DOD weighs future comm strategy
- By Bob Brewin
- Nov 01, 1998
BEDFORD, Mass.— With data communications requirements expected to jump exponentially by 2010, the Pentagon may opt to develop a new global satellite system to replace its aging constellation, even though industry vendors say they are prepared to meet its requirements.
Speaking at the annual Military Communications Conference here, Gen. Gary Salisbury, deputy director of the Defense Information Systems Agency, estimated a "fourfold increase" in the Defense Department's communications requirements by 2010. Salisbury expects satellite systems to pick up much of the increase, with throughput on satellites increasing from 1 gigabit/sec today to 13 gigabits/sec in 2010. Terrestrial communication systems will provide the rest of the capacity.
Richard Williams, an engineer with DISA's Center for Systems Engineering, projected that traffic between DOD fixed sites would jump to 1.8 gigabits/sec by 2010. Demand from tactical users, meanwhile, would increase 50 times, with up to 6 gigabits/sec in capacity, in order to support a DOD policy that calls for the ability for U.S. forces to simultaneously fight a war in two major, geographically separated theaters.
Salisbury said internal studies by the Pentagon indicate it would be cheaper for DOD to build and own its own satellite system, probably operating in the Ka-band which provides higher data rates than the existing Defense Satellite Communications System which uses the X-band. Salisbury said that even if the Pentagon built its own new satellite system, it would still need to acquire 3G of capacity from commercial providers.
Executives of commercial satellite companies disagreed with Salisbury, saying they could provide DOD with cost-effective service with low up-front costs.
The economic downturn in Asia has made it possible for DOD and DISA "to drive a good bargain [for satellite capacity]," according to Troy Ellington, a vice president of Space Systems/Loral.
Speaking at a panel session here, Ellington said that as the result of the downturn, DOD "can do a better job [on price] than...a year ago." DISA has an offer pending on the street for a trans-Pacific network that will rely heavily on satellite circuits for connectivity, and Ellington urged DISA "to get an offer out there" for the capacity it needs.
Ellington also urged DOD to buy large-scale capacity on worldwide satellite networks planned by his company and others that would provide the Pentagon with "assured access" to those systems. Observing that DOD prefers to build its own satellites because it can incorporate such protections as radiation hardening and security, Ellington argued that commercial operators have started to incorporate the same technology in their systems to protect their investments.
Bob Rankine, a vice president with Hughes Space and Communications, said the commercial satellite industry is building systems over the next decade with more than enough capacity to satisfy DOD requirements.
Rankine said that over the next decade, commercial providers will orbit 243 geostationary satellites to serve customers around the world. Planned low-Earth-orbit systems, such as the Teledesic "Internet in the sky'' backed by Microsoft Corp.'s Bill Gates and cellular telephone pioneer Craig McCaw, will increase that total to roughly 1,000 satellites.
Government will become "the largest customer" for these new systems, Rankine predicted, saying DOD can get a deal through "pre-arranged business agreements" that will allow it to take advantage of "competition in the marketplace."
William Chan, head of the Communications and Information Technology Division at the Air Force-funded Lincoln Laboratory, said that whatever systems DOD builds need to be "more data oriented" than the existing satellite system developed to serve voice and low data rate users.
The Pentagon also needs to develop a new communications protocol to handle satellite data because Transmission Control Protocol/Internet Protocol does not allow for the inherent latency in satellite signals.