Emma Kelly/GENEVA

Airline telecommunication giant SITA has committed itself to the next generation of aeronautical datalink services - VHF datalink mode 2 (VDL-2) - by awarding a $23 million contract to Harris for a global network of VHF ground stations (VGS).

The VDL-2 aircraft-to-ground datalink protocol will provide a much needed capacity increase over the datalink service provided by VHF through the aircraft communications addressing and reporting system (ACARS).

VDL-2 provides a 31.5Kbit/s data rate per VHF channel, compared to VHF ACARS' 2.4Kbit/s. The increased capacity is required as air-to-ground datalink traffic increases as it replaces voice communications. The VDL-2 standard has been developed by the International Civil Aviation Organisation for the future aeronautical telecommunication network (ATN). SITA competitor ARINC committed to VDL last year.

SITA will replace its 800 VHF Aircom ground stations with the VGS from next year. VDL-compatible avionics are due for delivery in 2001 and SITA plans interoperability tests in mid-2000. SITA will offer VDL Aircom service throughout Europe, the USA and Australia by the end of 2002.

SITA is investing in VDL-2 to allow ATN implementation as soon as it is ready. "This is an important first step," says Philip Clinch, director of strategy and development, SITA Air-Ground Services. "Just as we made the investment in satcoms, we are doing the same with VDL. We are investing in VDL to show the aviation community that the ATN can happen."

Meanwhile, SITA has started to deploy its North American ground station network after clearing regulatory hurdles to allow it to offer air-to-ground services in the USA in competition with ARINC. Some 75 stations will be online by the year end, and 25 VHF Aircom ground stations will be set up in Canada before October. Coverage is also planned in Mexico and the Caribbean, and SITA is considering installing stations at the North Pole for new polar routes.

SITA's US launch follows ARINC's recent move into Europe. SITA is "not unduly worried" about ARINC in Europe, says Philippe Lallement, vice-president, SITA Air-Ground Services. "We will differentiate ourselves by providing a superb service. SITA is seen as good value for money, although we may not necessarily be the cheapest."

Source: Flight International