The FCC in a new order (PDF) set out the road to 4G data by banning the sale of all current devices that use the 700MHz band. The measure has a "sunset period" until June 12th to ease the transition but will demand that everyone either stop using equipment on those airwaves or have it modified to use a non-offending space. Most of the affected devices will be wireless microphones.

Most of the devices in the frequency range were cleared out with the digital TV transition in June of last year.

All of the steps are meant to clear the 700MHz space in time for public safety uses but also for cellular services. In the US and most other countries, the Long Term Evolution (LTE) standard for 4G will run on the newly freed bands, which are ideal for mobile data as they both carry over longer distances and are much more capable of penetrating indoors than 3G does today.

Verizon will be one of the first carriers to use 700MHz LTE and expects to have commercial 4G active sometime in mid-year. AT&T and T-Mobile are making their own transitions in 2011, while Sprint is for now still focused on its 2.5GHz WiMAX network.