Delay performance of multi-hop WRANs under the self-coexistence situation

TV White Space (TVWS) is becoming a useful communication medium through cognitive radio techniques. IEEE 802.22 Wireless Regional Area Network (WRAN) has been adopted as a standard in this regard. WRAN has a coverage radius of up to 30km. Due to large cells and opportunistic spectrum utilization, the self-coexistence situation, where multiple WRAN Base Stations (BSs) share the same spectrum band in the same region, is expected to be common. This paper explores the use of relay-based WRANs to improve the transmission performance under the self-coexistence situation; this performance improvement has not been reported to the best of our knowledge. In particular, we investigate the delay performance of multi-hop WRANs under the self-coexistence situation using simulations, and compare the performance to the case of single-hop WRANs without relay. We also evaluate the delay performance for hybrid scenarios where some of the Consumer Premise Equipments (CPEs) use relay while others communicate directly to BSs. Numerical results indicate that using relay transmissions for CPEs in the overlap area of self-coexisting WRANs can help decrease the average packet delay when the transmission resources become scarce.