首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
《Computer Networks》2008,52(5):988-997
A mobile ad-hoc network (MANET) is composed of mobile nodes without any infrastructure. Mobile nodes self-organize to form a network over radio links. The goal of MANETs is to extend mobility into the realm of autonomous, mobile and wireless domains, where a set of nodes form the network routing infrastructure in an ad-hoc fashion. The majority of applications of MANETs are in areas where rapid deployment and dynamic reconfiguration are necessary and wired network is not available. These include military battlefields, emergency search, rescue sites, classrooms and conventions, where participants share information dynamically using their mobile devices. These applications lend themselves well to multicast operations. In addition, within a wireless medium, it is crucial to reduce the transmission overhead and power consumption. Multicasting can improve the efficiency of the wireless link when sending multiple copies of messages by exploiting the inherent broadcast property of wireless transmission. Hence, reliable multicast routing plays a significant role in MANETs. However, to offer effective and reliable multicast routing is difficult and challenging. In recent years, various multicast routing protocols have been proposed for MANETs. These protocols have distinguishing features and employ different recovery mechanisms. To provide a comprehensive understanding of these multicast routing protocols and better organize existing ideas and work to facilitate multicast routing design for MANETs, we present the taxonomy of the multicast routing protocols, their properties and design features. This paper aims to aid those MANETs researchers and application developers in selecting appropriate multicast routing protocols for their work.  相似文献   

2.
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.  相似文献   

3.
Multicast routing in mobile ad hoc networks (MANETs) poses several challenges due to inherent characteristics of the network such as node mobility, reliability, scarce resources, etc. This paper proposes an Agent Based Multicast Routing Scheme (ABMRS) in MANETs, which uses a set of static and mobile agents. Five types of agents are used in the scheme: Route manager static agent, Network initiation mobile agent, Network management static agent, Multicast initiation mobile agent and Multicast management static agent. The scheme operates in the following steps: (1) to identify reliable nodes; (2) to connect reliable nodes through intermediate nodes; (3) to construct a backbone for multicasting using reliable nodes and intermediate nodes; (4) to join multicast group members to the backbone; (5) to perform backbone and group members management in case of mobility. The scheme has been simulated in various network scenarios to test operation effectiveness in terms of performance parameters such as packet delivery ratio, control overheads and group reliability. Also, a comparison of proposed scheme with MAODV (Multicast Ad hoc on-demand Distance Vector) protocol is presented. ABMRS performs better than MAODV as observed from the simulation. ABMRS offers flexible and adaptable multicast services and also supports component based software development.  相似文献   

4.
研究航天器部署在火星表面的无线传感器节点,首次提出了外层空间无线传感器网络(outer space wireless sensor network,OSWSN)的概念,指出该网络的节点以自组织方式组网。基于已有的地面无线传感器网络经典组播路由协议,结合无线自组织网络组播协议建树思想,设计应用于外层空间无线传感器网络的OSWSNMP(OSWSN multicast protocol)。与已有的MAODV组播路由协议以及应用于地面无线传感器网络的EMRS组播路由协议进行比较,在NS2上搭建OSWSNMP仿真环  相似文献   

5.
移动Ad Hoc网络(MANET)的路由协议对网络的性能有较大影响,尤其在多播的场景下,好的多播路由协议可以节省大量无线传输带宽。MAODV路由协议是在AODV路由协议的基础上进行的多播扩展,也是目前MANET网络多播路由协议的研究热点。通过使用OPNET网络仿真软件,对MAODV协议进行仿真建模,使OPNET在MANET场景下支持多播路由协议的仿真,为其它需要MANET网络多播路由协议的场景提供支持。对仿真建模的结果进行了多方面的验证,以保证建模的正确性和有效性。  相似文献   

