The communications regulator insists that the companies and organisations running these networks face legal action if caught but won't estimate how many offenders there are.
"Ofcom is aware that there may be illegal 5.8GHz systems operating in the UK," said an Ofcom spokesperson.
"In any frequency band, Ofcom will take action to preserve fair competition if illegal transmitters are reported to us, or if they are found during proactive work by Ofcom," said the spokesperson.
Earlier this month, Paul Munnery, managing director of Wireless CNP, claimed that Ofcom was poised to clamp down on companies that were running illegal 5.8GHz networks. However, the regulator, refuses to say whether this is correct.
When Ofcom opened up the 5.8GHz band at the end of last year, it imposed two conditions. Networks must support dynamic frequency selection (DFS) technology to minimise interference with military radar, because the Ministry of Defence already uses the band, and transmit power control (TPC), to ensure that each network transmits at the lowest possible power level.
Some experts have claimed that the regulator doesn't have the necessary equipment to find 5.8GHz networks that are violating these conditions. Ofcom, though, denies that it is toothless in the fight against offenders.
"Ofcom has said it's looking to the industry for self-regulation. In practice, this means they want wireless vendors to grass each other up, because Ofcom hasn't even got the necessary equipment to find an illegal 5.8GHz network. Ofcom's equipment only goes up to one gigahertz," one informed source told ZDNet UK earlier this month.
"Remote automated monitoring is difficult for high frequencies. However, Ofcom has mobile capability for manual monitoring and tracing of frequencies up to 50GHz," said the Ofcom spokesman.
Those familiar with the problem believe that there could be hundreds of illegal 5.8GHz networks. Ofcom won't commit to a figure but rejects the suggestion that this is an indication that it isn't up to speed with the issue.
"Just because we can't provide a precise estimate of the number of non-compliant systems doesn't mean we are not using special teams to address this problem," said the spokesperson.
