Tuesday, March 25, 2008
Google is suggesting a plan to open up the "white space" available on the tv spectrum to allow more consumers to get access to wireless Internet access after broadcasters move to all digital broadcasting in 2009. The space could be used for mobile web access, for example. Here's the text of Google's letter to the FCC outlining the plan. It says in part:
Under our own enhanced protection proposal, a TV white space device will not transmit on a channel until it first has received an "all clear" signal for that channel, either directly from a database of licensed transmitters in that area, or from a geo-located device with access to that database. That "permission to transmit" signal (at a maximum power level of 4W EIRP) would be sent on channels the geo-located device already knows are clear of licensed users. Any device without geo-location and database access would not transmit at all, unless and until it has successfully received advance permission from such a device.
Further, all TV white space devices would be blocked from transmitting by any wireless microphone beacon in that channel, using signals specifically designed to be easy to reliably detect, and coded to be identifiable to prevent abuse. These beacons should be quite inexpensive, and would be used in conjunction with existing wireless microphones, so there would be no need to replace legacy devices.
In addition, we are proposing a "safe harbor" for wireless microphones in channels 36-38. No TV white space device would be permitted to transmit in these channels. This will also protect medical telemetry devices and radio astronomy services, which are licensed to use channel 37.
Even in the absence of spectrum sensing, then, these enhanced measures should be more than adequate to protect all licensed uses.
Read more here in a New York Times article published today.