A Coexistence-Aware Spectrum Sharing Protocol for 802.22 WRANs

IEEE 802.22 is the first wireless standard based on cognitive radio (CR) technology. It defines the air interface for a wireless regional area network (WRAN) that uses fallow segments of the TV broadcast bands. CR technology enables unlicensed users in WRANs to utilize licensed (incumbent) spectrum bands on a non-interference basis to incumbent users. The coexistence between incumbent users and unlicensed users is referred to as incumbent coexistence. On the other hand, the coexistence between unlicensed users in different WRAN cells is referred to as self-coexistence. 802.22 defines several inter-base station (BS) dynamic resource sharing mechanisms to enable overlapping cells to share spectrum. However, those mechanisms do not adequately address some of the key issues concerning incumbent and self coexistence. In this paper, we propose an inter-BS coexistence-aware spectrum sharing (CASS) protocol for overlapping 802.22 cells that takes into account coexistence requirements. We show that the proposed protocol outperforms 802.22´s self-coexistence solutions using simulation results. To the best of our knowledge, the work presented here is the first systematic study of the self-coexistence problem in the context of 802.22 WRANs.