Posted: 02nd Aug, 2011 By: MarkJ
The
Institute of Electrical and Electronics Engineers (IEEE) has finally published the first completed
IEEE 802.22 standard for broadband wireless networking via the "
white space" of radio spectrum that exists between TV channels; otherwise known as a
Wireless Regional Area Network (WRAN).
Several companies and operators, such as Microsoft, BT and Neul, are currently taking part in trials of "
white space" wireless networking (
here and
here) in an effort to both determine the technology's feasibility and to help Ofcom establish the appropriate licence exempt regulation (
here).
As expected the IEEE's new standard supports both the
VHF and
UHF TV bands, which could deliver wireless broadband services over a large area of "
up to 100km from the transmitter". Each WRAN would also be rated to deliver
download speeds of up to 22Mbps per channel and "
without interfering with reception of existing TV broadcast stations", although this would be shared (contended) with other users.
IEEE Statement on 802.22
This technology is especially useful for serving less densely populated areas, such as rural areas, and developing countries where most vacant TV channels can be found.
IEEE 802.22 incorporates advanced cognitive radio capabilities including dynamic spectrum access, incumbent database access, accurate geolocation techniques, spectrum sensing, regulatory domain dependent policies, spectrum etiquette, and coexistence for optimal use of the available spectrum.
In principal such a technology would have many advantages because related services typically exist between the
470MHz and
790MHz frequencies, which travel further and more easily through walls. Each TV channel is given a slice of this spectrum and a small gap (the white space) is then left between the channels to limit the potential for interference. We should know whether or not such services will be viable by the end of this year.
It's also known that Ofcom is investigating the possibility of deploying white space technology in the
FM Radio band, albeit only once the UK government has freed it up by forcing us all to use the costly and problematic
Digital Radio (DAB) standard instead (
here). Such a move would be deeply unpopular.
The IEEE 802.22 Working Group
http://www.ieee802.org/22/