Mark D. Dankberg

A robust satellite system architecture for the mobile user objective system

The Department of Defense (DoD) is pursuing development of a mobile user objective system (MUOS). This next generation satellite system will provide voice and data services to ground, airborne and shipborne users with special emphasis on serving a large population of handheld subscribers. A major element of the MUOS architecture will likely be a DoD owned and operated satellite system in the current UHF MILSATCOM frequency band. This paper outlines an innovative architecture for a DoD UHF satellite system which provides substantial system wide capacity and reliable service to a wide range of subscriber types, including handhelds. In particular, the system is robust in the face of the severe channel impairments historically encountered in this band. The key attribute of the architecture that enables handling the impairments is path diversity with diversity combining. The overall diversity combining architecture is described and performance estimates are presented.

Next generation FLTSAT tactical network control

The US Navy Fleet Satellite Communication System (FLTSAT) relies on a set of information exchange subsystems (IXS) to manage shared satellite resources. The navy has developed application specific IXS protocols for end-user communities. The goals are to develop a single common, interoperable IXS capable of serving the requirements of any user community; and simultaneously, to improve the quality of service offered to end-users. To meet these goals, ViaSat has developed a system called multi-user UHF Satcom for TDMA-1 (MUST). Through innovative multislot control, MUST is able to provide high-performance access to the TDMA-1 navy demand assignment multiple access (DAMA) waveform. Simulated performance comparisons show that MUST has the capability to provide over twice the throughput of OTCIXS II. In addition, it offers a wide variety of user-oriented services, such as voice, reliable packet transfer, and tactical data transfer.<<ETX>>

Integrating message, voice, and tracking data on UHF DAMA networks

The Copernicus TADIX approach (using the MUST protocol) provides a significant performance and capability improvement over the current IXS systems. A key part of this improvement is the Copernicus TADIXS ability to simultaneously manage different types of communication services (message, voice, and tracking data). The MUST protocol has the unique ability to allocate DAMA channel capacity so that the requirements of each communication service are satisfied. Furthermore, the Copernicus TADIXS approach to use of the DAMA channel results in better throughput and less delay. The need to increase the availability of UHF SATCOM is clear, and it will become even more important as advanced communication systems try to use the crowded UHF SATCOM channels.<<ETX>>

A compact simulator for CNI RF environments

The authors describe the architecture, waveform simulation capabilities, and applications of an RF environment simulator capable of simulating up to 1000 simultaneous communication signals operating at frequencies from low HF to microwave. The simulator uses a modulator architecture and an innovative programmable emitter module to simulate a broad range of waveforms, signal structures, and platform dynamics effects in a compact physical size. The purpose of the simulator is to provide a test environment that adequately stresses the increasingly complex electronic warfare and communications, navigation, and identification (CNI) systems found on modern military platforms.<<ETX>>