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Special forces communications requirements; a look at some of the specialised equipment available.

Special Forces Communications Requirements

A Look at Some of the Specialised Equipment Available

The whole concept of a hypothetical future East-West conflict is now being re-examined in the light of the rapidly changing political situation, the mutual reduction of conventional forces, the receding likelihood of a nuclear conflict and the increasing number of low-intensity and non-conventional conflicts in world trouble spots. We are now witnessing the increasing proliferation of regional conflicts, terrorism and urban guerilla activities, not all of which are necessarily associated with the Third World.

The United States have recently acknowledged this change in outlook by appointing an Assistant Secretary for Special Operations and Low Intensity Conflicts in the Department of Defense. It is not in fact easy to define what requirements the above entail: they are usually concerned with the unusual and the unexpected, they can involve both the civil and the military and may mean the conduct of highly individualistic operations by special forces under minimal supervision at some distance from own forces or bases.

Special forces may be involved in a number of different types of missions - amphibious raids, security operations, deception patrols, counterintelligence operations, clandestine recovery operations, specialised demolition raids and even the rescue of hostages. These call for a high degree of independence of action and good intelligence, combined with the ability properly to command and control a rapidly changing situation which has only one constant factor - the unexpected.

Most countries now have their own special operations forces, although in some cases these are either supplemented or trained by outside agencies. Since special operations are regarded as highly confidential, little is heard from official sources or manufacturers about their deployment or the range of equipment in use.

The United States, which are reviewing much of their activity in this field, have set up the Joint Advanced Special Operations Radio System (JASORS) programme: this is concerned with the development of a highly reliable, interoperable, secure, light-weight manpack with a very low probability of intercept and detection. Little is being revealed about technical specifications though it has been admitted that JASORS is an expedited research, development and acquisition programme aimed at integrating many of the current special operations forces [C.sup.3] programmes.

Recently the Boeing Helicopter Company rolled out the MH-47E special operations helicopter. This new version of the Chinook is said to possess the most sophisticated avionics ever installed in an US Army aircraft which enable the helicopter to communicate and navigate with precision anywhere in the world, at low level, at night and under adverse weather conditions. Sikorsky for its part is developing a Special Operations Aircraft (SOA) based on the Black Hawk and designated MH-60K. Initial procurement plans call for 16 MH-47Es with an option for a further 34 and for 22 MH-60Ks with an option for another 38.

Such sophistication underlines the fact that some of the special operations missions are of such sensitivity that they must be capable of having communications and [C.sup.3] links extending from the highest levels of government down to the individual deployed in the field. This means that communications equipment can range from simple hand-held radios to comprehensive [C.sup.3] facilities in vehicles or aircraft. For instance, Rockwell International's Collins Division has developed the ASC-15B(V)1 consisting of four radios in a single mobile command and control communications system which can be fitted in a helicopter or used as a stand-alone ground command post.

Apart from the physical characteristics of small size and low weight, special operations radio sets have to be rugged, water-resistant and highly reliable. The equipment should ideally offer a high degree of interoperability, apply adaptive power techniques, have very low levels of interception and detection, a high level of automatic operation including frequency management, feature-adaptive variable bandwidth operation, integrated electronic warfare capabilities, integrated COMSEC facilities, remote control capability, automatic message or information compression and an ability to cover both line of sight and transcontinental ranges. It is obvious that no single piece of equipment can offer all that is required, although modern electronic modular techniques can be adapted for ease of operation and to cover an optimum number of requirements.

The fact is that there is a wide choice of equipment covering HF, VHF, UHF and SHF together with a variety of encryption devices. In recent years SHF SATCOM has become a major component in special operations forces communications, while UHF SATCOM provides additional flexibility for voice and data traffic. To a limited degree HF offers an alternative to SATCOM and is a valuable back-up. The increased capability of electronic circuits and continuing miniaturisation play an important role in reducing size and weight as well as in reducing the vulnerability of emissions to electronic warfare, particularly HF. This can be further improved by variable power outputs and enhanced antennae.

