White Space Prototypes Fail to Accurately Sense Spectrum During NFL Test
Potential disruption of wireless audio systems during sporting events were front and center this weekend as the FCC Office of Engineering and Technology (OET) completed a series of tests at FedEx Field in Landover, MD during a pre-season telecast of a Washington Redskins game. “The NFL’s position is that we’re happy to be supportive and assist in the testing process and it’s clear after this weekend that this technology in not ready for primetime,” says Glenn Adamo, NFL VP, Media Operations and Broadcasting. “As the technology stands today it would interfere and cause harm to our game day operations and broadcasters.”
The FCC tested prototype devices submitted by Philips Electronics North America Corp. and the Singapore-based Institute for Infocomm Research (I2R) and the tests took place in four locations: on the field prior to the game, in a tailgate area, in the 400 level/upper deck and in the press box. During the test the OET would first take a baseline reading of spectrum and then ESPN would fire up wireless microphones to see if the devices could sense the microphones.
According to reports in TR Daily, in four of the six scan tests, both with the mics off and with them on, the Philips device found all channels occupied even those that were unoccupied. The I2R device had more trouble detecting activity on the wireless mic channels. The device also regularly detected digital TV signals, even though it was designed to scan all channels except DTV channels, and it often missed analog TV signals.
“The question that begs to be asked is if the devices sense something when there is nothing there then how can they be accurate when something is there?,” says Adamo.
“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,” says Mark Brunner, senior director-public and industry relations for Shure.
Ken Kerschbaumer, editorial director of Sports Video Group and executive director of the Sports Technology Alliance, told TRDaily that members of his group “hope the FCC pays attention to the results of its own tests this weekend and requires the developers of the devices to go back to the drawing board. The current state of these devices means they will not only negatively impact broadcasters and the wireless microphone community but they will also disappoint consumers. These devices need to be 100% accurate when it comes to frequency sensing and right now they aren’t even close to that standard. And that’s not spin, just simple facts. Time after time the test results, whether in the lab or in the field, show that these devices do not work. How the FCC acts on those results will let us know whether they’ve been serious about the testing or whether it has been a charade.”
Rob Kenny, FCC spokesman, says that once field testing is concluded the analysis will become part of a full report that includes field and lab results as well as public comments as warranted and recommendations on how to proceed.
While Kenny could not comment on the results of the test he said it was not a pass/fail test and part of building a record regarding White Space devices. “We’re hopefully to move forward with the report this Fall and then figure out next steps, whether it’s a request for guidance or proposed rulemaking.”
Ed Thomas, a senior technology policy adviser for Philips, told TRDaily that the Philips device was made to detect signals at -125 dBm (decibels below one milliwatt), rather than the -114 dBm sought by manufacturers, so a commercial device won’t think channels are occupied when they aren’t.
“They can’t rant and rave that it doesn’t work,” Mr. Thomas said of opponents of opening up the white spaces to personal/portable unlicensed devices. “The fact of the matter is – wireless microphones are protected. All broadcast channels are protected, including a whole carload of them which aren’t entitled to protection.” He added that any devices that failed to detect occupied channels, such as the I2R device, would simply fail FCC certification.
Rob Kenny, FCC