White Space Devices Fail to Score at FedEx Field
August 15, 2008
Wireless microphone manufacturer Shure, Inc. said that white space devices failed to accurately detect wireless microphones during FCC tests conducted before a Redskins vs. Buffalo Bills pre-season game on Aug. 9 at FedEx field.
“The FCC’s tests of prototype white space devices at FedEx field prior to Saturday’s game between the Redskins and the Bills conclusively show that spectrum sensing white space devices will cause harmful interference to wireless microphones during live events,” said Mark Brunner, Shure’s senior director of public and industry relations.
Simply stated, the prototype devices were unable to consistently identify operating wireless microphones or distinguish occupied from unoccupied TV channels. More troubling, the devices failed to detect the presence of wireless microphones when switched on—an occurrence that takes place multiple times during any NFL game.
“Given the poor performance of these sensing devices, there is no reason to believe that the other proposed protections, such as beacons, will be any more capable of providing reliable and robust interference protection to wireless microphone transmissions,” Brunner said. “These tests reveal fundamental deficiencies of sensing devices—issues that cannot be pushed off with a promise to resolve these problems at some later time during certification testing.”
Brunner added that Shure appreciated that the FCC, NFL and ESPN acknowledged the importance of wireless mics at sporting events and agreed to the testing. He further called the use of wireless microphone technology as “critical” to players, referees and fans.
“If these sensing devices cannot be counted on, then the FCC must put them on the bench."
Scientific American covered the testing in their article Could Next-Gen Cell Phones Interrupt a Football Game?. The article disputes Brunner’s statement that the sensing devices failed. It quotes Kiran Challapali, a project leader at Philips Research saying, “Our prototype was tested for its ability to detect over-the-air ATSC (Advanced Television System Committee, or digital TV) and NTSC (National Television System Committee, or analog) signals, in addition to wireless microphones. We also successfully detected wireless microphones when switched on, in every instance."
You may recall from my earlier reports on the FCC white space device testing, that the Philips sensing unit was extremely sensitive, significantly limiting the number of channels available for use by the device.
The Scientific American article said the FCC would not reveal what it has found in its field tests.