With so many variables implicit in the types of operation, scale of deployment and scope of the forces involved it can be appreciated that special operations forces require a large variety of radios, both on the ground and in the associated aircraft and, possibly, naval vessels. Special operations also pose a considerable planning problem, particularly where joint operations are concerned, when all-round coordination or interagency operations are required. Facilities for updating information must also be available while the force is en route to the target zone, as well as the provision of last-minute deployment information.

The following review of current equipment is an indication of what is available and in use by special forces in many parts of the world. * BR Communications' 25-watt, 4180 portable HF transceiver offers connectivity, first time and every time, and combines real-time frequency management and automatic spread-spectrum message reception. It is said to be an HF set which for the first time ever can automatically select authorised propagating channels free from interference: it is not necessary for the operator to test a frequency first (which can often reveal the authorised frequencies) nor is he limited to a small selection of channels. Without radiating on any frequency the 4180 transceiver scans the entire 2 to 30 MHz band. It then identifies those authorised, propagating channels that are clear of interference. Responding to menu-driven commands, it will tune to any of the recommended channels for SSB transmission of voice or data; alternatively it can be CW-keyed.

It can also receive 40-character Chirpcomm (R) messages from any Chirpcomm transmitter. The Chirpcomm spread-spectrum technique spreads the data energy over the entire HF spectrum, thereby eliminating the need for frequency management. * Harris has developed the comprehensive RF-5000 Series Digital HF Tactical Communication System, which offers high performance with a significant reduction in size and weight. The system is intended for tactical communications in rapid deployment, vehicular, man-portable, airborne or marine applications. Components are packaged in rugged housings and waterproofed to a depth of one metre to meet MIL-STD-810D requirements.

The system is based on the RF-5020R/T transceiver that acts as the common exciter for a variety of power amplifiers and antenna couplers. This allows matching of specific power amplification components to the communication need. The result is a voice and data communications system that can support a 2400 Baud high-speed data modem with forward error correction and code diversity, embedded data encryption, data buffer store/forward, Linear Predictive Code (LCP) voice digitisation, ECCM frequency-hopping, automatic link establishment, and HF/VHF voice and data retransmission.

Each of the above capabilities are plug-in module options - an important consideration for man-portable sets. The modules also permit configurations tailored to suit specific mission requirements. An uncommitted option slot for use in future upgrades or to cater for a unique user demand is also part of the chassis design. Considerable efforts have been made by the manufacturer to simplify the man/machine interface.

The system incorporates a Digital Signal Processor (DSP)-based Intermediate Frequency (IF) subsystem. The DSP data bus allows additional digital signal processors, used for functions such as data modems, voice digitisers and channel sounders, to interface directly with the IF sub-system. This eliminates the degradation that often occurs with external voice or data processors.

The RF-5000 is available in three power outputs levels - 20, 125 and 400 watts. The system offers strategic system performance in a tactical package and is currently used for a wide range of military applications, including HF satellite data transmission, satellite communication back-up, weapons control and for video imagery transmission. * A recent European launch has been made by the INISEL group of Spain with the RTM-880 VHF FM frequency-hopping transceiver, which broadens the choice of tactical radios for use in severe countermeasures environments. * The family concept of tactical radios has been exploited by Marconi Communication Systems with its Scimitar range of automated radios, which cover the radio spectrum from HF to UHF and feature comprehensive self-diagnosis down to replaceable sub-assemblies.

The Scimitar H was introduced in response to a perceived demand for a 20-watt manpack and a 100-watt vehicular installation with a remote control facility. It is based on a common receiver/exciter and a number of modules which may be added to meet specific user demands. The system has USB, LSB, AM, CW and automatic rebroadcast modes and includes built-in frequency agile ECCM. The Scimitar H also has a squelch system which operates purely on the receive signal operating in conjunction with the automatic gain control feature.

