Cooperative Sensing-Before-Transmit in Ad-Hoc Multi-hop Cognitive Radio Scenarios

摘要

Currently, the radio spectrum is statically allocated and divided between licensed and unlicensed frequencies. This results in its inefficient usage. Cognitive Radio (CR) is a recent paradigm which aims at addressing this inefficiency. It allows unlicensed users to opportunistically access vacant licensed frequency bands, as long as any harmful interference to incumbent users is avoided. In this context, providing appropriate medium access control (MAC) protocols is a core issue. However, the existing proposals omit relevant issues, are too complex, or are based on unrealistic assumptions in practical terms. Therefore, in this paper, we propose and analyze, through simulation, what we intend to be a really practical CR MAC protocol for distributed (i.e., ad-hoc) multi-hop CR scenarios, with high variability in terms of the availability of vacant frequency bands in time and space. Evaluation results confirm that the proposed approach, designated as CoSBT-MAC, can result in relevant benefits.