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1.
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   

2.
Logarithmic Store-Carry-Forward Routing in Mobile Ad Hoc Networks   总被引:7,自引:0,他引:7  
Two schools of thought exist in terms of handling mobility in mobile ad hoc networks (MANETs). One is the traditional connection-based model, which views node mobility as undesirable and tries to either remove (through recovery schemes) or mask (through tolerant schemes) the effect of mobility. The other is the mobility-assisted model, which considers mobility as a desirable feature, where routing is based on the store-carry-forward paradigm with random or controlled movement of mobile nodes (called ferries). It is well known that mobility increases the capacity of MANETs by reducing the number of relays in routing. Surprisingly, only two models, diameter hop count in the connection-based model and constant hop count in the mobility-assisted model, which correspond to two extremes of the spectrum, have been systematically studied. In this paper, we propose a new routing model that deals with message routing, as well as trajectory planning, of the ferries that carry the message. A logarithmic number of relays are enforced to achieve a good balance among several contradictory goals, including increasing network capacity, increasing ferry sharing, and reducing moving distance. The model considers the dynamic control of ferries in terms of the number of ferries, trajectory planning of ferries, and node communication and synchronization. The effectiveness of the proposed model is evaluated analytically, as well as through simulation  相似文献   

3.
ABSTRACT

Security is an essential service for mobile network communications. Routing plays an important role in the security of mobile ad-hoc networks (MANETs). A wide variety of attacks targets the weakness of MANETs. By attacking the routing protocols, attackers can absorb network traffic, injecting themselves into the path between the source and destination. The black hole attack is one of the routing attacks where a malicious node advertise itself as having the shortest path to all nodes in the network by sending fake route reply. In this paper, a defense scheme for detecting black hole node is proposed. The detection is based on the timing information and destination sequence numbers maintained in the Neighborhood Route Monitoring Table. The table maintains the record of time of Reply. A black hole node will send a route reply message without checking the routing table as the legitimate node normally does. This reduced reply time is used to detect the black hole node. To improve the security further, the destination sequence number is checked with the threshold value, which is dynamically updated. The simulation results demonstrate that the protocol not only detects black hole attack but also improves the overall performance.  相似文献   

4.
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   

5.
The mobile ad-hoc network is well studied on the routing issues, and the security constraints around achieving higher quality of service (QoS) values are well analyzed. The main task is to establish the path to the target with reliable intermediate nodes based on quality parameters because of the lack of node mobility and central management. In a multi-constrained QoS issuance, more than the QoS requirements must be satisfied at the end of the application. There are several secure routing protocols available to improve the QoS of Manet by routing packets securely. However, they do not meet the performance requirements. To solve this problem, and efficient Multi-Constrained Network Feature Approximation (MCNFA) technique is proposed based on safe routing. The method first determines the list of paths between source and destination. According to that, the method approximates the congestion, latency, and hop count values for each route. According to the value obtained in approximation of various parameters, the legitimate weight is computed for all the routes towards the destination. According to the value of the legitimate weight, a single route is selected to perform data transmission. The MCNFA approach improves the routing performance and increases the throughput ratio and other QoS factors. The performance of the proposed method will be assessed using NS2 simulation. The results show that the proposed scheme can maintain a longer network lifecycle in tight scenarios suitable for delay-tolerant networking. The performance is compared with energy recognition and MCNFA technique-based energy-saving routing protocols in various QoS scenarios.  相似文献   

6.
Mobile Ad Hoc Networks (MANETs), which provide data networking without infrastructure, represent one kind of wireless networks. A MANET is a self-organizating and adaptive wireless network formed by the dynamic gathering of mobile nodes. Due to the mobility of mobile nodes, the topology of a MANET frequently changes and thus results in the disability of originally on-the-fly data transmission routes. The dynamic properties of MANETs are therefore challenging to protocol design. To cope with the intrinsic properties of MANETs, Dynamic Backup Routes Routing Protocol (DBR2P), a backup node mechanism for quick reconnection during link failures, is proposed in this paper. DBR2P is an on-demand routing protocol and it can set up many routes to reach a destination node in a given period. Even when a link fails, those routes from the source node to the destination node can be analyzed to obtain backup routes to sustain quick reconnection. The information of backup routes can be saved in a specific on-the-route node and enables backup routes to be found immediately in situation regarding disconnection. As a result, DBR2P could more thoroughly improve the quality of routing protocol than those proposed in the past.  相似文献   

