基于实时道路信息感知的VANET路由算法

为降低车辆自组织网络VANET (vehicle ad hoc network)数据传输中的丢包率和数据延迟,提出一种基于分段机制改进的地理路由算法RSAR (real-time segment aware routing)。通过将道路状态量化为道路车辆密度、网络连通性、通信负载等参数进行路由规划,设计网络有效期机制,控制路由更新的频率。实验结果表明,RASR较公开的地理路由算法在VANET城市环境中有更好的表现。     

Location verification and trust management for resilient geographic routing

In this paper, we consider the security of geographic routing (GR) protocols. In GR, neighbors exchange their location information. Based on this information, a node forwards packets to the neighbor that is closest to the destination. Although GR is widely used in ad hoc and wireless sensor networks, its security has rarely been studied; there are a number of attacks that are possible on GR. In one attack, misbehaving nodes can falsify their location information. Also, malicious nodes can drop packets that they need to forward towards the destination. The first contribution of the paper is to propose a location verification algorithm to address the attacks falsifying the location information. The second contribution of the paper is to propose approaches for trust-based multi-path routing, aiming to defeat attacks on GR. We discuss the proposed approaches in detail, outlining possible attacks and defenses against them. In addition, we show, via simulation, how trust-based route selection is able to circumvent attackers and route around them. This paper summarizes and extends results reported by the authors in a previous article [K.-D.K. Nael, B. Abu-Ghazaleh, K. Liu, Towards resilient routing in WSNs, in: Proceedings of the First IEEE/ACM Workshop on QoS and Security in Wireless Networks (Q2SWinet 2005), 2005, pp. 71–78].     

VANETs路由协议综述

随着车联网VANETs(Vehicular Ad hoc Networks)应用日益受到关注,研究者对VANETs路由协议进行了深入研究.为此,首先总结VANETs的特点及应用,再介绍了基于位置的、基于拓扑以及基于广播路由的概念,并着重分析和总结了近期路由协议的核心思想以及特点,此外,还从应用场景、前提条件、虚拟设备要求、电子地图需求、路由恢复策略以及转发模式六个方面对路由协议进行全面比较,最后,展望了VANETs路由技术的未来研究方向.     

一种基于QoS的VANETs多路径路由协议的设计*

为显著提高路由决策性能,在信息熵的基础上提出了用熵值定量描述链路稳定性的算法;同时综合考虑用户带宽的个性化需求,在多路径路由协议(AOMDV)的基础上设计出一种适用于城市车载Ad hoc网络的QoS路由协议BLS-AOMDV。理论分析论证了BLS-AOMDV协议的有效性及可行性。基于NS2的仿真结果表明,新协议在丢包率、时延、路由开销上都要优于传统的AOMDV多路径路由协议,因此更加适合于城市VANETs应用范畴。     

An efficient void resolution method for geographic routing in wireless sensor networks

Geographic routing is an attractive choice for routing data in wireless sensor networks because of lightweight and scalable characteristics. Most geographic routing approaches combine a greedy forwarding scheme and a void resolution method to detour a void area that has no active sensor. The previous solutions, including the well-known GPSR protocol, commonly use the right-hand rule for void resolution. However, the detour path produced by the right-hand rule is not energy-efficient in many cases. In this paper, we propose a new void resolution method, called void resolution-forwarding, which can overcome voids in the sensor network energy-efficiently. It exploits the quadrant-level right-hand rule to select the next hop for the current node during circumventing a void area. We show by experiments that the proposed method is efficient and scalable with respect to the various voids and network density and that it outperforms the GPSR protocol significantly.     

移动Ad hoc网络多径路由协议*

给出移动Ad hoc网络多径路由的分类方法,系统地描述了当前各种典型的MANETs多径路由协议,并比较和分析了这些协议的特点及适用情况.最后结合该领域当前的研究现状,指出多径路由协议存在的问题和未来的研究重点.     

