Not so long ago, the highlights of an in-flight experience were prepackaged meal, the drink trolley and a few magazines. With luck, there may have been an in-flight movie. Now hunger for entertainment and connectivity is driving development of cabin communications based on broadband satellite services.
Today, passengers want audio and video content. They would like Internet and e-mail. A leading desire, it seems, is the ability to pick up one’s own mobile phone to tell friends and family: “I’m on the plane!” This demand for connectivity with the outside world is driven by expectations created at home and in the office, and business aircraft, especially, suck in cascades of data to provide high-flying occupants with such goodies as streaming video, voice over Internet protocol (VoIP) and high-speed Internet access. Passing large amounts of data requires a broad data pipe, and for aircraft flying significant distances, that means broadband satellite communications.
The industry took a hit when Boeing terminated its Connexion broadband venture following disappointing market uptake, but interest continues to increase for such services from suppliers like Arinc, Inmarsat and OnAir, as well as several equipment manufacturers. There also are other suppliers of high-bandwidth services that operate, like Connexion, in Ku-band, such as SKYLink from Arinc Direct. There is no doubt that Ku-band systems have the edge when it comes to high-bandwidth, always-on connectivity, although such capability comes at a price.
Meanwhile Inmarsat, whose generations of L-band geostationary satellites have been a key foundation for aeronautical satellite communications services, is catching up on Ku-band with its fourth-generation I-4 satellites. A pair of spacecraft — one over the Atlantic Ocean and one over the Indian Ocean — provide connection speeds of up to 432 kilobits per second (kbps), and once a third satellite is orbited over the Pacific, only the polar regions will be outside the service’s reach. The I-4s provide 228 narrow spot beams that will be the backbone of Inmarsat’s broadband services, including the aeronautical SwiftBroadband due to be rolled out this year. In addition, the new satellites provide 19 wide beams to support existing Swift64 Aero services and, as with previous generations, a background global beam provides low-data-rate coverage over a still wider area to support a low-cost voice service.
The latest Inmarsat system is Internet protocol (IP)-based, opening up the possibility of many new applications, and uses packet data to deliver always-on connectivity. Mobile packet data service is an affordable solution for modest amounts of data transfer, as it is billed by the megabit and not by connection time. As well as facilitating e-mail, Internet access and voice communication, always-on connectivity can support live TV and videoconferencing, along with aircraft-related technical services such as weather and chart updating, remote monitoring of onboard systems and telemedicine. Voice and data can be handled concurrently. Effectively, aircraft can become airborne extensions of the terrestrial networks that many organizations now rely upon.
Inmarsat provides Internet connectivity, mainly to business and corporate travellers, with its Swift64 service. This service offers speeds of up to 64 kbps per channel using the wide beams on the I-3 and I-4 satellites. Channels can be operated in combination to provide speeds of up to 256 kbps per Swift64 terminal, with data compression and acceleration further boosting the effective data rate. Nevertheless, there may be a good case for upgrading to SwiftBroadband. Inmarsat has hinted that the cost of accessing the Internet over the new network will be less than users pay now with Swift64, and customers wanting still higher speeds will be able to access rates up to 864 kbps by acquiring terminals that combine two SwiftBroadband channels.
In the Asia-Pacific region Japan’s Multifunction Transport Satellite (MTSat) provides an alternative to Inmarsat. The satellite, placed into orbit in February 2005, also uses spot beams for high-bandwidth coverage. Avionics original equipment manufacturers are making it possible to use both systems. Honeywell, for example, has issued instructions to guide would-be MTSat users who use Honeywell’s satellite communications terminals how to amend the stored Owner Requirements Tables to include the MTSat ground station at Kobe, Japan.

Aircraft Equipment

To achieve an air-to-satellite link, an aircraft must be equipped with an antenna that can be steered to point at the selected satellite and an onboard transceiver/data terminal. For Ku-band systems, it was necessary to shrink the large antennas normally associated with terrestrial and maritime operation.
