When Dell, Earthlink, Google, HP, Intel, Microsoft and Philips got together to create a prototype "white space" device—that is, a box capable of two-way high-bandwidth wireless communication in the frequencies now occupied by analog TV signal—you would have thought the combined muscle would ensure success. But the White Spaces Coalition has failed its first test with the FCC, with two prototypes that don't seem to know
their ass an occupied channel from their elbow an empty one.
Two different prototypes were submitted for the test, both from the Coalition. (I'm going to go out on a limb and say that, judging from the gallery below, Dell had more sway than HP.) The testing didn't focus so much on how well the devices could transmit and receive broadband signal, although Prototype A could do both. The real focus was how well they could "listen" before they "spoke."
The danger is that licensed high-powered devices and unlicensed low-powered devices operating on a crowded frequency band need to know how to be polite and share the space. Prototype A, the more complete package, was pretty miserable at this, failing to recognize active NTSC signal 20% of the time, and strong digital TV signal over half the time. Even when there was no signal present, 15% of the time Prototype A said that there was.
Prototype B, the slimmer box shown below, had an updated receiver but could not transmit. It was able to score a little higher on the tests but also failed. The other test was to determine interference with wireless microphones that use the same frequency band. The FCC determined that both prototypes failed this as well. Prototype A was "generally unable to sense wireless microphones," Prototype B's performance was "mixed."
The Coalition isn't exactly throwing in the towel, according to the UPI:
The White Spaces Coalition said in a statement it was encouraged "that FCC engineers did not find fault with our operating parameters and remain confident unlicensed television spectrum can be used without interference."
For a PDF of the testing details with all the charts and graphs you can eat, click here.