Last week, the FCC approved a plan to auction off wireless spectrum in the 700MHz band, which is being abandoned by television stations as TVs move to digital technology by early 2009.

The commission has decided to sell chunks of the spectrum in a variety of geographic sizes covering both metro and rural communities. How will this spectrum get used?

That’s officially undetermined as yet. However, there is talk of using part of the spectrum for a unified nationwide public safety network that delivers consistent mobile broadband services to first responders.

In addition, would-be mobile WiMAX operators and subscribers are likely licensee candidates. One of the issues that has arisen with regard to mobile WiMAX is the scarcity of spectrum available for it, particularly in the U.S., where Sprint Nextel and Clearwire own virtually all the 2.5GHz licenses.

It is desirable for mobile WiMAX deployments to be delivered in licensed bands, because they give the carrier licensee complete control over the use of their slice of the spectrum pie, thereby allowing that carrier to confidently offer enforceable service-level agreements.

Some WiMAX services have been slotted for the 5GHz, unlicensed band, which lowers the cost of service entry and enables providers to get services deployed faster. However, with unlicensed spectrum, all users are considered equal, making it difficult for operators to control the effects of interference generated by other operators’ services and additional outside sources.

IEEE 802.16e-2005 mobile WiMAX technical specifications allow for deploying services in a number of spectrum frequencies. However, different countries have different governmental usage permissions. In the U.S., for example, mobile WiMAX revolves largely around the 2.5GHz band. In other parts of the world, the most prominent WiMAX bands used will be 3.5GHz and 2.3/2.5GHz, though India, too, is also looking into 700MHz for mobile WiMAX use.

Joanie Wexler is an independent networking technology writer/editor in Silicon Valley.