ViaSat Inc. has developed a mechanically steered, tail-mounted dish antenna that is less than 0.6 meters in diameter used to support the SKYLink Mobile Broadband service that Arinc Direct launched initially for business jets. The complete antenna and avionics package weighs less than 18 kilograms. A full aircraft installation comprises the antenna, antenna control unit, the onboard transceiver/router terminal and an aircraft subnetwork.
L-band antennas can be made smaller and lighter than their Ku-band counterparts, with phased array antennas such as the HGA-7000 from Chelton Satcom Inc., the CMA-2102LW from CMC Electronics and the AMT-3800 HGA from EMS Satcom having the advantage of no moving parts, inherent reliability and low profile. However, as planar devices installed on the fuselage, these antennas require significant real estate plus penetrations of the hull/pressure vessel for coaxial wiring.
Mechanically steered systems have moving parts and a higher profile, but their plan dimensions are smaller than phased array systems. The mechanical antennas are designed for mounting atop the vertical stabilizer, a protective radome being substituted for the normal stabilizer tip. The AMT-50 from EMS Satcom weighs about 8 kilograms and has an antenna less than 0.3 meters in diameter. The full system includes the antenna, antenna driver and diplexer/low noise amplifier. Chelton competes with its tail-mounted HGA-6000.
CMC Electronics added the Airbus A320 to its tally of Airbus aircraft equipped with the CMA-2102LW SatLite compact Inmarsat antenna when the airframer selected this unit as seller-furnished equipment for its narrowbody family. SatLite weighs less than 7.6 kilograms, meets the Arinc 781 specification for low-weight, L-band satellite communications and will work with classic Inmarsat avionics, Swift64 and the new broadband generation. Bruce Bailey, commercial aviation vice president of CMC, expects to see 500 systems installed in A320 family aircraft throughout the next five years as well as scores more following earlier selections for A330, A340 and A380 aircraft. The antenna also has been chosen by All Nippon Airways for its long-range Boeing 737-700ERs.
High-speed data terminals are available from such manufacturers as Honeywell, Rockwell Collins, EMS Satcom, Thales Avionics and Thrane & Thrane. Recently produced terminals are readily upgradeable for SwiftBroadband operation. Collins’ latest HST-2110 and 2120 high speed transceivers, designed for use with the company’s established SAT-6100 satellite communications, offer one and two Swift64 channels, respectively, while both have provision for SwiftBroadband. When the service is turned on, a software service bulletin will be issued to enable this feature, says Tim Rayl, senior marketing director with Rockwell Collins business and regional systems. Honeywell’s HD-128 high-speed digital transceiver offers two channels of Swift 64 in a single box and, likewise, can be upgraded for SwiftBroadband.
EMS Satcom’s eNfusion HSD-400 high-speed data terminal will similarly provide two channels of SwiftBroadband. The unit delivers voice and data services. Used with an AMT-50 or AMT-3800 antenna plus a CNX cabin gateway networking device it forms the complete eNfusion Broadband high-speed data system, which has been selected by the French Marine Nationale (Navy) for six of its maritime patrol aircraft, with an option for two more, under the Aviasat program.
Thales Avionics, meanwhile, has launched its TopFlight terminal to meet the Arinc 781 specification for second-generation Inmarsat avionics. A typical package would cost about $100,000, compared with an estimated $500,000 for a Connexion installation, says Ranier Koll, general manager of Thales Avionics. TopFlight, packaged in a single box, weighs just 11.3 kilograms and will support two SwiftBroadband channels. Thales says the IP-compatible system will be able to work with secure phone equipment and is suitable for military and air traffic control applications.
Danish manufacturer Thrane & Thrane has produced a prototype SwiftBroadband-capable terminal based on the Explorer 700 design which works with Inmarsat’s Broadband Global Area Network. The definitive system planned for launch this year will be designated Aero-SBB and will support two channels of SwiftBroadband, a backup Swift64 channel, up to four voice channels and a channel providing low-speed data for the flight deck.

