Air-to-ground telephones for airline passengers are becoming more commonplace.

Graham Warwick/ATLANTA

Passengers on certain British Airways flights are the first in the UK to enjoy something US air travelers have come to expect - air-to-ground telephones on aircraft. BA is the first airline to put into operation Europe's new terrestrial flight-telephone system (TFTS). Its North American counterpart has been in use for more than a decade.

In November 1994, GTE Airfone recorded its 50 millionth call since introducing air-to-ground telephone services in October 1984. Some 40 million of those calls have been made since 1990 and GTE recorded almost 14 million calls in 1994. In the USA, passenger-telephone use is on the increase, boosted by increased competition, improved quality and expanded services.

At its peak, the analogue Airfone system was installed in more than 2,000 aircraft. It is being replaced by next-generation digital systems and, for the first time, GTE is facing competition. The company's Genstar digital system is being installed on almost 600 aircraft, Claircom Communications' AirOne system on more than 2,000 aircraft and In-Flight Phone's FlightLink system on some 900 aircraft.

Digital technology brings a dramatic improvement in voice quality, previously a major deterrent to passenger use. It also enables enhanced services, such as ground-to-air and seat-to-seat calling and facsimile and data communications.

In-Flight Phone was first in the market with digital technology, when its FlightLink telephone system entered service in May 1992 on a US Air Boeing 757. The system, has also been selected by America West, Continental and Carnival Airlines. In-Flight Phone says that call volume is ahead of projections and phone usage is ahead of the competition.

Claircom, now wholly owned by US telecommunications giant AT&T, introduced its AirOne system in January 1993, on an Alaska Airlines McDonnell Douglas MD-80, and it has been selected by American, Delta, Northwest and Southwest Airlines. The company expects to record 1 million calls this year, reaching 5 million annually over the next two years.

GTE's Genstar, was introduced in December 1993, on a Delta Boeing 727, and the system has been selected by USAir, United and Reno Airlines, as well as, Air Canada, Canadian International Airlines, Aeromexico and Mexicana.

Claircom and GTE each operate their own ground-station networks in the USA, Canada and Mexico. In-Flight Phone has ground stations in the USA and Canada, with additional sites in Greenland and Iceland to extend terrestrial coverage across the North Atlantic, and is negotiating a licence to establish a Mexican network.


With the North American major-airline market now saturated, attention has switched to Europe, where the situation is, as usual more complex. While the US service-providers own their ground stations, in Europe they must use national TFTS ground-network operators.

In some countries, such as France and Germany, a single entity, usually the national telecommunications authority has been licensed to operate TFTS ground stations. In others, such as the UK, two competing networks have been licensed.

Four TFTS ground stations are operational in the UK, two in France and one in Sweden, with a second Swedish site scheduled to become operational in 1995, along with sites in Finland and Norway and up to five in Germany.

Competing service providers have emerged in Europe in the form of the Jetphone consortium, created by British Telecom (BT) and France Telecom, and Mercury FlightLink, a joint venture between In-Flight Phone and Mercury Communications of the UK.

BA launched Jetphone service in mid-February on its London-to-Scotland shuttle flights, with the intention of expanding availability later, to include all European flights. Five Boeing 737-400s and six 757s have been equipped with GTE Airfone handsets and GEC-Marconi avionics. A total of some 1,200 telephones have been installed.

Other European airlines are following suit. Air France is equipping 110 short- and medium-haul aircraft for Jetphone service, using Claircom handsets and Mors avionics. Scandinavian Airline Systems (SAS) has chosen Jetphone as service provider and Claircom as equipment supplier.

Mercury FlightLink plans to begin trial service in June with Crossair. The Swiss regional carrier will install a telephone-only system and has yet to select a supplier. Air UK will install In-Flight Phone FlightLink equipment aboard its Fokker 100s, for trials beginning later in 1995. Parent Mercury Communications has licences to operate ground stations in the UK, Belgium and Sweden, but Mercury FlightLink will be able to use any European TFTS site.

The international market is gaining importance for US telephone-system suppliers. In addition to Air France and SAS, Claircom has sold hardware to Air Inter, KLM, Kuwait Airways, Lauda Air and Lufthansa, often for use with satellite-communications (satcom) systems.

In addition to BA, overseas customers for GTE's Genstar hardware are Varig of Brazil, where Airfone has been licensed to establish a ground-station network during 1995, and China Southern Airlines, which plans to use the equipment with satcom systems on its Boeing 777s.


That satellites represent competition for terrestrial systems was well illustrated earlier this year, when Swissair decided to equip 29 Airbus A319/A320/A321s with Honeywell/Racal multi-channel satcom systems. The airline says that it rejected the TFTS because only satcom could provide seamless gate-to-gate coverage across its network of destinations, which extends to Eastern Europe and the Middle East.

