International Data Link Society’s guide to:

TACTICAL DATA LINKS (TDLs)

Interoperable Systems Management and Requirement Transformation (iSMART)iSMART is an interoperability assurance and information management process used to assure effective communication between complex military systems that utilise information exchange in order to prosecute their assigned roles. Through interoperability requirement management, analysis and through-life evaluation ensures that any interoperability issues among systems can be identified in the early stages and aid in reducing the risk of costly changes later in the programme lifecycle.

e Systems Management and Requirement Transformation (eSMART)eSMART provides a single integrated software environment with underlying functionality on the iSMART process. Data can be drawn from multiple standard environments and the tool facilitates the application of Subject Matter Expert experience.

AbbreviationsBISA - Battlefield Information System ApplicationBLOS - Beyond Line Of SightBPS - Bits Per SecondCAS - Close Air SupportCIU - Concurrent Interface UnitCLEW - Conventional Link Eleven WaveformECM - Electronic Counter MeasuresEPLRS - Enhanced Position and Location Reporting SystemEW - Electronic WarfareFBCB2 - Force XXI Battle Command Brigade and BelowHCI - Human Computer InterfaceHF - High FrequencyIJMS - Interim JTIDS Message Standard/SpecificationJBD - Joint Battlefield DigitisationJDN - Joint Data NetworkJU - JTIDS UnitLOS - Line Of SightNATO - North Atlantic Treaty OrganisationNEC - Network Enabled CapabilityNU - NILE UnitsPPLI - Precise Participant Location and IdentificationRASP - Recognised Air and Surface PictureRF - Radio FrequencySADL - Situational Awareness Data LinkSLEW - Single-tone Link Eleven WaveformTDMA - Time Division Multiple AccessTDS - Tactical Data SystemUHF - Ultra High FrequencyVHF - Very High Frequency This leaflet has been produced with the assistance of Lockheed Martin UK IS&S Limited, a leader in the fields of training consultancy, integration and testing of TDL systems and the implementation of NEC concepts. We are grateful for their contribution in making the production of this document possible. Download copies of this leaflet and information about the worldwide data links professional community online at: www.idlsoc.com Lead Author : Dr Grigorios Koutsogiannis CEngSeries Editor: IDLSoc Technical CommitteeIssue: 1.0 November 2009 © Copyright International Data Links Society

BowmanThe replacement for the ageing Clansman radio system, Bowman uses a secure integrated communications and information system operating in the HF, VHF and UHF bands for the land elements of all three Services. It offers a number of services, including secure voice and data message communication, improved situational awareness and EW resilience.

Bowman will also act as the core infrastructure for BISAs, an essential element of the JBD initiative. As a C² system, it provides secure voice and data communication, a Network Data Service to improve the overall throughput, speed of data delivery and own position reporting.

Multi-Link OperationsMany platforms are able to operate on several links concurrently and as a result form a more comprehensive situational awareness picture. Some platforms are designated as forwarders, able to transfer data from one data-link to another.

Multi-link operations allow for a dramatic increase in the number of interconnected units or systems. However, system complexity is increased and requires additional planning and management of the network.

Data Forwarding UnitA multi-link unit nominated as a Data Forwarding platform allows the transfer of track information between different links and may be used to forward commands across links.

The data forwarded is based on that received and not limited to message implementation of the host processing system of the forwarding platform. Data forwarding units require additional resources over and above their own local reporting requirements.

Gateways “In the NEC environment, gateways will enable information sharing between multiple links where communication would other be incompatible and unavailable”.

Concurrent Interface UnitA unit that is not designated as a data forwarder but is able to operate on multiple links simultaneously is termed a Concurrent Interface Unit. The aim is to build a composite tactical picture from multiple data sources.

InteroperabilityInteroperability describes the ability for assets to provide services to and accept services from other assets utilising them to facilitate more effective operation.

Interoperability is a key factor in the integration process and should be considered on a number of levels: RF, Data, Protocol and HCI. These levels describe the physical transfer of messages, the message, conformity to defined protocols and that information is displayed and interpreted correctly by the receiving operators.

What are TDLs?TDLs are military communication links, developed for the transmission of digital tactical information using standardised message formats, protocols and bearer characteristics.

Why the need for TDLs?TDLs facilitate secure, ECM-resistant, high capacity communication between military assets over an extended range, including beyond line-of-sight

Network Enabled Capability (NEC)NEC is the coherent integration of sensors, decision-makers, weapon systems and support capabilities to achieve effective and efficient sharing and exploitation of information between national and coalition armed forces. NEC promotes more agile forces, better decision superiority and effective synchronisation, improved control of tempo and greater optimisation of resources.

This is achieved by using ‘network centric thinking’ which focuses on the development of integrated systems into a network that allows interaction between all systems without prescription. The concept involves the exploitation of available capabilities in novel, more agile ways providing increased flexibility within the battle space.

The underlying network forms the core component of NEC, a Network of Networks created by linking network nodes and gateways carried by deployed operational assets or existing communication backbones. Networks are formed only as and when needed.

Link - 16Link-16 describes the J-series messages format optimised for use within the MIDS/JTIDS TDMA architecture. Functionality within Link-16 allows the simultaneous operation of a number of different nets (up to 127) defined by use of discrete frequency hopping patterns, thus increasing network capacity. The architecture promotes network survivability and further flexibility is offered by optional message packing which can increase data capacity at the expense of ECM-resistance.