Range of Services

Air time and service providers are taking full advantage of improved infrastructure and projected equipment capabilities to deliver broadband services. A major driver of the demand is the wish of aircraft occupants to use their own mobile phones, laptops and other portable electronic devices while airborne.
Gulfstream is Arinc’s launch customer for SKYLink Mobile Broadband. Connected users can download data from the Internet at some 3 megabits per second (Mbps) or transmit data at 128 kbps. A derivative system developed for commercial aircraft can deliver data to the aircraft at speeds up to 5 Mbps to the aircraft and from the aircraft at 256 kbps. Both systems utilize transponders on SES Americom satellites to provide service over North America. SES Americom, in partnership with Arinc, is extending coverage to much of Europe and the Middle East, with coverage of North Atlantic due to follow. Latin America and Asia also are in the partners’ sights.
L-band service is offered by OnAir, a joint venture between Airbus and Sita Inc. that aims to satisfy the connectivity and personal telephone needs of airline passengers rather than just business jet users. OnAir estimates that more than 700 million passengers annually could be interested in onboard GSM service by 2009. Based on SwiftBroadband, the service offers shared data rates of up to 864 kbps and will support GSM phone use. It will be available for both Boeing and Airbus aircraft beginning in 2007. EMS Satcom will supply its AMT-3500 intermediate-gain antenna for Airbus, while Thales Avionics will provide its TopFlight SwiftBroadband terminal to support the air-to-ground link.
Passenger mobile phones will communicate safely with ground networks via a miniature onboard picocell base station, which will keep the power emitted by individual cell phones within flight-safe limits. System features enable the cabin crew to control the level of service. For instance, during designated quiet periods, they can switch to data-only operation to avoid nuisances to other passengers. “OnAir is creating a whole new market,” says Inmarsat CEO Andrew Sukawaty. “Inmarsat’s aeronautical services originally targeted long-haul, twin-aisle aircraft, with low bandwidth limiting the offer. Now the development of lightweight, compact avionics is bringing broadband to the single-aisle, short-haul market.”
OnAir CEO George Cooper expects the Western European single-aisle, short-haul sector to provide the greatest demand for voice, with data services appealing more to long haul. The company also plans to extend OnAir service to other regions, including the Middle East and Asia-Pacific.
Air France, British airline BMI and Portugal’s TAP plan to undertake commercial trials of the OnAir service. Meanwhile, the Airbus/Sita joint venture has concluded an agreement with Ryanair under which the low-cost carrier will introduce the service on its entire fleet of more than 200 Boeing 737s. Agreements with several other airlines are said to be close. OnAir is confident that the telecom regulatory environment needed to support its onboard cell phone offering will be in place in good time for service launch. OnAir has been working hard with the pan-European telecoms regulatory body, the European Conference of Postal and Telecommunications Administrations, to develop a framework that will minimize the number of separate national approvals needed before a carrier can offer the new service to passengers. Pricing is expected to be in line with roaming charges for international cell phone calls, starting at $2.30 to $2.50 a minute but falling to $1.50 per minute over five years as conventional mobile communication prices fall.
OnAir faces competition from rival provider AeroMobile, a joint venture between Arinc and Telenor. This partnership’s claim is that it safely connects the global GSM network to the airline industry at a price point similar to current GSM mobile phone roaming charges. AeroMobile will provide GSM voice and short messaging plus GPRS data on both narrowbody and widebody aircraft. Swift64 will be the satellite communications platform used initially, with a transition to SwiftBroadband following later. Having obtained seven national telecom authority licences and 45 roaming agreements with cellular operators around the globe, AeroMobile expects to become operational in 2007, says David Coily, marketing and strategic relationships director. Qantas plans to evaluate the service, testing it on a Boeing 767 on Australian domestic routes over a three-month period in mid-2007.
