Jack Kontney /
03.08.2009 08:25 AM
Originally featured on BroadcastEngineering.com
DTV transition delay to have no effect on TVBDs
With the move of the DTV transition now delayed until June 12, the Federal Communications Commission is continuing its process to develop rules of engagement for the development and approval of TV band devices, commonly called white space devices. TVBDs will operate in the unused TV spectrum below 698MHz, with the provision that they not interfere with broadcast TV or wireless microphone systems.
To ensure that its policy of aggressive prevention of harmful interference is effective, the FCC will require TVBDs to incorporate a number of safeguards, including spectrum-sensing and use of a geolocation frequency database. Technology firms also have formed a White Spaces Database Group. The database will track all broadcast TV stations and will permit the registration of wireless microphone systems for protected operation at specific times and locations. In theory, TVBDs will query the database for available frequencies, then use frequency-sensing to avoid unregistered wireless systems in operation. It is also worth noting that, as is currently the case, wireless microphone systems will be responsible for avoiding interference with each other.
One company that has positioned itself to help is Spectrum Bridge, which hopes to track, acquire and broker availability of unused TV spectrum to potential users. Recently, the company launched a new Web site, ShowMyWhiteSpace.com, which allows anyone to see which TV channels are currently available at any given street address in the United States. The site also allows wireless microphone users to preregister their information with Spectrum Bridge, which will ensure its secure delivery to a white spaces database manger once this functionality is formalized by the FCC and launched.
The number of open TV channels in any given location varies widely, with major urban areas being very crowded and rural communities boasting vast expanses of available bandwidth. Technology companies, along with the government, are hopeful that this, along with the new licenses auctioned off last year in the 700MHz band, will result in the proliferation more powerful and lower-cost broadband Internet access.
Still at issue are the physical requirements of the devices themselves, and the FCC certification requirements that must be met before TVBDs can be offered for sale to the public. The commission is currently accepting input from interested parties to help set standards that will meet its goals of protecting broadcast TV and wireless microphone operation while fostering the next generation of advanced consumer wireless devices.