White space standard gets lukewarm reception

American standards body the IEEE has finished work on 802.22.

American standards body the IEEE has finished work on 802.22.1 and 802.22.2, part of the 802.22 standard for white space radio. This defines how wireless broadband systems can interleave themselves between other signals, potentially opening up unused spectrum in previously allocated bands.

With theoretical maximum figures of 100km range and speeds of up to 22Mbps, 802.22 is designed to bring internet access to remote rural areas through wireless regional area networks (Wrans). However, with each cell supporting a maximum of 12 users, one cell at maximum range would support a population density of one user for every 82 square kilometres, 650 times more sparse than the Scottish Highlands.

802.22 is designed to operate between 54 and 698 MHz, mostly within broadcast TV spectrum. By sensing which channels are in use, referring to a database of known transmitters, and adjusting its own transmissions to eliminate interference, 802.22 is designed to automatically morph its own presence to fit around existing services.

UK white space pioneer Neul, which is developing its own Weightless standard said in a statement that while it was pleased to see white space ideas endorsed it was not going to adopt 802.22 initially, although it would review this if the standard proved successful.

"802.22 is designed for rural broadband: high bandwidth, high power terminals and a relatively small number of users per basestation. The Weightless standard is aimed entirely at M2M [machine to machine]: low bandwidth, extremely low power terminals and many thousands of devices per basestation. The standards do not compete at all," the company said.

"[We] have a high bandwidth mode that can be used for rural broadband. This already offers similar performance to that promised by 802.22. We are believers in open standards for wireless devices and may adopt 802.22 if it is successful. However, such standards are most valuable where it is essential to ensure interoperability between devices from different manufacturers. This is not really the case for rural broadband because most installations use access point and the consumer premises equipment from the same manufacturer," Neul said.

The company also said that it doubted the rural broadband market was big enough to support economic development of the necessary custom chips, and M2M was needed in addition to make the market large enough for commercial exploitation.