Profile based routing in vehicular ad-hoc networks

One of the main problems in the VANET(vehicular ad-hoc network)routing algorithms is how to establish the stable routes.The link duration in these networks is often very short because of the frequent changes in the network topology.Short link duration reduce the network efficiency.Different speeds of the vehicles and choosing different directions by the vehicles in the junctions are the two reasons that lead to link breakage and a reduction in link duration.Several routing protocols have been proposed for VANET in order to improve the link duration,while none of them avoids the link breakages caused by the second reason.In this paper,a new method for routing algorithms is proposed based on the vehicles trips history.Here,each vehicle has a profile containing its movement patterns extracted from its trips history.The next direction which each vehicle may choose at the next junction is predicted using this profile and is sent to other vehicles.Afterward each vehicle selects a node the future direction of which is the same as its predicted direction.Our case study indicates that applying our proposed method to ROMSGP(receive on most stable group-path)routing protocol reduces the links breakages and increases the link duration time.     

车辆网络中一种有效自适应的复制路由协议

已经提出的一些基于复制的路由协议,如传染路由,不能以低代价实现高成功率.对车辆网络中设计了一种有效的基于复制的路由协议ARR.ARR是一种完全分布式协议,它包含两个设计目标:a)在消息生存期内将绝大多数消息成功发送;b)尽可能产生较低的发送代价.为了以低代价实现高成功率,ARR对一条消息的拷贝数量采取自适应策略.另外,为分配消息拷贝提出了两种分配方法.基于真实车辆行驶数据的仿真实验表明,相比其他四种路由协议,ARR以较低的发送代价实现了较高的发送成功率.     

Position-based routing in vehicular networks: A survey

Routing in vehicular network is a challenging task due to network partitioning, high vehicular speed, and city environment characteristics. These characteristics results in degraded performance in traditional routing protocols. Traditional routing protocols, addressing the issues of mobile ad hoc network, are applicable for MANET applications. Position-based routing protocols, which are mostly based on greedy routing, are more suited to highly dynamic and mobile network. In this paper, we survey state of art routing protocols previously used in vehicular networks, present open research challenges and possible future direction. We categorize protocols into two categories based on their communicating mode (vehicle-to-vehicle, vehicle-to-infrastructure) irrespective of their simulating environment (highway, urban). Both vehicle-to-vehicle and vehicle-to-infrastructure communication provides connectivity based on multi-hop paradigm in a seamless way. We discuss pros and cons for routing protocols belonging to each category. By doing qualitative comparison of routing protocols, it is observed that hybrid communication would be the better choice for both communication mode operable in either a city environment or an open environment.     

VANETs路由综述

针对车载自组织网络拓扑结构高动态性,阐述了路由协议研究的重要性;分析并比较了在车载自组织网络中各种路由协议的优缺点,并将现有的路由协议分为基于连通的、基于移动的、基于基础设施的、基于概率的以及基于地理位置的路由五类;根据每一类路由分析其研究现状及特性;最后展望了车载自组织网络路由技术的未来研究方向。     

城市环境车用自组织网络多路径路由

为应对无线网络通信路径耦合性和相互干扰的问题,提高无线网络通信性能,提出应用于城市环境车用自组织网络的多路径通信路由协议.根据城市环境道路网络特点,建立车用自组织网络多路径通信干扰模型;在此基础上提出基于交叉路口优化多路径通信路由,交叉路口附近的数据包基于多路径策略转发.实验结果表明,该多路径路由机制减少了数据冗余,有效避免数据碰撞,较大程度提高网络的数据包投递率并降低端到端延迟.     

基于车流信息的车载自组织网络路由协议*

车载自组织网络(VANET)具有高移动性和间歇连通性,而且拓扑变化频繁,特别是在事故或交通堵塞的时候,因此,采用了携带并转发的方式,即移动车辆携带数据直到遇见有可转发的车辆。与现有携带并转发的解决方法不同,本文采用分布式实时估计各路段延时的方法。基于对各路段延时的估计,车辆就能计算车低延时的路由路径,然后提出了分布式实时数据流统计辅助的路由协议(DRTAR)来转发数据。实验结果显示,提出的DRTAR协议性能优于其他算法。     

基于演化图论的可靠的VANETs路由协议

车载网络（VANETs）属于移动无线网络的特例,具有鲜明的特性。传统无线网络的路由协议难以直接应用于VANETs。节点的高速移动,引起网络拓扑动态变化,导致VANETs的通信链路频繁断裂。高动态网络的链路可靠性问题引起广泛的关注。为此,针对高速公路VANETs的路由可靠性进行分析,对演化图论进行扩展,建立扩展后的演化图论模型（EEGM）,并利用EEGM获取VANETs拓扑的动态信息,从而预先获取可靠路由的信息。在此基础上,提出基于演化图论的可靠路由协议（EG-RAODV）。仿真结果表明,与同类的其他协议相比,提出的路由协议在分组传输率、端到端传输时延、路由请求消息率以及链路断裂数方面得到了提升。     

