also organised at Central Telegraph Office, Agra. In 1953 one officer and three OR underwent the training in Hindi Morse Code.  Vacancies for one officer and three OR were demanded on the next course.      
            However, in 1955, on the recommendations of the Traffic, Procedure and Codes Committee, the Radio and Cable Board felt that since the Ministry of Education had not completed action on finalizing the Hindi script it is premature to evolve a Hindi Telegraph Code. It was decided that the working group of the Traffic, Procedure and Codes Committee will examine the existing Devnagari Script and put up suggestions regarding any modifications required to cater for the requirements of telecommunications using that script. The Radio and Cable Board would then approach the Ministry of Education to take these modifications into consideration while evolving the revised Hindi script.
After the 1965 war with Pakistan, a wireless link was established between Delhi and Rawalpindi. The CW link to GHQ Pakistan Army began working on 21 January 1966. The daily scheduled hours of working were 1000-1300 hours and 1600-1900 hours IST. Subsequently an RT duplex communication link DelhiRawalpindi was established on 19 September 1966.  A land line speech circuit between Amritsar-Lahore was established on the same date.
            A revised policy for the provision of Static Signal Communication (STATCOM) in the Army was issued vide Army Headquarters letter No 64603/Sigs 7(a) dated 15 July 1970.  The revised policy letter took into account the transfer of responsibility for Signal Despatch Service to Army Postal Service, extension of the STATCOM network to field formations (down to division/independent brigade level) in their permanent/semi-permanent locations and policy for the introduction of new techniques/equipment such as use of ARQ equipment on all unstable long haul VFT circuits and on all RTT circuits. 
In accordance with the provisions of No. 465 Radio Regulations, Geneva 1968 to discontinue the use of double side band radio telephone transmissions in fixed services in the band below 30 MHz, in 1970 the Department of Communications asked all user departments to implement this decision with immediate effect.  In keeping with the above policy, it was decided that progressively all Army static radio telephone links would be changed over to single side band (SSB).  As a first step, all radio telephone links ex Army HQ command headquarters would be converted to SSB working.
Line Communications
The first telegraph line in India was established in 1851 between Calcutta and Diamond Harbour, followed by the first telephone circuit between Calcutta and Fort William in 1877. Four years later, India got its first exchange in 1881 in Army HQ at Simla. Though India was ahead of most other countries in the field of telecommunications, the network was sparse and under developed. It was only when World War II came to India’s door-step after the Japanese invasion that urgent measures were taken and a comprehensive line communication system was established in conjunction with the P&T Department. The system comprised a military trunk telephone network and a teleprinter network, both manned entirely by the Army. It also catered for private telephone and telegraph circuits required to augment the civil system.  The construction and installation of the system was carried out jointly by the Army and the P&T Department.  Wherever qualified P&T technicians were not available, these installations were manned by military line mechanics.  Maintenance of the lines was carried out jointly by the Army and the P&T.   At the end of the war, the entire line network was handed over to the P&T Department, which became responsible for its operation and maintenance.  However, certain sections in the west that had not been completed when the war ended were handed over in 1946 and 1947, concurrently with the demobilization of the Army.
 The telephone system in Delhi had come up during the war in an ad hoc manner to meet urgent requirements at short notice. The network consisted of three auto exchanges and number of small manual exchanges with inadequate junction arrangements.  The switchboards were either obsolete or unsuitable for an area where telephone density was high.  The P&T Department exchanges with the number of AFHQ subscribers shown in brackets were located at the Secretariat (350); Connaught Place (100); Lothian (10); Old Secretariat (25); South Avenue “41” (500); Shah Jehan Road (10) and Air HQ (350).  With the departure of a considerable number of their trained technical staff to Pakistan after Partition in 1947, the P&T Department was hard pressed to keep the exchanges going.
            Plans were made to do away with the manual exchanges and furnish all subscribers in Delhi with auto telephones by August 1948. The Secretariat auto exchange would be allotted for the sole use of AFHQ both in the South Block of the Secretariat and in the hutments around it. This was a short term plan suitable for use in peace time.  The ultimate object was to centralize auto connections in Delhi on one exchange i.e. the Connaught Place exchange.  In this scheme AFHQ notified their requirements to the P&T Department as 1200 connections for use in peace time capable of expansion to 2000 to meet requirements during war or emergency.21  
            In 1948 a new all weather road was built between Pathankot – Jammu, as the earlier road ran very close to the India-Pakistan border.  The P&T trunk route to Pathankot along the old road was abandoned and a new route was constructed along the new road alignment. With this, the lines of communications to Jammu & Kashmir became safer, more reliable and less liable to interference by the enemy. Direct trunk communication was provided between Delhi-Srinagar using the 1+3 carrier system that was installed between Jammu-Srinagar. The equipment for this project was flown in to Srinagar and Jammu and the circuits engineered in record time by the P&T Department.
            The policy for Post Emergency Static Intercommunications enunciated in 1950 laid down guidelines for provision of static communications in India and the responsibility of the P&T Department in this regard. It was clarified that the P&T Department would be responsible for the provision of trunk telephone and telegraph circuits required by the Army in non-operational areas.  This included the provision and maintenance of carrier and VFT equipment and alternate circuits in the case of breakdown.  Depending on the volume of traffic, trunk telephone and telegraph circuits would be rented from the P&T Department for the exclusive use of the Army in the normal chain of command down to and including sub area headquarters.  Telegraph circuits down to area and independent sub area headquarters would be on teleprinters, which would be provided and operated by command signal regiments.  Telegraph circuits from area headquarters to sub area headquarters, where installed, would be provided by the use of fuller phone. Teleprinter switchboards would be provided down to command headquarters only.
            In 1966 two new concepts were introduced in the plan for development of static communications. These were the Defence Engineered Network (DEFNET) and Border Permanent Lines (BOPEL).  Earlier, speech and telegraph circuits rented by the Defence Services from the P&T Department were provided by patching up links on communication systems engineered primarily for commercial use. The DEFNET proposal envisaged that between major stations such systems should be provided on carrier and VFT systems engineered exclusively for Defence requirements. It also included measures for better maintenance, liaison, protection of important installations and exclusive attention to Defence circuits. The BOPEL catered for construction of PL routes in the border areas, where none existed earlier, which may be needed by Defence in the event of an emergency.
The implementation of DEFNET had to be held over for two years due to shortage of funds and representation from the P&T Department that improvement in Defence communications could be brought about by them with means easier and cheaper than DEFNET.  The two year moratorium of DEFNET expired in June 1969. However, the P&T Department was still not inclined to implement the DEFNET proposal on technical grounds.  They suggested extension of Defence trunk speech circuits on 4-wire basis from their carrier centres to Army premises as an alternative to DEFNET.  It was then decided that both the schemes viz. extension of Defence circuits on 4-wire basis and installation of carrier group systems in Defence premises as envisaged in DEFNET, would be tried out on a limited scale to evaluate the performance, feasibility and advantages of each.
In early 1971 measures were taken to introduce troposcatter communications as part of the static communication network. In view of the vulnerability of P&T Department telecommunication networks to enemy action in certain border areas, a necessity was felt for having medium range systems of communications which could be deployed at short notice to extend P&T Department circuits to the field formations.  Though rear area radio relay sections were included in the establishment of signal units, the distances envisaged would be beyond the capabilities of these sections.  With this in view, a case for procurement of some thin line mobile troposcatter (TLT) terminals was taken up with the Government for approval.
In 1971 a large number of circuits were hired form the P&T Department in anticipation of the imminent hostilities with Pakistan. These included speech and telegraph circuits on line and microwave as well as multi channel VHF links. After the conclusion of the operations most of these circuits were surrendered.  However, new circuits were hired between DelhiDacca and DelhiRawalpindi. Considerable work was done by signal units to rehabilitate static communication networks in Bangladesh which had been severely damaged during the war. Communications were also provided for resumption of railway services in Bangladesh to facilitate the evacuation of prisoners of war and move back of refugees. 
After the Simla agreement of July 1972 senior military commanders of India and Pakistan met at Suchetgarh and Wagah to delineate the line of actual control.  At Wagah, the talks were held on the Pakistan side and resulted in a major signal exercise.  Elements of both corps and divisional signals were deployed to provide skeleton command headquarters communications for the visiting dignitaries using both field and P&T systems.  Speech and telegraph circuits were engineered to Amritsar, Delhi and Udhampur from Rawalpindi and Lahore.
Signal Centre Procedure
            The signal office, which later became the signal centre, is an important area of concern for Signals. To ensure that urgent messages were not delayed, precedences are allotted by originators. The precedence given to a message does not indicate its importance but its urgency, and the priority that is accorded to it in the signal centre. In 1949 the nomenclature of precedences was changed, to bring them in line with those being used by the Navy and the Air Force. The new precedences were as given below:-
      Old                                                             New 
      MOST IMMEDIATE “OU”                    FLASH    “OC” 
      EMERGENCY  “O”                                EMERGENCY   “O” 
      IMMEDIATE  “OP”                                OPERATIONAL IMMEDIATE “OP” 
      IMPORTANT  “P”                                   PRIORITY    “P” 
      ROUTINE   “R”                                       ROUTINE    “R” 
      DEFERRED   “D”                                   DEFERRED    “NM” 
            The policy for Post Emergency Static Intercommunications issued in 1950 had some provisions concerning signal office facilities and signal staff. It was laid down that minimum essential signal office facilities including personnel from signal office working, cipher working, switchboard operating and local signal despatch service will be retained in each static formation headquarters in the normal chain of command down to sub area headquarters.  In localities where two formation headquarters existed e.g. area and sub area headquarters, or command and sub area headquarters,  duplication of signal office facilities would not be effected unless absolutely essential.
In 1957 a new phonetic alphabet was issued, superseding the one that had been in existence for several years. The new alphabet was as under:-22
Letter              Word                                       Letter                          Word
A                     ALFA                                     N                                 NOVEMBER
B                     BRAVO                                  O                                 OSCAR
C                     CHARLIE                              P                                  PAPA
D                     DELTA                                   Q                                 QUEBEC
E                      ECHO                                     R                                 ROMEO
F                      FOXTROT                              S                                  SIERRA
G                     GOLF                                     T                                  TANGO
H                     HOTEL                                   U                                 UNIFORM
I                       INDIA                                                V                                 VICTOR
J                       JULIETT                                 W                                WHISKEY
