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In the past two years, the development of new satellite communications-on-the-move products and service offerings has been heating up. Whether live news video streaming from moving vehicles, rear-seat entertainment for cars or new in-flight and in-train broadband services, these applications face similar technical and market challenges.
Industry players are innovating with an exciting variety of new solutions that take advantage of the relative strengths of Ku-band satellite: ubiquitous wireless coverage and ample cost-competitive bandwidth. The key challenge with on-the-move communications is maintaining the required line of sight to the Ku-band satellite. This means that ground antennas must continuously steer and track the satellite while the vehicle, vessel or aircraft they are serving moves about. A number of players supply the critical antenna systems for these kinds of applications, including maritime segment suppliers SeaTel, KVH Industries and Orbit; land-focused suppliers such as TracStar and RaySat’ aeronautical-focused players such as Rantec, Starling, AeroSat and EMS Satcom; as well as a growing field of new and existing market entrants, including ThinKom, QEST and Commtact. The prospects for new markets are driving traditional maritime suppliers towards land and air, aeronautical antenna-makers towards land, and vice versa. Also important to maritime and new airborne Ku-band on-the-go business opportunities is the supply of increasingly powerful Ku-band satellite coverage around the world, including major ocean traffic routes.
Maritime Crews and Cruise Connections“The maritime segment for motion-stabilized FSS (fixed satellite services) antenna systems represents an annual market of about $150 million in size. It has seen rapid growth over the last five years, and we expect it to start growing again fast,” says David Provencher, president of Cobham Satcom, of Orlando, Fla. Cobham subsidiary SeaTel, is a supplier of marine stabilized antennas that has shipped more than 20,000 systems for commercial cruise, private and military vessels, and oil platforms.
Better employee retention is a key motivator for commercial maritime companies as is maximizing time at sea, and giving crews broadband access to friends and family helps. “Oil rigs may have 200 to 300 people living there for a month or more and can have similar requirements,” says David Myers, executive vice president of CapRock Communications, which provides on-the-move maritime services for its energy industry clients via Ku-band FSS and uses SeaTel stabilized antennas.
Industry players see a trend in the maritime field to connect ships as remote offices, providing everything from the latest weather forecast to dealing with customs filings and records, or maintenance. “However, as soon as you make it a corporate office extension, the price for per megabyte usage with traditional pay-per-use Inmarsat BGAN (Broadband Global Area Network) or similar services goes through the roof,” says Richard Deasington, director, vertical marketing, iDirect. More than 1,500 ships at sea employ specialized mobile VSATs from iDirect. “Compared to Inmarsat service costing $4.50 to $11 per megabyte, service such as one using iDirect VSATs over Ku-band can cost on the order of 75 cents to $2 per megabyte. Broadband VSAT over Ku-band can be order of magnitude lower in cost,” he says. An example is the global VSAT IP network provided by Orange Business Services to support French marine services company Bourbon. The new VSAT service using iDirect networking made it affordable for Bourbon to provide its crew with expanded Internet access and to improve other ship and fleet management operations.
It should be noted however, that equipment costs are substantially lower with Inmarsat, and Ku-band capacity over ocean areas is quite limited. “Our users know they are gaining access to the only truly seamless global satellite network, powered by a brand new fleet of Inmarsat-4 satellites, that is guaranteed to work when others fail and offers global coverage and longevity that cannot be matched by VSAT or Ku,” says Piers Cunningham, director of maritime business for Inmarsat. “This is why we have over 200,000 maritime terminals in operation today and continue to activate terminals at a record rate. It is also why seafarers, who absolutely must have reliable communications for safety reasons, all use Inmarsat,” he says. End-user airtime prices for Inmarsat services are set by its distribution partners, and users are able to continuously monitor their usage in real time.
Challenge: Efficient, Smaller, Lighter AntennasImplementing antennas small, light and low-cost enough to fit on a vehicle, train or plane able to track a satellite while in motion poses technical challenges. “If you go to very small antenna sizes, there are two problems,” says Deasington. “One is the gain decreases. On the transmit side, the smaller the antenna reflector, the wider the transmit beam width, so if your beam width is quite wide you could cause adjacent satellite interference, and violate [U.S. Federal Communications Commission] and [International Telecommunication Union] sidelobe rules.”
One solution to the problem of adjacent satellite interference with small Ku-band dishes is to spread the signal across a wider bandwidth. By using spread spectrum technology, ViaSat is able to use the compact KVH TracPhone V7 antenna, which is 75 percent lighter and 85 percent smaller by volume than traditional 1-meter VSAT antennas, according to KVH. The larger VSAT modem manufacturers, including iDirect, Hughes and ViaSat, also are introducing spread spectrum products. iDirect uses DS-SS (direct sequence spread spectrum) technology to enable transmissions to smaller on-the-move terminals. ViaSat’s ArcLight technology also includes spreading, as does Hughes’ broadband-VSAT-for-mobile solution. Spread spectrum requires more transponder bandwidth than conventional transmission formats. “Even so, it’s still far less expensive and offers much higher data rates than Inmarsat broadband service, for example,” says Provencher. Also, modems can compensate for the bandwidth increase in other ways. For example ViaSat’s CRM (code reuse multiple access) technology saves bandwidth through reuse, countering the spread spectrum increase.
Doppler compensation is another technical challenge with on-the-move systems. “If the aircraft or fast vehicle is moving, the frequency it receives will go down or up, so you need features in your terminals to deal with the changes in frequency as vehicles or aircraft approach or recede from a satellite at up to hundreds of miles per hour,” says Deasington. For its new in-flight services, Panasonic has licensed iDirect technology that addresses the Doppler effect .
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