Date Added: Jan 2012
Cognitive radio technology gets much attention of wireless network research environments as a new way to utilize the precious spectrum efficiently. IEEE 802.22, Wireless Regional Area Network, is the first international standard based on cognitive radio technology which intends to provide broadband access by utilizing unused TV channels, also known as TV white spaces. This standard provides PHY and MAC layers functionalities in an infrastructure-based wireless access network. In this paper, the authors describe overview of 802.22 standard from MAC perspective and discuss research challenges related to it. They mainly discuss for two research issues, QoS and coexistence.