The Swissair decision is seen as a landmark, as it is the first major airline to elect to equip its narrow-body aircraft with satcom systems. So far sales for wide-body, long haul, airliners have dominated the industry. Although the long-haul market is far from exhausted, the major carriers, representing 40% of the world fleet, have made their equipment selections. The short-haul market offers the promise of new business.

Satellite-operator Inmarsat says that more than 500 aircraft have been approved to use its satcom services. While one-third of those are equipped for data-only cockpit services, a growing majority is equipped with multi-channel systems for both cabin-voice and cockpit-data communications, the organisation says.

Avionics supplier Honeywell/Racal says that it has orders for more than 600 multi-channel systems from 32 airlines, with close to 300 units already delivered. Applications range from Swissair's decision to fit three-channel MCS-3000s in its narrow-bodies, to BA's plan to provision its long-haul fleet for eventual installation of dual six-channel MCS-6000s. Rockwell-Collins says that it has orders for more than 400 SAT-906 six-channel satcom systems from more than 20 airlines, with around 180 units already in use.

Inmarsat aeronautical services now in place include voice at 9.6kbit/s, facsimile at 4.8kbit/s and data at 10.5kbit/s. Later this year, service providers will introduce Inmarsat's Data 3 standard, which will enable an aircraft to be connected with any X.25-standard terrestrial telecommunications-network.

Products now available are Aero H, for voice/facsimile/data; Aero L, for low-rate data; and Aero C, for store-and-forward messaging. Aero H is the system principally used by airlines, although Aero L is suitable for air-traffic-control (ATC) communications. Inmarsat is now working on Aero H Evolved, to become available when the organisation's next-generation satellites are launched, beginning in 1996.

Aero H Evolved will offer lower call costs - a major disadvantage of satellite- over terrestrial-based communications - through the use of spot beams and a half-rate voice codec (the airborne system which codes and decodes voice transmissions). Compared with the global beams generated by current-generation spacecraft, spot beams directed at high-density regions will allow Inmarsat to make more efficient use of satellite capacity.

The service will be operated with existing high-gain antennas. Two main antenna types are available: top-mounted and conformal side-mounted. Around half of the sales to major airlines so far have been of Canadian Marconi's top-mounted CMA-2102, with the remainder split between side-mounted designs from AlliedSignal/Dassault and Ball.

The new codec may be implemented before the first next-generation Inmarsat 3 is launched in the second quarter of 1996, the organisation says. This will halve the transmission rate to 4.8kbit/s, without any loss of quality, and will consequently halve the cost of voice calls, Inmarsat believes. This will close the gap with terrestrial systems, which typically cost $2/min per call compared with $9-11/min for satcom.

Beyond Aero H Evolved lies Aero I, which is expected to be approved by the Inmarsat Council, at the end of March. Aero I will use the spot-beam capability of the new Inmarsat 3s to offer cheaper, simpler, services to smaller, lighter, airborne systems. The service will be aimed at regional-airline and general-aviation users and will not be suitable for ATC use, the organisation says.


Regional and Gneral Aviation (GA) represents a significant market for both terrestrial and satellite systems, designed to meet less demanding, "non-airline", standards. Magnavox reports regional-airline interest in its Magnastar system, which is connected to GTE's Genstar ground network. The company has shipped more than 150 units to GA customers, with around 100 already flying, and is projecting sales of some 1,500 systems.

Claircom's AirOne hardware and network is used for AlliedSignal's Flitefone 800 system. Some 200 GA aircraft have been equipped so far. The earlier analogue Flitefone still dominates the market, with some 4,000 aircraft equipped. AirCell is targeting the lower end of this market with a low-cost, cellular-based, system and plans to begin large-scale testing by mid-1995. Around 100 aircraft will be equipped with AirCell airborne cellular telephones for the US trial.

Satcom systems are firmly established in the business-aviation market, providing the global coverage required by international corporations. Sales, have been dominated by Honeywell/Racal, with its original single channel Satfone and latest three channel MCS-3000 systems. Collins is planing to introduce a four-channel system for the GA market and Sextant Avionique is pursuing sales of its C3SAT System 2000.

More than 200 aircraft have been equipped with AlliedSignal's Satellite Data Communications System, for which Inmarsat's Aero C store-and-forward service is used, to provide global coverage for subscribers to the company's Airborne Flight Information System, a messaging service for corporate-aircraft operators.

Canada's CAL is the only company developing satcom avionics to operate with a satellite system other than Inmarsat's. CAL and Westinghouse have joined forces to develop a voice/facsimile/data system, the Aerosat 1000, for use with the American Mobile Satellite spacecraft to be launched in 1995. The partners are promising low installation and call costs and are targeting both the GA and air-transport markets.

Source: Flight International