7.
为MANETs路由构建了通过节点运动数据来实现的链路稳定路由LDPR,利用节点运动信息对链路生存时间进行初步预测,同时加入了双路由结构。采用LDPR路由来估计二个节点的链路连通时间时需考虑二个节点相对速度矢量。LDPR路由先对链路生存时间进行预测,确保链路发生断开前使备份路由处于工作状态。在路由被建立后,利用源节点来计算路由生存时间。参数优化结果得到:当节点数上升后,路由的开销率也不断增大,吞吐量发生了减小,传输时延也更大。相比较AODV路由,LDPR路由的开销率以及传输时延都较低,吞吐量较高,可见提出的LDPR路由运行效率更高。  相似文献   

8.
Vehicular ad hoc networks (VANETs) are a promising architecture for vehicle-to-vehicle communications in the transportation field. However, the frequent topology changes in VANETs create many challenges to data delivery because the vehicle velocity varies with time. Thus, designing an efficient routing protocol for stable and reliable communication is essential. Existing studies show that clustering is an elegant approach to efficient routing in a mobile environment. In particular, the passive clustering (PC) mechanism has been validated as a more efficient approach compared to traditional clustering mechanisms. However, the PC mechanism was primarily designed for mobile ad hoc networks (MANETs), and may be unsuitable for constructing a cluster structure in VANETs because it does not account for vehicle behavior and link quality. In this paper, we propose a passive clustering aided routing protocol, named PassCAR, to enhance routing performance in the one-way multi-lane highway scenario. The main goal of PassCAR is to determine suitable participants for constructing a stable and reliable cluster structure during the route discovery phase. Each candidate node self-determines its own priority to compete for a participant using the proposed multi-metric election strategy based on metrics such as node degree, expected transmission count, and link lifetime. Simulation results show that, compared with the original PC mechanism, PassCAR not only increases the successful probability of route discovery, but also selects more suitable nodes to participate in the created cluster structure. This well-constructed cluster structure significantly improves the packet delivery ratio and achieves a higher network throughput due to its preference for reliable, stable, and durable routing paths.  相似文献   

9.
Mobile ad hoc networks (MANETs) are mobile networks, which are automatically outspread on a geographically limited region, without requiring any preexisting infrastructure. Mostly, nodes are both self-governed and self-organized without requiring a central monitoring. Because of their distributed characteristic, MANETs are vulnerable to a particular routing misbehavior, called wormhole attack. In wormhole attack, one attacker node tunnels packet from its position to the other attacker nodes. Such wormhole attack results in a fake route with fewer hop count. If source node selects this fictitious route, attacker nodes have the options of delivering the packets or dropping them. For this reason, this paper proposes an improvement over AODV routing protocol to design a wormhole-immune routing protocol. The proposed protocol called defending against wormhole attack (DAWA) employs fuzzy logic system and artificial immune system to defend against wormhole attacks. DAWA is evaluated through extensive simulations in the NS-2 environment. The results show that DAWA outperforms other existing solutions in terms of false negative ratio, false positive ratio, detection ratio, packet delivery ratio, packets loss ratio and packets drop ratio.  相似文献   

10.
Wireless Mobile Ad-Hoc Networks (MANETs) are infrastructure-less networks commonly used for dynamic connection between nodes. These networks work without any external router for maintaining the connection and the nodes themselves behave like a router. Ad-Hoc On Demand Distance Vector (AODV) routing is a widely used protocol for managing communications between the mobile nodes. A blackhole attack is one in which the nodes create a false route through them and then perform malicious activities on the transmitted packets. This paper presents a modification of the existing AODV routing protocol to prevent blackhole attacks in MANETs in an erratic terrain with a high probability of packet loss. A mathematical proof is given to confirm the effectiveness of the proposed algorithm with respect to the previous solution in the literature.  相似文献   

