authentication, and authorization Only the AES-GCM authenticated encryption cipher algorithm is supported. EAP-TLS or EAP-TTLS must be used for authentication and encryption key derivation. IEEE 802.22 defines an X.509v3 certificate profile which uses extensions for authenticating and authorization of devices based on information such as device manufacturer, MAC address, and FCC ID (the Manufacturer/ServiceProvider certificate, the CPE certificate, and the BS certificate, respectively). This could allow for a type of customer lock-in where the network providers refuse network access to devices that have not been vetted by manufacturers of the network providers' choice (i.e. the device must possess a private key of an X.509 certificate with a chain of trust to a manufacturer certificate authority (CA) that the network provider will accept), not unlike the SIM lock in modern cellular networks and DOCSIS "certification testers" in cable networks. Comparison with 802.11af In addition to 802.22, the IEEE has standardized another white space cognitive radio standard, 802.11af. While 802.22 is a wireless regional area network (WRAN) standard, for ranges up to 100 km, 802.11af is a wireless LAN standard designed for ranges up to 1 km. Coexistence between 802.22 and 802.11af standards can be implemented either in centralized or distributed manners and based on various coexistence techniques. See also IEEE 802.11af, a standard for wireless LANs in TV white space Geolocation Database How is spectrum sensing done References IEEE 802 Wireless networking standards