Satcom: Broadband in the Cabin

Not so long ago, the highlights of an aircraft passenger’s in-flight experience were the prepackaged meal, the drinks trolley and a few magazines. With luck, there may have been an in-flight movie.

Today, far more is expected. Passengers want audio and video content on demand-radio, music, film, and live television. 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!"

Hunger for entertainment as well as connectivity with the outside world is driven by expectations created at home and in the office. Business aircraft, especially, suck in cascades of data to provide high-flying occupants with such goodies as streaming video, voice-over-Internet protocol (VOIP) communication, fast Internet downloads, e-mails with large-file attachments, access to corporate intranets-aka virtual private networks (VPNs)-and always-on connectivity. Passing large amounts of data requires a broad data "pipe," and for aircraft flying significant distances, that means broadband satellite communications.

Although it will take time to master the complexities involved in bringing affordable broadband satcom services to the market, interest continues to increase for such services from suppliers like ARINC, Inmarsat and OnAir, as well as several equipment manufacturers.

Boeing recently confirmed that it is terminating its Connexion broadband satcom venture following disappointing market uptake. Industry sources suggest that, although the system functions well, cost, installation and weight issues have limited its appeal. However, there are other suppliers of high-bandwidth services that operate, like Connexion, in the Ku band. One example is 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 satcom services, is catching up on Ku band with its latest, fourth-generation, satellites. The I-4s can transfer data at 432 Kbits/s, although uplink and downlink speeds may vary depending on the terminals used. Rates approaching half a megabit per second can be regarded as pushing into broadband territory, even though they may not rival the 3-5-Mbit/s uplink speeds offered by SKYLink and Connexion. Two new Inmarsat I-4 satellites are now operating over the Atlantic and Indian Ocean regions, and once a third is orbited over the Pacific, as intended, only the polar regions will be outside fourth-generation Inmarsat coverage.

The I-4s maintain the spot beam revolution that commenced with the previous I-3 generation, but take it much further. Whereas each I-3 provided just seven concentrated spot beams for high data rate communications, the I-4s generate some 228 narrow spot beams that will be the backbone of Inmarsat’s broadband services, including the aeronautical SwiftBroadband due to be rolled out soon. These beams, directed to areas where high data usage is expected, can be dynamically reconfigured if required. In addition, the new satellites provide 19 wide spot beams to support existing Swift64 Aero services over entire regions. And, as with previous generations, a "background" global beam provides low data rate coverage, 4.8 Kbits/s, over a still wider area, about a third of the Earth’s surface per satellite. This will support a low-cost voice service.

The latest Inmarsat system is IP-based, opening up the possibility of many new applications, and uses packet data to deliver always-on connectivity. Mobile packet data service (MPDS) is an affordable solution for modest amounts of data transfer, as it is billed by the megabit and not by connect time. As well as facilitating e-mail, Internet access and voice communication, always-on connectivity can support live TV and video conferencing, 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.

Currently Inmarsat provides Internet connectivity, mainly to business and corporate travellers, with its Swift64 service. This service offers up to 64 Kbits/s per channel, using the wide spot beams on the I-3 and I-4 satellites. Channels can be operated in combination to provide up to 256 Kbits/s (four channels) per Swift64 terminal. Data compression and acceleration can further boost effective data rate to almost 0.5 Mbits/s.

Nevertheless, there may be a good case for upgrading to SwiftBroadband when it becomes available. Inmarsat has hinted that the cost of accessing the Internet over the new network will be less than users pay now with Swift64, typically $8 to $10 per megabyte. Furthermore, customers wanting higher speed still will be able to access rates up to 864 Kbits/s by acquiring terminals that combine two SwiftBroadband channels. Double-bonding to four channels is theoretically possible, and data rates could be further enhanced through compression and acceleration. Overall, data rates could be brought more nearly into line with those achievable using Ku band.

In general, Swift64 users wishing to upgrade to broadband will be able to do so with a combination of minor hardware changes and a software upgrade. Depending on the terminal used, some may be able to limit changes to a software upgrade only. Legacy "classic" Aero H, H+, I and L satcom systems will still be supported, says Inmarsat. The London-based company demonstrated SwiftBroadband at the Dubai Air Show last November and has been carrying out similar demos for potential customers in Europe and the United States. The full portfolio of SwiftBroadband services is expected to become available during 2007.

In the Asia-Pacific region, there is an alternative to Inmarsat. In February 2005 Japan launched its Multifunction Transport Satellite (MTSAT), which similarly utilizes spot beams for high-bandwidth coverage. Avionics OEMs are making it possible to use both systems. Honeywell, for example, has issued instructions to guide would-be MTSAT users who have equipped with the company’s satcom terminals on 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 Ku-band operation. ViaSat Inc., to quote one manufacturer, has developed a mechanically steered, tail-mounted dish antenna that is less than 2 feet (0.6 m) in diameter. This is used to support the SKYLink Mobile Broadband service that ARINC Direct launched some three years ago, initially for business jets. The complete antenna and avionics package weighs less than 40 pounds (18 kg). An important factor in keeping antenna size and weight down was the adoption of code reuse multiple access (CRMA) spread spectrum transmissions to minimize power and bandwidth requirements. 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. Inmarsat antennas are mechanically or electronically steered (phased array). Latter types such as the HGA-7000 from Chelton Satcom Inc., the CMA-2102LW from CMC Electronics or the AMT-3800 HGA (high gain) from EMS Satcom, have the advantage of no moving parts, inherent reliability and low profile.