11.
《Computer Networks》2008,52(1):130-154
In mobile ad hoc networks (MANETs), the mobility of the nodes is a complicating factor that significantly affects the effectiveness and performance of the routing protocols. Our work builds upon recent results on the effect of node mobility on the performance of available routing strategies (i.e., path-based, using support) and proposes a protocol framework that exploits the usually different mobility rates of the nodes by adapting the routing strategy during execution. We introduce a metric for the relative mobility of the nodes, according to which the nodes are classified into mobility classes. These mobility classes determine, for any pair of origin and destination, the routing technique that best corresponds to their mobility properties. Moreover, special care is taken for nodes remaining almost stationary or moving with high (relative) speeds. Our key design goal is to limit the necessary implementation changes required to incorporate existing routing protocols into our framework. We provide extensive evaluation of the proposed framework, using a well-known simulator (NS2). Our first findings demonstrate that the proposed framework improves, in certain cases, the performance of existing routing protocols.  相似文献   

12.
移动自组网基于邻居变化率稳定路径选择方法   总被引:11,自引:0,他引:11  
节点移动是导致移动自组织网络性能下降、限制网络规模扩展的关键因素之一.寻找稳定路径是减小节点移动影响的有效手段.现有的稳定路径寻找方法存在以下局限:需要节点具有地理位置定位的硬件功能支持,或需要信号强度上传的交叉层功能支持.为此,提出了不需要特殊硬件支持、可独立于底层协议工作、基于邻居变化率的稳定路径选择方法.以AODV(Ad hoc on-demand distance vector)按需路由协议为基础,扩展为NCR-AODV(Neighbor change ratio Ad hoc on-demand  相似文献   

13.
《Computer Communications》2007,30(14-15):2892-2903
Enterprises that may rely on critical equipments which are constantly moving around, for example, hospitals – need to ensure they can know the current location of vital but mobile assets. Besides, the sensor node on each device should inform us whether those relative equipments are functional or does not work at all in a hazardous environment, so that vital equipments can be maintained or fixed beforehand. A sensor network is a potential solution to this kind of application, because every node can be found through the routing processes. Due to its working environment and the mobility of sensor node, this kind of sensor network is very similar to MANETs (Mobile Ad-hoc Networks). This study proposes a jumping ant routing algorithm (JARA) which combines the advantages of reactive and proactive routing to speed up the route discovery time and reduce the route discovery overhead in sensor network.  相似文献   

14.
一种基于分治策略的多路径Ad Hoc路由协议   总被引:1,自引:0,他引:1  
在无线自组织网络(MANET)中,比起单路径路由协议,多路径路由协议提供了更好的可靠性、容错性、负载平衡等,并且提供较小的端对端延迟、提供较大的有效总带宽;但是,当网络规模较大、通信节点之间相距较远时,多路径路由协议的开销会很大,多路径的条数也减少.针对这一问题,提出了一种基于分治思想的多路径路由协议(DCMR).当通信节点之间必须经过的节点较多时,将这些节点划分为较小的节点集,对各个节点集分别进行路径查找及维护.模拟实验表明,该协议明显提高了路由寻径效率,减小了网络维护开销,并且实现简单,更具实用性.  相似文献   

15.
一种基于稳定簇的混合路由协议CBHRP   总被引:6,自引:0,他引:6  
臧婉瑜  于勐  谢立 《计算机学报》2001,24(12):1262-1271
移动算组网是一种没有有线基础结构支持的移动网络,具有带宽有限和拓扑结构易变的特点。这些特点使得设计一个合适的路由协议具有一定的挑战性。该文针对移动自组网提出了一种基于稳定簇结构、按需路由和预先路由混合、支持单播和组播通信的路由协议CBHRP。CBHRP具有路由控制开销小、主机移动对拓扑结构改变的影响小、通信的初始延迟低和应用范围广的特点。  相似文献   

