Commercial communications equipment is driven by market requirements that evolve at a greater rate than military systems. To take advantage of this equipment, military command and control, communications and intelligence (C3I) systems must incorporate commercial technologies while operating existing military communications systems. These systems also must be flexible enough to change as technology advances. In the past, modifications to fielded C3I systems have been cost-prohibitive and time consuming. Evolving commercial off-the-shelf (COTS) technology can provide cost-effective systems that maintain interoperability with existing and future systems.
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Figure I: Simplified Purple communications architecture Click picture for detailed view (39Kb) |
California Microwave's Government Group has participated in military exercises with US and Canadian forces to demonstrate the capability of improving the joint command's connectivity, reducing equipment cost, size and complexity and integrating commercial and military technology into a joint communications system.
The Purple Communications Exercise was a demonstration sponsored by the US Air Force in conjunction with California Microwave, Inc (CMI). It was conducted at Davis-Monthan Air Force Base, Arizona and surrounding areas. The exercise demonstrated improved joint connectivity between the US Army and US Air Force operational elements by using commercial products that reduced equipment size and weight but had increased capability relative to the military systems that the COTS replaced.
During the exercise, tactical communications system components were either replaced or augmented with CMI-provided commercial or ruggedised radio frequency (RF), baseband and gateway-switching commercial systems.
The network was based on a simulated deployed joint task force (JTF) consisting of a JTF node, air force forces (AFFOR) node, air operations centre (AOC) node and an army forces (ARFOR) node. Split-based operations and enhanced horizontal and vertical system integration were demonstrated as shown in Figure I. Improved connectivity between nodes was demonstrated with the RadioLink and wireless LAN extensions. Split-based operations and enhanced node interoperability were demonstrated with ruggedised COTS line-of-sight (LOS) and satellite communication (SATCOM) equipment. The exercise focused mainly on data communications but in one case, digital trunk groups were extended, demonstrating voice capability.
The X-SAT and LYNXX terminals played a key role in the exercise. The X-SAT terminal is a fly-away, transit case defence satellite communications system (DSCS) X-Band satellite terminal built to commercial standards. It provided a satellite link with a US Air Force satellite terminal at a 256Kb/s traffic rate. The 256Kb/s digital trunk group (DTG) carried two 32Kb/s data circuits. This demonstrated how a small fly-away commercial terminal could interface with existing US Air Force satellite terminals to provide an easily deployable split-base operations capability for forward deployed forces. X-SAT modem waveforms were compatible with US military and international satellite standards.
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Figure II: LYNXX INMARSAT configuration Click picture for detailed view (11Kb) |
The LYNXX (INMARSAT-B terminal) was used to provide worldwide dial-up access to the public switched telephone network (PSTN) and supports digital data rates up to 64Kb/s. INMARSAT-B is a digital service that facilitates cost-effective utilisation of the INMARSAT satellite. Figure II shows the configuration used in the Purple Communications Exercise. Voice, data and compressed video were demonstrated with this link and double-hop encryption was demonstrated at 64Kb/s.
The troposcatter satellite support radio (TSSR) is a CMI-developed tactical microwave line-of-sight system used by the US Air Force. This radio connects remote satellite and troposcatter communications systems to deployed tactical air base operations. The 14Ghz microwave radio is small and easy to erect and supports conditioned diphase signals from 72 to 4608Kb/s. It supports video and pseudo non-return to zero rates greater than 6Mb/s. In conjunction with the digital radio multiplexer (DR-MUX), the TSSR provides 4T1 or E1 communications trunks. In the Purple Communications Exercise, TSSRs were used to link different operations centres and to provide a live video demonstration over an 18-mile TSSR shot that was set up and operational within 10 minutes of arrival on site.
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Figure III: Summary of CGS-100 gateway functions Click picture for detailed view (29Kb) |
Two wireless technologies were demonstrated during the exercise, the RadioLink and a wire-less ethernet extension. The RadioLink provided an internode connection between the AOC and AFFOR. The LAN radio provided an intranode extension for the AOC.
RadioLink operates in asynchronous or synchronous modes and supports data rates up to 64Kb/s. It is a robust system that uses frequency and space diversity with error-checking and correcting algorithms to ensure a reliable communications channel in a multipath, noisy environment. RadioLink has been interfaced with privacy devices. It supported a point-to-point protocol exchange between physically separated computer network routers and remote server access via serial-line internet protocol (SLIP) or point-to-point protocol (PPP).
Wireless LAN, a 10Mb/s (ethernet rate) LAN radio, provided a link between military routers and the AOC node. It demonstrated the feasibility of inter-LAN connectivity and local LAN extensions in a tactical environment.
The CGS-100 is CMI's low-cost, multifunction, tactical communication server. It provides pro-tocol and format conversion between many military systems as well as commercial interfaces and protocols. The CGS-100 provides automated message preparation and interoperable tactical data communications in joint and combined operations as well as connectivity to strategic systems and databases. It serves as a tactical communications front end providing high-capacity information-handling over many communications interfaces. It also provides routing, security and auditing capabilities.
The CGS-100 provides all interface and protocol conversions necessary to interoperate with the military internet. In addition, the CGS-100 maps text-based message addresses and routing indicators to standard SMTP e-mail addresses. It performs all host registration procedures needed for the tactical packet network (TPN). Figure III summarises the gateway functions of CGS-100.
The introduction of COTS into military systems provides low-cost and low-weight solutions with increased capabilities. The military technology assessment, requirements and acquisition process must adapt accordingly to take advantage of this evolving capability.
