The FCC is planning an auction of funding for mobile broadband service, and accurate data about where service is available will be critical. But there has been considerable controversy about that – so much so that the FCC in December said it would investigate concerns that some wireless carriers overstated their coverage areas in data submitted to the FCC.
Results from drive tests conducted by the Vermont Department of Public Service suggests carriers have indeed overstated coverage, but the Vermont drive tests also demonstrate the difficulties of challenging the carrier-reported data.
FCC and Wireless Carriers Coverage Areas
The mobility fund auction targets areas where no carrier offers service at speeds of 5 Mbps or higher. As the Vermont PSD explains in a 10-page report, the FCC developed a wireless coverage map that divides each state into thousands of one-kilometer blocks. The data that the FCC collected from wireless carriers resulted in 1,310 square kilometers in Vermont deemed eligible for auction out of a total territory of approximately 25,000 square kilometers. That’s about 5% of the state.
To successfully challenge service, challengers must measure each carrier claiming to offer service in an FCC one-kilometer block, the Vermont report explains. In addition, the challenge must encompass 75% of the block, with each test point having a radius of 400 meters.
As the report explains, mounting a successful challenge using drive tests is difficult because in most cases “the main roads transect the blocks obliquely, that is, along a side or a corner.”
The PSD did its best to address this by drive-testing all major roads and targeting more detailed testing for those one-kilometer blocks in which most of the state’s residential and commercial buildings (65%) were located.
The upshot was that the PSD tested 23% of the blocks in the state. That included 7% that were deemed to have 5 Mbps coverage and 16% that appeared not to have coverage. Of those 16%, however, only 3% were considered successful challenges because they met the 75% testing threshold. The other 13% were considered “provisional” challenges. It would seem, though, that if the major road transecting a block lacks coverage, the rest of the block also is likely to lack coverage.
It would also seem that if so many major roadways lack coverage, areas not transected by a major roadway would be equally or more likely to lack coverage. In other words, the data suggests that Vermont’s auction-eligible areas are considerably more than the 5% of the state that was calculated based on carriers’ reported data.

The Rural Wireless Association issued a press release citing the Vermont report and alleging that T-Mobile, in particular, has overstated its wireless coverage. The RWA said in the release that some of its rural wireless carrier members in various parts of the country had drive-tested areas where T-Mobile said it provided coverage and found that T-Mobile failed 95% of the tests.
The Vermont PSD created maps showing the results of its testing by carrier, which are available at this link.
The Vermont data could be instructive for those FCC staffers currently investigating whether wireless carriers overstated coverage in their filings with the commission.