SAN FRANCISCO — Military satellite radio vendors are lining up to offer mobile radios to provide secure communications through the U.S. Navy’s constellation of Mobile User Objective System (MUOS) satellites. It will take years, however, for the military services to replace or upgrade the tens of thousands of tactical satellite communications radios carried in tanks, trucks, ships, aircraft and backpacks to take advantage of the advanced capabilities advertised by MUOS program officials.

Before any of the new MUOS-compatible radios can be fielded, contractors need access to a waveform that will enable them to transmit and receive data through the satellite’s advanced digital payload. General Dynamics plans to finish developing the waveform next summer. Until then, MUOS will use its legacy UHF payload to provide communications links through existing satellite radios.

MUOS satellites are designed to address growing demand for military communications with a cellphone-like service that uses a payload on the spacecraft as the cell tower. The new MUOS waveform is based on the waveform used in commercial 3G networks, but modifying the waveform to send messages to a distant satellite and back to terrestrial facilities has proved challenging.

General Dynamics is developing the MUOS waveform on the PRC-155 two-channel networking radio as part of the Joint Tactical Radio System (JTRS) Handheld, Manpack, Small Form Fit program. The PRC-155 will be the first MUOS terminal in the field, said Chris Brady, vice president of assured communications for General Dynamics C4 Systems of Scottsdale, Ariz. That radio, which will be manufactured by General Dynamics and Rockwell Collins Inc. of Cedar Rapids, Iowa, supports several waveforms, including the Soldier Radio Waveform, which carries data across networks with different types of radios, and the U.S. Army’s Single Channel Ground and Airborne Radio System, Brady said in an email.

Other radio vendors are keeping close tabs on General Dynamics’ progress developing the MUOS waveform through the JTRS Open Information Repository, a resource designed to link vendors to open-source software initiatives.

The Defense Information Systems Agency receives far more requests for narrowband communications capacity than it can grant with the Navy’s current fleet, former government officials said. As a result, the military services are expected to make it a priority to acquire radios to take advantage of the MUOS digital payload, which is designed to offer 10 times the capacity of each Navy UHF Follow-On satellite, the officials added.

Nevertheless, the number of new and upgraded radios fielded in the coming years will depend on several factors, including the health of satellites in the UHF Follow-On constellation and the fiscal environment, said Ken Arndt, product manager for Harris RF Communications of Rochester, N.Y.

Pentagon officials, who announced plans in January to cut $487 billion from the Defense Department’s 10-year spending plan, face the prospect of more than $500 billion in additional national security budget cuts as a result of deficit reduction legislation passed in 2011.

Harris plans to provide MUOS capability through its Falcon 3 AN/PRC-117G tactical satellite radios. Those software-defined, multiband radios used in ground vehicles and command posts were redesigned in 2010 to become MUOS-compatible. Once the MUOS waveform is ready, Harris will begin loading it onto approximately 10,000 AN/PRC-117G radios fielded, Arndt said.

Raytheon is upgrading its ARC-231 multiband, multimode radios to communicate with the digital MUOS payload under a U.S. Army contract awarded in 2011. The company has fielded more than 5,000 ARC-231 radios in Army aircraft to offer line-of-sight and satellite communications, said David Patton, ARC-231 senior program manager for Raytheon Network Centric Systems in Fort Wayne, Ind.

Raytheon engineers are developing the MUOS capability, but the work cannot be completed until they obtain the MUOS waveform. “When that is released, we will port it into our radios,” Patton said.

Raytheon also wants to upgrade AN/PSC-5 multiband, multi-mission radios carried by soldiers and special operations forces to link with the digital MUOS payload. “The AN/PSC-5 and ARC-231 share common hardware and software modules,” Patton said. “So the upgrade we develop for the airborne radios would serve the ground radios as well.”

Raytheon does not have a contract to provide MUOS capability on AN/PSC-5 radios, but company officials hope to receive orders once the MUOS constellation takes shape. “There appears to be some hesitancy for organizations to start procuring that equipment because of MUOS delays,” Patton said.

The U.S. Navy plans to launch the first MUOS satellite Feb. 16. General Dynamics C4 Systems has completed the first MUOS ground station in Hawaii, and company officials are building terrestrial facilities in Australia, Italy and Virginia.



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Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She...