K                     KILO                                      X                                 X-RAY
L                      LIMA                                      Y                                 YANKEE
M                     MIKE                                      Z                                  ZULU
            In December 1971 certain changes were made in the designation of the staff employed in signal centre, exchange, crypto centre, transmitters and receivers. The old and new designations which came into effect from 1 April 1972 were as given below:-23
            Existing                                                           New
Duty Signal Officer                                        Officer in Charge Signal Centre
Assistant Duty Signal Officer                                    Duty Signal Officer
Officer Commanding  Exchange                    Officer in Charge Exchange.
            -                                                           Duty Exchange Officer
Senior Cipher Officer                                     Officer in Charge Crypto Centre
Duty Cipher Officer                                       Duty Chief Officer
Officer Commanding  Transmitters.               Officer in Charge Transmitters.
Officer Commanding  Receivers                     Officer in Charge Receivers
Communication Boards & Committees
During World War II a number of inter-departmental and inter service boards were created for co-ordination, planning and speedy execution of communication projects.  Some of these were the Wireless Telegraphy Board (India); the Signals Board (India), later renamed the Departmental Telecommunications Board; the Services Communication Board (India); the Defence Service Line Communication Board; and the Telecommunications Development Board. The composition, charter and responsibilities of these boards underwent several changes as the war progressed. Some of these boards were still in existence at the time of Independence, in some form or the other.
In 1950 a Frequency Planning Committee was formed under the Ministry of Communication with a view to examine in detail the Draft Frequency Plan and analyse the overall percentage of the radio spectrum space allotted to India.  It was also asked to integrate the minimum frequency requirements of all telecommunication users in the country for presentation at the Radio Administrative Conference to be held in September 1950 at the Hague
In May 1950 the Services Communication Board met to decide on the division of responsibility the three Services on signal matters on which no clear cut orders existed. It was decided to constitute a sub-committee, consisting of one member from each Service and the CAFSO, to examine and draw up recommendations on ‘The Division of responsibility of the Three Services on Signal matters’. The recommendations of sub-committee would be then examined by the Services Communication Board and submitted to the Chiefs of the Staff Committee for approval.   
In June 1950 during its 38th meeting the Inter Departmental Wireless Board noted that the Atlantic City Convention of 1947 did not cater for any allocation to the Off Route (OR) Frequency requirements in the VHF band of 80-20 Mcs for the use of the Indian Armed Forces and the Civil Aviation Department.  The European countries, Australia and New Zealand had set aside 132-144 Mcs for the exclusive use of the ‘OR’ Services.  The Inter Departmental Wireless Board decided to allot 132-144 Mcs band for the exclusive use of the Defence Services and the Civil Aviation Department for ground to air working.  Since WS No CN-348, then used for air to ground communication, had the existing range of 100-118 Mcs, arrangements would be made for the modification of this set to operate on 118-144 Mcs. 24
            In 1951 a delegation of the Services Communication Board attended the Extraordinary Administrative Radio Conference (EARC) at Geneva. On its return the delegation submitted its report to the Government. India accepted the Aeronautical Plan, the Maritime Mobile Telephony Plan and the Region III Plan (10 Kcs – 4,000 Kcs). The Conference had decided to implement the Atlantic City Radio Regulations progressively, spread over a period of about six years.  This would result in further congestion of the spectrum space in ‘fixed bands’, in which almost all the Army circuits were operating. The Army would have to re-distribute the frequencies for various circuits to ensure economical use on time/geographical sharing basis.  Certain frequencies in use would become ‘out of band’ according to new allocations and the operation of such frequencies ‘would have to be discontinued to allow other services to operate. 
A frequency sub-committee under the auspices of the Services Communication Board was set up to study the implications of Final Acts of the Conference.  Meetings of the sub-committee were held daily for a period of one month, at the end of which it prepared a list of frequencies in use by the three Services, for submission to the International Telecommunication Union (ITU).  It is interesting to note that the countries of the Soviet Block did not sign the Final Acts of the Conference and thus reserved their right to use any frequency at any time for any Service.  This was likely to affect our radio communications because of the fact that the USSR and the Peoples Republic of China are quite close to our Northern Frontiers.25
A meeting of the Secretaries of the various Ministries was held in March 1952 to consider the report of the Indian delegation to the EARC.  It was agreed at the meeting to set up the Radio and Cable Board immediately, which could then set up a technical sub-committee to deal with the work arising out of the EARC.  The committee also recommended that a committee of the Cabinet be constituted to deal with telecommunications problems.  The Cabinet Committee could be advised by the Radio and Cable Board, composed of technical representatives of Defence, Communications, Commerce and Industry, Natural Resources, Scientific Research and Information and Broadcasting.  All matters relating to ciphers would be excluded from the purview of the Board. 
       After prolonged discussions between various Ministries of the Government of India, an agreement was reached to form a Telecommunication Committee of the Cabinet as also a Radio and Cable Board to advise the Committee on matters affecting wireless and line communications in India.  The Telecommunication Committee of the Cabinet would be chaired by the Minister for Communications and the Radio and Cable Board by the technical representative of the Ministry of Communications. The Defence Services were to be represented in the Cabinet Committee by the Defence Minister and in the Radio and Cable Board by the Chairman, Joint Communications-Electronics Committee, as the Services Communications Board was now known. 
           The Services Communications Board functioned mainly as an advisory body to the Chiefs of Staff Committee on all signal matters.   In addition the Board was charged with the responsibility of co-ordination of all signal matters affecting more than one Service. The Chiefs of Staff Committee in February 1952 approved the revised charter and also agreed to the re-organisation and expansion of the Services Communications Board in keeping with its enlarged charter of responsibilities, which now included joint signal planning; standardisation of signal equipment; methods and procedure; planning of wireless transmitting and receiving stations and frequency planning. It was also felt that Services Communications Board should be renamed as an appropriate joint committee in line with the other advisory committees to the Chiefs of Staff e.g., Joint Planning Committee, Joint Intelligence  Committee.  Accordingly the Services Communications Board was redesignated the Joint Communications Electronics Committee (JCEC) on 14 July 1952
The three service members of the JCEC were the heads of Signals in the three Services viz. Director of Signals, Army HQ; Director of Naval Signals, Naval HQ; and Director of Signals Air HQ.  The service member having served longest on the committee was the chairman. Service and civilian officers could be co-opted from other departments as necessary for the consideration of specific matters. The secretary of the committee was a service officer from the secretariat of the JCEC. To cope with the added commitments, additional staff was sanctioned in January 1953 and the number of officers increased from two to five. According to the revised establishment the JCEC Secretariat, which was also known as the Joint Communications Electronics Staff (JCES), would now have two lieutenant colonels/majors or equivalent, two captains or equivalent and one scientific officer (Signals). 26
           After the return of the Indian delegation from the EARC, the Ministry of Communications formed a new organisation known as Wireless Planning and Co-ordination Branch directly under the Ministry to consider and implement the decisions of the EARC.  The Frequency Sub-Committee of the Joint Communications Electronics Committee periodically reviewed the recommendations of the Ministry of Communications with the view to coordinate action by the three Services.  
            Several important developments took place in the wake of the Sino-Indian conflict in 1962. The Defence Services Line Communication Committee (DSLCC) was sanctioned by the Government in July 1963. The secretariat for the committee was provided by a newly raised section in the Signals Directorate (Signals 7).  The DSLCC would be responsible to plan and coordinate the requirements of line communications for the Defence Services.            
During the 1962 operations, it was revealed that China had gathered a lot of information by intercepting wireless links of Government agencies such the Political Department, Police, P&T Department and the Assam Rifles.  Unlike the Army, these agencies did not follow an elaborate RT procedure and the standard of wireless discipline of their operators was also not satisfactory.  A good deal of valuable information was, therefore, being given away by them to neighbouring countries. At the instance of the Signals Directorate, the Central Monitoring Agency was set up under the Ministry of Defence to detect breaches of wireless security in the border areas and to bring them to the notice of the Ministries concerned for remedial action. 27
            The Tactical Communications Committee was also formed at Army HQ with the SO-in-C as Chairman.  The charter of duties of the committee was as under:-
·                     Examine General Staff Policy Statement No 76 (revised) 1961 and recommend systems and techniques of signal communications to be adopted in the Army;
·                     Examine signal communications systems of field units and formations up to and inclusive of corps headquarters; independent artillery and anti aircraft artillery brigade headquarters and units; and air support signal units.
·                     Examine cases sponsored by Directorates at Army HQ and recommend to the most suitable type of signal equipments, scale and establishment.
·                     Periodically review the systems, establishment of communications, personnel and equipment of field formations and units and recommend changes where necessary.
Recognising the urgent need to develop the electronics industry in India, an Electronics Committee was set up by the Government in August 1963 under the chairmanship of Dr. H. J. Bhabha.  The SO-in-C was a co-opted member of this committee, which was asked to assess the total requirements of the country in respect of various items of electronic components and equipment; survey the existing and potential sources of supply and to recommend how best these could be tapped; recommend measures for the planned development of electronics, so that the country could become self-sufficient in this field during the next 10 years and in the most economical manner. The committee submitted six interim reports before the final report was prepared.  Among the important recommendations of the committee were the setting up of additional electronic factories in the public sector; production in collaboration with foreign firms; and encouragement to the private sector to undertake the production of smaller electronic equipment and components.28
     Along with the case for creation of Central Monitoring Organisation (CMO) in 1963, Signals Directorate had also recommended the formation of the Communications Electronics Security Agency (CSA) and the Communications Electronics Security Policy Committee (CSPC). However, the formation of the CSA and CSPC was then not agreed to by the Government. In 1970, the case for creation of these two agencies was again initiated, since the CMO, due to its limited resources, had not been able to undertake work connected with the monitoring of microwave links and allied subjects of important nature.  The CSA would be responsible for communications security policy, doctrine and coordination; control of the CMO; control of clandestine radio operations; and collation, cataloguing and dissemination of electronics intelligence.
