The 3G-like capability that will eventually be available to warfighters from the U.S. Navy’s Mobile User Objective System (MUOS) is U.S.-only for now, but the spacecraft’s legacy UHF payload will remain available for allied use, according to U.S. Strategic Command.

The Lockheed Martin-built MUOS satellites feature both the Wideband Code Division Multiple Access (WCDMA) payload and Boeing’s legacy UHF payload flying on the military’s existing Ultra High-Frequency Follow-On (UFO) satellites.

“Legacy narrowband will not go silent,” said Harold Haney, chief of the Space and Missile Defense C4 Division at U.S. Strategic Command. “I still have a legacy payload on MUOS. Once UFO goes away our international partners will use the MUOS legacy payload.”

However, Haney said the U.S. is willing to talk with allies about sharing the WCDMA payload.

“The WCDMA waveform is currently a U.S.-only system, but that could change in the future,” Haney said.

Eventually, if allies are allowed to use the WCDMA payload on MUOS, the ground segment might require software or other design changes.

“I envision that there will be some redesign requirements, because remember, it’s an open environment,” Haney said. As an example, he cited the U.S. Advanced Extremely High Frequency (AEHF) satellites, which feature extreme data rate (XDR), low data rate (LDR) and medium data rate (MDR) payloads.

“On those payloads I can separate you based upon where I want to put you on the payload,” Haney said. “If I want to put you on just the XDR side of AEHF and I say I want to do something on the LDR/MDR side, I can separate it. But on MUOS you can’t.”

Full operational capability for MUOS is slated for 2015, and officials are still testing the WCDMA payload, which is not yet fully operational.

The constellation is planned to include four operational spacecraft and one on-orbit spare. The WCDMA payload is designed to provide video, data and voice services to soldiers similar to those provided for commercial cellular phones. Today’s narrowband system forces soldiers to be stationary to acquire a signal; MUOS is designed to allow soldiers to move around the battlefield and have access to more than 10 times the data rates offered today.