ESPN told the Federal Communications Commission the results of the "white-spaces" field test at the Washington Redskins' FedEx Field in August were "not encouraging."
In a letter to the FCC Friday, the sports network said tests of prototype unlicensed devices that would share the digital-TV spectrum used by broadcasters and wireless microphones showed that "sensing technology cannot be the foundation for protecting license holders.”
The devices are designed to sense when a channel is occupied, but ESPN said that in the majority of instances, the devices did not correctly sense the presence of either TV-station signals or wireless microphones.
ESPN participated in the field test, providing microphones similar to those it uses during its Monday Night Football broadcasts.
Another technology that has been proposed for preventing the unlicensed devices -- which include laptops and so-called smart radios -- from interfering with incumbent spectrum users is a "beacon" technology.
ESPN urged the FCC to do "thorough" field tests of the beacons, which it said used the same sensing technology that did not succeed at FedEx Field.
Jake Ward, speaking for the Wireless Innovation Alliance, saw the test quite differently.
He told B&C the FedEx Field test "was a tremendous success,” saying, “100% of wireless mikes were protected and at least one of the devices successfully detected vacant channels on the spectrum. Absolutely no harmful interference was caused during either of the filed tests,” he said, with the other test he referred to occurring on Broadway before and during a portion of a performance of The Phantom of the Opera.
The alliance is comprised of computer companies -- like Google and Microsoft -- that argued that the devices will work without interfering and should be allowed as a way to get more efficient use out of valuable spectrum, in the process expanding the reach of broadband, which is a government priority.