Unicast routing protocols for urban vehicular networks: review,taxonomy, and open research issues

Over the past few years, numerous traffic safety applications have been developed using vehicular ad hoc networks（VANETs）. These applications represent public interest and require network-wide dissemination techniques. On the other hand, certain non-safety applications do not require network-wide dissemination techniques.Such applications can be characterized by their individual interest between two vehicles that are geographically apart. In the existing literature, several proposals of unicast protocols exist that can be used for these non-safety applications. Among the proposals, unicast protocols for city scenarios are considered to be most challenging.This implies that in city scenarios unicast protocols show minimal persistence towards highly dynamic vehicular characteristics, including mobility, road structure, and physical environment. Unlike other studies, this review is motivated by the diversity of vehicular characteristics and difficulty of unicast protocol adaption in city scenarios.The review starts with the categorization of unicast protocols for city scenarios according to their requirement for a predefined unicast path. Then, properties of typical city roads are discussed, which helps to explore limitations in efficient unicast communication. Through an exhaustive literature review, we propose a thematic taxonomy based on different aspects of unicast protocol operation. It is followed by a review of selected unicast protocols for city scenarios that reveal their fundamental characteristics. Several significant parameters from the taxonomy are used to qualitatively compare the reviewed protocols. Qualitative comparison also includes critical investigation of distinct approaches taken by researchers in experimental protocol evaluation. As an outcome of this review, we point out open research issues in unicast routing.     

社会感知多副本车载自组织网络机会路由协议

为提高车载自组织网络(vehicular Ad hoc networks, VANETs)中消息投递的效率, 提出了一种社会感知多副本车载自组织网络机会路由协议(SAMOR)。协议结合了车载自组织网络中节点的社会性特点和多副本路由方案的优势, 采用携带—存储—转发的机会路由方式进行消息投递。利用节点间的相遇历史区分社区节点和全局节点, 并使用所提出的节点社区中心性和网络中心性的度量方法, 得到了节点的效用。在路由过程的扩散阶段, 节点间按效用分配副本, 在转发阶段, 副本继续向效用高的节点转发。仿真结果表明, SAMOR实现了较高的消息投递成功率和较低的延迟。     

多跳Ad Hoc网络基于路由协议的拥塞控制

为解决Ad Hoc网络的DSR路由协议在通信过程中存在拥塞问题,提出了改进DSR路由协议的思想,即联合“最短路径”和节点发送接收数据包时的“传输状态”来避免拥塞。仿真结果表明,改进后的路由协议有效地减少了发生拥塞的几率,从而提高了无线多跳Ad Hoc网络环境下Web通信的性能。     

Survey of network coding-aware routing protocols in wireless networks

In recent times, there have been many advances in the field of information theory and wireless ad hoc network technologies. Regarding information theory progression and its connection with wireless ad hoc networks, this study presents fundamental concepts related to the application of the state-of-the-art Network Coding (NC) within wireless ad hoc networks in the context of routing. To begin with, this paper briefly describes opportunistic routing and identifies differentiation between NC-aware and NC-based routing mechanisms in wireless ad hoc networks. However, our main focus is to provide a survey of available NC-aware routing protocols that make forwarding decisions based on the information of available coding opportunities across several routes within wireless ad hoc networks. The taxonomy and characteristics of various representative NC-aware routing protocols will also be discussed. In summary, we provide a comparison of available NC-aware routing schemes and conclude that NC-aware routing techniques have several advantages over traditional routing in terms of high throughput, high reliability, and lower delay in a wireless scenario. To the best of our knowledge, this work is the first that provides comprehensive discussion about NC-aware routing protocols.     

