Google makes pitch for unlicensed white space spectrum

Google didn't come away with any pricey spectrum in the Federal Communications Commission's 700 Mhz auction, but that doesn't mean the search giant isn't cooking up big ideas. Google has pitched the FCC on plans to utilize the unlicensed "white space" spectrum that will be left behind by TV broadcasters.

In a letter to the FCC from Richard Whitt, Google's Washington telecom and media counsel, the company outlines plans for mobile broadband services using the white space spectrum that will be vacated by broadcasters. News of the letter surfaced on Monday at a Google media conference call (Techmeme).

Here's a look at Google's FCC letter and a few of the finer points (PDF download):

As Google has pointed out previously, the vast majority of viable spectrum in this country simply goes unused, or else is grossly underutilized.1 Our nation typically uses only about five percent of one of our most precious resources. Unlike other natural resources, there is no benefit to allowing this spectrum to lie fallow. The airwaves can provide huge economic and social gains if used more efficiently, as seen today with the relatively tiny slices utilized by mobile phones and WiFi services.

The unique qualities of the TV white space -- unused spectrum, large amounts of bandwidth, and excellent propagation characteristics -- offer a once-in-a-lifetime opportunity to provide ubiquitous wireless broadband access to all Americans. In particular, this spectrum can provide robust infrastructure to serve the needs of under-deployed rural areas, as well as first responders and others in the public safety community. Moreover, use of this spectrum will enable much-needed competition to the incumbent broadband service providers.

These plans have been outlined to the FCC before by Google, but it seems clear that the company is ratcheting things up a bit. The goal: Create a network that uses unlicensed spectrum better. Android devices will also play a role here. What's interesting is that Google seems to have big plans for using unlicensed spectrum for broadband services. The message: Let Verizon and AT&T bid big on spectrum Google will take the back door.

Realizing the pitch will raise a ruckus, Google's letter takes a step in trying to allay concerns of broadcasters. The biggest concern that white space spectrum will hamper digital TVs and other devices.

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.

The overarching message from Google is this: White space spectrum is being wasted and it can be used while protecting licensed spectrum. The FCC's goal should be to use the white space as a testbed for future services. The FCC has listened to Google before. If it does so again unlicensed spectrum could become interesting in a hurry.