Newly published FCC white space rules lay out wireless mic protection

Many broadcasters and wireless mic users were disappointed in the Nov. 4 rulemaking by the FCC to authorize unlicensed devices to operate in the TV band on unused channels known as white spaces.

For ENG crews regularly using wireless mics, IFBs and other RF devices as part of a typical production setup in the field, the prospect of relying on these newly authorized TV band devices to detect the presence of their wireless mics and select an unused frequency that does not threaten interference is worrisome. Those worries were amplified when FCC testing of prototype white space devices at FedExField in Washington, D.C., and in the Broadway theater district in New York City in the fall revealed the prototypes were unable to accurately identify frequencies used by wireless mics.

On Nov. 14, the FCC released its new rules to the public. The document establishes several provisions aimed at protecting wireless mic users. In general, the protections fall into two categories: those for wireless mics used regularly in the same geographic area, such as sports arenas and theaters, and those for itinerant applications of wireless mics, such as ENG. Furthermore, the commission created separate rules for two categories of TV band devices: fixed and personal/portable.

For known geographic locations where wireless mics are used, the commission rules call for their registration in a database of TV spectrum use by geographic area. TV band devices, with the exception of personal/portable devices operating in client mode (under the control of a fixed device or another personal portable device with geolocation and database access capabilities), must include the abilities to identify their geographic location and access an Internet database of protected channels in use in their locale; thus, the devices would be restricted from use in locations with known wireless mic transmissions and avoid causing harmful interference to them.

Channels 2 to 20 will be restricted to fixed device use. According to the commission, it anticipates that many of these channels will be left unused by fixed TV band devices and be available for itinerant wireless mic applications, such as ENG. In 13 major markets where land mobile operators use channels between 14 and 51, the commission also requires two channels between 21 and 51 to remain free of TV band device use and available for itinerant wireless mic applications.

In the months leading up to the decision to authorize use of unlicensed TV band devices, many opponents had expressed the fear that in the event of authorization there would be no way to rein in millions of consumers using such devices should they cause harmful interference once the devices become available.

The rules address this concern in two ways. First, the rules say the commission “will act promptly to remove any equipment” causing interference from the market and require “responsible parties to take appropriate actions to remedy any interference that may occur.” Second, before any TV band devices are made available to the public, they are subject to certification by the FCC Lab to ensure they meet the commission’s requirements.

The commission will authorize TV band devices that don’t include geolocation and database access capabilities. Such devices, which rely solely on spectrum sensing technology, the rules say, will be “subject to a much more rigorous set of tests” by the FCC Lab to ensure they meet “a ‘Proof of Performance’” standard.

To read the new rules in their entirety, visit