During World War II, owing to heavy losses of ships, it had become necessary to print certain documents in India so as to make them available for quick distribution in the Eastern Theatre and for that purpose a section called GSI (s) was established in the Military Intelligence Directorate. At this time, there existed a combined inter-service Signals & Cipher Security Committee. Main instructions about the security of Army ciphers continued to come from the War Office in UK and in respect of Navy and Air Force ciphers from the Admiralty and the Air Ministry respectively. After cessation of hostilities, the Joint Cipher Bureau was formed in July 1946.  In 1947, the Joint Cipher Bureau became an inter-service and inter-departmental organization. After Independence, it was decided that the Joint Cipher Bureau should remain with Ministry of Defence.  The charter of the JCB was discussed in the 6th meeting of JCEC held on 4 August 1953. It provided the permanent secretariat for the Cipher Policy Committee and the Director JCB was the chairman of the Cipher Technical Sub Committee. It was responsible for production, supply, distribution and central accounting of crypto material. It was also responsible for keeping existing systems under technical review and render advice to the services on cases of loss and compromise.
            The International Radio Consultative Committee (CCIR) was one of the permanent organizations of the International Telecommunication Unit (ITU), which was set up in Geneva to maintain and extend international cooperation for the improved and rational use of telecommunications of all kinds.  The CCIR dealt with technical and operating questions relating specifically to radio communications.  In 1970 the JCEC submitted a paper to the Chiefs of Staff Committee recommending that since the Services were one of the major users of radio communications in the country, they should be included in the CCIR deliberations right from the earliest stage and adequately represented in all future assemblies. It recommended the setting up of a National Committee under the Wireless Advisor to the Government of India for coordinating the work of the CCIR studies and also to systematize the programming and presentation of the work to the concerned International Study Groups and thence to the Plenary Assembly.  The Director JCES was to be nominated as a permanent representative on this Committee.  These recommendations were approved by the Chiefs of Staff Committee.
Amateur Activities
            Amateur radio has been a popular hobby ever since the invention of wireless. Known as ‘Hams’, amateur radio enthusiasts have often rendered valuable service during natural calamities and accidents. In India the hobby was quite popular not only in the military but also among civilians, many of whom developed an interest in the activity during their visits abroad. After Independence the growing expansion of radio amateur activity amongst the service personnel was noted with interest and encouraged.  Besides being a modern scientific hobby it provided a means of making service personnel more radio minded and played a part in the advancement of technical development and research in the field of radio.
            Within the first year after Independence amateur radio clubs had been formed in a number of service institutions and signal units. These included Army HQ Signal Regiment, New Delhi; School of Signals, Mhow; Signal Training Centre, Jubbulpore; UP Area Independent Signal Company, Lucknow; Southern Command Signal Regiment, Poona; Eastern Command Signal Regiment, Ranchi and IMA, Dehradun. The Amateur Radio Club at Mhow progressed very rapidly and had a membership of over 150 at that time.  It was affiliated to the IRAL, Bombay and to the RSGB, London.  It had its own QSL bureau and was a pioneer in publishing a magazine devoted to radio amateur interests known as the ‘QRZ’.  This magazine was designed to cover world amateur activities as well as to give hints and tips to new comers.  The club had its own building, generators, workshop and component stores besides having a station ready to go on the air on all amateur bands below 56 Mc/s. 29
            Fortunately, many senior officers in the Corps were themselves ardent radio amateurs and encouraged the activities of the radio clubsSome of the wellHams’ in Signals were Major General B.D. Kapur, Major General R.Z. Kabraji and Brigadier P.S. Gill. The latter was responsible for setting up the radio club in IMA, Dehradun, where he was posted as an instructor in the rank of major in 1947. He has described his experience in the following words:-
On reaching the Academy on 11th January 1947, I learnt I was to replace Major (Titch) A. C. Iyappa - our senior-most Indian Signals officer, later to become our first Indian Signal-Officer-in-Chief. He was to soon go away on promotion (Lt Col) as Commander Signals 4th Indian Division, to gain experience, as he put it, and to make up for lost time as POW of the Japanese, in the war years. It must be said to his credit that despite being offered a higher position and rank, he voluntarily chose to first command a Regiment. 
ACI was a thorough gentleman, a natural leader and a dependable friend. He believed in (and practiced) setting the highest example in all matters. And, this remarkable man showed me the ropes and informed me that Signals must attract the cream of the 2nd and 3rd (Post-war) Courses of cadets, under training at the time. 
There existed in those days at Dehra Dun itself, the Signals Research & Development Establishment under Colonel Watnam of the Royal Signals.  On the Signals Net so to speak, an idea was born - the IMA should have a Radio Club complete with a Ham Radio Station to introduce Cadets to the exciting world of Amateur Radio. 
Watnam’s boys soon put together a 25 watt Radio Transmitter on a (wooden) Bread Board capable both of CW (Morse) and voice using what the Radio Hams now-a-days call the Ancient Modulation (AM), instead of Amplitude Modulation. A Dipole Antenna and a disposals Receiver - Hillicrafters BC-342, remnant of some discarded SCR 399 - completed the Station which could operate on 7 & 14 Mhz Ham-bands. Thus was born the IMA Radio Club, and with it my own initiation into HAMMING. The Club, on week-ends especially, became a hive of activity and a popular gathering place for all and sundry. 
In 1947, an organization for allocating Call Signs and such like was as yet unknown. So, after scanning the Ham Bands along with Col Watnam, it was thought that call sign VU2MA was not in use and was adopted. And soon enough, it became well known far and wide, as the Military Academy Station in Dehra Dun, India.
The HAM Radio Station VU2MA went from strength to strength. The Second Course Sword-of-Honour Cadet (HBS Grewal) opted for the SIGNALS, and a little later, this Station received a bigger and a better Transmitter from CSO Southern Command – Brahm Kapur (VU2HM) - ever keen to encourage Amateur Radio. Thus over a half Century ago, I acquired the thrilling and the most absorbing hobby of all hobbies – the Amateur Radio30       
            In 1948 the Government decided to help amateur activity in India and instructions were issued to the provincial governments to recommend fresh licenses or renewal of licenses even if the applicant was not desirous of conducting experiments/research. At that time there were approximately 50 licensed amateurs in the country and 20 fresh applicants.  It was expected that by the end of the year India would have approximately 100 amateurs.
            The Services Club at Mhow continued to progress. It applied for a second license to experiment on VHF facsimile, for mobile working etc. The QRZ became a printed magazine and was considered to be the best Ham organ in the country. The club, in adopting the activities of RSGB, began conducting Morse training on the air on 14.1 Mc/s from 2000-2030 hours daily. The QSL Bureau was functioning well and it was hoped that a Bombay PO Box number for the Bureau, when allotted, would greatly facilitate Indian Hams. A new amateur call book was being compiled for South East Asia including dominions of India and Pakistan and this would be published shortly.
After his stint at Dehradun, Major P.S. Gill was posted to Poona, where he set up another radio club. Describing his experiences, he writes:-
Having been bitten already by the Ham Radio bug, it was but natural to get myself a Ham-Radio set up. Soon a BC 610 Transmitter Station (VU2KD) was installed in Officers Mess to work the Ham-bands. It served also to retain contact with VU2MA at the IMA Dehra Dun and to see how it was fairing. While it was exciting contacting distant stations overseas, it was also a lot of fun listening to all and sundry stations that filled the air and to acquire a fairly accurate picture of who all operated when and from where and on what frequencies. 
One fine morning the Signal Company Commander at Colaba Point Bombay, which formed an integral part of SCSR reported that vast quantities of transmitters and receivers and accessories had been washed ashore directly into its area, some of it still in original protective packing. It seemed the departing British or American troops had dumped at sea surplus signal equipment but had not made a very good job of it. Around two and half wagon loads of equipment were brought to Poona and, after cleaning and minor repairs some twenty mobile half KW stations (SCR 399) were recreated, which later in the year were to play an important role in the Operation Polo. Apart from this, Ham Radio Clubs at the IMA Dehra Dun & School of Signals Mhow were gifted a BC 610 transmitter each.31  
In 1949 the P&T authorities permitted amateur radio clubs to send slow Morse for practice. Until then Services personnel had to obtain a “Non-Commercial Certificate” from the P&T Department before amateur transmitting licenses were granted to them.  The Services Communication Board (India) sponsored a case to exempt certain qualified Services personnel from technical and/or Morse examination.  This was accepted and it was decided that Army personnel applying for amateur transmitting licenses will be exempted from the Morse/technical examination provided they possess the requisite qualifications.  This was an experimental measure for one year from 1 October 1949. Detailed instructions in this regard were published in Army Order 1104/49. 
            In 1962 Brigadier K.S. Gill was appointed CSO of the newly created HQ IV Corps, which was raised after the Chinese attack. During an earlier tenure as CSO XXXIII Corps in 1961, he has written about his Ham activities as under:-
Shillong, the beautiful hill-station, turned out to be an excellent Ham Radio location - ideal for experimentation. I remember a case of freak (VHF) reception - we picked up Bn to Coy VHF links from nearly a thousand miles away. We gathered from the intercepted conversations that our troops (17th Division I think) had gone into Goa to see off the Portuguese. 
With a 60 watt Rig fed into a rotatable Cubical Quad 3 Bander Antenna there was no dearth of contacts world-wide. The Corps Commander, Lt Gen K. Umrao Singh -VU2US- was an ardent Ham. Then there was in Shillong’s EME Workshop, Ram -VU2TN - Captain TN Ramakrishan, another very keen Ham. 
In April 1962, a DX-Expedition to AC5 Land, otherwise known as Bhutan, led by VU2US was mounted, with the station call sign VU2US/AC5. This Station was operated by the four of us almost continuously for 96 hours from Eastern Bhutan, thus affording Radio Hams the world over a chance to bag a rare AC5 contact. My good friend, Brigadier Rustom Kabraji -VU2BK- fondly known as KAB on the air- and Commandant School of Signals at the time, joined us from Mhow to complete the Team. As expected, among the World HAM Fraternity it was a major event, as AC5 (Bhutan) had come alive on the HAM-Radio firmament after a gap of several years.32 
            Amateur radio activity in the Army continued to flourish and by 1964 Amateur Radio Clubs had come up in several other establishments such as the School of Artillery, Deolali; No 1, 2 and 3 Signal Training Centres and all command signal regiments. Subsequently, the authority to conduct tests in respect of service personnel was delegated to CSOs Command.
Tactical Communications Committee
For the first 15 years after Independence, there was little change in communication philosophy and techniques. Tactical communications followed the chain of command and were based on line, wireless and despatch riders. At regimental level, field cable was used for line and VHF sets for wireless. Line communications above brigade employed a mix of field cable and permanent lines, supplemented by HF wireless sets. The Corps was also responsible for the Signal Despatch Service (SDS), using a variety of transport, such as jeeps and motor cycles. In inaccessible areas, aircraft, river-craft and animal transport were also used for carrying SDS mail.
The Sino-Indian conflict of 1962 brought to light several lacunae in the existing tactical communications, especially in the mountains. An important event was the formation of the Tactical Communication Committee (TCC) that was set up at this time, largely due to the efforts of the SO-in-C, Major General R.N. Batra. The TCC was chaired by the SO-in-C and had representatives from all important directorates of the General Staff Branch and Heads of Arms. The first report submitted by the committee was in regard to the signal communications for a mountain brigade group. The report was approved by the COAS who directed that the recommendations of the committee should be tried out in a mountain brigade group selected for the task and that the committee should now study the signal communications at a mountain division level. Accordingly, an exercise was conducted in 4 Mountain Division in which the communications of a brigade group operating in the mountains were tested.
The second meeting of the TCC was held on 2 November 1964, during which many important decisions were taken. The committee made detailed recommendations in respect of communications provided by a mountain divisional signal regiment to formation headquarters and supporting arms. A summary of the recommendations is as follows:-
Wireless Communications The following should be changed over to VHF :-

