Telecom regulator Ofcom wants to make high-power WiFi equipment with a 10km range legal in the UK.

The organisation is considering raising the power limits for the 2.4GHz band by a factor of 100, and also increasing power for fixed wireless links in the 5.8GHz lightly licensed band - possibly up to 25W.

"This could give a much need boost to broadband services utilising both bands," says commentator Steve Kennedy.

"Rural broadband providers have been begging to use 2.4GHz with external aerials with high gain to cover long distances. It could work there, with minimal interference - as there's only the rural community there in
the first place."

Ofcom is likely to boost the limits from the current 100mW to 10W in both bands. Following its current practice, this goes well beyond other countries in relaxing spectrum rules. In this case, it would be meeting or exceeding an EU directive that proposes to raise the power limit from 2W to 4Win the 5.8GHz band, and going beyond the US, where some higher-power WiFi equipment is already legal.

The high-power WiFi kit is intended to meet the needs of rural wireless, so Ofcom's main concern is that it does not get over-used in urban areas and swamp the city's airwaves.

This could mean a registration scheme for high-power WiFi (much like the "light licence" scheme in the 5.8GHz band). More intriguingly, it could mean a system that makes the high-power kit "location aware" so, apparently, it will know where it is, and only work at high power if it's in an approved area.

Ofcom has begun a consultation on the following options:

  • Allow the increased power anywhere
  • Allow the increased power in rural areas with location awareness to minimise interference.
  • Allow increased power in all but large and major urban conurbations, with a registration scheme .

The proposals are based on the results of research Ofcom commissioned, which found there was no reason not to go ahead with higher power levels.

This report found, among other things, that higher-power kit wouldn't be put into many of today's WiFi WLANs, since there is no big market for this high power kit (it's not widely used even in the US where it's legal). Instead, a separate class of long-range WiFi would emerge for wireless broadband.

This would be self-selecting, and naturally gravitate to rural areas, since WLAN interference on wireless broadband would be higher than the reverse, so wireless broadband operators would automatically avoid the cities where their kit wouldn't work so well.

Despite this, the proposal is raising health concerns: "2.4GHz is the frequency microwave ovens use and 10W though low power could have significant health risks," said Kennedy, in his Euro Tech Blog. "Shoving your hand near 10W would cook it slowly."