6.
A mobile ad hoc network (MANET) is a collection of mobile hosts that form a temporary network on the fly without using any fixed infrastructure. Recently, the explosive growth in the use of real-time applications on mobile devices has resulted in new challenges to the design of protocols for MANETs. Chief among these challenges to enable real-time applications for MANETs is incorporating support for quality of service (QoS), such as bandwidth constraints. However, MANETs having a high ratio of topology change make routing especially unstable; making stability is an important challenge, especially for routing having a quality of service provision. In this paper, we propose a reliable multi-path QoS routing (RMQR) protocol with a slot assignment scheme. In this scheme, we examine the QoS routing problem associated with searching for a reliable multi-path (or uni-path) QoS route from a source node to a destination node in a MANET. This route must also satisfy certain bandwidth requirements. We determine the route expiration time between two connected mobile nodes using global positioning system (GPS). Then, two parameters, the route expiration time and the number of hops, are used to select a routing path with low latency and high stability. Simulation results show that the proposed RMQR protocol have some outstanding properties when compared with Lin's [Lin C-R. On-demand QoS routing in multihop mobile networks. In: Proceedings of the twentieth annual joint conference of the IEEE computer and communications societies (INFOCOM), vol. 3(22–26), 2001, p. 1735–44], Liao's [Liao W-H, Tseng Y-C, Wang S-L, Sheu J-P. A multi-path QoS routing protocol in a wireless mobile Ad Hoc network. Telecommunication Systems 2002;19(3–4):329–47], and Chen's [Chen Y-S, Tseng Y-C, Sheu J-P, Kuo P-H. An on-demand, link-state, multi-path QoS routing in a wireless mobile Ad-Hoc network. Computer Communications 204;27(1):27–40] protocols.  相似文献   

7.
基于MAODV多播路由协议的改进协议   总被引:2,自引:1,他引:1  
MANET(移动自主网)是由一组带有无线收发装置的移动终端组成的一个多跳的临时性自治系统,网络中的节点互相通信而不依赖于预先架设的固定基础设施,在军用和紧急救援等特殊环境的应用前景非常广阔。多播是有利于成员组通信的方式,高效的多播路由是MANET网络多播路由的主要难题。文章在MAODV的基础上,提出了基于GroupH ello(GRPH)消息机制、路由发现和路由维护的MAODV多播路由协议的改进协议,仿真实验显示改进后的协议减少了开销、降低了时延,在高动态的网络中尤为明显。  相似文献   

8.
The group-oriented services are one of the primary application classes that are addressed by Mobile Ad hoc Networks (MANETs) in recent years. To support such services, multicast routing is used. Thus, there is a need to design stable and reliable multicast routing protocols for MANETs to ensure better packet delivery ratio, lower delays and reduced overheads. In this paper, we propose a mesh based multicast routing scheme that finds stable multicast path from source to receivers. The multicast mesh is constructed by using route request and route reply packets with the help of multicast routing information cache and link stability database maintained at every node. The stable paths are found based on selection of stable forwarding nodes that have high stability of link connectivity. The link stability is computed by using the parameters such as received power, distance between neighboring nodes and the link quality that is assessed using bit errors in a packet. The proposed scheme is simulated over a large number of MANET nodes with wide range of mobility and the performance is evaluated. Performance of the proposed scheme is compared with two well known mesh-based multicast routing protocols, i.e., on-demand multicast routing protocol (ODMRP) and enhanced on-demand multicast routing protocol (EODMRP). It is observed that the proposed scheme produces better packet delivery ratio, reduced packet delay and reduced overheads (such as control, memory, computation, and message overheads).  相似文献   

9.
This paper proposes an efficient anonymous routing protocol for mobile ad hoc networks (MANETs). This protocol considers symmetric and asymmetric links during the wireless communication of MANETs. A MANET is one type of self-organized wireless network that can be formed by several wireless devices such as laptops, tablet PCs, and smartphones. Different wireless transmission ranges of different mobile devices lead to a special communication condition called an asymmetric link. Most research on this topic focuses on providing security and anonymity for the symmetric link without considering the asymmetric link. This paper proposes a novel distributed routing protocol beyond the symmetric and asymmetric links. This protocol guarantees the security, anonymity, and high reliability of an established route by avoiding unreliable intermediate nodes. The routes generated by the proposed protocol are shorter than previous research. The proposed protocol enhances MANET performance in assuring security and anonymity.  相似文献   

