High altitude balloons and unmanned solar-powered aircraft may be the key to rural broadband, if a major European Union project is successful. Over the next year, Capanina intends to develop aerial links capable of delivering up to 120 megabits per second to anywhere in the world, transmitted from aerial platforms hovering up to 22 kilometres above the ground.
"We're looking to support a thousand times more users than a satellite," said Dr David Grace, principal scientific officer of the project and member of the Communications Research Group at the University of York. "The service is halfway between a satellite and terrestrial systems, so we can take the best of both."
Initially using test platforms tethered at an altitude of just 300 metres, the project will investigate not only the technical issues of providing a two-way high speed broadband link from the sky, but also the business models needed to turn it into a commercial service. There are also regulatory issues -- although the frequencies it will use are already available in most of the world, Europe has still not opened the 29GHz to 31GHz band required. "We'll be pressing for these to be made available," said Dr Grace.
Although wireless broadband of a more conventional kind is already on the verge of widespread deployment, Dr Grace said that the aerial platform approach had some unique advantages. "802.16 may have a 70-kilometre range, but that has to be line of sight. The chances are there'll be a building in the way, but you'll always have line of sight to a high altitude platform," he said. Deployment could be very rapid, due to the lack of underground cabling or the need for masts. Dr Grace added that the project was investigating 802.16 alongside other protocols, and that consortium members already had representation on the relevant ITU and ETSI standard bodies.
Other project members include BT Exact Technologies and SkyLINC Ltd from England; Swiss organisations Contraves Space AG and the Centre Suisse d'Electronique et de Microtechnique; Italians Carlo Gavazzi Space and EuroConcepts; and the Japanese Communications Research Laboratory, which has worked with NASA and US company Aerovironment on similar ideas.
In four years' time, the project hopes to see commercial services in operation from tethered balloons -- although the high altitude platform (HAP) side may take longer. "There are no high altitude platforms in production yet," said Dr Grace. "There could be a whole industry established for these vehicles. We're at the same point now as satellites were in the 1960s."