FINAL REPORT - Stakeholders - Ofcom

A number of airlines and equipment manufacturers have shown considerable interest in
the Gatelink concept. In particular the Rockwell-Collins Integrated Information System
(I 2 S) programme supports the integration of Gatelink to multiple aircraft systems, a file
server and a secure interface unit to enable safety and non-safety applications to be
supported.
British Airways, Swissair and Condor have all been involved in trials of Gatelink systems.
In 2000, EUROCONTROL published an in depth study into Wireless Airport
Communications Systems (WACS), which considered potential WLAN solutions for
Gatelink. The material in this section is largely taken from the published reports.
The three main Wireless LAN candidate technologies which could be used for Gatelink
are:
• Systems operating at 2.4 GHz conforming to IEEE 802.11b standards:
• GHz FHSS / DHSS
• GHz DSSS HDR
• High Performance Radio Local Area Network (HiperLAN) according to ETSI
HiperLAN standards:
• 5.2 and 5.8 GHz HiperLAN/1 and HiperLAN/2
• 17.1 GHz HiperLAN
• Systems conforming to Digital European Cordless Telecommunications (DECT)
standards.
Trials already conducted have shown that 2.4 GHz technology is usable in an airport
environment using either DSSS or FHSS modulation. Systems operating at 5 and 17 GHz
are less well developed. While these systems have the potential to offer improved data
throughput, they do so at the expense of usable range.
Gatelink offers a huge potential for Airline Operational Communications (AOC), Airline
Administrative Communications (AAC) and Air Passenger Correspondence (APC). The
role in Air Traffic Control is less clear.
The deployment of Gatelink to support non-safety services is likely to be driven by local
business cases and may support emerging Collaborative Decision Making (CDM)
applications and applications involving the (re)allocation of CFMU slots, but the additional
burden of supporting ATC is likely to increase costs and timescales. The adoption of a
mature system, some years after deployment, to support ATC in the presence of
alternative communications means should be considered.
Systems operating at 2.4 GHz can either use Frequency Hopping Spread Spectrum
(FHSS) or Direct Sequence Spread Spectrum (DSSS) modulation schemes. Current
FHSS systems have a data rate of between 1 and 2 Mbps. Current DSSS systems have a
data rate of 2 Mbps, but future systems are planned with a rate of up to 11 Mbps.
The characteristics of Gatelink are summarised in Table 5-9 below.
Parameter Value Notes
Service topology Uplink point-to-point,
Downlink point-to-point
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