This past fall, the FCC voted unanimously to allow fixed, low-power wireless devices to operate over vacant spectrum between active TV channels, as long as they didn’t cause interference.
David Donovan, president of the Association for Maximum Service Television (MSTV), delivered a scathing warning last week before a gathering of sports production professionals, hosted by The Sports Video Group, in which he warned that those frequencies — currently used for wireless microphones, cameras and other ENG-type services — could and probably would be stepped on, or interfered with by these unlicensed devices.
And, if such interference were to occur, there would be no way to trace it back to the source, because theoretically thousands of these devices would already be in the marketplace. A recall of the problematic device could take months.
The move to use this “white space” spectrum comes from the government’s desire to bring broadband access to rural areas or those where cable Internet access is problematic. Congress didn’t take into account, however, the fact that this could lead to a laptop running on a Wi-Fi network to cause a wireless microphone operating within the same frequency to stop working.
In October, the commission invited comment on whether low-power devices should be permitted on TV channels 2-4, which are used by TV interface devices such as VCRs, and whether fixed low-power devices could be permitted on TV channels 20-51, excluding channel 37.
At least for now, the FCC is forbidding mobile devices to operate on channels 14-20, used for public safety in 13 cities, and on channel 37, used for radio astronomy and wireless medical telemetry services.
Donovan said the IEEE has begun working on the process of testing these fixed devices for potential interference, as directed by the FCC, but they haven’t even begun to test mobile devices because these products have not even been manufactured at this point.
Based on the schedule laid out by the FCC, the commission will issue a Report & Order in October 2007, finish its testing of existing TV receivers by the end the end of 2007 and accept applications to certify equipment by December 2007. Following this schedule, all of these unlicensed devices will enter the proposed white space band in March of 2009; right after the mandated transition to DTV operation is scheduled to be complete. That’s when the available broadcast spectrum will be reduced from channels 2-69 to 2-51.
A number of wireless equipment manufacturers, such as Shure Brothers and Total RF, have filed extensive comments with the FCC, but, according to Donovan, have gone largely unrecognized. The commission is said to be relying on a process called “spectrum sensing” to isolate interference and other methods to turn off the interfering device. These are World War II-era military security methods for identifying interference, however, which might not work with modern-day conditions.
Meanwhile, major computer makers and consumer electronics companies, including Intel and Microsoft, have lobbied the FCC to make the white space spectrum available license-free for high-speed Internet services, as well as in-home networks.
Although the new wireless devices won’t be operational until 2009, the issues and Report & Order regarding this are set to be decided in 2007. That’s why Donovan says the time is now for the broadcast industry to lobby Congress and let its voice be heard.
