Business & GA, Commercial

Paving the Way for Airborne Broadband

By George Marsh | February 1, 2004
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Broadband–true broadband, prefixing bits per second with "mega" rather than "kilo"–is high on the wish list of people wanting to stay connected while on the move. Corporate executives and government officials, used to a large data "pipe" in the office and at home, want the benefits of fast Web access, e-mail, corporate network connectivity, and video conferencing wherever they go, including on their business aircraft. While taking careful note of evolving platforms from Connexion by Boeing and others, the bizjet community is watching another player, as it assiduously installs broadband building blocks to an already impressive infrastructure.

An international consortium formed to provide deep sea mariners with reliable global communications, Inmarsat has for some time been a provider of mobile communications services to users at sea, on land and in the air. Its Aero H, L and I satcoms are well established in corporate and commercial air transport.

About four years ago, the company fielded a global area network (GAN) for land portable data communications. An aeronautical version of GAN–known in aviation as Swift64–followed in 2002-2003. It can be viewed as a forerunner of a next-generation, broadband (Aero B-GAN) service, which Inmarsat intends to launch once its land-based B-GAN system is up and running, two or three years from now. (By that time, it will probably be called something else.)

Up to now, London-based Inmarsat has been coy about discussing definitive plans for B-GAN and subsequent developments. But, with the first of its fourth-generation geostationary yes" satellites set for launch in the second half of 2004, Inmarsat is divulging details of how it intends to roll out commercial B-GAN services from mid-2005, followed by aeronautical services from 2006-2007. Payloads on the I4 birds would be approximately 100 times more powerful than those available within the spot beam coverage of today’s Aero I service.

Under a $700-million contract from Inmarsat, European spacecraft manufacturer EADS/Astrium is producing four I4s. Initially, two of these have been earmarked for active use over the Atlantic and Indian oceans, with one kept on the ground as a spare. Their bus structures are being built at Astrium’s factory in Stevenage, UK, while the payloads are the responsibility of another UK facility, at Portsmouth. These components are sent to Toulouse, France, for final assembly, along with U.S.-built antennas and German solar arrays.

These formidable satellites will serve mobile users with data speeds of up to 432 kilobits/sec (Kbits/s). This capability compares with the data capacity of third-generation telecommunications systems, in particular the Universal Mobile Telecommunications System (UMTS), which will offer 384 kbps or more.

One Step at a Time

To put matters in perspective, it’s useful to consider how Inmarsat has been building towards this goal in a strategic, step-by-step fashion.

By the mid-1990s, the organization was touting its Aero services. Aero H is an upper-end, high-gain service–compliant with future air navigation system (FANS) specs and relevant standards and recommended practices (SARPs)–with up to 10.5-Kbit/s capacity. This makes it viable for voice and data traffic, but the sizable, mechanically driven antenna has restricted the system’s appeal chiefly to long-haul carriers. Aero L is a lower-gain, fixed-antenna system for customers satisfied with simpler, data-only capability.

Aero I, which entered service in 1998, is an intermediate solution, offering voice, telephony and fax within the coverage of the spot beams–a novel feature of Inmarsat’s third-generation satellites. Since these beams are focused on the world’s more developed countries, where most aircraft fly, their extra power enables aircraft to carry lighter, lower-gain antennas. Aero I, in particular, has proved popular on business and regional aircraft. Outside spot beam coverage and within the less concentrated global footprint, Aero I service is degraded to data only at 600/1,200 bits/s–much less than the 4.8-Kbit/s data rate available within the spot beams.

