Friday, March 6, 2009

Beware the White Space Data Base

Some of you may have read about new consumer devices that are supposed to take advantage of so-called "white spaces" in TV spectrum. In other words, you'd buy a phone or a wireless internet device and operate it on an unused local TV channel. These devices are supposed to be used with spectrum sensing software or a data base that enables consumers to know if a local TV station or emergency service is using TV spectrum. If they are, then you're not allowed to use that channel.

I just checked one such on-line database and boy was it wrong. It showed that channel 42 is available in Palm Springs. Wrong! That's KESQ-TV's over-the-air analog channel, and it will be our DTV channel after June 12th. Whoever created this database operates it with reckless disregard for the truth. Another example of why you can't believe everything you read on the internet.

There is a big legal fight brewing over this technology because proponents of it tested the devices and the tests showed their spectrum sensing technology (which is supposed to detect local signals) doesn't work. The FCC approved it anyway. This is going to be a long, expensive fight, and consumers will be the losers if they buy these devices and then find out they don't work because they either cause interference or receive interference from licensed users. By the way, how'd you like to have the people who dispatch police and fire to your house in an emeregency unable to do so because someone was jamming their radios with a cordless phone or internet router? Yes...first responders and broadcasters already share spectrum!

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