MANET中基于DSR的一种最小能耗路由协议

如何高效地利用无线节点的有限能量是移动Ad Hoc网络(MANET)路由协议的一个重要考虑因素.鉴于动态源路由协议(DSR)没有考虑节点的能量限制,本文基于DSR协议提出了一种节能路由算法:MECP-DSR.它采用每报文能量消耗最小作为路由选取标准,并且在发送数据报文时对节点的发射功率进行控制.该文的仿真结果表明,MECP-DSR大大降低了节点的能量消耗,有效提高了移动Ad Hoc无线网络的生存期.     

Minimum energy hierarchical dynamic source routing for Mobile Ad Hoc Networks

In this paper, Minimum Energy Dynamic Source Routing (MEDSR) and Hierarchical Minimum Energy Dynamic Source Routing (HMEDSR) protocols for Mobile Ad Hoc Networks (MANET) are proposed. The objective of MEDSR protocol is to reduce energy consumption in MANET while maintaining connectivity in the network. The objective of HMEDSR is to reduce the overhead of MEDSR. The overall result is that energy spent in transmitting overhead packets is reduced. This reduction allows more energy in transmitting data packets. The Dynamic Source Routing (DSR) protocol is modified to implement both MEDSR and HMEDSR protocols, and these implementations are tested with a network simulator (Network Simulator (NS-2)). The simulation results show that both MEDSR and HMEDSR protocols reduce energy consumption per data packet by 25% compared to DSR, but HMESDR further reduces energy consumption by 12% compared to MEDSR by controlling overhead packets.     

A dynamic cross-layer routing protocol for Mobile Ad hoc Networks

A new cross-layer routing protocol, named Dynamic Packet Guidance (DPG), is introduced for Mobile Ad hoc Networks (MANETs). Simulation results show that DPG is quite useful for usage in dense networks of mobile nodes, with medium-to-high speeds, and low-to-medium load. In these scenarios, DPG provides a superior performance compared to several well-known ad hoc routing protocols. The low end-to-end delay and smaller overhead that DPG achieves in such scenarios positively impacts the scalability of MANETs and reduces the energy requirements of nodes in such networks. DPG also shows immunity to failing nodes, as it operates consistently almost independently of failing nodes up to a certain ratio.     

移动Ad Hoc网络中的安全问题

移动自组网(Mobile Ad HoC Network)是一种无基础设施的无线网络由于它具有开放的媒质、分布式的合作、动态的拓扑结构和受限的网络能力等特点,所以特别容易受到攻击.为此文章结合移动Ad Hoc网络的特点分析了移动Ad Hoc网络面临的安全威胁,并对移动Ad Hoc网络的安全路由和安全报文传送问题进行了详细讨论.     

一种安全的Ad Hoc On-demand路由协议

由于Ad Hoc网络固有的弱点,设计安全、有效的Ad Hoc路由协议是困难的.本文从新的角度设计了一个简单、安全的On-demand路由协议.在路径请求和响应阶段,源节点和目的节点的身份分别被隐藏,只有那些位于目的节点选择的最优路径上的节点可以获得完整的路由信息,从而产生有效的前向和反向路径.同时,一个公开的单向Hash函数可以利用隐藏的路由信息构建单向Hash链用于路由信息的认证,从而不需要预先的共享密钥.在一次路由计算中,只有源节点和目的节点需要进行一次非对称密码运算.     

Efficient Broadcasting in Mobile Ad Hoc Networks

This paper presents two efficient flooding algorithms based on 1-hop neighbor information. In the first part of the paper, we consider sender-based flooding algorithms, specifically the algorithm proposed by Liu et al. In their paper, Liu et al. propose a sender-based flooding algorithm that can achieve local optimality by selecting the minimum number of forwarding nodes in the lowest computational time complexity O(n logn), where n is the number of neighbors. We show that this optimality only holds for a subclass of sender-based algorithms. We propose an efficient sender-based flooding algorithm based on 1-hop neighbor information that reduces the time complexity of computing forwarding nodes to O(n). In Liu's algorithm, n nodes are selected to forward the message in the worst case, whereas in our proposed algorithm, the number of forwarding nodes in the worst case is 11. In the second part of the paper we propose a simple and highly efficient receiver-based flooding algorithm. When nodes are uniformly distributed, we prove that the probability of two neighbor nodes broadcasting the same messageneighbor nodes broadcasting the same message exponentially decreases when the distance between them decreases or when the node density increases. The analytical results are confirmed using simulation.     