More advanced payloads carried on I3 satellites, launched as replacements for aging second-generation birds, permitted a rise in data rates to the 64-Kbit/s level delivered by the integrated service digital network (ISDN) telephone lines familiar to most earthbound Internet users. This enabled Inmarsat to develop its Global Area Network for land mobile use. GAN users benefit from data speeds which, while not quite up to the 172-Kbit/s capability of general packet radio services (GPRS) available on second-generation mobile phones, are in the same league. Users say that GAN services demonstrate voice quality and data transfer speeds superior to those of mobile wireless. They can connect to Internet and other computer networks at 64 Kbits/s, (128 Kbits/s, if two channels are used in tandem) and receive either ISDN or mobile packet data service (MPDS). Recently Inmarsat enhanced GAN coverage in the Middle East by transferring one of five satellites it had standing by in orbit to the active fleet.

Using the Web typically results in the downloading of data in bursts, so MPDS likewise relies on transmission in bursts, rather than in a continuous serial stream. Given the amount of unused time in any one user’s data stream, it is possible to interleave "packets" from several users, making better use of channel capacity and cutting the cost per user. Data intended for an individual user is separated out again on reception.�>Packet data, a basis for Internet protocol (IP), is preferred for Web browsing, e-mailing, database querying, and local area network and intranet connectivity. Mobile ISDN is better suited to transferring large files and photos, video streaming and video conferencing, high-quality audio, storing and forwarding, and secure voice and data. Business jet users are likely to want both.


When Inmarsat extended its 64/128-Kbit/s capability into the air as Swift64, it implemented ISDN capability first, in April 2002, and added MPDS the following summer. Swift64, an Aero-GAN service, has made a flying start with corporate and government operators. It underpins Rockwell Collins’ Airshow 21 integrated cabin electronics solution selected by Bombardier for its Global 5000 intercontinental business jet. Honeywell-Thales reports strong interest following a demonstration tour by Honeywell’s Cessna Citation 2, in which communications and entertainment are provided by Thales’ MCS-7000, seven-channel Aero H+ satcom system, combined with a Thrane & Thrane HS-700 Swift64 high-speed data unit. Tenzing Communications and Rockwell Collins successfully tested Swift64 e-mail on an Airbus A318 and have moved on to 128 Kbits/s. Teledyne Controls already incorporates this higher speed in its SmartCabin Office concept, which uses twin Swift64 channels and a high-speed HSD-128 data terminal from EMS Technologies.

Nor is 128 Kbits/s the limit. EMS recently announced it is quadrupling Swift64 channels in its new HSD-X terminal, to provide a nominal 256 Kbits/s.

Corporate aircraft that already are equipped with Inmarsat-capable antennas can be upgraded to the Swift64 standard for about a tenth of the cost of installing the Ku-band infrastructure required for Connexion, industry insiders say. Although Connexion by Boeing is genuinely broadband, Inmarsat’s installed base gives it an advantage in markets valuing a technology that is both appropriate–easily providing the e-mail connectivity that business travelers particularly value–and affordable. Well over 100 corporate aircraft are by now equipped for Swift64 operation.

VIP Choice

An important milestone for the service came with its selection to equip the U.S. Presidential/VIP fleet. HSD-128 twin-channel Swift64 avionics from EMS Technologies are on most of the 19 U.S. Air Force-operated aircraft. On "Air Force One" Boeing 747s, these are combined with Rockwell Collins’ SAT-906 multichannel Aero H installations.

Swift64 is apparently a hit with users like U.S. Defense Secretary Donald Rumsfeld, though such high-fliers would always like more from the system. To provide it, engineers have multiplexed up to eight simultaneous voice links on a single Mobile ISDN channel, bonded two Swift64 channels to achieve data rates of almost 128 Kbits/s, and used signal compression to boost rates even further, to around 0.5 megabits/s, according to Vincent Cirelli, Rumsfeld’s chief of airborne and travel communications.

Cirelli told delegates at Inmarsat’s latest aero conference, held at Tyson’s Corner, Va., that Inmarsat’s fourth-generation satellites would help meet the U.S. government’s need for still higher bandwidths, and urged all speed in developing a 432-Kbit/s aero version of B-GAN.

Corporate users echo this sentiment and are reassured that in-flight entertainment/ communications providers are factoring the anticipated service into their plans. Rockwell Collins, for instance, says that the HST-900 unit it developed to add Swift64 to Aero H can be upgraded to work with B-GAN. Thrane & Thrane says it intends similar upgrade capability.

