【作者】 胡鹏；

【导师】 洪佩琳；

【作者基本信息】 中国科学技术大学 ， 通信与信息系统， 2006， 博士

【摘要】 无线自组网是一种特殊结构的无线通信网络，其通信依靠节点之间的相互协作，以无线多跳方式完成，因此网络不依赖于任何固定设施，具有自组织和自管理的特性。这种特殊的组网方式使得无线自组网不仅适用于军用通信，也适用于环境监测、灾后现场临时通信等民用通信领域。然而，动态的网络拓扑给无线自组网的路由设计提出了严峻的挑战。论文分别对与路由相关的无线自组网路由协议、邻居管理和节能算法等问题展开深入分析和探讨，主要研究贡献归纳如下： 第二章在深入分析IEEE 802.11协议从单跳到多跳时遇到的问题的基础上，提出了一种容忍链路丢失的基于优先级转发的路由协议PBF(Priority-Based Forwarding)。PBF利用了概率路由的思想，根据无线信号的实时传播情况与分组中预定的候选转发节点集，动态选择下一跳节点，减轻了链路丢失对路由协议的影响。PBF的主要特点之一是利用先验的参考路径，简化了候选转发节点集的操作，因而具有良好的可扩展性。PBF还提出了“路由救助”(route salvage)的思路，即在所有候选转发节点都没收到分组的时候，满足特定条件的第三方节点可以主动承担分组转发。模拟实验表明，相比于其他常见的路由算法，PBF能够产生较好的吞吐量与时延特性。 第三章介绍了自组网中的邻居模型，针对当前较为实用的单接口多信道自组网邻居管理展开研究，首先在建立数学模型的基础上提出了适用于网络初始化阶段的基于公共信道模型的随机邻居发现协议RND(Random Neighbor Discovery)及其两个扩展算法：DPF(Discovery Probability First)与WTF(Working Time First)。类似于Birthday协议对单信道邻居发现的建模，RND及其扩展算法对基于时隙的多信道网络设置发送与接收概率，使得邻居可以在较小的时间与操作开销下有效发现。模拟实验结果与两个扩展算法的理论／数值解基本吻合。第三章还针对通用的多信道网络模型，提出一种基于多重公告的邻居管理机制MANM(Multiple Announcement Neighbor Management)。MANM机制通过周期遍历所有信道，并在每个信道中发送公告消息，实现不同信道的邻居节点间的相互发现、删除等管理和维护操作。MANM首次提出了跨信道的邻居管理概念，并定义其具体的操作规范。理论分析和模拟实验都验证了MANM简单高效的管理方式使其在不影响自组网业务的前提下，实现了尽可能完全的邻居管理。 第四章在研究现有的基于节点休眠的节能算法基础上，揭示了现有休眠算法对网络中的路由考虑不足的问题，并提出一种联合考虑路由转发与拓扑管理的节能算法JRT(Joint Routing and Topology management)。该算法通过将按需路由协议的路由操作与休眠调度联合考虑，增加了节点对网络业务的预知。为了克服节点休眠可能造成的网络分割，JRT还包括一种保守的局部分割避免算法。JRT协议以休眠节能为动机，在路由转发和拓扑管理两个因素的共同制约下实施休眠调度。理论分析和模拟实验的结果表明JRT使得网络在不降低服务能力的情况下，产生较好的节能效率。 随着自组网规模的扩大，使用枯燥繁琐的IP地址标识节点不利于开展上层应用，同时，随着无线自组网在与因特网的交互，节点有必要理解Internet中的普遍存在的域名概念。虽然DNS在固定网络中是路由之上的协议，但是其在按需自组网中的工作模式与路由协议相当类似。基于这个现象的发现和分析，本论文第五章中提出了一种支持域名解析功能的按需路由协议RXDN(Routing Extension by Domain Name)。RXDN将路由发现过程扩展了域名解析的功能，与直接更多还原

【Abstract】 A wireless ad hoc network is a special structure of the wireless communications network, in which the communications between the nodes rely on mutual collaboration in wireless multi-hop manner, and therefore the network is self-organized and self-managed without any infrastructure. The special type of networking makes wireless ad hoc networks not only applicable to military communications, but also useful for areas like environment monitoring, disaster rescue and etc. However, the dynamic network topology poses severe challenges to the design of routing protocols. Focused on the ad hoc routing, this paper discussed and analyzed the problems of routing protocol, neighbor management as well as energy-efficient algorithm and other related areas. The major contributions of this thesis are listed as follows:Chapter II presented the in-depth analysis of IEEE 802.11 from single-hop to multi-hop, then proposed a linkloss-tolerant Priority-Based Forwarding (PBF). Exploiting the idea of opportunistic routing, PBF selects the next hop on-the-fly based on both the realtime propagation instance and a predefined list of candidate forwarders, thereby reducing the influence of link loss on the routing protocols. One of the main features of PBF is to simplify the process of the list of candidate forwarders by utilizing of reference path generated previously by routing protocols, and therefore PBF exhibits more scalability. Route salvage is the other method of PBF. PBF allows some third-party node which meets the need of several demands take the responsibility of current packet forwarding while the packet is not received by all the candidates. Simulation results showed that PBF produced better throughput and delay than other common routing protocols.Chapter III introduced the neighbor model of ad hoc networks, targeted for the neighbor discovery in the general single-radio multi-channel ad hoc networks. Based on the mathematics model, this chapter proposed a Random Neighbor Discovery (RND) protocol which is adaptive to the common channel model, and two extended algorithms: DPF (Discovery Probability First) and WTF (Working Time First). Being similar to the model of Birthday protocols in single-channel environment, RND and its two extended algorithms, configure the transmitting and listening probability such that neighbor discovery can be performed at the low cost of time and operation. Simulation results were consistented with the theoretical calculation. Considering the neighbor management in general network model, we also proposed a Multiple-Announcement Neighbor Management (MANM) method. With MANM, each node generates multiple announcements including its neighbor and channel information, and periodically broadcastes each announcement in corresponding channel such that all the neighbors on all channels can collect the neighborhood information. Analysis and simulation results indicated that MANM is a promising method for discovering multi-channel neighbors as well as an extensible platform which provided basic support for various services in multi-channel ad hoc networks.In Chapter IV the study of existing energy-efficient algorithms based on the node sleep revealed the shortage consideration on routing algorithms for network, and proposed JRT (Joint Routing and Topology management). JRT promoted the prediction of traffic by conbine the on-demand routing protocol with node sleep. A conservative local-partition-avoiding method was introduced in JRT in order to keep the global connectivity of ad hoc networks. Motivated by energy-effiency, JRT scheduled node states under the condition of routing and topology management. Theoretical analysis and simulation results showed that JRT enhanced the effiency of energy-saving without degrading the capability of network services.Domain Name System from traditional Internet can not work well in Mobile Ad Hoc Network due to its lack of fixed infrastructure. This problem becomes more serious with the integration of ad hoc networks and Internet. Chapter V focused the on-demand Mobile Ad Hoc Network as the research object and更多还原