10.
Due to mobility of wireless hosts, routing in mobile ad-hoc networks (MANETs) is a challenging task. Multipath routing is employed to provide reliable communication, load balancing, and improving quality of service of MANETs. Multiple paths are selected to be node-disjoint or link-disjoint to improve transmission reliability. However, selecting an optimal disjoint multipath set is an NP-complete problem. Neural networks are powerful tools for a wide variety of combinatorial optimization problems. In this study, a transient chaotic neural network (TCNN) is presented as multipath routing algorithm in MANETs. Each node in the network can be equipped with a neural network, and all the network nodes can be trained and used to obtain optimal or sub-optimal high reliable disjoint paths. This algorithm can find both node-disjoint and link-disjoint paths with no extra overhead. The simulation results show that the proposed method can find the high reliable disjoint path set in MANETs. In this paper, the performance of the proposed algorithm is compared to the shortest path algorithm, disjoint path set selection protocol algorithm, and Hopfield neural network (HNN)-based model. Experimental results show that the disjoint path set reliability of the proposed algorithm is up to 4.5 times more than the shortest path reliability. Also, the proposed algorithm has better performance in both reliability and the number of paths and shows up to 56% improvement in path set reliability and up to 20% improvement in the number of paths in the path set. The proposed TCNN-based algorithm also selects more reliable paths as compared to HNN-based algorithm in less number of iterations.  相似文献   

11.
可扩展的MAODV协议   总被引:2,自引:2,他引:2  
周舜  张信明  麻俊  陈国良 《计算机工程》2005,31(18):96-98,101
随着近年来人们对移动Ad hoc网络和多播兴趣的日益增加,出现了许多适用于MANET上的多播路由协议.该文综述了这些移动Ad hoc网络上的多播协议,介绍了MAODV协议,提出了一种新的多播路由可扩展性解决方案.模拟结果显示,采用提出的技术增强了多播路由协议的性能和可扩展性.  相似文献   

12.
In this paper, the problem of dynamic quality-of-service (QoS) multicast routing in mobile ad hoc networks is investigated. Lots of interesting works have been done on multicast since it is proved to be a NP-hard problem. However, most of them consider the static network scenarios only and the multicast tree cannot adapt to the topological changes. With the advancement in communication technologies, more and more wireless mobile networks appear, e.g., mobile ad hoc networks (MANETs). In a MANET, the network topology keeps changing due to its inherent characteristics such as the node mobility and energy conservation. Therefore, an effective multicast algorithm should track the topological changes and adapt the best multicast tree to the changes accordingly. In this paper, we propose to use genetic algorithms with immigrants schemes to solve the dynamic QoS multicast problem in MANETs. MANETs are considered as target systems because they represent a new generation of wireless networks. In the construction of the dynamic network environments, two models are proposed and investigated. One is named as the general dynamics model in which the topologies are changed due to that the nodes are scheduled to sleep or wake up. The other is named as the worst dynamics model, in which the topologies are altered because some links on the current best multicast tree are removed. Extensive experiments are conducted based on both of the dynamic network models. The experimental results show that these immigrants based genetic algorithms can quickly adapt to the environmental changes (i.e., the network topology changes) and produce high quality solutions following each change.  相似文献   

13.
Mobile Ad hoc Networks (MANETs) are self-organized and fully distributed networks that rely on the collaboration of participating devices to route data from source to destination. The MANET paradigm is expected to enable ubiquitous mobile communication and thus the proliferation of pervasive applications. The MANET Working Group (WG) of the Internet Engineering Task Force (IETF) is responsible for standardizing an appropriate Internet Protocol (IP) based routing protocol functionality for both static (mesh) and dynamic (mobile) wireless ad hoc network topologies. In this paper, we provide a background on the possibility to use MANETs for enabling future pervasive internet and innovative ubiquitous services. We also describe the work achieved by the MANET WG thus far on the area of secure unicast and multicast routing for MANETs. We also examine non-IETF work on this area, chiefly based on adaptive and hybrid routing. The paper then presents comparative performance evaluations of discussed routing protocols. It is mainly observed that there is a need for adaptive hybrid routing approaches in order to support future innovative and pervasive applications. Consequently, we present our conclusions.  相似文献   

14.
陈华 《计算机工程》2007,33(6):158-160
描述了一种在Ad Hoc网络中基于熵度量的MAODV协议(EMAODV),提出了衡量路径稳定性的新尺度——熵,利用熵的度量来选择长寿的、稳定的路径,减少了重构路由的次数,在Ad Hoc网络的网络拓扑频繁变化的环境中较好地提供QoS保证。仿真实验结果表明,EMAODV协议快速有效,具有较高的可靠性。EMAODV协议为动态Ad Hoc网络的建立和评价稳定的路径提供了一种新的有效 途径。  相似文献   

