节点度估计和静态博弈转发策略的Ad Hoc网络路由协议

针对Ad Hoc网络路由发现过程中广播路由请求分组导致的广播风暴问题，提出了一种基于节点度估计和静态博弈转发策略的Ad Hoc网络路由协议NGRP.NGRP考虑边界影响，采用分段函数的思想将网络场景分为中心、边和角区域，分别估算网络中节点在不同区域的节点度，避免了周期性广播Hello消息获取节点度导致的开销；NGRP路由请求分组的转发采用静态博弈转发策略，利用节点度估算参与转发路由请求分组的节点数量，将转发和不转发作为策略集合，设计效益函数，通过纳什均衡获得节点转发路由请求分组的转发概率，从而减少了路由请求分组广播过程中产生的大量的冗余、竞争和冲突，提高了路由发现过程中路由请求分组的广播效率.运用NS-2对协议的性能进行大量的仿真，结果表明：NGRP的分组投递率、路由开销、MAC层路由开销和吞吐率这4项指标明显优于AODV+FDG，AODV with Hello和AODV without Hello协议.     

A learning automata-based fault-tolerant routing algorithm for mobile ad hoc networks

Reliable routing of packets in a Mobile Ad Hoc Network (MANET) has always been a major concern. The open medium and the susceptibility of the nodes of being fault-prone make the design of protocols for these networks a challenging task. The faults in these networks, which occur either due to the failure of nodes or due to reorganization, can eventuate to packet loss. Such losses degrade the performance of the routing protocols running on them. In this paper, we propose a routing algorithm, named as learning automata based fault-tolerant routing algorithm (LAFTRA), which is capable of routing in the presence of faulty nodes in MANETs using multipath routing. We have used the theory of Learning Automata (LA) for optimizing the selection of paths, reducing the overhead in the network, and for learning about the faulty nodes present in the network. The proposed algorithm can be juxtaposed to any existing routing protocol in a MANET. The results of simulation of our protocol using network simulator 2 (ns-2) shows the increase in packet delivery ratio and decrease in overhead compared to the existing protocols. The proposed protocol gains an edge over FTAR, E2FT by nearly 2% and by more than 10% when compared with AODV in terms of packet delivery ratio with nearly 30% faulty nodes in the network. The overhead generated by our protocol is lesser by 1% as compared to FTAR and by nearly 17% as compared to E2FT when there are nearly 30% faulty nodes.     

一种新颖的移动自组网灰洞攻击检测方案

移动自组网(mobile ad hoc networks,MANETs)是典型的分布式网络,没有集中式的管理节点,网络拓扑动态变化,而且网络带宽有限.移动自组网无网络基础设施的特点,使其易于受到各种拒绝服务攻击(denial of service,DoS).灰洞攻击是一种类型的拒绝服务攻击,攻击者在网络状态良好的情况下,首先以诚实的方式参与路由发现过程,然后以不被察觉的方式丢弃部分或全部转发数据包.首先介绍了相关工作、DSR算法、聚合签名算法和网络模型.然后基于聚合签名算法,给出了用于检测丢包节点的3个相关算法:证据产生算法、审查算法和诊断算法.证据产生算法用于节点产生转发证据;审查算法用于审查源路由节点;诊断算法用于确定丢包节点.最后分析了算法的效率.ns-2仿真结果表明,在移动速度中等的网络中,提出的算法可以检测出多数丢包节点,且路由包开销较低.舍弃含丢包节点的路由后,数据发送率有相应的改善.     

双向路径重选的自组网负载均衡路由协议

基于跨层负载感知和双向路径重选的自纽网负载均衡路由协议（CLBLR）在路由发现阶段和路由维护阶段，将整个路径中各节点MAC层的总平均估计时延和路径总业务流负载结合起来，共同作为路由选择和路由调整的重要依据，通过双向路径重选方法实现最优路径选择和网络业务流的均衡分布和均衡传输．协议通过禁止中间节点对路由请求进行应答和阻止不必要的路由请求分组，经由重负载中间节点转发，以保证路由发现时能够利用最新负载信息，并避免了节点在重负载情况下成为新建路由的中间节点，使协议具有一定的拥塞控制功能，以间接的方式实现了请求接纳控制．上述措施使分组传输路由很好地避免了拥塞节点，减少了网络瓶颈对网络性能的影响．仿真表明，CLBLR在分组丢失率、平均端到端时延和路由附加开销等方面具有良好性能，其优良的分布式控制特征能适应自组网的动态环境．     

