FCC opens TV band to unlicensed devices
The FCC has voted to allow unlicensed devices to use "white spaces" in the TV band for wireless broadband. Preliminarily, only devices that determine available channels based on geolocation and a database of existing users will be authorized, but procedures have been put in place to allow future approval of devices that choose available channels based on only signal-sensing.
This is a preliminary report based on listening to the discussion at the FCC meeting and review of the public notice issued by the Commission following its meeting. The actual report and order may reflect edits made after the meeting and so may not be exactly the same as this description.
Both fixed location and personal portable transmitters will be permitted. Fixed devices will be allowed to use higher power than portable devices. Portable devices must have automatic power control that reduces operating power to the minimum required to link successfully to a base station or other portable device with which it communicates.
Initially, both fixed and portable devices must rely on geolocation and a database of existing users. Portable devices that do not themselves incorporate geolocation and a user database may not operate unless they establish a link with, and are assigned a channel by, a base station that does use geolocation and a database. Both broadcast stations and venues where large numbers of wireless microphones are in use may be registered in the database. All white space devices must also incorporate spectrum-sensing, which is intended to avoid interference to other wireless microphones and broadcast signals that may not be registered in the database.
Fixed devices will be registered in a database. Portable devices will not be registered. No provision was made for any licensed devices, including backhaul point-to-point links in rural areas, but a notice of inquiry will be issued to explore higher powered rural operations.
Operation near cable television head-ends will be restricted. Other than that, all TV channels in the range 2-51 will be open to these new devices. VHF channels were not withheld, nor were Channels 14-20, which are used for public safety operations in major cities.
In the future, the FCC will allow unlicensed devices that select operating channels based on only spectrum-sensing. These devices must be tested and certified by the FCC Laboratory before marketing and must prove that they avoid interference to existing operations. Applications for equipment certification will be placed in public notice. In what appears to be a first for the FCC, the testing of these devices will be open to the public, and public comment on test results will be permitted.
The commissioners did not all agree that devices that only sense existing spectrum use are ready for mass marketing at this time. At least one also felt that white space devices would not be able to operate successfully at all in the largest cities.
Some commissioners stressed that white space devices would remain secondary to television broadcast services, but it is not clear at this point that the intent of some white space proponents to achieve stronger spectrum rights was completely rejected.
While prospective manufacturers of white space devices assured the FCC that it was in their self-interest to avoid interference, the FCC did not establish any expedited procedures for dealing with interference complaints, nor did it provide for recall of defective products and forfeitures for causing interference.
It is not clear what will happen now other than almost certain skirmishes as white space hardware is submitted for FCC Laboratory testing. Dealing with any problems that arise will be left to a Commission that will almost surely have a new chairman and perhaps other new commissioners.
