Fighter aircraft, ground forces and anti-aircraft weapons all operate within the same battle area and to be effective in their individual missions all must know their own location and the geo-graphic relationships with friendly and hostile forces. It is imperative that accurate information is shared immediately. To meet the command and control needs of these fast-moving forces, huge amounts of data must be exchanged between automated systems.
The joint tactical information distribution system (JTIDS), also known as Link 16, provides a proven method of situational awareness and information exchange in all combat environments. Link 16 information is broadcast omnidirectionally at hundreds of thousands of bits each second and can be received by any terminal within range. It operates over 51 frequencies between 960 and 1215MHz and information flows directly from many transmitters to many receivers using a form of time-sharing known as time division multiple access (TDMA).
The effect of being able to pass great amounts of data between large numbers of participants is called situational awareness. Users are able to utilise all available information to assure the survivability of their own platform and the success of their mission. With Link 16, members of a task force can share sensor data and co-ordi-nate timing via the high-speed TDMA network. The sharing of messages by air and ground forces reduces dual targeting and redundant expen-diture of weaponry. In addition, the broadcast of status and location messages enables asso-ciated members and command control facilities to monitor progress of a mission.
| Table I LINK 16 TERMINAL PHYSICAL CHARACTERISTICS AND CAPABILITIES (TERMINAL LRUS) | |||||
| Class 2 (Data Processor Group/Receiver Transmitter) | Class 2M | Class 2H (Nominal) | MIDS LVT (Terminal/Remote) Power Supply | MIDS FDL | |
| Volume (ft3) | 0.89/0.69 | 1.3 | 4.9 | 0.5/0.3 | 0.45 |
| Size (in) | 12.75W x 7.62H x 15.8L/10.12W x 7.62H x 15.56L | 14.0W x 7.7H x 22.5L | 13.5L x 7.5W x 7.62H/13.5L x 2.25W x 7.62H | 13.5L x 7.5W x 7.62H | |
| Weight (lb) | 125 | 83 | 340 | 46/14.3 | 50 |
| Input Power | 115V, 3 Phase, 400Hz | 28Vdc | 115V, 3 Phase 400Hz | 115V, 3 Phase, 400Hz or 280Vdc plus 120V, 1 Phase, 50/60Hz or 115V, 3 Phase, 50/60Hz or 28Vdc (via adapter) | 115V, 3 Phase 400Hz |
| I/O Interface | 1553 MUX | ADDSI X.25 | 1553 MUX | 1553 MUX ANSI 3910 Hi Speed MUX, CCITT X.25, IEEE 802.3 Ethernet |
1553 MUX ANSI 3910 Hi Speed MUX, IEEE 802.3 Ethernet |
| Cooling | Platform Supplied | Integral Blower | Platform Supplied | Platform Supplied | Platform Supplied |
Link 16 terminals periodically and automatically broadcast a precise position location and identification (PPLI) message. PPLIs provide a reliable identification of the platform in which the termi-nal is installed, reducing or eliminating the risk of damage from friendly fire. Furthermore, com-mand and control and/or sensor centres can transmit an identification of those sites within their Link 16 track files, providing an indirect method of combat identification.
These capabilities were implemented initially via a series of hardware product lines known as class 1, class 2, and multifun-ction information distribution system (MIDS). GEC-Marconi Hazeltine and Rockwell Collins' avionics and communication division supply class 2 terminals to the US Government and currently the class 2 is in production and will be integrated in multiple platforms. MIDS is in its engineering/manufacturing development phase and will enter production in 1998/99.
The first JTIDS terminal was developed in 1974 to service large command control facilities and platforms such as the E-3 AWACS. The terminal was designated as class 1 and was a large rack-mounted unit that employed an early version message protocol called Interim JTIDS message standard. GEC-Marconi Hazeltine and Rockwell began development of the class 2 fighter-sized terminal in 1980 that initially was planned for installation in the F-15 air superiority fighter. In the intervening years, the class 2 was improved to allow it to provide Link 16 to other platforms and systems including the Tornado, UK Air Defense Ground Environment, F-14D, modular control equipment, ABCCC, Joint STARS and USN submarines. This terminal used a more capable message protocol called tactical digital information link (TADIL J). A high pow-ered version of the class 2 line, called the class 2H, employs a linear power amplifier to increase RF output to 1000 watts. The class 2H is used on command control/surveillance platforms such as the E-3 AWACS and E-2C airborne early warning (AEW) system. A cabinet-mounted ver-sion of the Class 2H is used to service navy combatants including carriers, cruisers and destroyers. An army variant also was developed to meet tactical and mobility needs.
| Link 16 displays have been designed to enable users to control, access and assess available data rapidly |
| Table 2 FUNCTIONAL CAPABILITIES | ||||||
| Class 2 (Data Processor Group/Receiver Transmitter) | Class 2M | Class 2H (Nominal) | MIDS LVT (Terminal/Remote) Power/Supply | MIDS FDL | ||
| Interoperability | IJMS/TADIL-J* | IJMS/TADIL-J* | IJMS/TADIL- J/VMF | IJMS/TADIL-J | IJMS/TADIL-J | |
| TACAN | Internal | Internal | Internal | Internal | Compatible w- external >ARN-118 | |
| *Some systems have been configured with TADIL-J only. | ||||||
The US, France, Germany, Italy and Spain joined forces to develop the MIDS LVT and formed an international programme office located in Crystal City, Virginia, to manage the programme. Commercially, MIDS LVT development is man-aged by a corporation called MIDSCO that is headquartered in Wayne, New Jersey. MIDSCO is a multinational consortium comprised of GEC-Marconi Hazeltine (US), Thomson-CSF (France), Italtel (Italy), Siemens (Germany) and ENOSA (Spain). The baseline MIDS LVT is suitable for installation in aircraft and ground/airborne command control platforms. A MIDS LVT 2 variant also is in development for army tactical activi-ties. Tables I and II highlight the characteristics and capabilities of the Link 16 terminal family.
The most recent Link 16 development is the F-15C/D MIDS fighter data link (FDL) programme. The FDL is a reduced-capability terminal that meets the operational needs of the F-15 C/D air superiority platform. The MIDS FDL retains 80-per-cent commonality in hardware and software with the MIDS LVT design, but some capabilities common to the class 2 and MIDS LVT are reduced or eliminated to achieve operational requirements for F-15 C/Ds.
 | MIDS Fighter data link (FDL) terminal configuration |
These developments and their production programmes are providing both the US and its international defence partners with insights into the improvements in capability that are being reaped from the inform-ation age.
