RF Shorts – July 14, 2011
White Space Update
ITBusinessEdge provides a new update on what’s happening with “white space” technology in the article The White Space Landscape is Still Forming by Carl Weinschenk.
He writes that “Observers say that even if the white space industry gets answers they don’t like from Congress and the FCC, businesses will be launched and bring value to subscribers, though it may be a bit more modest than if the FCC and Congress don’t disappoint.”
Weinschenk sees an opportunity for sharing spectrum that I’m not sure will ever happen with broadcast signals, but could be a possibility when it comes to certain wireless microphones.
“Now, for instance, a broadcaster may be able to use bandwidth at a particular spectrum spot during the day and a wireless Internet service provider (WISP) could use the same spectrum at night,” said Weinschenk. “Far more complex co-habitation arrangements are possible, especially as the technology is perfected. Put simply, the potential for stretching the spectrum soup is significant.”
TV Signals Could Bolster GPS Systems
Elsewhere in this week’s RF Report I reported on researchers using TV signals to power sensors. Tom Butts has alerted me to another non-broadcast use of DTV signals. The ATSC A/153 mobile DTV standard includes precision time stamping that could be used by a device to determine its location in indoor locations where GPS isn’t available.
An article, Patent: Future iPhones to tap broadcast TV signal for indoor positioning on 9TO5Mac references another article Apple Reveals the Next Chapter for iBooks & New Chip for iOS devices. That article reported that Apple had briefly mentioned the inclusion of a hybrid positioning system that used both satellite and TV signals involving some Rosum Corp. technology. In the first quarter of 2010, Rosum and its partner, Sianom, developed a system for location and synchronization in indoor and urban environments.
I wonder how well this would work in such areas as Los Angeles where TV stations transmit from two main transmission sites located close together. In any event, with Siano and Rosum chips in an iPhone, it would appear to be trivial to add the ability to receive ATSC Mobile DTV programs.