16.
SmallWorld Model-Based Polylogarithmic Routing Using Mobile Nodes   总被引:3,自引:0,他引:3       下载免费PDF全文
The use of mobile nodes to improve network system performance has drawn considerable attention recently. The movement-assisted model considers mobility as a desirable feature,where routing is based on the store-carry-forward paradigm with random or controlled movement of resource rich mobile nodes.The application of such a model has been used in several emerging networks,including mobile ad hoc networks(MANETs),wireless sensor networks(WSNs),and delay tolerant networks(DTNs).It is well known that mobility increases the capacity of MANETs by reducing the number of relays for routing,prolonging the lifespan of WSNs by using mobile nodes in place of bottleneck static sensors,and ensuring network connectivity in DTNs using mobile nodes to connect different parts of a disconnected network.Trajectory planning and the coordination of mobile nodes are two important design issues aiming to optimize or balance several measures, including delay,average number of relays,and moving distance.In this paper,we propose a new controlled mobility model with an expected polylogarithmic number of relays to achieve a good balance among several contradictory goals,including delay,the number of relays,and moving distance.The model is based on the small-world model where each static node has"short"link connections to its nearest neighbors and"long"link connections to other nodes following a certain probability distribution.Short links are regular wireless connections whereas long links are implemented using mobile nodes.Various issues are considered,including trade-offs between delay and average number of relays,selection of the number of mobile nodes,and selection of the number of long links.The effectiveness of the proposed model is evaluated analytically as well as through simulation.  相似文献   

17.

A Mobile ad hoc Network (MANET) is an infrastructure less network that permits nodes to make a wireless network with mobility. In MANETs, the node linkages breaks are frequent due to all nodes are in movement. When neighbor nodes travel out of other node communication range connection among both mobile nodes breaks. Thus it makes delay and packet loss in the network. In the present Traffic Control method, several times, since the highest traffic, heavy rain, accidents, or other reasons, there may be probabilities of jam on roads. Thus, people could get delay owing to the highest traffic. Therefore, it is highly preferred to have an effective way to track the traffic on roads and thus select the suitable road that is traffic free. To resolve these problems, the volunteer Nodes of Ant Colony Optimization Routing (VNACO) is proposed. The primary objective of VNACO is to reduce both the delay and routing overhead in Peer to Peer (P2P) MANETs. Here, peer node act as a volunteer node and mobile node for transmitting data from source to destination. During data transmission, the relay node moving out of communication range when the volunteer node overheard the dropped data packet then deliver the data to the corresponding relay node. As a result, minimizes both the delay and packet losses. In VNACO, the volunteer’s nodes are elected based on node aptitude. Node aptitude is calculated by iterating node connectivity, transmission processing time, node energy and available bandwidth. In addition, an ant colony optimization algorithm to finds the optimal route and reduce the routing overhead in P2P MANETs. The significant application of this mechanism is utilized for the traffic management system. Network simulation results indicate that the VNACO mechanism is minimizing 22% delay and reducing 14% packet losses compared to the baseline protocol.

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18.
在移动Ad Hoc网络中,节点移动造成网络拓扑实时变化,并增加了路由的复杂性.已有稳定性路由算法往往关注于建立一条相对稳定的路由,而忽略了路由建立后稳定路由对于节点移动的适应性.针对这一问题,首先提出了一种针对稳定性路由的移动自适应策略,该策略主要包括3个关键技术:路由建立过程中稳定性参数的双向评估、节点移动状态改变时...  相似文献   

19.
An efcient hop count route fnding approach for mobile ad hoc network is presented in this paper.It is an adaptive routing protocol that has a tradeof between transmission power and hop count for wireless ad hoc networks.During the route fnding process,the node can dynamically assign transmission power to nodes along the route.The node who has received route request message compares its power with the threshold power value,and then selects a reasonable route according to discriminating algorithms.This algorithm is an efective solution scheme to wireless ad hoc networks through reasonably selected path to reduce network consumption.Simulation results indicate that the proposed protocol can deliver better performances with respect to energy consumption and end-to-end delay.  相似文献   

20.
徐会彬  夏超 《计算机工程》2013,(12):60-64,69
车辆自组织网络中网络拓扑的高动态性及节点的高速移动会导致路径频繁断裂。针对该问题,提出一种基于稳定路径的路由协议。利用节点的移动信息预测链路的使用寿命连结失效时间(LET),通过同方向行驶的节点组建链路,并选用最大LET的链路构建路径,使路径趋于稳定,同时减少控制开销。仿真结果表明,与DSR算法相比,该路由协议能增强路由稳定性,提高网络吞吐量。  相似文献   

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