·         Mountain Division - Divisional command RT net (D1).
·         Artillery Brigade - Brigade net to regiments (D5).
·         Mountain Brigade - Brigade forward net (B1).
·         Artillery Regiments - Regimental and battery nets.
·         Divisional Engineer Regiment - Regimental and company nets.
·         Infantry Battalions - Standby sets (AN/GRC-9 or WS 62 or equivalent) provided for special roles should be replaced by manpack VHF sets of equivalent power output (AN/PRC-25 with a booster unit or equivalent).
·         A pool of HF sets should also be held at formation headquarters to provide the necessary HF back-up to cater for occasions when VHF links may become ineffective due to abnormal dispersion or heavy screening.
Level And Scale Of Communications

  • Infantry Battalions Wireless communications from platoon headquarters  to sections are not considered necessary. Commanders of RCL, MMG and Mortar platoons should have wireless communications and should work on the battalion forward net. The control set of the battalion forward net should be AN/PRC-25 with a booster unit, or equivalent.
  • Artillery Regiments The existing system of regimental and battery net or a combination thereof should continue. Radio-wire integration should be provided at each battery command post and regimental headquarters.
  • Engineer Regiments All wireless communications in the regiment should be provided by the Corps of Engineers.  The signal section attached from the mountain division signal regiment would cease to exist.
  • Mountain Brigade Headquarters The B21 net should be eliminated, and there is also no requirement for the brigade headquarters to be an outstation on the divisional D4 (radio telephony ‘Q’) net, since the mobility in a mountain division is limited. One wireless set of the same type as is used on the battalion forward net should be available for the brigade commander to listen-in on such nets, during the interim phase when B-1 net remains on HF. A VHF receiver should be provided in addition to a HF receiver. Two wireless sets VM-50 or equivalent should be held at the brigade headquarters for improvised ground-to-air communications within the brigade. In an independent mountain brigade group, rear links should be provided using medium power wireless sets of the VC-102 type and a pool of four low-power HF sets should be provided for the B21 net (to ‘B’ echelon and the services). Radio-wire integration facility should be provided at brigade headquarters.
  • Artillery Brigade Headquarters One low-power wireless detachment should be included for wireless communication to the Air OP flight. One VHF detachment should be provided for working on the divisional command net (D1 net). No wireless detachment need be provided for rear links to the corps artillery.  If such links are required they may be provided either from the resources of the divisional signal regiment or from the corps. Radio-wire integration should be provided.
  • Divisional Headquarters Wireless sets deployed in the headquarters should be carried in pairs as far as possible, two in each vehicle in order to reduce the number of vehicles. The D1 (Divisional Command RT ‘G’) net should be a VHF net.  An automatic rebroadcast detachment should be included to cater for extended ranges. The D6 net for traffic control is essential and should be included as a normal commitment. Two AN/PRC-25 or equivalent sets should be authorized to the divisional signal regiment for local protection duties. Two detachments should be provided for step up of two of the divisional nets (D1 and D2 or D1 and D4). I Section should have three VHF receivers and two HF receivers. One standby HF detachment should be provided at main divisional headquarters to cater for various commitments e.g. back-up for VHF nets, wireless communication for the services, provision of B21 nets for brigades which are sent out on independent roles, and so on. A wireless detachment for working on the D4 net should be provided for the divisional maintenance area. Facilities for radio-wire integration should be provided at both main and rear divisional headquarters.
  • I and FS Company A pool of five manpack HF low-power sets should be provided for the I and FS Company for patrols, to be manned by the company itself.
  • Standby wireless sets are required to be held with units to provide immediate replacement of faulty equipments or casualties.  A scale of 16 percent of the number of operational sets should be provided as standby equipments. Standby wireless detachments which include both equipment and personnel should also be provided on an adequate scale to meet special or additional commitments. 
  • The committee recommended that, conforming to the policy, existing wireless sets should be replaced as indicated below:-
                        Existing           Ultimate          Interim (until ultimate equipment is available)

