Effects of Location Awareness on Concurrent Transmissions for Cognitive Ad Hoc Networks Overlaying Infrastructure-Based Systems
Issue No.05 - May (2009 vol.8)
Li-Chun Wang , National Chiao-Tung University, Hsinchu
Anderson Chen , National Chiao-Tung University, Hsinchu
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TMC.2008.72
Through wide-band spectrum sensing, cognitive radio (CR) can identify the opportunity of reusing the frequency spectrum of other wireless systems. However, wide-band spectrum sensing requires energy consumption processes. In this paper, we aim to relieve the burden of spectrum scanning in a CR system by means of location awareness. We investigate to what extent a CR system with location awareness capability can establish a scanning-free region where a peer-to-peer connection of the secondary CR users can coexist with an infrastructure-based connection of the primary user. We compute the concurrent transmission probability of a peer-to-peer connection and an infrastructure-based connection in a system based on the carrier sense multiple access with collision avoidance (CSMA/CA) medium access control (MAC) protocol. It has been shown that the frequency band of the legacy system can be reused up to 45% by the overlaying cognitive ad hoc network if certain location techniques help CR users locate primary and other secondary users. In summary, a CR system equipped with location awareness techniques can dramatically reduce the need of spectrum sensing thanks to the capability of identifying the concurrent transmission region in a hybrid infrastructure-based and ad hoc overlaying systems. Hence, from another aspect, the issue of wide-band spectrum sensing in CR systems is resolved fundamentally.
Ad Hoc Networks, Cognitive Radio, Carrier Sense Multiple Acces, MAC Protocol
Li-Chun Wang, Anderson Chen, "Effects of Location Awareness on Concurrent Transmissions for Cognitive Ad Hoc Networks Overlaying Infrastructure-Based Systems", IEEE Transactions on Mobile Computing, vol.8, no. 5, pp. 577-589, May 2009, doi:10.1109/TMC.2008.72