15.
16.
Mobile ad-hoc network (MANET) has got tremendous success and attention due to its self-maintenance and self-configuration properties or behavior. Based on wired and wireless networks, the network topology of MANETs changes rapidly by means of routing attacks. Hence, providing security to this infrastructure-less network is a major issue. The routing protocols for ad-hoc networks cope well with the dynamically changing topology but are not designed to accommodate defense against malicious attacker. Malicious nodes have opportunities to modify or discard routing information or advertise fake routes to attract user data to go through themselves. In this article, we discuss a hybrid technique using anonymity, one-way trapdoor protocol, hash functions, and elliptic curve cryptographic to mitigate attacks in the MANET. The simulation is carried on NS-2 and the simulation results are dissected on different system execution measurements, for example, packet send and received, packet dropped, average network throughput, end-to-end delay, and packet delivery ratio.  相似文献   

17.
A trend in future 4G wireless networks is the integration of MANETs into all-IP systems, which may enhance the flexibility and pervasiveness of 4G networks. One of the most crucial challenges in this field is the design of Protocol Interoperability to achieve the integration of MANET routing protocols and Mobile IP into the IP routing systems. This problem has not been effectively addressed by researches published thus far. This paper contributes solutions to solving this challenge. The protocol architecture and protocol interfaces are designed, which are suitable for gateways and mobile nodes in such Internet integrated MANETs supporting Mobile IP. Propagation methods of Mobile IP signalling messages with MANET routing information piggybacking are designed. Finally, an enhanced Mobile IP protocol suitable for MANET system is contributed. In summary, the contribution of this paper is a thorough scheme for establishing an IP/MIP/MANET integrated system.  相似文献   

18.
19.
Identity-Based cryptography has been proposed in mobile ad-hoc networks (MANETs) to provide security. However, the figure of the Private Key Generator (PKG) is not adequate in the MANET setting, since it may not be reachable by all nodes, can fail during the life-time of the protocol or can even be attacked, compromising the whole system. Previous works distribute the task of the PKG among a set of nodes by means of a secret sharing scheme.In this paper we propose an efficient solution to emulate in a dynamic and distributed way the role of the PKG in so that even new nodes joining the network are able to issue shares of the master key of an Identity-Based scheme. In this way, the distributed PKG spreads dynamically among the nodes as the network increases. Furthermore, the techniques we propose may be suitable for other protocols over MANETs.  相似文献   

20.
Multi-hop wireless networks, such as sensor-, ad hoc- and mesh-nets, can be differentiated in terms of participating devices and usage scenarios. However they share strong characteristics and requirements, such as node cooperation to enable multi-hop forwarding and dynamic routing protocols to deliver packets. As a result of these similarities, protocols designed for all these wireless networks revolve around a common core of functionality, for example coping with link and node dynamics. They differ only in additional network-specific functionality, such as tree routing structures in sensornets, and parameterization, for example buffer sizes.This convergence of functionality and design goals, as well as the sheer number of proposed protocols in each network class, motivates the idea of applying protocols to more than just their one original class. However, network-layer protocols are usually developed for and tested in only one class of wireless network due to the lack of a platform that allows testing of protocols across different classes of networks. As a result, we unnecessarily constrain the range of settings and scenarios in which we test network protocols.In this article, we propose a platform for protocol testing and evaluation in multiple, heterogeneous networks and discuss the requirements and challenges of such a solution. As a first step and case study, we present the detailed architecture of TinyWifi, a platform for executing native sensornet protocols on Linux-driven wireless devices as found in wireless mesh and mobile ad-hoc networks (MANETs). TinyWifi builds on nesC code base that abstracts from TinyOS and enables the execution of nesC-based protocols in Linux. Using this abstraction, we expand the applicability and means of protocol execution from one class of wireless network to another without re-implementation. We demonstrate the generality of TinyWifi by evaluating four well-established protocols on IEEE 802.11 and 802.15.4 based testbeds using a single implementation. Based on the experience of building TinyWifi and the presented evaluation, we deduce the feasibility of a cross-network evaluation platform and sketch the requirements for inclusion of further network classes.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号