The present invention relates to wireless systems and, more specifically to an enhanced CBP (“Contention Based Protocol”) mechanism that allows efficient, scalable, and backward-compatible cross-channel inter-cell communications for IEEE 802.22 systems.
A contention-based protocol (CBP) is a communications protocol for operating wireless telecommunication equipment that allows many users to use the same radio channel without pre-coordination. The “listen before talk” operating procedure in IEEE 802.11 is the most well known contention-based protocol.
Section 90.7 of Part 90 of the United States Federal Communication Commission rules define CBP as: “A protocol that allows multiple users to share the same spectrum by defining the events that must occur when two or more transmitters attempt to simultaneously access the same channel and establishing rules by which a transmitter provides reasonable opportunities for other transmitters to operate. Such a protocol may consist of procedures for initiating new transmissions, procedures for determining the state of the channel (available or unavailable), and procedures for managing retransmissions in the event of a busy channel.”
There are a number of important issues or problems that need to be more fully resolved regarding the current CBP mechanism used for inter-cell discovery and communication. A non-comprehensive list of the issues that need to be addressed is as follows:                Directional Antenna at the CPE        WRAN Cells Discovery and Detection        Inter-Cell Communication Adjacent Channel Sensing Quiet Period Communication        Inter-Cell Communication for Cross-Channel Spectrum Sharing        
What is proposed is a set of fundamental remedies to respectively resolve each of these issues. The nature of these issues and problems, as well as their solutions, will be described in greater detail below.