A framework for dynamic selection of backoff stages during initial ranging process in wireless networks

The only available solution in the IEEE 802.22 standard for avoiding collision amongst various contending customer premises equipment (CPEs) attempting to associate with a base station (BS) is binary exponential random backoff process in which the contending CPEs retransmit their association requests. The number of attempts the CPEs send their requests to the BS are fixed in an IEEE 802.22 network. This paper presents a mathematical framework that helps the BS in determining at which attempt the majority of the CPEs become part of the wireless regional area network from a particular number of contending CPEs. Based on a particular attempt, the ranging request collision probability for any number of contending CPEs with respect to contention window size is approximated. The numerical results validate the effectiveness of the approximation. Moreover, the average ranging success delay experienced by the majority of the CPEs is also determined.