无线Mesh应急通信网络的TDMA MAC协议研究
发布时间：2018-08-25 16:06
【摘要】：无线网格网(Wireless Mesh Networks,WMN)是由一组带有无线收发设备的通信节点组成,拥有动态自配置、自组织和自修复功能的分布式网状网络。应急通信网络作为WMN的一种典型应用,在面对重大事故或灾难后的紧急救援中发挥着至关重要的作用。然而,现有关于WMN MAC协议研究及实现主要集中在基于IEEE 802.11s的竞争接入协议,该方案存在着资源利用率低、时延大、跳数小等诸多问题。为解决上述问题,本文研究了基于调度的信道接入机制,设计与实现了集中式和分布式两种基于分配的WMN MAC协议。首先,针对跳数较少的小规模WMN设计了集中式的MAC协议。为提高信道资源的利用效率,本协议中采用了紧凑的时隙结构和时隙分配方案。网络中处于主控地位的基站节点根据本节点及所有其它从节点的业务需求,以一个OFDM符号块为单位动态的分配全网各节点的传输时间。文章详细描述了所设计的集中式WMN MAC协议的帧结构以及节点入网、节点离网、时钟同步、带宽请求分配和差错控制等协议运行过程,并在硬件平台上实现验证了所设计协议的有效性。由于集中式MAC在WMN跳数增多时存在较大的控制时延,本论文针对大规模WMN设计了一种分布式的MAC协议。相对于集中式WMN MAC协议而言,分布式WMN MAC协议中所有节点的地位对等,不存在一个主控的基站节点来管理全网的时隙分配。针对该网络拓扑结构,本文提出了一种分布式时隙分配算法,各节点根据两跳邻节点关系动态地分配时隙。该算法不受网络规模限制且能更快的适应网络拓扑结构的变化。最后,论文在OPNET仿真平台上从网络模型、节点模型和进程模型三个层次模拟了所设计的分布式WMN MAC协议。仿真结果表明所提算法比IEEE 802.11s、固定分配的时隙分配两种算法拥有更高的吞吐量以及更小的时延。
[Abstract]:Wireless Grid Network (Wireless Mesh Networks,WMN) is a distributed mesh network which is composed of a set of communication nodes with wireless transceiver devices and has the functions of dynamic self-configuration self-organization and self-repair. As a typical application of WMN, emergency communication network plays an important role in emergency rescue after major accidents or disasters. However, the current research and implementation of WMN MAC protocol mainly focus on the competitive access protocol based on IEEE 802.11s, which has many problems, such as low resource utilization, large delay, small hops and so on. In order to solve the above problems, this paper studies the channel access mechanism based on scheduling, and designs and implements two distribution-based WMN MAC protocols, centralized and distributed. Firstly, a centralized MAC protocol is designed for small scale WMN with fewer hops. In order to improve the efficiency of channel resource utilization, a compact slot structure and slot allocation scheme are adopted in this protocol. In the network, the base station nodes in the main control position dynamically allocate the transmission time of each node in the whole network according to the service requirements of the node and all other slave nodes, and take a OFDM symbol block as the unit. This paper describes in detail the frame structure of the centralized WMN MAC protocol and the running process of the protocols, such as node access, node off-network, clock synchronization, bandwidth request allocation and error control. The validity of the designed protocol is verified on the hardware platform. Due to the large control delay of centralized MAC when the number of WMN hops increases, this paper designs a distributed MAC protocol for large-scale WMN. Compared with centralized WMN MAC protocol, all nodes in distributed WMN MAC protocol have equal status, and there is no one master base station node to manage the time slot allocation of the whole network. For the topology of the network, a distributed slot allocation algorithm is proposed, in which each node dynamically allocates time slots according to the two-hop neighbor node relationship. The algorithm is not limited by the network size and can adapt to the network topology changes more quickly. Finally, the distributed WMN MAC protocol is simulated on the OPNET platform from three levels: network model, node model and process model. Simulation results show that the proposed algorithm has higher throughput and lower delay than IEEE 802.11s.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN915.04
本文编号：2203427
[Abstract]:Wireless Grid Network (Wireless Mesh Networks,WMN) is a distributed mesh network which is composed of a set of communication nodes with wireless transceiver devices and has the functions of dynamic self-configuration self-organization and self-repair. As a typical application of WMN, emergency communication network plays an important role in emergency rescue after major accidents or disasters. However, the current research and implementation of WMN MAC protocol mainly focus on the competitive access protocol based on IEEE 802.11s, which has many problems, such as low resource utilization, large delay, small hops and so on. In order to solve the above problems, this paper studies the channel access mechanism based on scheduling, and designs and implements two distribution-based WMN MAC protocols, centralized and distributed. Firstly, a centralized MAC protocol is designed for small scale WMN with fewer hops. In order to improve the efficiency of channel resource utilization, a compact slot structure and slot allocation scheme are adopted in this protocol. In the network, the base station nodes in the main control position dynamically allocate the transmission time of each node in the whole network according to the service requirements of the node and all other slave nodes, and take a OFDM symbol block as the unit. This paper describes in detail the frame structure of the centralized WMN MAC protocol and the running process of the protocols, such as node access, node off-network, clock synchronization, bandwidth request allocation and error control. The validity of the designed protocol is verified on the hardware platform. Due to the large control delay of centralized MAC when the number of WMN hops increases, this paper designs a distributed MAC protocol for large-scale WMN. Compared with centralized WMN MAC protocol, all nodes in distributed WMN MAC protocol have equal status, and there is no one master base station node to manage the time slot allocation of the whole network. For the topology of the network, a distributed slot allocation algorithm is proposed, in which each node dynamically allocates time slots according to the two-hop neighbor node relationship. The algorithm is not limited by the network size and can adapt to the network topology changes more quickly. Finally, the distributed WMN MAC protocol is simulated on the OPNET platform from three levels: network model, node model and process model. Simulation results show that the proposed algorithm has higher throughput and lower delay than IEEE 802.11s.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN915.04
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1 范雯琦;无线Mesh应急通信网络的TDMA MAC协议研究[D];国防科学技术大学;2014年
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