A Notice of Proposed Rulemaking proposing greater coverage areas for unlicensed “white space” devices operating in the TV bands was adopted at the FCC’s open meeting last week and released earlier this week. We have written about these white space devices before (see, for instance, our articles here and here). These devices operate at relatively low powers in unused portions of the TV bands. They are designed to offer wireless services, including broadband. Advocates of these operations see them as an inexpensive way to offer broadband services to underserved areas, including parts of rural America.
The concern of course with these devices is that if their use is not managed correctly, their operations could interfere with existing TV operators (including LPTVs, TV translators, broadcast auxiliary services, and wireless microphones). Thus far, operations have been limited to power levels of 10 watts or less from antenna heights that did not exceed 250 meters height above average terrain. The advocates for these devices, including Microsoft, have argued that these low power levels make it difficult to serve rural areas given their small coverage area. NAB, on behalf of broadcasters, and advocates for wireless microphone operators, have urged caution in any increase in the coverage of these operations if they could possibly cause interference to existing users of the spectrum. After significant discussion and compromise between the NAB and Microsoft, the NPRM adopted last week tries to strike a balance between these positions.
Among the proposals advanced in the rulemaking are the following:
- Increasing the maximum permissible power for fixed white space devices operating in “less congested” (e.g., rural) areas in the TV bands from 10 watts to 16 watts.
- Increasing the maximum permissible antenna height above average terrain (HAAT) for fixed white space devices from 250 meters to 500 meters.
- Establishing minimum required separation distances from protected services in the TV bands for white space devices operating with higher power and HAAT.
- Setting up a notification process for white space operators to let TV stations know when they plan to operate using the higher powers and heights set out in the rulemaking.
- Allowing higher power mobile operations within defined “geo-fenced” areas.
- Establishing rules for narrowband white space devices used in Internet of Things applications.
- Whether to allow white space devices to operate with higher power levels than currently allowed when located inside an adjacent TV channel’s service contour.
On each of these topics, the FCC asks numerous questions to determine the service benefits that would be obtained from a change in the rules and the potential for interference to TV stations and other existing users in the TV band. The FCC poses numerous ideas on how to mitigate interference – including the required separations from other spectrum users necessary to insure interference-free operations. Comments on these many questions will be due 30 days after this notice is published in the Federal Register. Reply comments are due 60 days after that publication.