CNS Core: Small: MAC Layer Failure Control and Avoidance in Cognitive Radio Networks

University Of North Carolina At Charlotte, Charlotte NC

Investigators

Abstract

Cognitive radio has recently emerged as a promising technology to overcome the imbalance between the increase in spectrum access demand and the inefficiency in spectrum usage by allowing dynamic spectrum access. However, a fundamentally unexplored issue in cognitive radio networking design is how to avoid and control the failures at the medium access control (MAC) layer during spectrum access. This issue is becoming a serious barrier to the success of cognitive radio networks (CRNs). The potential MAC layer failures during spectrum access are unique in CRNs. They will significantly degrade the network performance and sometimes may even block the whole network's operation. Currently, no existing work addresses how to avoid the MAC layer failures or how to mitigate the effect on performance degradation caused by the failures in CRNs. This research is potentially transformative as it will help generate innovative techniques to numerous applications of the CRN technology, e.g., public safety networks, emergency networks, health monitoring, and cognitive mesh networks. It will also have significant impacts on research in emerging technologies with dynamic spectrum access, such as vehicular networks, mobile health, and opportunistic interconnections of heterogeneous wireless networks. The proposed MAC layer designs can also be applied to systems of Internet-of-Things (IoT) with low-power, low-cost IoT devices dynamically accessing the wide spectrum. The research objective of this proposal is to design, analyze, and evaluate new MAC layer failure control and avoidance protocols for cognitive radio networks (CRNs) without a common control channel. The proposed MAC layer designs aim at minimizing the failure rate caused by various factors during spectrum access and minimizing the average spectrum access delay. This research is the first that systematically addresses the unique failures at the MAC layer during spectrum access in CRNs under practical scenarios. This project includes three major research tasks: (1) rendezvous congestion control to avoid network congestion and to speed up the rendezvous; (2) handshake failure avoidance to avoid synchronous deadlocks and to derive the optimal size of a time slot for handshake; and (3) transmission failure mitigation to adapt the optimal frame size and to maximize the overall throughput. This research will offer a complimentary yet fundamental building block to existing CRN MAC research. This project also integrates research findings into related graduate courses and diversity support. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.