By Frank Wells
Niles, IL (June 26, 2008)–On June 17, 2008, the White Spaces Coalition filed a response with the Federal Communications Commission to the latest round of objections to their proposals for unlicensed device operation in the spectrum now used by analog television and for wireless microphone/intercom applications. The Coalition, whose members include members include Dell, Google, Hewlett-Packard, Microsoft, Palm, Philips Electronics North America, and TDK, say in the response that they are “committed to bringing consumers powerful and innovative wireless technologies” utilizing the frequencies that will be opened up by next year’s mandated full migration of television to digital transmission. Further, the Coalition says that, “We fully understand that in bringing consumers new spectrum-based technologies, the Commission must balance the vast benefits of innovation with the legitimate concerns of incumbents.”
At the heart of the ongoing debate are the differing perspectives of the “incumbents” and the Coalition on methods to provide the protection from interference by new technologies to existing users of the spectrum. The Coalition maintains that “the best way to achieve this balance is for the Commission simply to require that personal/portable white spaces devices use spectrum sensing technology to detect and protect existing uses of the TV broadcast bands.” Existing users of the spectrum cite the FCC evaluations of Coalition members’ demonstration hardware as evidence that, thus far, the technologies are inadequate and apparently not so simple. The Coalition’s latest letter does not concede any inadequacies in the approach, instead saying that, “We recognize, however, that the Commission has a difficult task when analyzing new technologies, and that adopting rules which include more protection for incumbents than is technically necessary may allow the Commission to open up the white spaces more quickly.”
On that basis, the Coalition says they will now support, “in the spirit of compromise,” additional protections to legal wireless microphone operation. In addition to spectrum sensing capability, the Coalition is now supporting a requirement that white space devices recognize a wireless microphone protection beacon and avoid TV channels where such beacons are operating—a requirement proposed, as a companion to spectrum sensing techniques, by mic manufacturer Shure (partly in response to the poor performance, from their perspective, of the early tests of spectrum sensing technologies). The Coalition does, however, propose some modifications and limitations to the beacon requirements proposed by Shure. Shure further proposed that the FCC identify two VHF TV channels and four UHF TV channels to be exempted from unlicensed device operations. The Coalition letter says that their “members do not plan to use white spaces spectrum below channels 21 to ensure protection for public safety operations in channels 14-20, effectively reserving channels for wireless microphone operations as desired by Shure.”
Asked by Pro Sound News to respond to this latest Coalition filing, Shure’s senior director, public and industry relations, Mark Brunner, welcomed the Coalition’s “recognition of the need to protect all wireless microphones,” and called the response an “important step forward in working toward a realistic and effective interference protection plan.” Shure does have issues with the details of the Coalition’s proposed compromise, both with weakening their beacon proposal and with the suggestion that the spectrum in channels 14-20 is the equivalent of Shure’s exemption proposal. “The Coalition continues to base its proposed protection largely on spectrum sensing technology that would be incorporated into portable white space devices and disabling beacons,” Brunner explains. “Despite their efforts, Coalition members have not been able to show that spectrum sensing technology offers effective protection to wireless microphones. We therefore encourage further study, development and testing, including dynamic frequency selection techniques, prior to rulemaking. Shure strongly supports the idea of identifying sufficient appropriate channels that will be kept free from new devices. Unfortunately, Public Safety authorization on TV channels 14-20 greatly reduces the proposed amount of appropriate “spectrum reserve” for wireless microphones.
“Regarding the VHF channels (and 14-20 for that matter), the pro audio industry migrated to higher band UHF over 15 years ago–ironically, because there was more clear spectrum–and that while we appreciate the Coalition’s offer of some set aside channels, returning to VHF means overhauling a majority of the manufacturers’ portfolios and the users replacing much of their installed base, which amounts to a wholesale gutting of today’s wireless microphone infrastructure. This is why Shure has supported the adjacent DTV channels as set asides, and in rural markets where the adjacent channel count is very low, 4 reserved UHF and 2 VHF channels.”
Wireless Innovations Alliance