ECCM, based on built-in frequency agility around a selected hopset, has already been mentioned, but a second level of ECCM protection is available via an optional module designed specifically for use with the vehicular system. This is a powerful unit which provides both high-grade digital encryption and medium speed frequency agility. It is interesting to note that the vehicular version has been adapted for naval use as the Makaira system, which provides secure HF communications for fast patrol boats and other small vessels. * In the United Kingdom, operational experiences during the early 1980s led to a formal requirement for a new, lightweight, long-range patrol radio. Two British companies - Racal-Tacticom and MEL - responded to this request, MEL being eventually awarded a contract. The radio, designated PRC 319, made its debut at the 1985 Royal Navy Equipment Exhibition, where its compact form and low weight excited considerable interest.

The PRC 319 is a microprocessor-based design of 50 watts maximum output. It features an extension of the HF band up to 40 MHz, thus encroaching on the VHF band. This offers a close support VHF capability using SSB. The radio can match a variety of antennae and features an easily detachable, fully automatic, fast-tuning antenna tuner (TURF). To maximize the advantages of covert operations, the TURF can be operated remotely from a distance of up to 50 metres via a single coaxial cable.

The MEL PRC 319 was put into service with the British Army in 1986 and, following a series of trials in the United States, a number of sets were purchased. The radio is also used by another NATO country and has undergone extensive trials with special forces in a number of other countries. * Motorola has had considerable experience in producing several generations of Portable Emergency Transceivers (PET) for special forces. The original PT-25 was developed for a Canadian customer in the mid 1970s and later versions were nomenclatured AN/URC.

The need for a manpack satellite radio was highlighted during the planning of the rescue operation of American hostages in Iran. Although there was an ongoing US Government programme at that time, the operation required more terminals than the four PSC-1s which then existed. In order to overcome the problem it was decided to modify the PT-25 to include a satellite communication capability. When the rescue attempt took place the radios were used to maintain links between the command elements in Egypt and the Pentagon as well as a direct link with the US President.

The use of the PT-25 in Iran created interest in other areas and it has now become a mainstay of special forces operations and was used in the Grenada operation and was doubtless equally useful in Panama.

The URC radio has now been sold in more than twenty countries and customer requirements led, in 1984, to a project to optimize the radio for UHF line of sight and SATCOM communications. The result is the LST-5 series, which is less than half the size of the original unit. More recently the LST-5B has become available packaged in a standard suitcase and complying with airline regulations for "carry-on" luggage.

Motorola has now introduced the LST-5C with a more efficient transmitter to extend battery life. * Another of the tactical families is the Plessey System 4000, which is also the basis of the Australian Army's Project Raven communications system. From its initial design concept it was recognised that future tactical communications would face increasingly hostile electronic countermeasures and surveillance techniques. In order to address this technical challenge Plessey employed the latest techniques in computer-aided design and manufacture, with the extensive use of both digital and linear integrated circuits. The digital devices are mainly CMOS, and two NSC 800 processors are used for software control of the transceiver and hopper/COMSEC functions. For specialist digital functions, semiconductor Uncommitted Logic Array (ULA) devices have been used featuring up to 3 300 gates.

Care has been taken to keep size and weight to the minimum. The data highway is under the control of a software and keyboard-driven microprocessor.

The System 4000 is characterised by the interactive Communication Management System (CMS) which enables any operator, anywhere in the network, to be aware of assigned frequencies, hopping codes and barred frequency details. Recommended power settings help to maintain satisfactory communications with minimum interference. * Although Racal-Tacticom initially appeared to have lost out to MEL in meeting the British Army requirement, development work continued and emerged as the BCC39. It gained its first export order while still undergoing prototype trials. The radio is designated BCC39 in manpack or patrol form and VRQ319 in vehicular form. Of modular construction, it is possible to separate the various items by use of remoting leads to suit differing methods of transport or deployment. The keyboard can be detached and carried by hand, with the transceiver stowed in a rucksack. The antenna tuning unit can be remoted up to 50 metres from the main unit and even the battery can be detached and carried in the most convenient manner, powering the equipment via a suitable lead. Typically, a covert mission could feature an operator in a small hide with the equipment broken down for optimum deployment and used for example in conjunction with a burst transmission device.

