What the Mobile User Objective System will bring to UHF SATCOM

Abstract

The Operational Requirements Document (ORD) for the Mobile User Objective System (MUOS), the replacement for the current UHF MILSATCOM, requires a great increase in communication capacity and Quality ofService (QoS). To achieve these objectives, MUOS is moving away from operation over individual 5-kHz and 25-kHz bandwidth transponders and adapting a commercial third generation (3G) Wideband Code Division Multiple Access (WCDMA) cellular phone architecture using geosynchronous satellites in place of cell towers. Because the WCDMA waveform will not be interoperable with the current UHF waveforms, each MUOS satellite carries a legacy payload, similar to that flown on the currently deployed UFO 11 satellite, to allow for a gradual transition to the MUOS WCDMA waveform.While the current narrowband UHF MILSATCOM system provides reliable service to many users, it provides unacceptable service to many other users, and worse, there is insufficient capacity to provide any service at all to many potential users. The MUOS constellation offour satellites provides greater than 10 times the capacity ofthe current UHF constellation, but because the MUOS waveform will eliminate the needfor dedicating resources to individual services, its ability to fulfill user communication requirements will actually be much greater than this. The current UHF waveforms are unable to provide efficient transport for Internet Protocol (IP) packets which has prevented the migration to modern net centric IP communication services. MUOS implements an all packet core networking infrastructure that supports both net centric IP communication services as well as traditional circuit-switched services.In this paper the authors briefly explain the MUOS architecture, service and transport classes, and QoS, and compare this to what is available using the current UHF system. The paper also discusses what MUOS users will need to do to prepare for transition to the new MUOS WCDMA waveform. SYSTEMS IMPROVEMENTS REQUIRED BY THE MUOS ORDThe operational requirements for the Mobile User Objective System (MUOS) demand a considerable increase in total communication capacity over the current UHF Follow-on (UFO) narrowband SATCOM system, as well as improved availability, improved Quality of Service (QoS), and the ability to serve handheld terminals.Within the MUOS program the current UHF waveforms, defined by MIL-STD-188-181, 182 and 183, are referred to as the legacy waveforms, and that is the way this paper will refer to them. The legacy waveforms (introduced back in 1992) do not always meet user needs, can be complex to use, and often require link margins that users can't reliably achieve. The biggest failing of the legacy system is that it has insufficient capacity to provide service to a large percentage of its potential users. All potential users with MUOS compatible radios will be able to use MUOS. MUOS WAVEFORMOVERVIEW MUOS adapts a commercial third generation (3G) Wideband Code Division Multiple Access (WCDMA) cellular phone architecture for use in a military UHF...