Posted on May 3, 2011
Last week (April 29th) Microsoft notified the FCC it wants to be an administrator for TV Band White Spaces.
Interpreting the announcement’s significance requires an accurate comprehension of much misunderstood TV Band White Spaces. Put briefly, the FCC has reserved enough spectrum for about fifty TV channels. Since each station has a limited broadcast contour, channels can be reused in different parts of the country. To illustrate, different station owners use channel 7 in New York, Detroit, Chicago, Denver, Albuquerque, San Francisco, and San Diego without interfering with one another, owing to geographic separation. Theoretically, each city has fifty channels available, but FCC regulations require that stations not interfere with those in nearby cities. That’s why WABC can broadcast on channel 7 in New York City, but no station may use channel 7 in close-by Newark, New Jersey.
Posted on March 28, 2011
The Wireless Internet Service Provider Association (WISPA) held a two day conference in Orlando last week. Three points merit attention.
First, two companies demonstrated a wireless LAN over unoccupied TV channels. This is significant because many industry observers mistakenly assume vacant TV bands are only in rural markets. Although Orlando’s MSA population is over two million, at least four White Space TV channels were available.
One company is Silicon Valley based Adaptrum. They’re developing cognitive radio chips able to promptly identify available spectrum based upon geo-location and signal sensing. Apparently their ambition extends beyond TV bands. For example, the Nation Science Foundation concluded in 2005 that only about five percent of communications spectrum between 30 MHz and 3,000 MHz is used at any given time. Frequency agile cognitive radios could spontaneously identify and use such idle spectrum. The process would be transparent to the wireless LAN user who would merely experience reliable service without realizing where, or how, his smartphone or tablet computer obtained bandwidth. Read more…