An adaptive version has been developed in order to make HF communications simpler and more reliable by overcoming problems of frequency congestion, fading and other types of propagation anomalies. In standby mode, the receiver consistently scans a number of channels on either side of the set frequency. The receiver can assess the quality of the operational channels, identifies the "quietest" available and rests on that channel, carrying out checks from time to time to confirm the selection.

In a net of four radios they would each scan and adopt their best channel in the light of local conditions. Then, when one transmits, it sends a short message on each channel nominating the intended channel. They all automatically move to that channel to maintain effective communication. * Racal-Tacticom was a pioneer in frequency-hopping and has had considerable success with the Jaguar family of combat radios. In 1987 this technology was used to develop the first-ever MILSPEC, frequency-hopping, hand-held transceiver - the Caracal (PRM 4740A). It is intended for military or special applications where a hand-held or body-worn radio with enhanced security is required. With a power output of one watt, 2320 channels are available and the radio is capable of operation in either simplex or two frequency simplex modes. The choice of power output has been dictated by a need to provide reliable communications within the deployed group while conserving battery life and ensuring low probability of intercept. The Caracal also comprises high-grade internal digital encryption. * Also used by special forces is Racal's Cougarnet, a totally secure FM radio based on a personal radio and an amplifier applique unit. It operates in the VHF or UHF band to offer inter-agency links and has the option of a 16 kbit/s encryption unit. * The SPIDER is Signaal's latest VHF/FM combat net radio. Compact, lightweight and providing both voice and analog data communications, it has a simplified keyboard for ease of operation, a single rotary switch and a large liquid crystal display. The radio is interoperable with all current VHF/FM radios, including those featuring tone-modulation for squelch purposes. Surface-mounted technology is widely used to create its compact dimensions, with a volume of just 2.8 litres and a weight of less than 4 kg. It operates in the extended frequency range of 30 to 108 MHz, which gives 3 120 available channels, a capability that offers increased flexibility of frequency management and reduces the probability of interception and jamming.

RF power levels are adjustable to reduce detection and prolong battery life. During periods of adverse propagation conditions, an extra 5-watt burn-through RF power is available for short transmissions. Four levels of display illumination and seven audio level adjustments are possible. When level one (whisper mode) is used the microphone audio gain is increased during transmission. An optional crypto/data module adds selective call facilities and burst transmission of 99 pre-coded numerical messages. During a six week period in February and March 1989, the Royal Netherlands Marine Corps successfully used the radio during exercise Cold Winter held in Norway. * Israel has a well-deserved reputation for innovation and self-reliance in military electronics and much of its product range has been improved as a direct result of combat experience. This expertise is emphasised by the emergence of an Israeli version of the Single-Channel Ground Airborne Radio System (SINCGARS) which Tadiran will coproduce with General Dynamics, a technical accolade no doubt due to operational experience with the CNR-900 VHF frequency-hopping radio.

This radio is available in a number of configurations - manpack, vehicular and airborne. It operates over the range of 30-88 MHz (2 320 channels) and offers second-generation ECCM features, COMSEC and data error correction, while being fully compatible with existing equipment such as the VRC-12, PRC-77 or VIC-1.

For HF requirements, Tadiran offers the HF-2000 family which is modularly adaptable to a wide range of configurations and features AUTOCALL (TM), by which calls are selected automatically on the best available frequency. The PRC2200 20-watt manpack consists of two basic modules - the transceiver (RT-2001) and the detachable antenna coupler (CP-2003). The RT-2001 has a low-rate internal modem, and a selection of HF modems with rates from 50 to 2 400 Baud, both synchronous and asynchronous, is available to upgrade performance. For applications where space is a major constraint, board level-compatible modems are available. * In July 1989 the French Defence Ministry announced an order worth FF 225 million for the production of manpack and vehicular radios for the French Army's VHF PR4G tactical communications programme. The contract calls for the production of tens of thousands of these radios by TRT, Crouzet, SECRE and CEIS. The PR4G family comprises manpack, vehicular, hand-held and airborne transceivers. Manpack and vehicular versions will enter service at the end of 1991, while the airborne and hand-held units will be available from late 1993 and by mid-1995 respectively.

