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

认知无线电作为一种很有前途的技术，通过允许动态频谱接入来克服频谱接入需求的增加和频谱利用效率低下之间的不平衡。然而，认知无线电组网设计中一个根本未探索的问题是如何避免和控制频谱接入过程中介质访问控制(MAC)层的故障。这一问题正在成为认知无线电网络(CRN)成功的严重障碍。频谱接入期间的潜在MAC层故障在CRN中是独一无二的。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，还没有解决如何避免MAC层故障或如何减轻CRN中故障对性能降低的影响的现有工作。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、紧急网络、健康监测和认知网状网。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、移动医疗和异类无线网络的机会互连。提出的MAC层设计也可以应用于具有动态接入宽带的低功耗、低成本物联网设备的物联网系统。该方案的研究目标是设计、分析和评估新的无公共控制信道认知无线电网络(CRN)的MAC层故障控制和避免协议。提出的MAC层设计旨在最小化频谱接入过程中各种因素造成的故障率和最小化平均频谱接入时延。这是第一个系统地解决实际场景下CRN中频谱接入过程中MAC层的独特故障的研究。该项目包括三个主要研究任务：(1)避免网络拥塞和加快交会速度的交会拥塞控制；(2)避免握手失败以避免同步死锁，并推导出握手时隙的最优大小；(3)减少传输失败以适应最优的帧大小和最大化总体吞吐量。这项研究将为现有的CRN MAC研究提供一个免费但基本的构建块。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NSF的法定使命，并通过使用基金会的智力优势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.