【作者】 张海军；

【导师】 蔡开裕；

【作者基本信息】 国防科学技术大学 ， 计算机技术， 2009， 硕士

【摘要】 无线Mesh网是一种高速率、高容量的多点对多点网络,由于具有不需要集中式的网络管理和基础设施等显著特点,无线Mesh网在近年来受到越来越多的关注。无线Mesh网灵活的网络结构、便利的网络配置和高效的容错能力等特性正好符合应急指挥网络的需求。应急指挥Mesh网络(Emergency Command Mesh Network)是政府机关应对紧急事件,应准备发展的新一代应急指挥通信网络,它是在传统无线Mesh网络(WMN,Wireless Mesh Network)的基础上发展而来的。本文对应急指挥Mesh网络信道分配技术进行了研究。多接口多信道技术是当前WMN中的研究热点,利用多接口多信道的通信方式可以大大提高网络的整体性能。但是多接口多信道技术的应用,也为研究工作带来了许多新问题。例如,多接口多信道的WMN容易受到来自外界或网络内部其它相同频率信道的无线干扰,导致网络吞吐量和稳定性的大幅度下降。如何有效的进行信道分配以减小这种干扰,已经成为当前WMN研究的关键技术之一,同时也是应急指挥Mesh网络研究的重点。目前,国内外在多信道分配问题上已有了一些研究成果,但是它们大多是为商用WMN而设计的,不能满足应急指挥Mesh网络的需求。本文针对应急指挥Mesh网络的特点,首先对集中式干扰感知的信道分配算法进行了改进,采用高通信量链路干扰最小的原则,提出了通信量优先信道分配-I模型及算法;其次,在此基础上,结合链路最小冲突的思想,提出了通信量优先信道分配-II模型及算法;再次,又在充分考虑网络通信量变化和信道切换接口数量两个因素对网络性能影响的基础上,给出了一个信道重分配度量准则,以配合信道分配算法的工作;最后,本文用NS-2仿真软件从五个方面进行了仿真。结果表明,本文提出的信道分配算法和信道重分配度量准则对应急指挥Mesh网络的吞吐量和稳定性有较大程度的提升,适用于应急指挥Mesh网络。更多还原

【Abstract】 Wireless Mesh network is a high-rate, high-capability and multi-point to multi-point network. Wireless Mesh network is received more and more attention due to their characters of no network administration and infrastructure. The characters of flexible structure, convenient configuration and efficient fault-tolerance capacity in wireless Mesh network accord with the requirements of wireless communication to the tasks of Goermnt well. Emergency Command Mesh Network is a new generation communication network which is designed for the actual demand of Govermnt e. It evolves from the traditional Wireless Mesh Network. The research of this paper is based on the Research on the Key Technology of Emergency Command Mesh Network.At present, the technology of multi-interface and multi-channel is a focus of WMN. Some studies indicate that the technology of multi-interface and multi-channel can improve the performance of the network greatly. With the application of this technology, there are some new problems in the research of WMN. For example, WMN with multi-interface and multi-channel is prone to be interfered by other same frequency channel inside or outside the network, which reduces throughput and stability of the network greatly. How we can effectively assign channels, which can reduce the interference, has already become a key technology of WMN and Emergency Command Mesh Network.Now, there are some researches on channel assignment. But they are not suitable for Emergency Command Mesh Network.Firstly, aiming at the quality of Emergency Command Mesh Network, this paper improves the Interference-Aware Channel Assignment in Multi-Radio Wireless Mesh Networks. In view of the principle that there should be minimum interference in high traffic link, we propose Traffic First Search Channel Assignment-I channel assignment model and algorithm. Secondly, based on Traffic First Search Channel Assignment-I channel assignment model, combining with the thinking of minimum link interference, we propose Traffic First Search Channel Assignment- II channel assignment model and algorithm. Thirdly, after fully thinking of the influence of two factors (the changing traffic of the network and the number of switching channel), we propose a measuring criterion of channel assignment which cooperates with the work of the two algorithms. Finally, we simulate them in NS-2 (Net Simulator 2). The result indicates that the two algorithms and measuring criterion of channel assignment can promote the throughput and stability of Emergency Command Mesh Network to some extent. They are suitable for Emergency Command Mesh Network.更多还原