                        WS 88A          DA/PRC-261                          WS P type A
                        WS 88B          DA/PRC-261                          WS P type B
                        WS 31             AN/PRC-25                            AN/PRC-10
                        WS 62             low power SSB set                 AN/GRC-9, WS 62 or HM-30
                                                (yet to be decided)                                         
WS C 42       VHF set (AN/PRC-25 with      WS C-42 can be retained
                                                booster            or equivalent)             in certain nets

·         Certain existing HF nets were recommended to be changed over to VHF.  AN/PRC-25 with a booster unit or equivalent was recommended as the standard VHF equipment in the mountain division for this purpose.  Until this equipment becomes available, WS C-42 was recommended for interim issue only in certain units where portability is not vital (e.g. battery headquarters and to the rear in artillery regiments).  Where man portability is vital, it was  recommended that the nets concerned should remain on HF using AN/GRC-9 or equivalent until the one-manpack VHF low-power set is available (e.g. infantry battalion, mountain brigade headquarters).
            The recommended revised basic wireless communication layout for mountain division signal regiment is as show below:-

·         Radio Relay Communications Radio relay is necessary within the mountain division to provide high-capacity communications as quickly as possible after establishment of headquarters and before lines can be laid. Radio relay should be provided down to headquarters of mountain brigades.  All the detachments, however, should be provided by the radio relay section of the divisional signal regiment. The present C-41, though too bulky for mountain warfare, will have to be retained as an interim measure, but a lighter set for radio relay working should be found as soon as possible. The recommended typical radio relay layout is shown below:-

