The ASIC known as Iceni works across the whole UHF band (470 – 790MHz) and is easy to interface to micro-controllers and CPUs such as the ARM M3 making it ideal for M2M solutions. The chip is also small, low power and low temperature.
It can operate using both 6 or 8 MHz channels and uses daptive digital modulation schemes and error correction methods can be selected according to the trade-off between data rate and range required for a given application as well as supporting over-the-air encryption. The chip also supports programmable IO allowing it to control external parts of the solution including the RF stage and thus the transmit power (which is essential to meet any local regulations).
Neul currently dominate the whitespace arena and the technology is well suited to M2M applications - probably more sure than cellular based systems using 2G or 3G. The Neul solution can support thousands (if not more) end points and support large distances between devices (the greater the distance, the lower the bandwidth, but this generally isn't an issue for M2M installations).
Neul are conducting trials in the UK as well as other countries, however although Ofcom has made whitespace devices license exempt, it mandates a central database that contains geo-information about locations, frequencies supported and power levels. Unfortunately Ofcom have not yet implemented the central database solution.