Archive for October, 2010

As you may know, the FCC voted on September 23, 2010 to open up spectrum adjacent to television frequencies for the use of broadband wireless devices.  This is the so called “white space” decision.  The FCC voted 5-0 in favor of this action.  Here’s a short comment about the impact on small wireless users such as churches:

Shure SLX Wireless Microphone

In an effort to protect wireless microphones from interference, commissioners voted to set aside two TV channels nationwide for wireless microphones. Those channels should allow 12 to 16 wireless microphones to operate in an area at the same time, said Hugh Van Tuyl, a senior staff engineer with the FCC’s Office of Engineering and Technology (OET).

If large sporting events or other users need additional spectrum for wireless microphones, they can ask to be temporarily included on an occupied-spectrum database designed to steer wireless devices away from those spectrum bands.

Wireless microphone maker Shure applauded the FCC’s decision to set aside channels for microphones.

“It’s clear that the FCC carefully considered the needs of wireless microphone users while crafting this order,” said Sandy LaMantia, Shure’s president and CEO, in a statement. “The reserved channels will provide a safe harbor in which musicians, small theaters, houses of worship, and businesses can operate their wireless microphone systems without interference from new TV band devices.”

CCI Solutions summary for our customers.

Bottom line, there will be two bands of frequencies (12-16 wireless mic channels total) specifically reserved for wireless operation in each city region.  Wireless microphone uses in those reserved bands do not require licensing nor registration with the national white spaces database.  In fact, most users cannot register their wireless microphones in the national database.  Registration is reserved for large users of multiple channels of wireless systems such as theaters, travelling shows, etc.

Any user of a large number of wireless channels must state that they have exhausted all available “clear” frequencies in TV channels 7-51 prior to registering for protection from broadband devices.  This will require the deployment of wireless systems in the upper VHF frequencies as well as throughout the entire UHF spectrum, other than 700Mhz, of course.  Registering for protection without using other legal available spectrum is subject to disciplinary actions from the FCC.

The frequencies that the FCC ruling covered were TV Channels 7-51, except channel 37 which is reserved for radio astronomy use.  Those channels cover the following frequencies (174Mhz – 216Mhz and 470Mhz – 608Mhz and 620Mhz – 697Mhz).  A major unresolved issue is that the 2 special reserved channels may be outside the normal wireless mic frequencies that are currently used or that our customers can accommodate with their existing units.  Some of those reserved frequencies may even be in the old VHF spectrum (174Mhz – 216Mhz).  We won’t know which 2 channels are dedicated for wireless use in each city region until frequency allocations are published by the FCC.

We do not believe this represents a huge problem for our customers, however.  In each city region there are frequencies in which broadband devices may not be operated due to potential interference with TV broadcast signals.  Wireless microphones may be operated on those frequencies.  And many of those frequencies should fall into the normal wireless microphone system frequencies that our current customer units are designed for.

Finally, wireless microphones may also be operated on white space spectrum that also supports broadband devices.  Such use is not protected by the FCC and is subject to interference from broadband devices if those devices are operated within 4km of the wireless microphone.  That is similar to the situation today.  You can operate on any legal frequency that you care to, but you are not guaranteed that you won’t get interference on that frequency.

CCI Solutions Conclusion

700Mhz wireless operation remains as an illegal use.  Users must cease operating their 700Mhz wireless microphones.  This spectrum has been sold to Verizon Wireless and they are enforcing their rights to use this spectrum without interference from unauthorized users.  Continue to replace any remaining 700Mhz wireless systems as soon as possible to avoid potential “cease and desist” orders or legal action from Verizon Wireless or the FCC.

The FCC has allocated spectrum for the exclusive use of wireless microphones.  That spectrum may not be in the same frequency range as your current system’s capabilities.  Operation on the other frequencies we are accustomed to using is still legal.  Continue to use your existing legal wireless systems in the 470Mhz – 698Mhz bands.  Be aware of potential interference from new “broadband” devices.  If you are not operating in a “clear” channel you may need to change your channel allocations.  If you add wireless microphones, make sure they can operate in the “clear” channels in your area.  Contact your CCI Solutions technical representative for help in coordinating all of your wireless device frequencies.