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FCC Rules for NEW TV BAND DEVICES:
What This Means For Wireless Microphone Users

Posted on November, 18th 2008.

The FCC has finally released its rules allowing a new class of unlicensed consumer electronic products to operate in locally unused TV channels. These have previously been referred to as white space devices (WSD) but are now called TV Band Devices (TVBDs). They will mainly be used as broadband access devices.

TVBD are categorized as:
1.) Fixed
These are allowed to operate with effective radiating power up to 4W on channels 2-51, with the exceptions of channels 3, 4, and 37.

2) Personal/Portable
They are restricted to channels 21–51, and are also not allowed in channel 37 (reserved channel for radio astronomy and medical telemetry). They are limited to 100mW operating power or 40 mW if operating in a channel adjacent to an active station. This moderate power will reduce their range and therefore the possibility to cause interference.

Licensed operation of wireless mics takes precedence over TVBD. TVBD must coordinate around active licensed wireless mic systems.

The rules include several safeguards to avoid interference to wireless microphones:

Spectrum Sensing
TVBDs must include the ability to listen to the airwaves to sense wireless microphones (in addition to TV stations). Until they can demonstrate through "proof of performance" that they can reliably sense wireless mics and avoid causing interference they must also use a:

Geolocation/Database system
TVBDs must use location sensing in conjunction with a database of registered broadcast license assignments. The database will also include a list of protected areas for wireless microphones such as entertainment venues and sporting events. TVBDs must first access the database to obtain a list of permitted channels in the area before operating. A TVBD that lacks this capability can operate only under the direct control of a TVBD that has it. More

Alternative Technologies:

With the advent of HD TV, and the resulting anticipated changes to the rules regarding the UHF spectrum, several companies are offering alternative technologies as a proposed solution. One such alternative is the use of the 2.4 GHz range for transmission. While on the surface it seems viable, there are some serious drawbacks to the use of this frequency range. More

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What does the ruling mean to you?

We understand that the anticipation of the changes in the US Spectrum has caused a great deal of anxiety for many. With the recent ruling announced by the FCC we have a much clearer outlook of the future landscape for wireless microphones. In order to help understand what these changes mean to each user individually, Sennheiser offers personal consultation. Users can sign up here to receive a phone call from one of our RF specialists.

How can you support the "White Space" Debate?

We encourage everybody who is interested to actively support the "White Space" discussion to inform their legislators of the ramifications of these proposals. For your convenience, you can download a pre-written letter that you can send to your Congress(wo)man and your state Senators. Just click on the link below to download the sample.

Download Template

Continuous Education - Sennheiser RF Sound Academy

The Sennheiser Sound Academy seminars offer continuous education on the subject of RF technology. The RF seminar teaches how to plan for trouble-free RF operation in the toughest environments covering transmitter and receiver technology, antenna distribution systems, wireless monitoring systems, systems planning, and frequency coordination in crowded RF environments. Click here to find out how to sign up to the Sennheiser Sound Academy.