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

认知无线电是一种很有前途的技术，它通过允许动态频谱接入来克服频谱接入需求增加和频谱使用效率低下之间的不平衡。然而，如何避免和控制频谱访问过程中介质访问控制（MAC）层的故障是认知无线电网络设计中一个根本未被探索的问题。这个问题正在成为认知无线网络（crn）成功的一个严重障碍。在crn中，频谱访问过程中可能出现的MAC层故障是唯一的。它们会显著降低网络性能，有时甚至会阻塞整个网络的运行。目前，还没有研究如何避免MAC层故障，以及如何减轻crn故障对性能下降的影响。这项研究具有潜在的变革性，因为它将有助于为CRN技术的众多应用产生创新技术，例如公共安全网络、应急网络、健康监测和认知网状网络。它还将对具有动态频谱接入的新兴技术的研究产生重大影响，例如车载网络、移动医疗和异构无线网络的机会互联。提出的MAC层设计也可以应用于具有低功耗，低成本物联网设备动态访问宽频谱的物联网（IoT）系统。本提案的研究目标是设计、分析和评估新的MAC层故障控制和避免协议，用于没有公共控制通道的认知无线网络（crn）。提出的MAC层设计的目的是最小化频谱访问过程中各种因素造成的故障率和最小化平均频谱访问延迟。本研究首次系统地解决了实际场景下crn频谱访问过程中MAC层的独特故障。本课题主要包括三个主要研究任务：(1)交会拥塞控制，避免网络拥塞，加快交会速度；(2)握手失败避免，以避免同步死锁，并得出握手的最佳时隙大小；(3)传输失败的缓解，以适应最优的帧大小和最大的整体吞吐量。这项研究将为现有的CRN MAC研究提供一个补充但基本的构建块。该项目还将研究成果整合到相关的研究生课程和多样性支持中。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.