  • Telephone The scale and level of line communications provided at present was considered adequate.  However, provision should be made for a telephone exchange specifically for the divisional maintenance area. Line communications from company headquarters to platoon headquarters in infantry battalions are not considered necessary.  The scale of telephones in a mountain composite (pack) regiment should be increased so as to provide quantity 73 telephones in the regiment.
  • Telegraph There was a requirement of fuller phone links between mountain brigade headquarters and infantry battalions, and between artillery brigade headquarters and the artillery regiments. A teleprinter link was required between divisional headquarters and each mountain brigade headquarters.           
  • Patching Panel In view of the increase in the number of circuits in the main divisional headquarters, there is need of a patching panel to be provided to enable testing of circuits and flexibility in the use of equipment.  This patching panel should be capable of providing alternative switching of line, radio relay and wireless circuits.
  • Radio-Wire Integration These facilities should be provided at main and rear divisional headquarters, mountain brigade headquarters, artillery brigade headquarters and artillery regiments.
  • Facsimile In view of the advantages offered for this type of communication for clearance of survey data, fire plans and traces, facsimile terminals could be provided at the divisional headquarters and at mountain and artillery brigade headquarters, and artillery regiments in the first instance.
Line Communications
            Line has always been the primary means of tactical communications, except in mobile operations. Line communications in field formations was usually provided by field cable laid on the ground or slung on poles/trees. In the forward defended localities the cable often had to be buried. In 1947, the types of field cable used were D3, D8 and Assault No.2. Rearwards of brigade/division, carrier quad was usually laid, especially in the plains. Sometimes, PL routes were constructed rearwards of division and corps, in case time and resources were available. Cable in the mountainous regions and forward areas was laid by man pack from dispenser packs. Wherever possible, cable was laid from vehicles using ACLs.  PL was constructed by line construction sections authorised to static signal units such communication zone signal regiments.
            In the initial years line construction in the border areas was carried out by the Border Roads Organisation, based generally on their road construction programmes.  Manpower for line construction tasks was provided by Signals, in the form of line construction sections attached to each task force of the Director General Border Roads (DGBR).  The line construction programmes were worked out in consultation with the E-in-C and the CPWD, and approved by the Directorate of Military Operations.  These programmes were forwarded to CSOs Commands for their recommendations of priorities for line construction, taking into account the operational plans of the command headquarters concerned.  In 1963 it was decided that the Army will be responsible for the construction and maintenance of all PL routes in the border areas. All regular Army line construction sections under DGBR would be reverted to the Army HQ. All PL stores not required by DGBR would also be transferred to the Army.
During the period 1965-66 several PL routes were constructed in the North East where communication infrastructure was almost non-existent. Most of these routes were constructed by the Army, using the resources of local signal units. A large number of PL routes were also constructed in Bhutan by 41 Signal Task Force (GREF). The BOPEL scheme was also introduced, under which it was proposed to construct PL routes in the border areas for use by Defence in the event of an emergency.
During 1971, considerable amount of PL, multi core cable and carrier quad was laid in the Eastern Theatre in anticipation of the operations in East Pakistan, details of which have been given in Chapter 6. These routes were laid by the P&T Department and signal units deployed in the area. In addition, multi channel VHF links were hired from the P&T Department to the projected locations from where operations were to be launched.
Signal Despatch Service
Before commencement of the World War II, Signals were responsible for the delivery of important messages through the Despatch Rider Local Service (DRLS). The carriage of mail, both official and private, was the responsibility of the P&T Department. During the war, when Indian formations were deployed overseas, this system had to be modified. Field post offices were set up by the Army Postal Service (APS) for handling mail, while the DRLS continued to be manned by Signals. After some time, even this system was found unworkable, due to increase in volume of official mail and considerations of security. The responsibility for carriage of official mail was given to Signals and the Signal Despatch Service (SDS) came into being. Depending on the mode of transport used, the sub-divisions of the service were known as Motor Despatch Services (MDS), Air Despatch Service (ADS) or Train Despatch Service (TDS).
            At Army HQ in Delhi, the delivery of official mail was carried out by couriers held on the establishment of the Chief Administrative Officer (CAO). Soon after Independence, this responsibility was transferred to the Signals Directorate.  The Army HQ couriers held on the strength of the CAO were transferred to Army HQ Signal Regiment on 1 September 1948.
            In 1956 a meeting was held in the Ministry of Defence to consider the possibility of dispensing with the SDS and sending all army mail through the postal channels in the interests of national economy.  The P&T Department, when asked to state the amount of security that could be afforded to army mail in transit, stated that no special treatment can be given to army mail other than that which is afforded to the normal unregistered, registered and insured mail.  Maximum protection is afforded to insured mail but in case of loss of insured mail the postal authorities could be held responsible only for payment of the amount for which the missing article had been insured.  As the risk involved even in the occasional loss of a security document sent through postal channels was not acceptable, it was decided that SDS would be retained. 33
            After more than ten years, the proposal was revived. A work study team was constituted to study the system of handling SDS and postal mail in the Army.   The team examined the possibility of establishing one agency to handle the entire postal and SDS mail in peace as well as field areas.  Based on the report of the study team it was decided to hand over the SDS to Army Postal Service with effect from 1 July 1969.  Instructions for implementation of the scheme were issued vide Special Army Order 21/S/69 and Army Order 213/69. 
            Along with the transfer of responsibility, the terminology was also changed. Since the term SDS was well known in the service, it was decided retain the acronym and the new service was redesignated as Scheduled Despatch Service, which became the responsibility of the Army Postal Service. The Despatch Rider Service (DRS) was to continue with the Corps of Signals
            The issue of clearance of ‘live traffic’, which was cleared by SDS under special contingencies, also had to be resolved. With the transfer of SDS commitments to the Army Postal Service certain precautions had to be taken by Signals to ensure speedy clearance of live traffic.  To distinguish live traffic from other traffic envelopes containing live traffic had to be distinctly marked “LIVE TRAFFIC”.  Detailed instructions in this regard were issued by Signals Directorate. 
            After shedding the responsibility for SDS, the Corps of Signals remained responsible for operating non-scheduled despatch rider services forward of corps headquarters.  All official mail would be cleared by SDS with the exception of Top Secret despatches and other such despatches of operational importance which the originators wished to send through special couriers under their own arrangements.  If, in an emergency, it was not feasible or secure to send sealed SDS bags through Railway Mail Service or the P&T Department, the formations concerned would organize ad-hoc train courier service and augment the resources of APS for running this.34
            The Army Radio Engineered Network, better known by its acronym AREN, was conceptualized by Major General R.N. Batra, who headed the Corps of Signals during the period 1961-66. In fact, the seed was sown in 1957-61 when he was the Military Attaché in Washington and germinated when he was the helmsman of the Corps in 1961-66. The story of the birth of AREN is best described in the words of its progenitor. Speaking on the occasion of the Plan AREN commemoration on 11 October 1990, General Batra had this to say:-
And now for a little background on the beginning Plan AREN. I had not only been CSO Eastern and Western Command having attended several exercises in the field, but also had the subsequent advantage of seeing the Signals communication systems working in the American field force, as also a two weeks course at their Signal Corps School at Fort Monmouth whilst I was the Military and Naval Attaché in USA. These were made possible by developing good personal relationship with Major General Nelson, the American Chief of Signals (equivalent of our SO-in-C). Later, as SO-in-C, I attended the Commonwealth SO's-in-C conferences in 1962 and 1964 in the UK. On both these occasions the UK SO's-in-C were my old friends from pre-World War II days in India. On one of these visits, I not only spent a few days with the British corps headquarters in Europe, namely the British Army on the Rhine (BAOR), to study their Signals communications within their corps, but got a good briefing from the Commandant of their Signals School at Catterick Camp on their future thinking with regard to Signals communications in the field. It became apparent that both in the USA and UK, they   were not only depending on secure radio relay, but also going in for digital techniques.
               With this background, and having studied the limitations of linear Signals communication system in India with its good and weak points, and also realising that in the event of war our Armed Forces would basically either remain within our own territory, or at best exploit success to about a 100 miles or so within enemy territory, I  came to the conclusion that we too must plan out future Signals communications within each corps on the basis of secure radio relay systems but on an interconnected area grid system covering roughly 100 x 100 miles, each terminating at a nodal point, using computer controlled digital automatic electronic switch (AES). Divisional headquarters and brigade headquarters could then hook onto the nearest such nodal point. There were of course to be additional radio relay and AES terminals to meet the need of movements forward or backwards. This system should enable us to give each crucial appointment a fixed number, and no matter where he moved within the corps area, he could receive speech, teleprinter, FAX and data communications automatically.35
               The Commonwealth Military Communications Electronics Conference was held biannually in the United Kingdom to discuss mutually the current and future problems connected with the communication electronics activities of the three services of the various Commonwealth countries during the Sixties.  The 7th and 8th meetings held in August/September 1962 and  September 1964 in London were attended by the SO-in-C who was also the Chairman, Joint Communication Electronics Committee (JCEC) at that time, as the head of the Indian delegation.  On his return from UK in 1964, the SO-in-C quickly assembled a team of officers, to give concrete shape to his ideas. Apart from Brigadier I.D. Verma, the Brigadier Signals Staff, and Colonel K.S. Garewal (later replaced by Colonel Harchand Singh), the Deputy Director Telecommunications, the team included Lieutenant Colonels M.S. Sodhi, J. Mayadas, M.B. Hart and S.L. Juneja; and Majors R.K. Gupte, B.S. Paintal, M.K. Ghosh, M.C. Rawat and Sushil Nath. (Four of them - Verma, Garewal, Sodhi and Ghosh - rose to the rank of lieutenant general, and became SOs-in-C, while the others - except for Dick Hart who retired prematurely - became major generals).
               Recalling his experiences as a GSO1 in Signal Directorate in 1964-66, Major General J. Mayadas wrote:-
   It was in March 1964, I think, that Raj attended Mountbatten’s conference in UK on the new PTARMIGAN concept (area grid communications). On his return his enthusiasm was boundless. He quickly assembled a  planning team (Gary, Dick Hart, Lall Juneja, myself and others) to listen to his concepts of the combat zone and communication zones of the future, and to translate all this into block schematic communication (radio/line/RR etc) diagrams; translate all this into the 10 mountain divisions that were to be raised; come up with many answers to questions regarding equipment backing, how many communication zone signal regiments would be required to support the new field formations (12 eventually I think); how many new training centres to provide manpower (initially two more); select/nominate development and production agencies for the hardware; start costing exercise and so on. Plan AREN had arrived and Lt Col Patil joined the planning team.
   From then on it was a frenzied process, till the 1965 Pak war started. After the dust settled we were off again and AREN became the buzzword in the Army. There were monthly presentations – Raj’s enthusiasm and courage of conviction slowly brushed off on everyone, including General Chaudhuri and the Financial Adviser.35
               The new communication system conceived by General Batra was named AREN, which is an acronym for Army Radio Engineered Network. It sounded as 'RN', which were the two initials of his name.  Batra’s ardour and conviction were infectious, and with his persuasive skills he was able to convince General J.N. Chaudhuri, the Army Chief. In late 1965, he made the first formal presentation of Plan AREN to the Army Chief, the Army Commanders and Principal Staff Officers. Their response was heartening, and Batra knew that he had won the first round. His grasp of fundamentals, and their application in the field of combat communications, coupled with his domineering personality, convinced those who mattered in South and North Blocks that Plan AREN was essential, at any reasonable cost. Once this was achieved, it was easy to justify the associated raisings, and the funding for the project.
The general philosophy guiding the Plan AREN system of communication was as follows:
·         Voice communication will be the basic medium of two way traffic.
·         Traffic, for the purposes of record, will be cleared over teleprinter, facsimile and computer data channels.
·         Commanders will also be provided communication on move.
·         Step ups will be provided to ensure no break in communications.
·         All communications will be integrated and cryptographically secure.
·         The communications system will be reliable, effective, highly survivable, quick to establish, capable of handling large volume of traffic with speedy clearance, multi axial in nature and with longer ranges.
            The system was to consist of a network of communication centres/nodes inter connected by multi channel radio relay and forming a communication overlay covering the whole of the corps operational zone.  Direct trunk dialling would be provided for both static subscribers at headquarters and mobile subscribers, throughout the combat zone.  There could be 15 to 30 communication nodes. The formation of the grid network would depend on the operational situation of the corps.  A typical diagram, depicting area grid system of communications for a division, is given below:-
            The fifth meeting of Tactical Communication Committee (TCC) held on 18 August 1967 discussed the future concepts of integrated signal communications for the field force in the post 1976 period.  The entire range of the equipment was to be developed and manufactured indigenously.  The report conceived that the futuristic signal communications must be quick to establish, reliable and secure with survivability and high traffic handling capacity and should provide longer ranges with improved and lighter equipment.  The General Staff Policy Statement No 76, Issue No 3, was issued during December 1968. To implement the AREN project speedily, a Steering Committee was formed during November, 1969 to lay down major policies and speed up the developmental efforts.  To assist the Steering Committee in the implementation of the Plan, a Project Management Organisation (PMO) was sanctioned during November 1971.  The first Project Director was Brigadier N.A. Patil. The paper on Plan AREN was cleared by the Steering Committee on 1 November1971 and subsequently by the Political Affairs Committee of the Cabinet (CCPA) on 25 November 1971.
There is an interesting anecdote connected with the presentation of the paper to the Political Affairs Committee of the Cabinet which was chaired by the Prime Minister, Mrs. Indira Gandhi.  The SO-in-C, Lieutenant General E.G. Pettengell, was required to brief the Chief of the Army Staff, General Sam Manekshaw about the salient features of Plan AREN, before the meeting took place.  Due to certain pre-occupations the Chief could not find time to get the detailed briefing. He asked the SO-in-C to brief him during their ride in his car from his office to the Parliament House, where the CCPA meeting was to be held.  It is believed that the Cabinet was so impressed by the projected plan that sanction was accorded immediately.  However, while conveying the sanction, the Prime Minister wondered why the Army was content to have a brigadier heading such an important organization which was responsible for implementing such a modernistic plan of large proportions.  The Chief is supposed to have remarked that Brigadier Patil was the ideal man for the job and they were temporarily accepting a brigadier as he was not yet due for his promotion!
 Electronic Data Processing Systems (EDPS)
            As in many other countries, when computers started to be used in India, they were considered to be a tool for statistical purposes. The systems dealing with computers were called EDPS (Electronic Data Processing System) or at times ADPS (Automatic Data Processing System). In the 1950’s a major project was set up that marked the birth of EDPS in India. This was the National Centre for Software Development and Computing Techniques at Bombay under Prof. R. Narasimhan and his team from the Tata Institute of Fundamental Research (TIFR) which took up high level software development projects. The national entry of computers in India was the pioneering design of the TIFR pilot machine (1955) and TIFRAC automatic computer (1957) with ferrite memory 2048 words (40 Bits), single address, the state of art system at that time!   They were designed from scratch by Prof. R. Narasimhan, the doyen of computer development in India, and built by a team of six at the TIFR.  The first computer in the Ministry of Defence was established at the Defence Research and Development Laboratory (DRDL) in 1962 and was devoted to significantly the first of the defence computer applications during the War, working at range tables for weapon systems!  
           Use of EDPS and computers for the Indian army was conceived in early 1960’s by the Corps of Signals. The Army Headquarters EDP Steering Committee was formed with the SO-in-C as the Chairman in January 1964, to examine the need for introduction of EDPS in the Army both for static and field applications. The committee was also asked to submit recommendations with regard to the progressive introduction of these systems and the agency that should be made responsible for their detailed study, planning, coordination, installation and operation.  Four project teams were set up to carry out feasibility studies to uncover EDP prone areas in Military Secretary’s, Adjutant General’s and Master General of Ordnance’s branches and to develop an integrated system for Army HQ. EDPS trained signal officers were positioned with the first two branches to assist in these studies.
             This Steering Committee submitted its first report in May 1964 and among its more prominent recommendations was one which in effect urged the Government to accept EDPS as a tool of management in the Army. The COAS approved the following recommendations of the Steering Committee:-
·                     Introduction of EDPS is essential to process data relating to administrative and logistical support operations in the Army.
·                     The Corps of Signals should be made responsible for detailed study, planning and coordination of the EDPS.
·                     Government approval in principle should be obtained to the implementation of Phase I of the EDPS plan which envisaged installation of punch card equipment at Central Ordnance Depot, Delhi and of electronic computer system at Army HQ.
The Defence Minister’s Inter Services Committee established the EDP Advisory Group in July 1965 to look into the total requirements of the Services for use of EDP as a tool for decision making at all levels.  A study group was formed under the chairmanship of Dr S. Bhagavantam, the Scientific Adviser to the Defence Minister, to examine the introduction of EDPS in the Defence Services.  The SO- in-C was the Army member of the study group, which had representatives from the other two Services and the Ministry of Defence. Lieutenant Colonel A. Balasubrahmanian (Signals) was the Technical Secretary.
            The first meeting of the study group held on 20 February 1967 took a number of major decisions.  It was generally agreed that the programme of automation should be undertaken Service-wise. Detailed studies should be instituted by each Service for the examination of the use of computers for command and control applications, and nucleus cells should be created in each Service HQ to guide the conduct of these studies. For the obvious inventory control and personnel management functions, a sub-committee consisting of Lieutenant Colonel A. Balasubrahmanian, Principal Scientific Officer and Chief Statistical Officer, Army Statistical Organisation was formed to assess the load that would be generated by the three Services in terms of computer hours. 
        During those days only main frame computers were available, which required centralized facilities called computer centres. It was essential for one agency to manage them efficiently. Also in a large organization like the Army, in order that the EDP systems could be used by various users and data base shared by them efficiently, it was imperative that all planning and development took place on an integrated basis. With this end in view, the Chief of Army Staff entrusted the SO-in-C with the responsibility of developing EDPS in the Army. The choice was apt because the basic vehicle for integration of an EDP system is efficient communications.  Without a data communication network to interconnect the various EDP centres, it would not be possible to share the computing power and the same updated data base by systems of various branches/directorates and echelons of headquarters.