Ad hoc网络中的路由技术

Ad hoc网络是一些移动节点组成一个多跳的临时性无线自治系统，这种新型的通信网络具有动态变化的拓扑结构和分布控制的网络机制。文中针对Ad hoc网络作了简单的介绍并重点介绍了针对Ad hoc网络特性而提出的路由协议。     

Multicast Routing in Mobile Ad Hoc Networks

We focus on one critical issue in mobile ad hoc networks that is multicast routing. Advantages and limitations of existing routing protocols are illustrated. Optimal routes, stable links, power conservation, loop freedom, and reduced channel overhead are the main features to be addressed in a more efficient mechanism. In this paper, we propose a new on-demand multicast routing protocol, named Source Routing-based Multicast Protocol (SRMP). Our proposition addresses two important issues in solving routing problems: (i) path availability concept, and (ii) higher battery life paths. SRMP applies a source routing mechanism, and constructs a mesh to connect group members. It provides stable paths based on links' availability according to future prediction of links' states, and higher battery life paths. This protocol succeeded to minimize network load via designing optimal routes that guarantee reliable transmission and active adaptability. A performance comparison study with On-demand Multicast Routing Protocol (ODMRP) and Adaptive Demand-driven Multicast Routing (ADMR) protocol is undertaken. Analysis results show the strength of the SRMP nodes' selection criteria and its efficient energy consumption compared to the other two protocols.     

一个移动Ad Hoc网络中AODV-HC路由协议

提出了移动Ad Hoc网络中路由协议AODV-HC,该协议通过到目的节点的跳数,在链路中断时,能快速有效地修复路由路径,并通过到基础路径的跳数有效地减少广播风暴.实验结果表明AODV-HC比AODV有较少的平均延时和较少的路径节点跳数.     

Associativity-Based Routing for Ad Hoc Mobile Networks

This paper presents a new, simple and bandwidth-efficient distributed routing protocol to support mobile computing in a conference size ad-hoc mobile network environment. Unlike the conventional approaches such as link-state and distance-vector distributed routing algorithms, our protocol does not attempt to consistently maintain routing information in every node. In an ad-hoc mobile network where mobile hosts (MHs) are acting as routers and where routes are made inconsistent by MHs' movement, we employ an associativity-based routing scheme where a route is selected based on nodes having associativity states that imply periods of stability. In this manner, the routes selected are likely to be long-lived and hence there is no need to restart frequently, resulting in higher attainable throughput. Route requests are broadcast on a per need basis. The association property also allows the integration of ad-hoc routing into a BS-oriented Wireless LAN (WLAN) environment, providing the fault tolerance in times of base stations (BSs) failures. To discover shorter routes and to shorten the route recovery time when the association property is violated, the localised-query and quick-abort mechanisms are respectively incorporated into the protocol. To further increase cell capacity and lower transmission power requirements, a dynamic cell size adjustment scheme is introduced. The protocol is free from loops, deadlock and packet duplicates and has scalable memory requirements. Simulation results obtained reveal that shorter and better routes can be discovered during route re-constructions.     

Explicit Multicasting for Mobile Ad Hoc Networks

In this paper we propose an explicit multicast routing protocol for mobile ad hoc networks (MANETs). Explicit multicasting differs from common approaches by listing destination addresses in data packet headers. Using the explicit destination information, the multicast routing protocol can avoid the overhead of employing its own route construction and maintenance mechanisms by taking advantage of unicast routing table. Our protocol – termed Differential Destination Multicast (DDM) – is an explicit multicast routing protocol specifically designed for MANET environment. Unlike other MANET multicasting protocols, instead of distributing membership control throughout the network, DDM concentrates this authority at the data sources (i.e. senders) thereby giving sources knowledge of group membership. In addition, differentially-encoded, variable-length destination headers are inserted in data packets which are used in combination with unicast routing tables to forward multicast packets towards multicast receivers. Instead of requiring that multicast forwarding state to be stored in all participating nodes, this approach also provides the option of stateless multicasting. Each node independently has the choice of caching forwarding state or having its upstream neighbor to insert this state into self-routed data packets, or some combination thereof. The protocol is best suited for use with small multicast groups operating in dynamic MANET environment.     

Ad Hoc网络的安全机制

移动Ad Hoc网络是一种特殊的多跳移动无线网络,具有广泛的应用场合,其安全问题一直是影响其大规模发展的重要因素。本文探讨了移动Ad Hoc网络特有的各种安全漏洞以及相应的对策中存在的各种不足,并与现有网络中的安全对策进行了较深入的比较,完善了现有体系中的安全机制。     

Internet Connectivity for Ad Hoc Mobile Networks

The growing deployment rate of wireless LANs indicates that wireless networking is rapidly becoming a prevalent form of communication. As users become more accustomed to the use of mobile devices, they increasingly want the additional benefit of roaming. The Mobile IP protocol has been developed as a solution for allowing users to roam outside of their home networks while still retaining network connectivity. The problem with this solution, however, is that the deployment of foreign agents is expensive because their coverage areas are limited due to fading and interference. To reduce the number of foreign agents needed while still maintaining the same coverage, ad hoc network functionality can cooperate with Mobile IP such that multihop routes between mobile nodes and foreign agents can be utilized. In this work, we present a method for enabling the cooperation of Mobile IP and the Ad hoc On-Demand Distance Vector (AODV) routing protocol, such that mobile nodes that are not within direct transmission range of a foreign agent can still obtain Internet connectivity. In addition, we describe how duplicate address detection can be used in these networks to obtain a unique co-located care-of address when a foreign agent is not available.     