One market that satellite communications service providers will have their eye on is MagnaStar replacement. Existing MagnaStar phones on thousands of aircraft operating in North America which will go dead at the end of this year now that Verizon Airfone has decided to close or sell its communications service for general and corporate aviation. This follows Verizon’s failure to win spectrum allocation in a 2006 U.S. government auction. Airfone is a mixed terrestrial-satellite system, the satellite communications portion being based on Inmarsat Aero H, Aero H+ and Aero I systems. Florida-based Satcom Direct has seized the opportunity to offer a substitute. Under its PlaneSimple calling plan, subscribers will be able to make global voice calls at $5.50 per minute, plus a monthly service charge of $20. Satcom Direct exploits the Inmarsat infrastructure and the affordable low-earth orbit-based service from Iridium LLC.
Another contender for this market is AirCell Inc., with its AirCell Axxess EZ satellite communications. Supporting voice and narrowband data in its basic form, this system is designed to reuse existing MagnaStar aircraft wiring and component locations and gives operators the option of retaining key legacy system features such as call alerting and integrated fax capability. According to Jack Blumenstein, AirCell president & CEO, Axxess EZ also gives operators a rapid path to AirCell’s new air-to-ground broadband service that will debut in late 2007. The system will work with EMS Satcom’s eNfusion HSD-128 and HSD-400 terminals, offering two and four channels, respectively, of Swift service. Initially, these would be Swift64, but could be upgraded to SwiftBroadband.
Honeywell, which is concentrating on the corporate jet market, has been flight testing GSM technology on one of its corporate jets. Honeywell feels it has solved interference problems and that the corporate market will lead the way for approval of in-flight cell phones. “The solution for bizjets will move ahead, but the airline market will take a little longer to shake out,” says Eric Olson, Honeywell’s product marketing manager for cabin systems. Olson feels some of the issues with cell phone use are ethical, not technical. The possibility of annoying other passengers on long-haul flights is a key factor for airlines. “Our product, although it will apply to the airline market, is targeted at the bizjet market where we don’t have to worry about that.”
Honeywell’s system is an add-on to the communications already installed on the aircraft and makes use of an onboard wireless base station called a picocell, a small antenna that sets up a cell spot on the plane. The picocell keeps phones from interfering with aircraft systems or the ground cellular network by directing each phone to adjust to its lowest possible power level, says Honeywell. “So when you are flying on an airplane, the cellular network thinks of you as roaming someplace,” Olson says. “When I call you, I don’t need to know what airplane you are on. I can call your cell phone number directly and it will ring your phone.”
While the cell phone system will work with any air-to-ground communications system on the plane, the difference is in the number of simultaneous calls that can be made and the price of the calls, Olson says. The low-cost Iridium system allows one call per channel. The higher-bandwidth systems, like Swift64, put more simultaneous calls on the same link. With high-speed data the system allows seven simultaneous cell phone calls.
For fractional operators who do not want to pay for people to use the system, the entire cost of the call will show up on the individual’s cell phone bill. “For some companies, the [corporate] flight department pays for all communications costs on the aircraft. For other flight departments that don’t pay that cost, it can go directly to the user,” Olson says. On top of the Iridium or other satellite communications cost, there will be a typical cell phone roaming rider. With a personal digital assistant or short text message, the charge for each message is worked out by the service provider, he says.

The Future

Broadband satellite communications will enable airlines to differentiate themselves on the basis of the in-flight experience by offering a growing variety of data-rich services. Business jet occupants will benefit from an extension into the air of the same Internet/intranet/entertainment environments they are used to on the ground. Current indications are that all passengers will be able to enjoy the use of their own cell phones and other devices during flight.
The benefits of rapid data communication will spill over from the cabin to the flight deck and to offices on the ground, enhancing operational efficiency and flight security. Narrowband will still, however, have a place and the players we have mentioned will face competition from increasingly sophisticated but lower-cost services based on low orbiting platforms such as Iridium, Thuraya, Globalstar and Orbcomm. In particular, these will offer affordable regional solutions. Overall, hopes are high that satellite communications will be a key enabler in bringing commercial aviation into the data-centric 21st century. Recent progress suggests that this mode of communication will be well up to the task.