Based on the decision taken at the first meeting of the EDPS Study Group, a nucleus cell for EDPS was formed at Signals Directorate on 1 April 1967. Lieutenant Colonel (later Major General) B. S. Paintal, who had attended a course at Fort Monmouth in USA, was the first GSO1 of Signals 9, as the cell was designated. With his vision and dynamism, planning in all aspects of EDP including formal training of manpower was taken up with vigour.
             The second meeting of the EDPS Study Group held on 6 May 1967 recommended that the Honeywell computers being installed in the computer centre of the Department of Statistics, Cabinet Secretariat, be hired to handle workloads of the three Service Headquarters. Also, that the Government accept, in principle, EDPS as a tool of management and the  proposals of the three Services for staff to conduct systems analysis to extend the application of EDPS into as many areas as is necessary; and that the training facilities for EDPS which are currently available be  explored for arranging defence oriented courses. The Government computer centre was inaugurated at RK Puram, New Delhi on 9 November 1967. Two Honeywell computer systems were operational and two more were installed shortly afterwards. Out of the four computers, one was allocated for defence users, which included one for the Army, one for the Joint Cipher Bureau (JCB) and two for other Government users. 37
          The Army’s integrated EDP Plan (1969-78) was conceived in 1968. It visualized the use of computers for management information systems (MIS), command and control, fire control and war gaming. To ensure that information was timely, up-to-date and accurate, a data communication network interlinking static computers was also proposed. For field applications, use of area grid system part of Plan AREN was envisaged.   The integrated data plan also took note of the need for building up in house training capability in EDPS as also training of officers abroad and with civil institutes within the country. The plan was formally approved by the Army HQ EDPS Steering Committee on 30 November 1970 and by the Ministry of Defence Advisory Group in June 1972.

A top down philosophy for automation of management information systems at various headquarters was adopted. Accordingly, the process of automation was to commence at Army HQ and then percolate downwards to commands and lower headquarters. As a result, the Army HQ EDP Centre was raised with effect from 18 September 1969, to automate functions at Army HQ. It comprised staff for systems development, operation of a computer system and data preparation. Lieutenant Colonel V. M. Sundaram had the privilege of raising the computer centre. He also had the unique distinction of commanding it in successive ranks as a lieutenant colonel, colonel and brigadier. It was due to his foresight, meticulous planning and dedication that this organization was able to develop a number of systems and provide excellent support to the staff, both during peace and war. Initially, the Honeywell 400 system installed in RK Puram, New Delhi by Government of India was used. An ICL 1904 computer system, a second generation computer, was later installed in Signals Enclave, New Delhi, for exclusive use of the Army. This computer became operational in mid - 1971.

            The first MIS system was developed for Military Secretary’s branch for officers management, dealing with promotion boards; panels for various foreign postings and courses; and important appointments and courses in India. Initially, records of only officers of the rank of lieutenant colonel and below were computerized. Subsequently, records of senior officers up to the rank of major general were automated. The initial team of signal officers under Colonel Sundaram comprised Major Ganga Prasad and Major Purshotam Singh, who were commended by the Chief of the Army Staff for their pioneering work in the EDP field. Subsequently, a number of other important applications were automated, ranging from grant of honorary commissions to JCOs/OR on Republic Day, conduct of entrance examinations for entry into the Armed Forces Medical College, system of issue and release of soft – skinned vehicles and controlled stores, and relief programmes of infantry and artillery units.