移动Ad hoc网络中的密钥管理

首先阐述了移动adhoc网络中密钥管理的重要性,接着探讨了几种密钥管理的方法,包括局部分布式认证授权中心、完全分布式认证授权中心、自发证书、安全Pebblenets、指示性标志、基于口令验证的密钥交换等,并对这些方法进行了较完整的概括总结和深入的比较分析,最后提出了一些研究移动adhoc网络中密钥管理方法所必须注意的问题。     

Ad Hoc网络可靠性评估

针对一种特殊的通信网Ad Hoc网络,提出了一种可靠性评估算法,首先根据物理拓扑抽象出Ad Hoc网络模型,并充分分析Ad Hoc网络特点确定失效判据,依据失效判据进行可靠性建模,选择合适的可靠性模型。将Ad Hoc网络模型划分为逻辑上的一个个子区域,采用层次分析法确定各个子区域的权重系数,在各子区域内,利用最小定点割集确定Ad Hoc网络中的重要节点,同时根据生成树算法确定重要节点的权重系数,从而可以计算出Ad Hoc网络的可靠度。最后通过实例说明某Ad Hoc网络的可靠性评估。     

移动自组织网络中的入侵检测技术

文章介绍了入侵检测技术及其分类,指出了入侵检测技术在移动自组织网络中面临的挑战,提出了一种基于域的移动自组织(Ad Hoc)网络入侵检测系统,并给出了其网络分层结构和代理概念模型.     

Stimulating Cooperation in Self-Organizing Mobile Ad Hoc Networks

In military and rescue applications of mobile ad hoc networks, all the nodes belong to the same authority; therefore, they are motivated to cooperate in order to support the basic functions of the network. In this paper, we consider the case when each node is its own authority and tries to maximize the benefits it gets from the network. More precisely, we assume that the nodes are not willing to forward packets for the benefit of other nodes. This problem may arise in civilian applications of mobile ad hoc networks. In order to stimulate the nodes for packet forwarding, we propose a simple mechanism based on a counter in each node. We study the behavior of the proposed mechanism analytically and by means of simulations, and detail the way in which it could be protected against misuse.     

Dynamic Task-Based Anycasting in Mobile Ad Hoc Networks

Mobile ad hoc networks (MANETs) have received significant attention in the recent past owing to the proliferation in the numbers of tetherless portable devices, and rapid growth in popularity of wireless networking. Most of the MANET research community has remained focused on developing lower layer mechanisms such as channel access and routing for making MANETs operational. However, little focus has been applied on higher layer issues, such as application modeling in dynamic MANET environments. In this paper, we present a novel distributed application framework based on task graphs that enables a large class of resource discovery based applications on MANETs. A distributed application is represented as a complex task comprised of smaller sub-tasks that need to be performed on different classes of computing devices with specialized roles. Execution of a particular task on a MANET involves several logical patterns of data flow between classes of such specialized devices. These data flow patterns induce dependencies between the different classes of devices that need to cooperate to execute the application. Such dependencies yield a task graph (TG) representation of the application.We focus on the problem of executing distributed tasks on a MANET by means of dynamic selection of specific devices that are needed to complete the tasks. In this paper, we present simple and efficient algorithms for dynamic discovery and selection (instantiation) of suitable devices in a MANET from among a number of them providing the same functionality. This is carried out with respect to the proposed task graph representation of the application, and we call this process Dynamic Task-Based Anycasting. Our algorithm periodically monitors the logical associations between the selected devices, and in the event of a disruption in the application owing to failures in any component in the network, it adapts to the situation and dynamically rediscovers the affected parts of the task graph, if possible. We propose metrics for evaluating the performance of these algorithms and report simulation results for a variety of application scenarios differing in complexity, traffic, and device mobility patterns. From our simulation studies, we observed that our protocol was able to instantiate and re-instantiate TG nodes quickly and yielded high effective throughput at low to medium degrees of mobility and not much below 70% effective throughput for high mobility scenarios.     

移动自组网的CARPs协议分析

移动自组网备受关注的同时也暴露了其在某些方面的局限性,尤其是能量、带宽问题,因此有必要设计最佳路由协议来减少能量消耗、缩短路由、限制泛播,介绍了2种自适应的、无链接的路由协议及其子系统。当采用定向天线时,该协议能减少在分组传送过程中涉及的节点数量,因此减少了能量消耗,充分利用带宽。