Transmission Transition

TRANSMISSION TRANSITION



The Air Force is developing a successor to the Global Broadcast System,
which will deliver video and other content to warfighters around the world.

By Michael Burnett
 

In the mid-1990s, the Air Force developed a broadcast service that delivered news and information to U.S. forces deployed to places where they generally could not receive television or radio. That service, the Global Broadcast Service (GBS), grew to the point where it delivers tailored content to each of the services, often including detailed geospatial data and other information, which has had a profound impact on how warfighters in the field operate.

Now, the Air Force Electronic Systems Center (ESC), based at Hanscom Air Force Base, Mass., plans to scrap the GBS legacy transmission system, which relies on three ground terminals that communicate to to three satellites in the UHF Follow-On (UFO) system. The system will be replaced with Defense Information Systems Agency (DISA) Defense Enterprise Computing Centers (DECCs), which will communicate via the new Advanced Wideband Satellite (AWS) system.

The ESC early this year issued a draft statement of objectives for the contract, which it intends to award by the end of the year. The statement said how it proposes to transition GBS satellite broadcast management from the old system to the new one.

GBS is envisioned as a space communications system for “rapid one-way transmission of high-volume data,” designed to support deployed and traveling troops globally. “The GBS DECC-based system shall be capable of delivering the required range of intelligence, situational awareness, imagery, weather and unmanned aerial system video from available Department of Defense data sources across the Global Information Grid (GIG),” the statement indicated.

The company selected for the three-year, $30-million contract would be responsible for using COTS hardware and software to transfer the satellite broadcasts to two DECC sites before the end of 2010. The contractor would provide continued GBS maintenance and upgrades through the end of 2013.

ESC in May also released a draft request for proposals for the design of new GBS Transportable Ground Receive Suites, and called for discussions of the new receivers with industry. Military units with compact, one-meter GBS antennae can receive GBS broadcasts while they are on the move, and the new receivers must meet the same criteria.Raytheon holds the current GBS contact and plans to compete for the next one.

“This system, which has been continually going through refresh now, has been proven to be a critical war asset,” said Alan Goldey, Raytheon broadcast technology director and GBS program manager. “It is changing how the war is being fought. Now we are looking at a next phase of a major refresh, where Air Force Space Command and ESC are planning a major upgrade.”

Streaming Video

Goldey likens GBS to a commercial satellite television service, although of course GBS is available only to the U.S. military. Content is transmitted via three satellite uplinks, based in Virginia, Hawaii and Italy, to provide worldwide coverage. The Navy operates the UFO satellites, which each carry four dedicated GBS transponders.

“We respond to all of the combined commands’ needs for critical information, such as Central Command in Tampa, Fla., supporting the war in Southwest Asia,” Goldey said. “They can schedule frequently reoccurring broadcasts of critical national war information into the theater, which is broadcast via the satellites from national sources in the United States. Or they can do it in an instant.”

DoD mostly broadcasts streaming video into Southwest Asia today to present war-fighters with information from unmanned aerial vehicles, such as Predators, as it is collected. Broadcasts also provide weather, imagery and mapping and other types of information. Warfighters can make use of such critical information to track threat movements and to assist with calling in airpower and acquiring target information for combat operations.

“Each of the services likes to manage their own data and have it broadcast uniquely for their purposes,” Goldey remarked. Sometimes, that means the services might use GBS to boost morale. “A good example of that in terms of morale boosting was that we broadcast the Super Bowl to the troops on ship in the Pacific, where the troops did not have access to a landline. We broadcast that in real time and recorded it and rebroadcast it to submarines when they were able to receive it.”

Due to the complexity and reach of the GBS system, DoD chose to rely on COTS technology to refresh and upgrade the system. The original system stood up by Raytheon used asynchronous transfer mode (ATM), based on commercially available technology. From 2002 to 2005, Raytheon developed and deployed an IP-based system, which represented a major upgrade from the ATM system.

Now, the company has teamed up with Hewlett Packard and Harris to compete for the next GBS contract. HP currently is the provider of all of the computational equipment in the DECCs, and Harris is a major supplier of broadcast video products, Goldey emphasized.

The transition of GBS to the DISA DECCs will consolidate common broadcast functions from the military services to a single location. The GBS DECC will have a backup DECC to provide GBS with continual broadcast in the event of any system failures. The DECCs will manage content for the services, receiving input and scheduling broadcasts over DISA teleports.

“In some ways, this somewhat tracks commercial industry because this is somewhat analogous to the workings of AT&T and Verizon Internet services available to commercial subscribers,” Goldey reflected. “So there will be centralized data processing and sourcing of information and then redistribution of that either over the GIG and/or these worldwide teleports. You will be able to get this service wherever you are on the globe, whether on land or surface or eventually in the air.”

The AWS satellites used in the new system will provide nearly double the bandwidth and data rate transmission of the old system, Goldey estimated. Eventually, six AWS satellites will orbit the earth, but DoD will continue to make use of the UFO satellites until they run down.

“We are looking forward to the future, but until the DECC is fully stood up, we will continue to provide the service and operate our current satellite broadcast management, probably into the next two or three years,” Goldey added.

Capacity Increases

Several major companies responded to an original notice seeking sources from ESC, including Boeing, EDS, Hughes, Lockheed Martin, Raytheon and TRW. As of press time, only Raytheon had made a public statement about its intent to pursue the GBS transition contract.

A joint operations requirement document, issued by Air Force Space Command Headquarters in 2005, spells out the shortcomings of the current GBS system, and any successful bidder for the new contract would require the capabilities to overcome them.

Although the use of the UFO satellites provides near worldwide capability, DoD must lease Ku-band commercial satellite service to augment their coverage. Those satellite systems cannot meet modern demands for high-data dissemination rates, however, particularly with regard to high volumes of video and imagery.

“Current military satellite assets either cannot support, or would have difficulty delivering, multi-megabit broadcasts to multiple receivers using small antennas or to mobile users without significantly limiting or curtailing other critical two-way voice and data services to the warfighter,” the document read.

The new GBS system would provide increases in transmission capacity and set up the ability to broadcast nearly continuously to widely dispersed sites. Air Force Space Command anticipates new users will sign onto the GBS system as soon as it begins making use of uplinks through DoD Teleports, using X and Ka band communications, and delivering content via the Wideband Global Satellite Communications (WGS) satellites once they are in orbit.

The WGS satellites’ ability to deliver information across bands will play an important role in DoD plans to boost GBS throughput. The first satellite in the new constellation was launched this spring.

In its systems requirement document released in January, the GBS Joint Program Office (JPO) also anticipates that readily available COTS equipment will allow any military terminal with DoD standard L-band intermediate frequency capability to receive GBS broadcasts.

The GPS JPO also has set an objective of providing a minimum of 95 percent assurance of receipt of broadcast information. One of the key objectives of the new GBS contract is to “achieve full compliance with DoD requirements for transmission security of satellite links by leveraging the Joint Internet Protocol Modem at the DoD Teleports,” according to its draft statement of objectives.

DISA is currently funding development of the Joint Internet Protocol Modem as a key component of the open systems architecture of military satcom programs. (See MIT, Volume 12, Issue 4, page 16.)

To accomplish this, contractors must be aware of threats to GBS transmissions, particularly from enemy forces that might attempt to disrupt the broadcasts. The primary threat to GBS would likely manifest itself through electronic attacks or computer network warfare, according to GBS JPO. As such, the GBS team must take care to protect the new system from any disruptions as well as traditional denial-of-service attacks or malicious software to ensure transmission security. ♦