The J-series message format supports wide selection of data types including surveillance, EW, Mission Management, weapons assignments and air control, plus voice, text and limited imagery. JUs transmit PPLI messages establishing their position without ambiguity and provide significant amounts of supplementary data contributing to RASP. Network navigation is provided for JUs automatically through measurement of signal time of arrival from each terminal. Positional accuracy can be improved if accurate geodetic sources such as surveyed ground sites are present within the network.

Joint Range Extension Gateway (JRE)JRE facilitates operation of widely dispersed forces, avoids saturation of MIDS/JTIDS capacity (relief of relays) and may provide communication between surface, ground and low air units when no airborne relay is available (provided satcom capacity is available). It can also be used to reach back to a rear commander, reach forward to deep forces or act as a communications bridge

Joint Range Extension Application Protocol (JREAP)JREAP provides a means of exchanging tactical messages over a variety of long haul media, such as landline or satellite, in order to achieve BLOS communication. For the J-series protocols, there are three possible configurations:

a) interface up to four JRE media directly with a MIDS/JTIDS terminal, b) interface one or more JREAPs via a front end processor (C2P, DLP) or gateway (with data forwarding to from other TDLs and communication to a host TDS) or c) a stand-alone processor.

Situational Awareness Data Link (SADL)SADL facilitates the integration of CAS with the digitised battlefield via EPLRS providing fight-to-fighter, air-to-ground and ground-to-air communication. Since EPLRS is part of FBCB2, friendly troops are able to receive aircraft position and altitude data.

A-10C variants designed for forward air control (designated O/A-10C) are able to utilise SADL to perform Link-16 integration with other fighter units in order to receive position data for enemy aircraft, air defences and other targets beyond the aircraft’s range.

Link - 22Link-22 was designed primarily as a maritime platform replacement for Link-11 by providing secure ECM-resistant BLOS information exchange utilising the improved precision inherent in the J-Series messages.

The F-series message is more flexible than J-Series as it can accommodate the limited bandwidth at lower frequencies. Link 22 uses a dynamic TDMA architecture utilising either fixed or agile frequency waveforms operating in the military HF and/or UHF bands. NUs are able to participate in up to four Link 22 networks concurrently within a Super Network of up to eight such networks, which are operated as a single entity, although some of this is hardware dependent. Coverage is extended BLOS through use of HF and/or automated intra and extra network relays.

Variable Message Format (VMF) VMF is the title given to the variable format K-series binary message which is bearer independent. Therefore, standards are required to define the message headers appropriate to particular bearers.

The primary appeal of VMF is the independence from any particular waveform architecture resulting in enhanced cross-functional area applicability.

The VMF message format is a bit-oriented digital information standard incorporating a variable message length and providing a common means of exchanging data among combat units at different organisational levels. Since the message format is variable, this provides the functionality to transmit only the information required making VMF a viable solution for bandwidth limited environments.

Link - 11Link-11 is a half duplex maritime data link that uses the M-series message format and a nodal system that is able to operate either in roll call or broadcast modes. It is widely fitted throughout NATO.

Roll call operation utilises either CLEW or SLEW waveforms. CLEW can offer a data rate of 1364-2250 bps (user data rate 1800 bps) whereas SLEW offers more resistance to ECM. Operation in broadcast mode allows either a single or series of single data transmissions from a single source. Link-11 operates either within the HF band offering a theoretical BLOS capability of 300 NM or within the UHF band with range limited to LOS.

Link-11B is a ground-to-ground implementation of a subset of the M-series message catalogue. This full duplex link is a point-to-point system employing serial transmission often referred to as Serial Link-11 and is able to monitor the status of a point-to-point data link with an operation data rate of 2400 bps. The data rate may vary with the bearer.

Joint Tactical Information Distribution System (JTIDS)JTIDS describes a secure, high capacity, ECM-resistant communication system operating within the UHF band between 960-1215 MHz (L-band); relay support has been incorporated into the system design in order to extend the range BLOS.

Multifunctional Information Distribution Systems (MIDS)MIDS is a compact terminal built to the NATO Standard (STANAG 4175). The MIDS/JTIDS system was developed for use by all services and is able to support both IJMS (synch purposes) and Link-16 message formats. Its design is based on a node-less TDMA architecture, currently utilising rapid frequency hopping over 51 discrete frequencies. MIDS is a JTIDS system that adheres to NATO operational requirements.

Beacons (Fryktories)Troy to Argos(400miles in 8-12hrs)Data rate: 0.000028 bps

Great Wall of China - Signal TowersSignals included use of lights, semaphores drums and gunshots (700 miles in 12 hrs)Data rate: 0.000046 bps

Electric Telegraph(1 bit = dot/dash)Data rate: 2-3 bps

Satellite communicationSputnik transmitted at 20 & 40 MHz for 0.3 seconds

Link-16Data rate: 26.8 kbps

Inmarsat I4Commercial satelliteData rate: up to 492 kbps

UK NEC /JDN Backbone

Polybius Optical Telegraph10bits per letter & 8 letter per minute for short messages (without coding)Data rate: 1.333 bps

1180 200 < BC AD > 600-900 1150 1850 1890 1950 1960 1980-1990 2000 2010*Semaphores 1bps

Homing PigeonApprox 8 bits per char & 150 char per message over 400miles in 12 hrsData rate: 0.0278 bps

Wireless Broadcasting

Link-1Data rate: 1.2 kbpsLink-4Data rate: 3.8 kbps

Link-22Data rate: 4.05 kbps (HF) & 12.67 kbps (UHF) Skynet 5

Alphasat I-XLCommercial satellite due 2012

Link-11 A/BData rate: 1.36-2.4 kbps