A Highly Successful Frame Contention Strategy for Self-Coexistence in IEEE 802.22 Wireless Regional Area Networks

As the first standard for cognitive radio networks, IEEE 802.22 wireless regional area networks (WRANs) exploit television white spaces. Secondary networks have to preserve primary network communications and to coexist with other secondary networks. To support self-coexistence in the IEEE 802.22 WRANs, two spectrum access methods are provided; namely, spectrum etiquette and on-demand frame contention (ODFC). The IEEE 802.22 base stations conduct the spectrum etiquette if there is an exclusively available channel; otherwise, it performs ODFC. ODFC enables the base stations to share the operating channel. However, in ODFC, contention success or failure depends on a random number generator without other considerations and contention destination is randomly selected regardless of the traffic at the destination. This paper proposes a novel frame contention strategy called highly successful frame contention (HSFC). The outstanding features of HSFC are: (1) the contention source chooses the idlest base station as the contention destination (2) the contention source with more users has a higher probability to win the frame contention, and (3) the contention destination takes its own traffic condition into consideration when processing the contention request. The performance evaluation showed that the proposed HSFC increases contention success probability and throughput remarkably compared to the conventional ODFC.