A Japanese university team that developed an airship equipped with a wireless internet access point says a recent trial of the technology was a success.

The team, from Chubu University in central Japan, provided wireless LAN access from its Solan-1 airship to visitors at the recently concluded Aichi World Expo in Japan and proved the technology works, said Osamu Saiki, a Chubu University student working on the project.

The Solan-1 craft was generally tethered at a height of 30m above the ground and provided coverage over an area of radius 500m. This could be extended to around 1km from the airship in all directions if it was raised to 100m above ground; but strong winds often meant it didn't reach this height.

A second craft, the Solan-2, was also used at the Aichi World Expo and is on show this week at the WPCE (World PC Expo) show in Tokyo.

The Solan-2, which is tethered inside an event hall at the show, is equipped with an IEEE 802.11b/g wireless LAN access point and visitors to the exhibition can enjoy a free internet connection through the on-board base station. A second wireless link provides a connection between the airship and the internet.

The airship is solar-powered and thus also includes solar panels. And there are also a pair of remote-controlled cameras on the bottom of the craft that can send images via the wireless LAN connection.

Going forward, the university team plans to refine the technology. Problems encountered because of wind are one of the areas that the team will now look into, said Saiki. He also said they will work on ways of keeping the craft powered on days when it's raining or cloudy and sunlight is much lower than normal.

Airships have been considered for some time as a way to provide wireless telecommunications links over a wide area, either permanently or temporarily during events or disasters.

The Japanese government has been mulling a system that would use airships to provide cellular coverage to some of the country's mountainous areas, which are currently out of the range of ground-based cellular towers. In the US, Sanswire Networks LLC is planning a network of airships flying at altitudes of around 9km that would provide nationwide coverage.