基于STDMA的链式无线mesh网络的研究及实现

发布时间：2018-04-20 04:09

本文选题：无线mesh网络 + 链式　；参考：《中国矿业大学》2017年硕士论文

【摘要】：无线mesh网络的自组织特点满足物联网对节点具有自主管理能力的要求。MAC层接入机制的表现会直接影响网络的性能,CSMA和TDMA常被无线mesh网络作为MAC层接入机制。相关研究表明TDMA接入机制相比于CSMA接入机制更适用于距离远跳数多的网络场景,例如河流,海岸线,公路,国家陆地边界和地下矿山隧道,这些场景的地理性质要求mesh路由器的部署应严格按照狭长的链式方式,该场景又被称为链式无线mesh网络。虽然TDMA机制能提升链式无线mesh网络的性能,但其为每个节点分配不同的时隙的方式造成信道的浪费。因此,提高TDMA信道利用率是研究的核心和重点。首先,本文对无线mesh网络中的CSMA和TDMA接入机制进行归纳总结,介绍了TDMA接入机制相比于CSMA更适合跳数多的链式无线mesh网络。因为端到端时延常被用来评价无线mesh网络的性能,所以本文分别从数学理论和仿真模拟对比CSMA和TDMA接入机制在链式无线mesh网路中的端到端时延。其中,端到端时延数学理论基于排队论提出,理论公式分别反映了数据包冲突和数据包排队等待时间是影响CSMA和TDMA端到端时延的主要原因。通过比较端到端时延,验证了TDMA接入机制更适合距离远跳数多的链式无线mesh网络。其次,使用空间复用技术来解决传统TDMA浪费信道的问题。利用数学理论和仿真模拟在端到端时延方面验证空间复用TDMA优于传统TDMA,并指出数据包排队等待的时间少是空间复用TDMA端到端时延小的主要原因。针对无线mesh网络中关于空间复用TDMA研究方法不适用于链式网络结构的问题,本文基于空间复用TDMA理论,联合AODV路由协议的hello消息,提出自适应STDMA接入机制。该机制不需要事先人为的为每个节点分配时隙,只需通过交换hello消息自适应的完成节点时隙的分配。最后,在NS2仿真工具中实现了提出的自适应STDMA接入机制,并通过myEvalvid视频质量评价工具验证了提出的自适应STDMA接入机制相比于CSMA和TDMA接入机制更适用于距离远跳数多的链式无线mesh网络。
[Abstract]:The self organization characteristics of wireless mesh network meet the independent management ability of the Internet of things for nodes. The performance of the.MAC layer access mechanism will directly affect the performance of the network. CSMA and TDMA are often used as MAC layer access mechanism by wireless mesh network. The related research shows that the TDMA access mechanism is more suitable for the distance far jump than the CSMA access mechanism. Network scenarios such as rivers, coastlines, highways, national land boundaries and underground mine tunnels, the geographical nature of these scenarios requires that the deployment of mesh routers should be strictly in a narrow chain, and the scene is called chain wireless mesh network. Although the TDMA mechanism can improve the performance of the chain wireless mesh network, it is for each section The way to allocate different time slots causes the waste of channel. Therefore, improving the utilization of TDMA channel is the core and key of the research. Firstly, this paper sums up the CSMA and TDMA access mechanism in the wireless mesh network, and introduces the TDMA access mechanism which is more suitable for the chain wireless mesh network with more hops than CSMA. Because of the end to end delay. It is often used to evaluate the performance of the wireless mesh network, so this paper compares the end to end delay of the CSMA and TDMA access mechanism in the chain wireless mesh network from the mathematical theory and the simulation simulation. Among them, the end to end delay mathematics theory is based on the queuing theory, and the theoretical formulas reflect the packet conflict and the queue waiting time respectively. The main reason that affects the end to end delay of CSMA and TDMA is that by comparing end-to-end delay, it is proved that the TDMA access mechanism is more suitable for the chain wireless mesh network with many distance far jump. Secondly, the space multiplexing technology is used to solve the problem of the waste of the traditional TDMA channel. The space complex is verified by using the mathematical theory and the imitation real simulation in the end to end delay. TDMA is better than traditional TDMA, and it is pointed out that the time of queue waiting for data packets is less than that of TDMA end to end delay of space multiplexing. The problem that the method of spatial multiplexing TDMA research is not suitable for chain network structure in wireless mesh network. Based on the spatial reuse TDMA theory, the Hello message of the AODV routing protocol is proposed from the Hello message of the AODV routing protocol. The mechanism is adapted to the STDMA access mechanism. The mechanism does not need to allocate the time slot artificially for each node in advance, only by exchanging the assignment of the node time slot of the completion node of the Hello message adaptively. Finally, the proposed adaptive STDMA access mechanism is implemented in the NS2 simulation tool, and the proposed adaptive STD is verified by the myEvalvid visual quality evaluation tool. Compared with the CSMA and TDMA access mechanism, the MA access mechanism is more suitable for chain mesh networks with far distance.

【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5

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