E-mailing You From a GV High Above the Grand Canyon
Why leave your work productivity on the ground? Wednesday morning, Gulfstream Aerospace (Booth 11600, static display) officials invited Show News and others aboard a Gulfstream V 'classic' for a one-hour demonstration of its new $650,000 broadband satcom datalink system, soon to be certified as an option for large-cabin Gulfstream aircraft.
During the short flight, eight passengers, including AvWeek's Tony Velocci and B/CA's Bill Garvey, enjoyed spectacular views of the Grand Canyon, ate breakfast, surfed the Internet and checked their e-mail, using Gulfstream's Ku-band satellite Broad Band Multi Link. BBML uploads at 128 kbps, but downloads come through at 512 kbps to 3.5 mbps. That's several times as fast as Inmarsat's Swift64, which is especially apparent when surfing the web or downloading large file attachments. So folks on board can perform work tasks at the same speed as they do in their offices on the ground.
"We're typically 15 to 20 times faster than Swift64 for download," Robert Geary, Gulfstream's manager for completions, research and development said. "That's because we have dedicated, one-way uplink and downlinks, not one datalink that's shared by both functions."
BBML can use several different satcom systems, including Swift64 MPDS and Swift Broadband, when it becomes available. But, the fastest link that's currently available is Ku-band. For this function, BBML uses a second, mechanically-steered, Ku-band antenna, mounted behind the Inmarsat Aero-H antenna in the radome atop the fin, to transfer data with geostationary Ku-band satellite transponders. For U.S. operators, the system connects to AMC1, a bird owned and operated by SES Americom that's parked 22,300 miles above the equator.
However, when you factor in the slant range, signals must travel as much as 95,000 miles between the aircraft and the satellite, causing a 600-millisecond delay. BBML's file server on board the aircraft helps to overcome this phenomenon by "parallel fetching". Several sub-menus at websites are pre-loaded into the file server when a site is first accessed. That speeds up access when the user clicks on other pages at the website, Geary said.
At present, BBML Ku-band only is available over the United States because of Ku-band satellite contract restrictions, but Geary said that it will be available using other satellites over the North Atlantic, Europe and the Middle East by mid 2005. By March 2006, it should be available over the Pacific. "This will provide coverage over 95 percent of the routes most frequently flown by business aircraft operators," Geary said.
Gulfstream is pursuing the Ku-band satcom alternative because it piggybacks on ARINC's SKYlink Ku-band service. This link is dedicated to aircraft use only, so it won't compete for time slots with non-aviation users. However, as more aircraft gain SKYlink capabilities, system capacity eventually could become limited. But, there's a glut of Ku-band transponder time currently available on various satellites, so it's likely that capacity can be increased as necessary.