面向车载网的基于AODV优化路由协议的研究

车载网VANETs(Vehicular ad hoc networks)属于新型的通信模型,其可实现车间通信和车与基础设施通信。由于VANETs节点密度动态变化,节点的快速移动、移动模型的局限性等特点,为VANETs的数据传输提出挑战。鉴于此,提出优化的按需距离矢量AODV(Ad Hoc On demand Distance Vector)方案IAODV(Improved AODV)。在城市环境中,AODV在端到端传输时延、数据包丢失率方向性能较差。为此,IAODV采用限定源节点的路由跳数,降低AODV的端到端传输时延,同时为源节点提供备份路由,从而改善数据包丢失率。仿真结果表明,与AODV协议相比,IAODV在端到端传输时延、数据包丢失率得到有效提升。     

A QoS-aware routing algorithm based on ant-cluster in wireless multimedia sensor networks

QoS-aware routing algorithm is important in wireless multimedia sensor networks. This paper formulates a generalized QoS-aware routing model on the basis of multiple routing metrics and priorities of packets. We first introduce a 2D plain-based routing algorithm IPACR which improves the standard ant colony algorithm by optimizing the initial distribution of artificial pheromone in order to accelerate the algorithm convergence rate. Then a clustering-based routing algorithm ICACR is presented which can be well applied in a large scale network. ICACR is a variation of IPACR because it can be suitable for clustering cases to satisfy the larger scale situations. Both the numerical algorithm performance analysis and simulation of IPACR and ICACR are given. The results show that ICACR outperforms IPACR in terms of both network lifetime and QoS-aware routing metrics in large scale wireless multimedia sensor networks. Moreover, the simulation based on the real video traces shows that by extending the multi-path to ICACR for different priorities of video frames better performance can be achieved.     

一种基于AODV改进的城市车载自组网路由协议研究

针对城市环境下车载自组网的特点及AODV协议广播式路由探测的不足,采用贪婪转发的单播式路由探测和经典AODV协议的广播式路由探测相结合的路由探测方式,并且单播路由探测在选择下一跳转发节点时同时考虑贪婪转发和链路稳定两个因素,减少了广播帧的发送,提高了路由的稳定性。仿真实验表明,改进后AODV协议比经典AODV协议更加适合城市车载自组网。     

GeoSpray: A geographic routing protocol for vehicular delay-tolerant networks

Vehicular networks are characterized by a highly dynamic network topology, and disruptive and intermittent connectivity. In such network environments, a complete path from source to destination does not exist on the most part of the time. Vehicular delay-tolerant network (VDTN) architecture was introduced to deal with these connectivity constraints. VDTN assumes asynchronous, bundle-oriented communication, and a store-carry-and-forward routing paradigm. A routing protocol for VDTNs should make the best use of the tight resources available in network nodes to create a multi-hop path that exists over time. This paper proposes a VDTN routing protocol, called GeoSpray, which takes routing decisions based on geographical location data, and combines a hybrid approach between multiple-copy and single-copy schemes. First, it starts with a multiple-copy scheme, spreading a limited number of bundle copies, in order to exploit alternative paths. Then, it switches to a forwarding scheme, which takes advantage of additional contact opportunities. In order to improve resources utilization, it clears delivered bundles across the network nodes. It is shown that GeoSpray improves significantly the delivery probability and reduces the delivery delay, compared to traditional location and non location-based single-copy and multiple-copy routing protocols.     

A link availability-based QoS-aware routing protocol for mobile ad hoc sensor networks

With more and more wireless devices being mobile, there is a constant challenge to provide reliable and high quality communication services among these devices. In this paper, we propose a link availability-based QoS-aware (LABQ) routing protocol for mobile ad hoc networks based on mobility prediction and link quality measurement, in addition to energy consumption estimate. The goal is to provide highly reliable and better communication links with energy-efficiency. The proposed routing algorithm has been verified by NS-2 simulations. The results have shown that LABQ outperforms existing algorithms by significantly reducing link breakages and thereby reducing the overheads in reconnection and retransmission. It also reduces the average end-to-end delay for data transfer and enhances the lifetime of nodes by making energy-efficient routing decisions.     

New routing framework base on rumor routing in wireless sensor networks

Rumor routing is a classic routing algorithm based on agents’ random walk. This paper proposes a novel approach based on this routing algorithm. Here, we try to improve the latency and energy consumption of the traditional algorithm using propagation of query and event agents within straight lines, instead of using purely random walk paths. As can be seen in our results, this method improves the delivery ratio of the queries which is a drawback of traditional rumor routing. Due to the reduction of final path length between source and destination, we introduce a second layer geographical routing. Moreover, a method is proposed to reduce the cost of localization equipments by using cheaper equipments like AoA antennas. In order to compare the performance measures with traditional algorithm, a simulation framework is developed and extensive simulations are performed.     

