MUOS QoS Offerings and the Impact on Future UHF SATCOM

The mobile user objective system (MUOS) is DoD's next generation UHF SATCOM system. MUOS development includes not only design and on-orbit placement of satellites, but development and fielding of an integrated system that includes MUOS ground sites and the MUOS common air interface (CAI). The CAI defines the protocols used by MUOS terminals to gain access to the system and achieve sufficient quality of service (QoS) from the system. The open-standard MUOS CAI is a layered approach that strongly leverages commercial development of UMTS/WCDMA protocols. MUOS offers a variety of service types for user applications. An 'assured service' and a 'best effort' service are offered. Further, three distinct data transport services (stream, burst, and flow) and two distinct voice services (regular voice, voice recognition) are offered within the realm of 'assured service'. In order for users to take full advantage of MUOS capabilities, there must be an understanding of how these services work, so that user applications can be tailored appropriately. This is not always as straightforward as it appears-for example, there are instances where 'best effort' service may better meet a user's needs than does 'assured service', and there are instances where 'regular voice' may actually perform better than 'voice recognition'. In this paper, the authors explain the MUOS service offerings, and discuss how future applications should consider the MUOS service offerings during development