【作者】 刘振华；

【导师】 丁泉龙；

【作者基本信息】 华南理工大学 ， 通信与信息系统， 2010， 硕士

【摘要】 无线自组网络是分布式的网络,具有非集中式的特性,特别适用于各种无中心通信节点的应用场合。然而,当使用传统的基于最小跳数的路由协议的时候,网络负载容易集中在少数热点节点,造成节点过载甚至拥塞。在有线网络中,节点只需基于自身的业务量进行负载均衡。但在无线自组网络中,邻近节点间的竞争也起着相当重要的影响。这是因为,两个无线节点之间的通信会同时影响同一信道上的其他节点的通信。因此,无线自组网络中的负载均衡应考虑到信道竞争这一重要的因素。在本论文中,我们以DSR协议为原型提出了一个具有竞争感知功能的负载均衡路由协议——CALBR。该协议使用一个由节点的竞争判据(CM)和负载判据(LM)综合而成的路由判据。我们仔细分析了802.11 MAC协议中的信道接入和信道竞争,并在此之上提出了一个能反映信道竞争剧烈程度的竞争判据(CM)。除此之外,节点自身的负载也是网络负载很重要的一部分。在这里,节点在一定时间内的平均发送速率作为该节点自身的负载判据(LM)。新协议的路由判据是以上两个判据的加权和。CALBR以路由判据最小为原则选择最佳路径,从而有效的均衡了网络负载,提高了网络资源的利用率。仿真结果显示,新路由协议在网络吞吐量、端到端时延和包投递率等各项网络性能上均有明显的改善。更多还原

【Abstract】 The decentralized nature of wireless ad hoc networks makes them suitable for a variety of applications where there are no central nodes to be relied on. However, while using traditional minimum-hops routing protocols, network traffic load can be unbalanced and centered on some hot areas. When load balancing in wired networks is merely about traffic load on individual nodes, it is more related to the contention between nearby nodes in wireless ad hoc networks. That is because a communication between two wireless nodes can affect the transmission of other nodes nearby. Thus contention as an important factor needs to be included in balancing load over the network.In this thesis, we propose a Contention-Aware Load Balancing Routing protocol, CALBR, which is based on DSR. In our proposed routing protocol, we introduce a routing metric combined by two metrics of a node: Contention Metric (CM) and Load Metric (LM). Channel contention is studied by analyzing the transmission in 802.11 MAC and then a contention evaluating metric, CM, is proposed accordingly. Besides regional contention level between nodes, local traffic also plays an essential part of the whole load of a node. Here, the LM of a node, which is defined as the average sending data rate of the node over a period, is used to represent the local part of traffic load. Based on the two, we then use the integrated routing metric to find better routes to distribute traffic load and improve resource utility. The simulation on ns2 shows that the proposed routing scheme achieves significant improvement of network performance in terms of network throughput, end-to-end delay and packet delivery ratio.更多还原