The UK's low power GSM spectrum could finally get some use, according to PMN, the company set up to exploit it. But it looks like the reality is going to be very different from the original prospects for the technology.

Noodle, a UK outfit that pays consumers for incoming calls, is offering "Cellpoints" or low-power GSM base stations supplied by PMN, which route calls from Noodle customers over the Internet to their destination.

This is very similar to the idea originally suggested by Coffee Telecom, when Ofcom first suggested auctioning the guard band spectrum, originally allocated to prevent interference between DECT and GSM phones.

By the time the auction happened in May 2006, the business model had changed to indoor coverage for businesses, which PMN (Private Mobile Networks) has been trying to sell - but with less success than the company hoped.

"Enterprise fixed mobile convergence hasn't turned into a great revenue generator," said PMN director Dean Parsons. Enterprise users would only buy the service if roaming to the macro network could be guaranteed, and this is difficult to provide without the co-operation of network operators - who are understandably reluctant about the idea. "To manage an automatic switch, you either need agreement from the operator, or software on the phone," said Parsons.

Despite this slow start, the company has made a profitable business focussing on other options, said Parsons. These include low power systems that operate as an internal-only system, effectively an alternative to DECT for applications like warehouses, but with better handsets and better building penetration. The company also provides rapid-deployment GSM networks for the military or for construction companies, where the base station and handsets are built into a rugged suitcase, including battery back-up power for four hours.

PMN also sells low-power GSM systems for "infill", providing GSM services in remote areas.

Parsons isn't betting the company on the Noodle deal, or putting all PMN's eggs in any basket. "[PMN's parent company] Teleware paid £1 million for our licence and that has been paid back. PMN is the only company that can deploy its own technology. There's been a lack of impetus in using low-power GSM for fixed-mobile convergence, but that could change in future," he said.