However, as planar devices installed on the fuselage, they require significant real estate-about 3 feet by 1 foot in each case (1 m by 0.3 m)-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 less. They are designed for mounting atop the vertical stabilizer, a protective radome being substituted for the normal stabilizer tip. The AMT-50 mechanically steered unit from EMS Satcom weighs about 18 pounds (8 kg) and has an antenna that is under a foot 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 recently 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. CMC commercial aviation vice president, Bruce Bailey, expects to see 500 systems installed in A320 family aircraft over the next five years, as well as scores more following earlier selections for A330, A340 and A380 aircraft. The antenna has also been chosen by All-Nippon Airways for its long-range Boeing 737-700ERs. Meeting the ARINC 781 specification for low-weight, L-band satcoms, SatLite is 37 inches long by 13.1 inches wide by 2.64 inches high (94-by-33.3-by-6.7 cm) and weighs 16.75 pounds (7.6 kg). It will work with classic Inmarsat avionics, Swift64 and the new broadband generation.

High speed data (HSD) 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 satcom, 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 single line replaceable unit (LRU) terminal delivers voice and data services. Used with an AMT-50 or AMT-3800 antenna, plus a CNX cabin gateway networking device from the same company, it forms the complete eNfusion Broadband high-speed data system. eNfusion was recently selected by the French Marine Nationale (Navy) for six of its maritime patrol aircraft, with an option for two more under the Aviasat program.

The $6-million Aviasat program will bring network centric operational functionality to the Navy’s maritime patrol assets, under a finance package based on a fixed monthly fee over five years. Neil Mackay, senior vice president and general manager at EMS Satcom, comments: "Working with ourselves and our partner Eclipse, the Marine Nationale will gain access to the vital communications it needs, practically worldwide, with an upgrade path to SwiftBroadband."

Thales Avionics, meanwhile, has launched its TopFlight terminal to meet the ARINC 781 specification for second-generation Inmarsat avionics. Speaking at this summer’s Farnborough Air Show, General Manager Rainer Koll said that a typical package would cost about $100,000, compared with an estimated $500,000 for a Connexion installation. TopFlight, packaged in a single 6MCU box and weighing just 25 pounds (11.3 kg), 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. (The SwiftBroadband technology is supplied by EMS.)

Danish manufacturer Thrane & Thrane has produced a SwiftBroadband-capable terminal, as a trial prototype, based on the Explorer 700 design which works with Inmarsat’s Broadband Global Area Network, a land-based predecessor to SwiftBroadband. T&T says the definitive system it plans to launch next 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 is the wish of aircraft occupants to use their own GSM or CDMA mobile phones, laptops, blackberries and other portable electronic devices (PEDs) while airborne.

Connexion by Boeing will be no more but other Ku-band-based services are likely to fill the gap for high-end data users. Gulfstream is ARINC’s launch customer for SKYLink Mobile Broadband. Connected users can download data from the Internet at some 3 Mbits/s, or send data off the aircraft at 128 Kbits/s. A derivative system developed for commercial aircraft can transfer data at up to 5 Mbits/s to the aircraft and 256 Kbits/s from it. Both systems utilize transponders on SES Americom Ku-band satellites to provide service over North America. SES Americom, in partnership with ARINC, is extending coverage to much of Europe and the Middle East this year, with coverage of North Atlantic air tracks due to follow next year. Latin America and Asia are in the partners’ sights as well.

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 Kbits/s and will support GSM phone use. It will be available for both Boeing and Airbus aircraft from 2007. EMS Satcom reiterated at Farnborough that it will supply its AMT-3500 intermediate-gain antenna for Airbus aircraft, while Thales Avionics is to 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.

Commenting on the new service, Inmarsat’s CEO Andrew Sukawaty told reporters: "OnAir is creating a whole new market. 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 Chief Executive Officer George Cooper concurs, adding that he 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 plans, in due time, to extend OnAir service to other regions, including the Middle East and Asia-Pacific.

Early next year 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, CEPT, 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 declining to $1.50/min over five years as conventional mobile communication prices fall.

Competition
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 satcom platform used initially, with a transition to SwiftBroadband following later. Having obtained seven national telecom authority licences and 45 roaming agreements with cellular operators worldwide, AeroMobile expects to become operational next year, according to marketing and strategic relationships director, David Coiley. (Qantas plans to evaluate the service, testing it on a Boeing 767 used on Austrailian domestic routes over a 3-month period from mid 2007.

One market that satcom service providers will have their eye on is MagnaStar replacement. Existing MagnaStar phones on thousands of aircraft operating in North America may 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 its failure to win spectrum allocation in a U.S. government auction. Airfone is a mixed terrestrial/satellite system, the satcom 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 (LEO)-based service from Iridium LLC.

Another contender for this market is AirCell Inc., with its AirCell Axxess EZ satcom. 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 subsequently.

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 PEDs 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 and medium-earth 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.