QoS routing with traffic distribution in mobile ad hoc networks

Mobile ad hoc networks (MANETs) follow a unique organizational and behavioral logic. MANETs’ characteristics such as their dynamic topology coupled with the characteristics of the wireless communication medium make Quality of Service provisioning a difficult challenge. This paper presents a new approach based on a mobile routing backbone for supporting Quality of Service (QoS) in MANETs. In real-life MANETs, nodes will possess different communication capabilities and processing characteristics. Hence, we aim to identify those nodes whose capabilities and characteristics will enable them to take part in the mobile routing backbone and efficiently participate in the routing process. Moreover, the route discovery mechanism we developed for the mobile routing backbone dynamically distributes traffic within the network according to current network traffic levels and nodes’ processing loads. Simulation results show that our solution improves network throughput and packet delivery ratio by directing traffic through lowly congested regions of the network that are rich in resources. Moreover, our protocol incurs lower communication overheads than AODV (ad hoc on-demand distance vector routing protocol) when searching for routes in the network.     

能量驱动的移动Ad Hoc网络概率组播路由协议

在ODMRP协议中，由于采用周期性地广播Join-Query包来更新成员信息和路由信息，因此网络中流动着大量平凡的Join-Query控制包，造成网络开销增大，网络拥塞。采用能量驱动的概率转发的方法，根据每个节点的能量资源信息为每个节点设置相应的转发投递概率，抑制网络中的Join-Query控制包。模拟结果显示，能量驱动的MANET概率组播路由协议(p-ODMRP)在投递率满足需求的情况下，网络的控制开销减小20%左右，增加了网络寿命，协议的综合性能有明显提高。     

Survey of multipath routing protocols for mobile ad hoc networks

This survey investigates multipath routing protocols for mobile ad hoc networks (MANETs). The main objectives of multipath routing protocols are to provide reliable communication and to ensure load balancing as well as to improve quality of service (QoS) of MANETs. These multipath protocols are broadly classified into five categories based on their major goals. The goals are to improve delay, provide reliability, reduce overhead, maximize network life and support hybrid routing. Multipath routing protocols address issues such as multiple paths discovery and maintaining these paths. Issues, objectives, performances, advantages and disadvantages of these protocols are investigated and summarized. A checklist is provided as a guideline so that a network designer can choose an appropriate multipath routing protocol to meet the network's application objectives.     

基于博弈的MANETs信任模型研究

移动Ad-Hoc网络(MANET)是由一组带有无线收发装置的移动节点组成的无须固定设置支持的临时性的通信网络.MANETs具有开放的媒质、动态的拓扑结构、分布式的合作和受限的网络能力等基本特点.在MANETs中,节点之间相互信赖路由和转发数据包,节点间的合作是非常重要的.但是由于自私节点为了储存能量和其他资源,而不参与转发数据.由于MANETs通信没有第3方的中心认证,所以集中于强制合作是不适应的.基于博弈研究MANETs中的节点行为,根据节点的信誉度来获得资源,刺激节点共享资源和转发数据.提出了基于博弈理论的信任模型,鼓励包转发,约束自私节点.仿真结果表明该信任模型能够识别自私节点并且能在信任节点之间建立信任,提高了整个网络效率.     

Prevention of Black Hole Attack in Multicast Routing Protocols for Mobile Ad-Hoc Networks Using a Self-Organized Public Key Infrastructure

ABSTRACT

A mobile ad-hoc network (MANET) is an autonomous system of mobile nodes connected by wireless links in which nodes cooperate by forwarding packets for each other thereby enabling communication beyond direct wireless transmission range. Example applications include battlefield communication, disaster recovery operations, and mobile conferencing. The dynamic nature of ad-hoc networks makes them more vulnerable to security attacks compared with fixed networks. Providing security in mobile ad-hoc networks has been a major issue in recent years. Most of the secure routing protocols proposed by researchers need a centralized authority or a trusted third party to provide authentication. This destroys the self-organizing nature of ad-hoc networks. Black Hole attack is one of the routing attacks that occur in MANETs. In this attack, a malicious node uses the routing protocol to advertise itself as having the shortest path to the node whose packets it wants to intercept. In this article, we propose an enhanced certificate based authentication mechanism, where nodes authenticate each other by issuing certificates to neighboring nodes and generating public key without the need of any online centralized authority. The proposed scheme uses Multicast Ad-hoc On Demand Distance Vector Routing (MAODV) protocol as a support for certification. The effectiveness of our mechanism is illustrated by simulations conducted using network simulator ns-2.