A cellphone based on software-defined radio would be lighter, smaller, cheaper, and more power efficient. What’s more, it would be better at making calls: instead of being stuck with one frequency or even one cellular carrier, it would automatically search out the best and least expensive way of connecting. Ideally it would ease the upgrade problems for the infrastructure and for cellphones. The industry and people could migrate to the next generation of service with less cost. However, each generation takes 5-10 times the computing power. If we got ahead of the computer processing power needs with say the AMD fusion chip with 1 teraflop or Intels 80 core chip (both planned for about 2010), then 2-3 generations changes would not require new infrastructure.
This article talks about cognitive radio and the concept of a smart radio that can dynamically adapt to the environment and reuse licensed spectrum on an opportunistic basis. Most radio spectrum is unused most of the time at any particular spot. The broadcast TV channels are not broadcasting into your spot. The theory is that if your radio monitored where there was unused spectrum then if it as a smart software configurable radio, it could transmit on the unused spectrum even if it was licensed. It could then have far faster communication.
There is a smart radio prize challenge where one of the challenges is to be able to reconfigure a smart radio within 8 hours.
Less spectrum is available for unlicensed use since 2002
Tracking the effort and economic benefits to allowing the unused TV channels to be allocated for unlicensed use
Starting Feb, 2009 low-power devices can start using the some of spectrum freed up when old broadcast TV stations must finish switching to digital and give back the old analog broadcast bands. The way they fed TV to the rabbit ear antennas
A pdf of a slide presentation of spectrum management reform which includes using smart radios
The vision and progress towards cognitive radio from MIT technology review It might take 10 years to finally sort out. Some progress is being made in policy and in technology.