自组织车联网中GPSR路由协议的研究进展

由于贪婪周边无状态路由(GPSR)对于拓扑结构频繁变化的自组织车联网(VANETs)具有最适性,为此,针对GPSR提出了许多改进协议。首先对VANETs网络层路由协议进行分类比较,然后分析和总结近年来基于位置路由协议的核心路由机制和优缺点,重点分析典型的基于位置的路由协议GPSR在城市场景中存在的问题。最后,提出了GPSR未来可能的研究策略和发展方向。     

无线传感器网络安全路由研究综述

首先总结了无线传感器网络路由面临的主要安全威胁及其应对机制;然后根据协议所采用的核心安全策略对现有的安全路由协议进行了归纳、分类和比较,并着重对国内外重要的安全路由协议进行了介绍和分析。最后提出了几个无线传感器网络安全路由中需要进一步研究的问题。     

一种基于水声信道的无线传感器网络路由协议

以无线传感器网络的水下应用所面对的挑战为背景,针对水声信道的传输特点,在最小代价算法和目的节点序列距离矢量DSDV(Destination-Sequenced Distance-Vector)路由协议的基础上,提出了一种均衡节点能耗的路由协议算法.该协议按照最小能量代价建立多跳路由表,从而在数据传送时能够均衡各节点的能量消耗,达到延长网络生命周期的目的.仿真结果表明,相对于DSDV协议,本文提出的协议能够实现能量均衡,有效的延长网络生存周期.     

基于移动状态的车载自组织网络路由算法

传统的AODV协议应用于车载自组织网络,尽管分组投递率比较高,但在数据分组需要发送时才建立路由,网络延迟较大。而DSDV中通过周期性的路由更新机制,网络延迟小,但需维护大量不必要的路由,并且拓扑结构变化使许多路由无效,导致分组投递率非常低。为了综合满足VANET分组投递率和网络延迟的要求,将AODV和DSDV两种路由建立机制相互融合,形成混合式路由协议。首先,根据车辆节点的位置、速度和方向等移动状态周期性地选择稳定且距离适中的链路,形成网络主干并更新路由;其次,当数据分组目的节点路由不存在时,发起路由发现过程建立路由,在路由请求报文前进和路由应答报文回溯过程中求出路由过期时间。仿真实验表明,尽管路由开销有所增大,分组投递率略低于AODV,但是网络延迟显著降低。     

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.     

移动Ad Hoc网络基于路由协议的拥塞控制

为解决Ad Hoc网络的AODV路由协议在通信过程中存在的拥塞问题,提出了改进AODV路由协议的思想。根据网络链路拥塞度的大小采取不同措施和节点路由,建立不相关多径路由分流以避免拥塞。仿真结果表明,改进后的路由协议有效地减少了发生拥塞的几率,从而提高了移动Ad Hoc网络的性能。     

A survey on routing techniques in underwater wireless sensor networks

Underwater Wireless Sensor Networks (UWSNs) are finding different applications for offshore exploration and ocean monitoring. In most of these applications, the network consists of significant number of sensor nodes deployed at different depths throughout the area of interest. The sensor nodes located at the sea bed cannot communicate directly with the nodes near the surface level; they require multi-hop communication assisted by appropriate routing scheme. However, this appropriateness depends not only on network resources and application requirements but also on environmental constraints. All these factors provide a platform where a resource-aware routing strategy plays a vital role to fulfill the different application requirements with dynamic environmental conditions. Realizing the fact, significant attention has been given to construct a reliable scheme, and many routing protocols have been proposed in order to provide an efficient route discovery between the sources and the sink. In this paper, we present a review and comparison of different algorithms, proposed recently in order to fulfill this requirement. The main purpose of this study is to address the issues like data forwarding, deployment and localization in UWSNs under different conditions. Later on, all of these are classified into different groups according to their characteristics and functionalities.     

一种自适应的城市场景车用自组织网路由协议

针对城市场景车用白组织网VANET（Vehicular Ad Hoe Networks）的特性和车辆间通信时常中断的问题,在现有VANET路由协议的基础上,提出了一种改进的路由协议AAR。AAR基于实时交通流,能自适应选择路由,并能根据车辆的行驶速度、方向,对车辆位置进行精确预测。最后采用真实的城市道路场景,在NS2中进行了性能仿真,结果表明,与现有的VANET路由协议相比,性能有很大提高。