IEEE 802.22 is a standard for Wireless Regional Area Networks (WRAN). The primary focus of this standard is to enable wireless broadband access using the so-called “white spaces” in the TV frequency spectrum. These white spaces are unused TV channels that can be leveraged for wireless communication without interfering with existing TV broadcasts.

Here’s a concise overview of IEEE 802.22:

  1. Purpose: IEEE 802.22 aims to utilize vacant TV broadcast channels to provide broadband wireless access over a large area, potentially up to 100 km from the transmitter.
  2. Spectrum Usage: The standard makes use of the VHF and UHF TV bands between 54-862 MHz. These bands have good propagation characteristics, which allows for coverage over large areas.
  3. Cognitive Radio: IEEE 802.22 is one of the first standards to incorporate cognitive radio capabilities. This means that the devices can sense their environment and dynamically adjust their transmission parameters to avoid interference with other devices, especially TV broadcasts.
  4. Non-Interference Basis: Devices operating in the 802.22 standard must ensure that they do not interfere with existing TV broadcasts and wireless microphones. They use geolocation and spectrum sensing techniques to detect and avoid occupied channels.
  5. Applications: The primary application for IEEE 802.22 is to provide broadband access to rural and remote areas where laying traditional broadband infrastructure like fiber or DSL might not be cost-effective.
  6. Performance: An 802.22 base station can support up to 512 devices and provide a combined downstream data rate of up to 22 Mbps and an upstream rate of up to 6 Mbps.
  7. Network Topology: The standard is based on a point-to-multipoint topology, where a single base station communicates with multiple user devices.

In summary, IEEE 802.22 provides a unique solution to address the broadband needs of underserved or unserved rural and remote areas by making use of the vacant TV frequency spectrum. The adoption of cognitive radio capabilities ensures efficient use of the spectrum while protecting incumbent services from interference.