WGBX from rg 43 to RF 18. Verizon or ATT to use Ch43
The FCC has stated previously that they would work from the top down. Using a channel such as 43 in the middle of the band would create two problems:
One is adjacent channel interference to and from WHDH on ch 42. That is not an issue now because of the exception allowing it for stations with transmitters very close together, on the theory that DTV receivers can handle adjacent channel signals of approximately the same strength. Also, the stated reason by the FCC for clearing ch 51 is to create an open channel as a guard band, to protect data signals from adjacent TV channel interference.
The second problem would be that ch 43 is also used in other cities, such as Portland, ME. A mobile device that could transmit on ch. 43, or across the whole UHF band would have to be designed to poll the cell / data system on a channel not used anywhere for TV any time it is turned on or loses contact with the system - to be sure what channels could be used. That location system would have to work perfectly. TV transmitters are in fixed locations, and the signal coverage is predictable, but someone who had a cell phone could be almost anywhere, such as the 60th floor of a skyscraper, on the top of Mt. Washington, or in an airplane and could easily get assigned a channel in use for TV. Currently cell phones do hit the wrong systems now at times - but at worst likely affect only one other caller - not potentially many square miles of TV viewers.