05.02.2008 12:00 AM
Wi-Fi at 30,000 Feet
Airlines have two options for providing Internet access on planes. One would use evdo or other cell-phone data protocols to communicate with terrestrial relay stations using the 800 MHz frequencies recently auctioned for air-to-ground voice and data use. The other uses Ku-band transponders, perhaps already carrying data services, for Internet access.
The first has lower latency, making it better for gaming, VPN and voice-over-IP telephony, while the second offers greater bandwidth without the expense of building out a ground network, although the delay (latency) through a geostationary satellite could make gaming, VPN and voice-over-IP difficult.
An article on IDG’s Nordic site, “Wi-Fi on Southwest, Alaska Airlines Flights Set to Take Off”
has detailed information on how the Row44
airborne Internet access system will work. The system uses Ku-band frequencies and an antenna with 64 microwave horns located on top of the aircraft’s fuselage to connect to Hughes Network Systems transponders. Wi-fi access points provide a way for passengers to connect to the Internet. According to the article, the data rate available would be at least 30 Mbps and it would support VPN.