All input and output ports are EMP-hardened and the system uses integrated digital encryption. Fast frequency-hopping has been chosen for ECCM and free channel search caters for the jamming threat. A tactical terminal allows messages to be compiled and then transmitted in bursts.

Cypher Sets & Scramblers

Also available to special forces are easily portable cypher sets for tactical applications. Manufacturers include Cincinnati Electronics, Cossor, Crypto AG, Datotek, Elbit, Ericsson, Marconi, Plessey, Racal, Tadiran, Thomson-CSF and TST. * In Norway, EB Lehmkuhl produces a compact, hand-held cryptographic terminal named LEHMCODER Mini, which is produced in two versions. Hardware design is identical, the difference being in the software. The company has supplied a tactical crypto terminal to NATO forces; the Mini is considered to be ideal for use by airborne or special forces personnel. * In the United States NAPCO International Defense Electronics Division has introduced the KY-189 intelligent secure handset, a convenient word scrambler which is claimed to be unique. * MEL has developed the Guardian, a tri-service high-grade voice security system for HF/VHF/UHF radios which has been extensively trialled by the special forces of a number of different countries. Using just four boards it is of compact construction and weighs less than one kilogramme. By use of a new vocoder, MEL claims to have solved the problems associated with digital voice transmissions on HF. By overcoming the HF narrow band difficulty the company has produced a universal vocoder that covers the VHF and UHF bandwidths.

This review highlights just some of the equipment currently in use or available to special forces. For the future it is expected that greater integration of capabilities within miniaturised systems, using a variety of automatic adaptive techniques, as well as greater improvements in interoperability and connectivity, will result in ever more compact and lightweight radios which should be particularly suitable for special forces.

PHOTO : The MEL narrow band, secure voice Guardian unit for HF/VHF/UHF sets weighs less than 1 kg

PHOTO : and fits in the side-pocket of an MEL Callpac set.

PHOTO : A set like the BR Communications 4180 provides security by "silently" selecting a suitable

PHOTO : frequency.

PHOTO : The Harris RF-5000 components are broken down into rugged waterproof elements for ease of

PHOTO : installation. This is a 125-watt set installed in a Hummer.

PHOTO : The Marconi Scimitar H is available as a 100-watt vehicle-mounted set or, here, as a

PHOTO : 20-watt man-portable set.

PHOTO : Plessey has used the latest computer-aided design and manufacturing techniques to develop

PHOTO : its System 4000 series.

PHOTO : The Caracal PRM 4740A is famous as the first hand-held frequency-hopping transceiver ever

PHOTO : in the world.

PHOTO : The Signaal Spider has simple controls, weighs less than 4 kg and works on 30 to 108 MHz.

PHOTO : The Racal Cougarnet, also used by Special Forces, is a totally secure FM radio. An

PHOTO : optional 16 kbit/sec encryption unit is also available.

PHOTO : Motorola's LST 5B, of the LST series, developed for UHF line of sight and SATCOM.

PHOTO : The combat-proven frequency-hopping CNR-900 VHF set has made Tadiran's military

PHOTO : reputation.

PHOTO : Tadiran has developed the HF-2000 family, which is modularly adaptable to a wide range of

PHOTO : configurations.

PHOTO : The Mini was developed by Crypto, which has been an expert in secure communications for

PHOTO : many years.

PHOTO : Thomson-CSF's PR4G has been ordered in such large numbers and configurations that TRT,

PHOTO : Crouzet, SECRE and CEIS all had to be sub-contracted.
COPYRIGHT 1990 Armada International
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Copyright 1990, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

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Author:Parry, Don
Publication:Armada International
Date:Feb 1, 1990
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