DOD sings satellite bandwidth blues

Satellite issues loom for DHS

Satellite consultant Donald S. Arnstein, speaking at a MilSat conference in Washington, said Homeland Security Department agencies will begin to require military-grade antijamming techniques as they buy more commercial satellite services.


Jammers, he said, are echoing Internet denial-of-service attackers by hijacking satellites to prevent transmission or spy on signals. Arnstein is president of Saraband Wireless Corp. of Fairfax, Va.


The countermeasures that satellite providers need to take, he said, include:

  • Secret locations

  • Redundancy

  • Time diversity of signal on/off status

  • Spread-spectrum modulation

  • Mechanically movable spot beams.

'Commercial satellites often see inadvertent jamming from channel interference,' he said.

And some voices call for maximum user throughput

Military satellite strategists have complained about a lack of bandwidth. But one has qualified that to mean user-perceived throughput.

Mike Gipson, associate director of combat support at the U.S. Strategic Command at Offutt Air Force Base, Neb., said he is constantly juggling bandwidth. Even with 35 satellites flying in MilSat constellations, 'we have to direct the best birds to the highest-priority needs,' Gipson said.

The Defense Department last year launched four satellites, he said, two of them to support the Army's Central Command in Operation Iraqi Freedom. DOD has $20 billion worth of hardware in orbit plus $7 billion worth of terrestrial management, he said, but even so DOD had to buy an additional $400 million worth of commercial satellite services in 2003.

Limitless appetite

'Wideband satellite is the workhorse of Central Command,' Gipson said at a conference earlier this year. Soldiers and commanders are using it for surveillance, reconnaissance, imagery, videoconferencing, graphics and collaboration. Their bandwidth appetite is limitless and voracious, he said, far exceeding that of 13 years ago in Operation Desert Storm.

'We've launched the last of the Milstar, UFO and Discos birds,' he said. The next-generation military satellites, known as Wideband Gapfiller, Mobile User Objective System and Advanced EHF (extremely high frequency), will be capable of laser intercommunications and, he said, could serve '4,000 simultaneous networks and 6,000 users per satellite.'

Gary W. Blohm, director of space and terrestrial communications at the Army's Research, Development and Engineering Command at Fort Monmouth, N.J., said the Army is 'spread very thin with asymmetric attacks and urban peacekeeping. We no longer need just reachback' to the brass, but 'satcom on the move, peer to peer.'

Blohm said he wants 'hundreds of robust, small-aperture terminals less than a foot in diameter and capable of transmitting tens of kilobits to a megabit per second.'

He said such terminals ought to take only a minute or so to configure or be 'self-organizing with intelligent agents for smart handoffs.'

Michelle Bailey, program manager for Navy Satellite Communications Systems, reminded the industry audience that throughput'not bandwidth'is what matters to the user.

'We need management schemes, compression, Web caching, link acceleration and efficient encoding,' she said. 'The problem is that the Navy's 20-year-old infrastructure and encryption requirements prevent me from using some of your nifty schemes' for boosting throughput.
Her satellite wish list included:
  • Plug-and-play terminal connectivity

  • Surge capacity, possibly from leasing spare and excess commercial satellite capacity

  • One-touch-on, autoconfiguration and identical terminal operation

  • Autoupdated software

  • Ability to receive all frequencies by pointing in one direction at the sky

  • Multispectral cross-banding and 'as many transponders as possible'

  • Better prioritization and tagging schemes''The commanding officer doesn't always send the top-priority messages,' she said.

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