An Update on WhiteSpaces

Today the Wireless Innovation Alliance (a group of which PK is a member) sent a letter (PDF) to the Hill. In it, we ask members of Congress to see through the FUD that NAB has been spreading about interference. Much of the FUD about whitespaces is trying to fool the uneducated about what's being tested and what stage of the testing we're at. I wanted to try to catch you up on the latest goings on and clear out the fear, uncertainty and doubt.

Generally, when before a consumer device that transmits / receives radio frequencies goes to market, it has to submit the results of standardized tests to the FCC. This is to show that the device sends out and listens to the signals its supposed to, and doesn't interfere with other signals. Cell phones, the bluetooth wireless headset accessories for cell phones, and WiFi cards for computers are just a few examples of devices that have to be tested to meet specific broadcast and receipt frequency tolerances before a single device can be sold. We're not to that point for whitespaces devices.

Cell phones, bluetooth accessories, and WiFi cards each have their own frequency specifications. The specs for the different flavors of WiFi, for instance, had to be developed to determine what frequencies such a device could potentially work on, how loudly or powerful the signals could be broadcast on those frequencies, and what to do in cases of two devices sharing the same frequency. We're not quite yet to that point for whitespaces devices, either.

The whitespace devices that are currently being tested, would operate in the same frequency that TV signals do. So they could be used anywhere, say DC or San Francisco, these whitespace devices are supposed to sense other transmissions, like TV signals, and adapt to the different TV signals being broadcast in any locale. This sensing technology makes these whitespace devices smarter than a cell phone, or bluetooth or WiFi device, because instead of just broadcasting and receiving at the same designated frequency in all places, they can listen and adapt before they broadcast. It will be something new for consumer-oriented devices, but the military is well on its way to testing this kind of "listening before talking" technology in other frequency ranges with great success.

Right now, a few companies: Microsoft, Adaptrum, Motorola, and Philips, are trying out some very raw devices through testing at the FCC. These are by no means consumer-end products, they're more like proofs-of-concepts (resembling science experiments hooked up to laptops) that have the ability to do a lot of measuring and data output, so that the extremes of capacities of how a device could work can be recorded. The FCC is actually conducting the second round of testing that will provide data to hopefully allow for technical specifications under which a consumer device could be built. If and when that spec is drafted, device manufacturers will be able to build devices to said spec. And just like a cell phone, bluetooth accessory, or WiFi card, the end consumer whitespace devices to be built would have to be tested again by the FCC to ensure that they perform within the designated specifications.

NAB's propaganda tries to confuse the uninformed by pretending that we're at the final consumer device testing stage, and that products are about to enter the market. We're not there yet, we're just learning how these devices could work, all without interfering with TV signals. NAB also likes to confuse people on how prototype devices perform. For instance, during the testing of one prototype device in this recent round had a power-fluctuation issue that, besides being in the same box, had little association with the way prototype sensed, broadcast, or received signals. It'd be like testing out a computer program and then the computer's power supply goes bad--you don't fault the program's performance because of the unrelated power supply. Here, the tester simply switched to an identical prototype device and continued the test, which was completed without a problem.

We all know how WiFi has changed the game for the ways people connect quickly, easily and cheaply to high-speed Internet. And WiFi works on what is generally considered shabby spectrum with bad propagation characteristics, and a small slice of it at that. TV signals are broadcast on spectrum with high bandwidth potential that can travel long distances and penetrate buildings. Using just sections of that spectrum when not used by TV signals would have a dramatic impact on broadband speeds and ease consumer adoption. Let's make sure that the FCC gets to test these prototype devices, just like Britain's OfCom is testing, so we can realize the full potential of the airwaves and provide high-speed Internet connectivity to the masses.

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