Regional B-GAN

Inmarsat, meanwhile, hardly needs urging and is making steady progress. Recently, in a further step towards full B-GAN, it implemented a "Regional B-GAN" service. Today broadcast journalists in Iraq, for example, can send their dispatches at up to 144 Kbits/s via video phones connected to Inmarsat B-GAN terminals a little larger than a notebook computer, each containing a modem, integral antenna and transceiver. Embedded GPS sensors help users locate the appropriate spot beams from the satellites to relay their messages.

Regional B-GAN, delivering bandwidth capability comparable to that of third-generation (3G) cellular systems, was made possible by leasing transponders on another satellite constellation, Thuraya. One motive for doing this was that Inmarsat wanted mobile users to experience the benefits of being able to transfer data in volumes similar to those available to static users of 3G systems, prior to the arrival of B-GAN proper.

The award-winning regional broadband global area network extends the functionality and speed users experience with metropolitan GPRS networks, across a large swath of the Americas, Europe, the Middle East and India. Providing continuous coverage within the satellite footprint, it offers a secure 144 Kbits/s shared channel, "always on" access to the Internet and other IP-based networks, and billing according to the amount of data sent rather than time spent on line.

Laptops and other equipment can be connected to notebook-sized Regional B-GAN terminals via universal serial bus (USB) or Ethernet ports, or wirelessly by Bluetooth. Regional B-GAN’s value to business has been enhanced by adding virtual private network (VPN) access and configurability to Apple Mac as well as Windows operating systems. The service is available through distribution partners such as Telenor, France Telecom, Net Africa, Xantic and Stratos.

Inmarsat managing director Michael Butler describes Regional B-GAN as "an important stage in the evolution of our data services portfolio." He adds, "Our services are increasingly part of an integrated communications strategy for many multinational blue-chip enterprises who need to be assured that their communications networks remain accessible and secure 24 hours a day."

For this service, Inmarsat breaks with tradition by operating its own satellite access ground station, thereby gaining greater control over more of the communications chain. Alea Fairchild, director of industry analyst Greiner International, believes that the Regional B-GAN model, with its data-based user pricing, Web-based user-oriented interface, and Inmarsat-owned satellite access station, reduces risks for the future full B-GAN plus its aeronautical and maritime derivatives. Fairchild says, "Inmarsat is offering what many network providers have promised all along–anytime, anywhere connectivity on the extended Internet."

Inmarsat used GAN technology as a basis for its aeronautical Swift64 service. Regional B-GAN would logically lead to a "Swift144" aeronautical service, were it not for the forthcoming advent of the I4 satellites. Instead, Inmarsat intends to transition straight to "Swift432"–it’s a safe bet it won’t be called that!–effectively an "Aero B-GAN" based on data transfer at up to 432 Kbits/s. Implementation of a truly large data pipe at last, after years of broadband hype, will eventually allow a much more integrated approach to be taken to aviation data connectivity, with capacity shared between cabin-based services and those–such as air traffic control, condition monitoring and crew communications–required for the flight deck.

Extending full broadband benefits to aviators and mariners, once it is established with land mobile users, is certainly high on the agenda of Inmarsat, which has seen data revenues grow to about 40 percent of its total business. Simon Tudge, marketing manager-aeronautical business, says that the fourth-generation space infrastructure accounts for a major portion of the $1.6 billion the company is investing in broadband. He tells Avionics Magazine that a business case is being prepared for the third satellite, so far allocated as a ground-based spare. Stationed over the Pacific, it would join the other two in orbit, making coverage near global. This will be a key requirement for the air and maritime transportation sectors. Tudge says that, given the wide installed base of upgradable Inmarsat antennas and avionics already equipping corporate and government aircraft, the organization has a head start against less infrastructurally endowed competitors in the race for full aeronautical broadband.

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