Multiple path beyond-line-of-sight communications (MUBLCOM)

Abstract

MUBLCOM is a satellite communications project sponsored by DARPA under its Technology Re-investment Project (TRP). A consortium of Orbital Sciences Corporation (OSC) and Torrey Science Corporation (TSC) entered into an agreement to build and launch a satellite payload, build 10 voice terminals with data ports, a ground control station, and support four months of demonstrations and experiments. CECOM is acting in the role of Program Manager for this effort. The major goal of the program is to demonstrate an approach for beyond-line-of-sight battlefield communications extension for military forces and determining the viability of deploying a LEO constellation of up to 64 satellites to provide for a worldwide communications network applicable to both commercial and government users. This system will address many of DoD's needs for secure, mobile, interference resistant, voice and data communications by providing digital voice and data communications directly between small hand-held terminals that are rapidly deployable, cost-effective, virtually terrain independent, all-weather, and beyond-line-of-sight. The MUBLCOM payload will be hosted on a small Orbital Sciences Corp. satellite bus (MicroStar/sup TM/). Orbital's privately developed MicroStar/sup TM/ spacecraft platform, weighing approximately 100-lbs., serves as the basis for Orbital's ORBCOMM and MicroLab/sup TM/ programs. Payload transponders can also be mounted on towers or can be used in airborne relays, including UAVs to augment satellites in providing increased communications capacity in a given theater. Handover between transponders on satellites or other platforms is transparent to the user terminal. Instead of treating multipath as a source of interference to be avoided, in MUBLCOM the multiple paths provide the redundancy necessary for reliable communications. Upon completion of the on-orbit satellite checkout, the satellite and terminals will be available for a period of four months for government demonstrations.