U.S, European Split Emerging For Ultra-Wideband?U.S, European Split Emerging For Ultra-Wideband?

LONDON — Freescale Semiconductor has commended European lawmakers for the draft ultrawideband regulations it published late last week that the chip company considers brings the prospect of commercial UWB deployment nearer. However, recommendations from some European regulators could cause a split between U.S. and European approaches to introducing the short range wireless networking technology.

European regulators have been consulting on the interference issues related to the use of UWB devices below 10.6 GHz, with the European Conference of Postal and Telecommunications Administrations (CEPT) taking a central role in the long running process. The aim is to come up with a harmonised plan for UWB use throughout the continent and help develop a market for UWB chip and equipment makers.

One of the issues that has arisen during the consultation is that devices that conform to the existing UWB standards that have been agreed in the U.S. could cause interference with wireless networks operating at different frequencies in Europe.

Martin Rofheart, director of Freescale's Ultra-Wideband Operation, said the latest ECC TG3 draft “leads the way to significant opportunity for UWB products that we believe will enable co-existence with incumbent and future services. UWB vendors such as Freescale are eager to deliver commercial silicon to the European market as soon as rules are finalized and implemented in Member States.”

Rofheart said he “applauds the adoption, in part, of the FCC's limits and the efforts to protect identified WiMax and future 4G systems wherever they are placed in the world. As with all the worldwide regulatory efforts underway, we stand ready to assist with efforts to finalize a UWB mask that protects incumbent spectrum users, including participating in efforts to develop a demonstrably effective interference mitigation technology.” However, agreeing a final document that can be recommended to the ECC TG3 working group is proving contentious. For example Ofcom, the U.K. telecoms watchdog, which is conducting its own consultation ahead of responding to the EC mandate on UWB, reaffirmed in a document sent to the TG3 committee earlier this year and published on Ofcom’s web-site last week, that it considers the FCC’s limits are flawed.

“The U.S. has already developed a specification for UWB. However, Ofcom believes that this does not provide adequate protection against interference with other wireless devices in Europe because of the different uses of radio spectrum in the US and Europe”, the document concludes.

The document concurs with Rofheart’s view that there would be substantial benefits to introducing UWB in Europe, but , Ofcom warns, only “provided the right mask can be selected.”

The Ofcom memo also stresses that if the ‘right’ mask were adopted in a timely manner, “it is likely that regulators throughout the rest of the world will move toeards making UWB regulations similar to those being proposed in Europe. This would reduce the threat of large numbers of devices conforming only to U.S. specifications entering the European market.”

Among other recommendations to prevent interference, Ofcom said there needs to be limits set on the power limits on UWB transmitters, “however, these masks should not be set too low as this would affect the performance of UWB”.

It sugggsted UWB devices operating in the 3.1-4.2GHz bands should be fitted with detect and avoid systems, which automatically search for nearby broadband wireless signals and then switch frequency to prevent interference. If a device is not fitted with detect and avoid then it should not transmit above a power level of -85dBm/MHz.

It also said UWB transmitters should use Transmit Power Control technology to limit the power output of a UWB device when there are a number of other UWB devices in close proximity, and that a minimum pulse repetition frequency needs to be established to prevent interference with other wireless devices.

Ofcom also suggested the European Commission should conduct a mandatory review three years after the introduction of UWB that would assess the levels of spectrum noise and potential interference created by UWB devices.