Netted Iridium Service To Provide Broadcast Capability to Far-flung U.S. Forces

WASHINGTON — A new tactical broadcast service from Iridium Communications LLC will be ready for operations by the end of the year, and U.S. Central Command is expected to begin using the service shortly thereafter to connect far-flung troops in Iraq and Afghanistan.

Bethesda, Md.-based Iridium’s constellation of 66 satellites in low Earth orbit has until now supported only point-to-point telephony. The new service, called Distributed Tactical Communications System, or Netted Iridium, will enable mobile warfighters to broadcast voice or data signals via satellite to multiple users simultaneously with faster connections than the standard Iridium service, Scott Scheimreif, Iridium’s vice president for government programs, said in a Nov. 18 interview.

The concept was originally pushed by the U.S. Marine Corps, which had tactical units that needed more ultra-high frequency (UHF) communications support than could be provided by the Navy’s UHF Follow-On satellite constellation. The Marine Corps Warfighting Laboratory at Marine Corps Base Quantico, in Virginia, in 2002 worked with Iridium to develop an ad hoc network that would use the company’s satellites in a broadcast mode. The demonstration was successful, but as interest in the capability grew, it became apparent that the design was not easily scalable for many more users over larger distances, Scheimreif said.

In 2008, the Naval Surface Warfare Center in Dahlgren, Va., took the lead for Netted Iridium and issued a five-year task order contract to Iridium in June to upgrade the network. The first software upgrade for the satellite fleet and its ground stations will be completed by the end of the year, making the service available for full-time operations whenever the military wants to start using it, Scheimreif said.

The original Netted Iridium architecture was able to simultaneously support 250 different networks anywhere in the world with 95 percent reliability to all users within 160 kilometers. The upgraded software will support 2,000 simultaneous networks with 95 percent reliability to all users within 400 kilometers. Netted Iridium has been tested to work at distances as great as 900 kilometers, albeit with less reliability, Scheimreif said.

Netted Iridium is especially well-suited for Afghanistan, whose mountainous terrain can limit the availability of signals from satellites in geostationary orbit above the equator, Scheimreif said.

“We’ve heard anecdotally about warfighters who’ve had to climb to the tops of mountains to get communications, and in doing so remove themselves from strong, defendable positions and into harm’s way,” Scheimreif said. “With a [low Earth orbit] constellation, I might not have communications at this instant, but I know within a matter of two or three minutes the satellite will be over me and I can send my communications or position information.”

Another advantage of Netted Iridium is the ability to carry a radio that weighs only half a kilogram, Scheimreif said. The radios are built by NexGen Communications LLC of Dulles, Va., which is owned by ITT Corp. The company has built about 500 Netted Iridium radios that are being deployed to Afghanistan following an urgent-need request from U.S. Central Command to senior Pentagon brass, Scheimreif said. NexGen Communications on Nov. 9 was awarded a $9.7 million Navy contract to deliver 1,450 more Netted Iridium radios by March 2010.

The U.S. government, primarily the military, accounts for about $75 million, or one–quarter, of Iridium’s annual revenue. The Pentagon’s Defense Information Systems Agency purchases Iridium services on behalf of all the military services via the Enhanced Mobile Satellite Services contract, and the agency is negotiating a contract modification to include rates for the new service, Scheimreif said.

The Navy’s UHF Follow-On satellite constellation is expected to degrade to an unacceptable level of capability sometime next year, and the first satellite in the replacement system, dubbed the Mobile User Objective System, has been delayed until at least 2011 by development troubles. Iridium believes its new service can fill much of that gap in communications coverage.

“I would argue it satisfies a significant portion of the Navy’s narrowband satellite communications requirements,” Scheimreif said. “Granted, there are some protections we don’t have, but Netted Iridium could free up a lot of the resources on the degrading UHF system so they can be allocated to those who must have that capability. We are just one of many tools the government is considering implementing to fill the gap.”