应用累积系数确认的网络编码机会路由协议

发布时间：2018-07-26 14:25

【摘要】：在无线mesh网络中,机会路由通过高效使用无线传输的广播特性显著地提高了无线网络的吞吐量.引入网络编码,使得机会路由协议可以避免复杂的调度,更加易于实现.然而,网络编码的引入给机会路由协议带来新的问题:转发节点应该发送多少编码包?MORE等协议依据平均链路状况信息来预计节点转发编码包数目的方法,无法准确判定发送的冗余.以CCACK为代表的研究采用逐跳反馈的方式来减少编码包的冗余发送.首先,针对采用正交向量确认的CCACK机制进行分析,说明了CCACK尽管可以减少确认开销,减少误判,但却带来了"信息空间已覆盖而无法正交"的漏判问题.在此基础上,提出了一种基于累积编码系数反馈确认的网络编码机会路由协议CFACK.该确认机制中转发节点通过侦听下游节点的编码系数向量,并与来自上游节点的编码系数向量进行相关性分析,从而获知下游节点信息是否覆盖自身信息.证明了在无差错网络环境下该确认机制不存在误判和漏判的可能,同时,在有差错网络环境下对该确认机制的有效性进行了分析.结果表明:在一般节点分布情况下,利用额外的一次携带确认,可以确保90%以上的准确性.仿真测试结果表明:CFACK相比CCACK,显著提高了网络的吞吐量,平均提高率为72.2%,同时在编码计算、存储和包头开销上都少于CCACK.
[Abstract]:In wireless mesh networks, opportunistic routing significantly improves the throughput of wireless networks by using the broadcast characteristics of wireless transmission efficiently. By introducing network coding, opportunistic routing protocol can avoid complex scheduling and is easier to implement. However, the introduction of network coding brings new problems to opportunistic routing protocols: how many coding packets should be sent by forwarding nodes? The redundancy of the transmission cannot be determined accurately. Hop-by-hop feedback is used to reduce redundant transmission of coded packets, represented by CCACK. Firstly, the CCACK mechanism using orthogonal vector validation is analyzed, which shows that CCACK can reduce the cost of confirmation and misjudgment, but it brings about the problem of "information space is covered but can not be orthogonal". On this basis, a network coding opportunity routing protocol (CFACK) based on the feedback confirmation of cumulative coding coefficients is proposed. In this mechanism, the forwarding node listens for the encoding coefficient vector of the downstream node, and analyzes the correlation with the coding coefficient vector from the upstream node, so as to know whether the downstream node information covers its own information. It is proved that there is no possibility of misjudgment and omission in the environment of error-free network. At the same time, the validity of the mechanism is analyzed under the environment of error-free network. The results show that in the case of general node distribution, the accuracy of more than 90% can be ensured by using additional carrier confirmation. The simulation results show that compared with CCACCK, the throughput of the network is improved significantly, and the average increase rate is 72.2%, and the cost of coding, storage and packet header is lower than that of CCACK.
【作者单位】：中南大学信息科学与工程学院;
【基金】：国家自然科学基金(61173169,61202494) 教育部新世纪优秀人才计划(NCET-10-0798)
【分类号】：TN915.04

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