IEEE 802.22, established in November 2004, is a working group with the objective of creating a standard for providing fixed wireless broadband access in rural and remote regions. The IEEE 802.22 Wireless Regional Area Network (WRAN) system is designed to make use of available TV channels that are not utilized in these sparsely populated areas. It leverages the white spaces (frequency channels that remain unoccupied) within the allocated VHF/UHF TV Broadcasting bands, spanning from 54 to 862 MHz.
IEEE 802.22 WRAN is built upon cognitive radio technology. WRAN systems possess the capability to actively scan the radio spectrum to detect unutilized TV channels, effectively utilizing these channels for delivering fixed wireless access without causing interference to existing users, including TV receivers and wireless microphones.
The primary goal of IEEE 802.22 WRAN is to offer fixed wireless access, typically covering a cell radius of 33 km and extending up to a maximum of 100 km. The key characteristics of the IEEE 802.22 WRAN system include:
- Spectrum sensing to identify available TV channels.
- Use of 6 (or 7/8) MHz radio channels.
- Implementation of Orthogonal Frequency Division Multiplexing (OFDM).
- Channel capacity of up to 18 Mbit/s.
- User capacity:
- Downlink: Up to 1.5 Mbit/s.
- Uplink: Up to 384 kbit/s.
- Over subscription ratio of 50.
- Maximum subscribers per forward channel: 600.