              Some special applications were automated at short notice during the 1971 Indo – Pak war. The EDP centre was urgently tasked to compile the lists of Pakistani POW and detainees held at the end of the Bangladesh operations. HQ Central Command had attempted to undertake the task manually, but the lists were full of errors and suspect. The EDP Centre took on the task on war footing. Lieutenant Colonel A.S. Kahlon was made responsible for data creation and Lieutenant Colonel Inderjit Singh entrusted with report generation. Nearly one lakh (hundred thousand) records were created within four days using over sixty punch card machines and staff available with all government agencies including statistical organizations of India in Delhi. System software was used to delete duplicates and create turn around documents by trips to camps/detention centres for verification. These were taken under arrangements of Adjutant General’s branch by road/rail and air to concerned locations and updated and authenticated lists brought back within two days. The magnetic files were updated and the manpower group generated the first authenticated lists of nearly two thousand POW/detainees within a day, as they had written and tested the programmes while data authentication and creation was on. The assignment was completed within a week. A battle casualties report generation system was also developed for the Adjutant Generals branch. The commandant and staff of EDP centre were highly commended by the Adjutant General and SO-in-C for completing these assignments so speedily and accurately.

           In addition to setting up the Army HQ EDP Centre, a number of pilot   projects and study teams were sanctioned during the period 1969 to 1971 to examine the feasibility of automating other applications. These included a pilot punch card machine project for Signals Records, Jabalpur sanctioned on 18 September 1967, which was later upgraded to a computer based system, a pilot project for Central Ordnance Depot, Delhi Cantonment, automation of Infantry records office functions and feasibility study team for HQ Technical Group EME.

           The Corps did significant work in EDP field and many signal officers received recognition at the national level. Brigadier V.M. Sundaram, the first commandant of the Army HQ EDP Centre later became the President of Computer Society of India. He was also the chairman of the expert committee for government computerisation ordered by the Department of Electronics at the express wish of the Public Accounts Committee. Major General A. Balasubrahmanian, AVSM was the technical secretary of the Ministry of Defence advisory group on EDP from 1966 onwards. During the years 1972-79 he functioned as officer on special duty (computers) in the then newly set up Department of Electronics. He was the founder secretary and president of the Computer Society of India, the principal professional body of computer experts in India and was also India’s representative in International Federation for Information Processing (IFIP). Lieutenant Colonel S. K. Mair and Major C. L. Anand were selected for deputation with the External Affairs Ministry for automating the functions of the supply wing at the High Commission of India in London.  Major R. Thiagarajan was one of the first to undergo computer training at the Statistical Research Institute, Calcutta. He did pioneering work for National Informatics Centre (NIC), the Planning Commission, various universities and departments. He became an internationally recognized personality in IT field and toured many countries giving talks and participating in seminars and so on.  The Corps can justifiably be proud of introducing EDPS in the Army, seeing it through the gestation period, nurturing it in its infancy and bringing it to the present stage.


            The story of developments in signal communications and equipment during the period 1947-72 is in essence the story of the growth of the Corps of Signals.  During the first twenty five years of its existence as a fully Indianised force, the Corps literally grew from childhood to manhood.  The rapid technological advancements in the field of electronics resulted in radical changes in the type of equipment in the inventory of the Corps. Thermionic valves were replaced by transistors, leading to increased sophistication and miniaturization. The use of single side band and the exploitation of higher frequency bands had considerably enhanced the coverage of the radio frequency spectrum. Improved techniques in carrier telephony had augmented the availability of telephone and telegraph circuits on the available lines and radio links. Automatic exchanges had replaced manual switchboards and lighter and stronger cable had made the task of laying lines in forward areas easier. Similar advancements had been made in power equipment such as generators, charging sets and batteries.
Perhaps the most significant change was the introduction of radio relay, which combined the advantages of both radio and line. It gave communication planners greater flexibility in rendering communication support to field formations, which were able to get reliable telephone and telegraph circuits as soon as they arrived at a new location. It also led to the birth of revolutionary concepts like Plan AREN, which promised to provide commanders and staff a degree of flexibility unimaginable in the past. The decision to switch over from HF to VHF in radio links in field formations enhanced reliability and survivability of radio communications, which were earlier prone to interference from climatic conditions and diurnal changes in the stratosphere. 
Between 1947 and 1972 the Indian Army fought four major wars - the Jammu & Kashmir operation in 1947-49; the Sino-Indian conflict in 1962; the Indo Pak war in 1965; and the war with Pakistan in 1971 that resulted in the liberation of Bangladesh. As would be apparent from the detailed accounts of these operations, developments in signal communications and equipment was a major factor that affected the final outcome. The most radical changes occurred during the early 1960’s after the debacle in 1962. It was primarily to these far-reaching measures that he Corps acquitted itself with credit in 1965 and 1972.

This chapter is based mainly on the Corps of Signals Planning/Liaison Notes for the period 1948-57 and 1963-72; General Staff Policy Statement No. 76 of 18 March 1955 and No. 76 (Revised) of 22 May 1961; and personal inputs from officers. Specific references are given below:-
1.      GHQ (India) Letter No. 29175/Sigs (5) of 24 May 1944.
  1. General Staff Policy Statement No. 76 – Signal Equipment, issued on 18 March 1955.
  2. General Staff Policy Statement No 76 (Revised), issued on 22 May 1961.
  1. Corps of Signals Liaison Note No 11 of July 1949.
  2. Corps of Signals Liaison Note No 95 of December 1971.
6.  Corps of Signals Liaison Note No 32 OF January 1955.
7.   Corps of Signals Liaison Note No 81 of August 1968.
  1. Corps of Signals Liaison Note No 23 of July 1952.
  2. Corps of Signals Liaison Note No 76 of July 1967.
10.  Corps of Signals Liaison Note No 71 of May 1966.
  1. Corps of Signals Liaison Note No 13 of January 1950 
  2. Corps of Signals Liaison Note No 64 of October 1963.  
  3. Corps of Signals Liaison Note No 90 of December 1970 
14.  Corps of Signals Liaison Note No 96 of April 1972 
  1. Corps of Signals Liaison Note No 62 of April 1963
  2. Corps of Signals Liaison Note No 79 of March 1968
17.  Corps of Signals Liaison Note No 34 of July 1955 
18.  Corps of Signals Liaison Note No 80 of May 1968
19.  Corps of Signals Liaison Note No 62 of March 1963.
20.  Corps of Signals Liaison Note No 15 of July 1950.
  1. Corps of Signals Liaison Note No 3 of March 1948.
  2. Corps of Signals Liaison Note No 40 of January 1957.
  3. Corps of Signals Liaison Note No 95 of December 1971.
24.  Corps of Signals Liaison Note No 15 of July 1950.
25.   Corps of Signals Liaison Note No 22 of April 1952.
  1. Corps of Signals Liaison Note No 24 of January 1953.
  2. Corps of Signals Liaison Note No 64 of October 1963.
28.   Corps of Signals Liaison Note No 66 of April 1964.
29.   Corps of Signals Liaison Note No 6 of August 1948.
  1. Brigadier P.S. Gill, ‘Tales from HAM Radio – 1 (IMA Dehra Dun -1947)’,  The Signalman, January 2001.  
  2. Brigadier P.S. Gill, ‘Tales from HAM Radio – 2 (Poona 1948)’, The Signalman, May 2001.
  3. Brigadier P.S. Gill, ‘Tales from HAM Radio – 3 (Shillong & Tezpur 1962)’, The Signalman- September 2001
  4. Corps of Signals Liaison Note No 37 of April 1956.
  5. Corps of Signals Liaison Note No 88 of May 1970.
35.   Extract from speech of Lt Gen R.N. Batra (Retd) on the occasion of the Plan AREN commemoration, Delhi, 11 October 1990
36.  Extract from letter dated 22 April 1996 from Maj. Gen. J. Mayadas to Maj. Gen. Prakash Gokarn, giving inputs for proposed biography of Lt. Gen. R.N. Batra. (Mayadas and Batra were both Cottonians - alumni of Bishop Cotton School, Simla - though there was a seven year age difference between them). 
  1. Corps of Signals Liaison Note No 79 of March 1968.

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