车载自组织网络中基于蚁群算法的簇路由协议

由于车辆的高速移动及拓扑动态变化,构建稳定的传输路径是车载自组织网络VANETs(Vehicular ad hoc Networks)应用的关键。而簇技术建立稳定传输路径的有效技术之一。为此,提出基于蚁群算法的簇路由ACCR(Ant Colony algorithm based cluster routing)协议。蚁群系统是典型的启发性算法,能够解决簇划分问题。据此,ACCR协议利用蚁群算法选择簇头,提高簇的稳定性和数据传输性能。仿真结果表明,与ACO-CR协议相比,提出的ACCR协议的簇头寿命提高了近20%,数据传输率提高了近45%。     

A routing protocol for vehicular ad hoc networks using simulated annealing algorithm and neural networks

Vehicular ad hoc network (VANET) is special type of mobile ad hoc networks which establish communications between adjacent vehicles and also between vehicles and roadside units. Thanks to their dynamic and fast topology changes, inter-vehicular ad hoc networks are like dynamic networks without organizations. Hence, developing a reliable routing algorithm is regarded as a notable challenge in these networks. In this paper, a clustering-based reliable routing algorithm was proposed for VANETs with reliable applications. In this way, simulated annealing was used for appropriate clustering of nodes and the parameters of node degree, coverage and ability were considered in the proposed method. For selecting cluster head, radial basis function neural network was used and a suitable fitness function with velocity and free buffer size parameters was used. Each cluster has two gateway nodes which are used as the communication interface for transmitting data from one cluster to another cluster. The simulation results indicated the efficiency of the proposed method in terms of route discovery rate and packet delivery rate.     

Ad Hoc网络链路质量QoS多路径按需路由协议

传统的MANET路由协议是基于最小跳数的路由,没有考虑链路质量,不能适应网络拓扑的动态变化。针对这一问题,提出了一种Ad Hoc网络链路质量QoS多路径按需路由协议（QMORP）。QMORP采用移动预测来计算链路的生存时间,应用能量模型获得链路的剩余能量,综合链路生存时间和剩余能量两种因素来计算链路质量。选择链路质量大的路径转发分组。仿真实验表明,相比AOMDV协议,QMORP协议提高了网络的生命周期,降低了网络的平均端对端延迟、提高了网络的发包率和吞吐率。     

RIVER: A reliable inter-vehicular routing protocol for vehicular ad hoc networks

Vehicular Ad hoc NETworks (VANETs), an emerging technology, would allow vehicles on roads to form a self-organized network without the aid of a permanent infrastructure. As a prerequisite to communication in VANETs, an efficient route between communicating nodes in the network must be established, and the routing protocol must adapt to the rapidly changing topology of vehicles in motion. This is one of the goals of VANET routing protocols. In this paper, we present an efficient routing protocol for VANETs, called the Reliable Inter-VEhicular Routing (RIVER) protocol. RIVER utilizes an undirected graph that represents the surrounding street layout where the vertices of the graph are points at which streets curve or intersect, and the graph edges represent the street segments between those vertices. Unlike existing protocols, RIVER performs real-time, active traffic monitoring and uses these data and other data gathered through passive mechanisms to assign a reliability rating to each street edge. The protocol then uses these reliability ratings to select the most reliable route. Control messages are used to identify a node’s neighbors, determine the reliability of street edges, and to share street edge reliability information with other nodes.     

Bee life-based multi constraints multicast routing optimization for vehicular ad hoc networks

A vehicular ad hoc network (VANET) is a subclass of mobile ad hoc networks, considered as one of the most important approach of intelligent transportation systems (ITS). It allows inter-vehicle communication in which their movement is restricted by a VANET mobility model and supported by some roadside base stations as fixed infrastructures. Multicasting provides different traffic information to a limited number of vehicle drivers by a parallel transmission. However, it represents a very important challenge in the application of vehicular ad hoc networks especially, in the case of the network scalability. In the applications of this sensitive field, it is very essential to transmit correct data anywhere and at any time. Consequently, the VANET routing protocols should be adapted appropriately and meet effectively the quality of service (QoS) requirements in an optimized multicast routing. In this paper, we propose a novel bee colony optimization algorithm called bees life algorithm (BLA) applied to solve the quality of service multicast routing problem (QoS-MRP) for vehicular ad hoc networks as NP-Complete problem with multiple constraints. It is considered as swarm-based algorithm which imitates closely the life of the colony. It follows the two important behaviors in the nature of bees which are the reproduction and the food foraging. BLA is applied to solve QoS-MRP with four objectives which are cost, delay, jitter, and bandwidth. It is also submitted to three constraints which are maximum allowed delay, maximum allowed jitter and minimum requested bandwidth. In order to evaluate the performance and the effectiveness of this realized proposal using C++ and integrated at the routing protocol level, a simulation study has been performed using the network simulator (NS2) based on a mobility model of VANET. The comparisons of the experimental results show that the proposed algorithm outperformed in an efficient way genetic algorithm (GA), bees algorithm (BA) and marriage in honey bees optimization (MBO) algorithm as state-of-the-art conventional metaheuristics applied to QoS-MRP problem with the same simulation parameters.