IEEE 802.22 is a working group, formed in November 2004, which aims to develop a standard for fixed wireless broadband access in rural and remote areas. The IEEE 802.22 Wireless Regional Area Network (WRAN) system will take advantage of unused TV channels that exist in these sparsely populated areas. IEEE 802.22 will utilize white spaces (channels that are not used in the frequency band) in the already allocated VHF/UHF TV Broadcasting bands ranging from 54 to 862 MHz.
IEEE 802.22 WRAN will be based on cognitive radio technology. WRAN systems will be able to sense the spectrum to identify unused TV channels, and utilize these channels for fixed wireless access without interfering with excisting users, including TV receivers and wireless microphones.
The target of IEEE 802.22 WRAN is to provide fixed wireless access with a typical cell radius of 33 km and a maximum of 100 km. The main characteristics of the IEEE 802.22 WRAN system are:
Sensing the spectrum to identify free TV channels
6 (7/8) MHz radio channel
OFDM
Channel capacity of 18 Mbit/s
User capacity
downlink: up to 1,5 Mbit/s
uplink: up to 384 kbit/s
Over subscription ratio: 50
subscribers per forward channel: 600
Source :
www.telecomabc.com/numbers/80222.html
Posted: Wed Jan 18, 2012 8:45 am