Long-Reach Wi-Fi Under Fire
Vendors that try to stretch the range of wireless products have come under fire from a UK consultant for making airwave congestion worse. It is common in cities to find several Wi-Fi cells overlapping, and the longer the range, the more there are likely overlaped. Yet vendors often boast extended range, the wireless equivalent of shouting, as if it is an unalloyed good thing.
Bill Ray, of consultancy Arcchart, said long-range links are available from technologies such as WiMax, GSM and 3G, and there is a need for short-range wireless to minimise interference between neighbours. Yet even the IEEE standards body is extending the reach of Wi-Fi with the next generation 802.11n specification, which is designed for local links. Ray writes in a company newsletters: The latest standards to emerge from IEEE could easily see the effective range of Wi-Fi doubling with disastrous consequences.
The problem is that while a house in California might stretch the 45m limit of an access point, much of the world is less spacious: a typical Victorian terrace in London is only 5.5m wide, allowing the signal from access point to be shared by around 10 other properties.
Neither is the problem restricted to Wi-Fi. The original 10m range of Bluetooth is extending to 100m in the latest Class 1 products. And Ultrawideband (UWB), designed for high-data-rate links between devices within a room, is going the same way. Ray wrote: Wiquest recently announced UWB operating at range of 30m enough to cover five houses in Victorian terrace!.
He added: UWB operates on a wide range of frequencies and so has the potential to interface with just about anything but even before we see the standards settleing down companies are demostrating how they can extend the range.
Ray warned: Unless the industry recognises short-range wireless should be just that, it risks harming the usability of unregulated spectrum and very long spools of Cat5 cable might again become the cutting edge in connectivity.
