一种能量感知的Ad Hoc网络路由协议

Ad Hoc网络中的节点是由电池供电,整个网络是一个能量受限系统,如何节省节点的能量,尽可能延长网络的可操控时间逐渐成为衡量路由协议性能的重要指标.基于移动节点能量的不同级别,采取不同的转发策略,提出了一种基于能量感知的Ad Hoc网络路由协议--EARP.并与AODV协议进行了性能比较,仿真结果显示,EARP具有较低的能耗,较长的网络存活时间.     

城市环境下车载Ad Hoc网络路由协议研究

考虑到城市环境中障碍物对网络性能的重要影响,在NS2(Network Simulator version 2)中加入了代表障碍物的概率穿透模型,使仿真环境更接近真实环境。针对AODV(Ad hoc On-Demand Distance Vector Routing)协议应用在城市场景下的缺陷,提出了一种改进的AODV协议——GE-AODV(Geocast Enhanced AODV)协议,该协议是基于位置信息的协议,并采用了多播方式来转发控制信息。仿真表明,GE-AODV降低了网络时延和控制开销,提高了网络可靠性。     

Congestion Aware Geographic Routing Protocol for Wireless Ad Hoc and Sensor Networks

Geographic routing protocols forward packets according to the geographical locations of nodes. Thus, the criteria used to select a forwarding node impacts on the performance of the protocols such as energy efficiency and end-to-end transmission delay. In this paper, we propose a congestion aware forwarder selection (CAFS) method for a geographic routing protocol. To design CAFS, we devise a cost function by combining not only the forward progress made to a packet but also the amount of energy required for packet forwarding, forwarding direction, and congestion levels of potential forwarders. Among the potential forwarders, CAFS selects the next forwarder having the minimum cost. In our simulation studies, we compare the performance of CAFS with those of the maximum progress (MP) method and the cost over progress (CoP) method in various network conditions. The results show that compared with MP, the length of a routing path in terms of the number of hops becomes longer when CAFS is used. However, the shorter hop distance helps to avoid unnecessary retransmissions caused by packet loss in a wireless channel. In addition, since CAFS considers congestion levels of candidate forwarders, it reduces the queuing delay in each forwarder. Therefore, CAFS is superior to the MP and the CoP in terms of the energy consumption, end-to-end packet transfer delay, and the successful packet delivery rate.     

ACAR: Adaptive Connectivity Aware Routing for Vehicular Ad Hoc Networks in City Scenarios

Multi-hop vehicle-to-vehicle communication is useful for supporting many vehicular applications that provide drivers with safety and convenience. Developing multi-hop communication in vehicular ad hoc networks (VANET) is a challenging problem due to the rapidly changing topology and frequent network disconnections, which cause failure or inefficiency in traditional ad hoc routing protocols. We propose an adaptive connectivity aware routing (ACAR) protocol that addresses these problems by adaptively selecting an optimal route with the best network transmission quality based on statistical and real-time density data that are gathered through an on-the-fly density collection process. The protocol consists of two parts: 1) select an optimal route, consisting of road segments, with the best estimated transmission quality, and 2) in each road segment of the chosen route, select the most efficient multi-hop path that will improve the delivery ratio and throughput. The optimal route is selected using our transmission quality model that takes into account vehicle densities and traffic light periods to estimate the probability of network connectivity and data delivery ratio for transmitting packets. Our simulation results show that the proposed ACAR protocol outperforms existing VANET routing protocols in terms of data delivery ratio, throughput and data packet delay. Since the proposed model is not constrained by network densities, the ACAR protocol is suitable for both daytime and nighttime city VANET scenarios.     

一种基于竞争转发的城市场景车载 Ad Hoc网络路由算法

 论文提出了一种适用于城市场景下的基于竞争转发的车载Ad hoc网络路由算法,算法摒弃了HELLO消息的使用,利用分布式的竞争策略根据邻居节点所处的地理位置信息进行下一跳节点的选择.数据转发使用选定点路由同时利用了实时的道路交通信息和网络拓扑结构信息进行选定点选择.采取暂存转发策略处理网络分割现象.仿真结果表明该算法比其他类似算法具有更高的数据包递交率和较低的数据延迟.     

Scalable Routing Protocol for Ad Hoc Networks

In this paper we present a scalable routing protocol for ad hoc networks. The protocol is based on a geographic location management strategy that keeps the overhead of routing packets relatively small. Nodes are assigned home regions and all nodes within a home region know the approximate location of the registered nodes. As nodes travel, they send location update messages to their home regions and this information is used to route data packets. In this paper, we derive theoretical performance results for the protocol and prove that the control packet overhead scales linearly with node speed and as N ^3/2 with increasing number of nodes. These results indicate that our protocol is well suited to relatively large ad hoc networks where nodes travel at high speed. Finally, we use simulations to validate our analytical model.     

一种基于可靠性的车载自组织网络路由算法

提出了一种改进的GPSR路由算法.该算法在选择转发节点过程中同时考虑位置和方向,进而提高转发节点选择的正确性来增加通信链路可靠性.用VanetMobisim交通仿真软件构建真实的VANETs网络城市场景,结合NS-2进行仿真研究,结果表明,和传统GPSR算法相比,改进的GPSR路由算法在端到端时延影响不大的条件下,能够有效地提高数据包传递率,降低数据丢包率.因此,改进的GPSR协议更适用于对实时性要求不高、而对可靠性要求较高的VANETs网络.     

城市场景下基于速度信息的VANET路由协议的改进

车载自组网络(Vehicular Ad Hoc Networks,VANET)是指道路上由车辆搭载的无线通信装置构成的一种特殊的多跳无线移动自组织网络。VANET在实现多种智能交通方面应用的同时,还能满足用户在乘车时的娱乐等舒适性的需求,近些年来已成为无线自组网络研究的新热点。总结了近些年来出现的主要VANET路由协议的核心路由机制及其优缺点,并分析了各种技术对路由协议性能的影响。其后给出了一种基于速度信息的VANET路由协议改进方法,并通过实验验证了将改进方法与GPSR协议结合可以提高路由路径的稳定性,减少了端到端的平均时延,降低了VANET网络中拓扑的高动态性对路由协议性能的影响。     

一种适用于战术条件下的自组织网路由协议

应用于战术条件下的自组织网络,其拓扑具有长期稳定而短期突变的特性;其流量具有不均衡性,中心节点的流量比重较大.针对战术无线网络的这种特性设计了一种混合式路由协议(HRP),协议为近端节点采用先应式协议维护路由而为远端节点采用反应式协议维护路由,对远端节点的路由请求采用OLSR协议的MPR思想,限制反应式协议的路由开销.并且,在近端拓扑变化频度超过门限值后,发起针对繁忙节点的路由发现请求,保持到繁忙节点的路由常新,从而提高了路由命中率.仿真结果表明,应用HRP协议后,无论其选路质量还是应用层业务的时延和吞吐量指标都优于DSR和ZRP协议.     

Dynamic Relationship-Zone Routing Protocol for Ad Hoc Networks

A new dynamic relationship-zone routing protocol (DRZRP) for ad hoc networks is proposed. In this protocol, each node in the network establishes a neighboring-zone with a radius of ρ hops, and activates a relationship-zone according to the service request frequency and service hotspot condition. DRZRP establishes proactive routing for neighboring-zone and relationship-zone of the node, and the relationship-zone of the node can be dynamically maintained, including: initialization, relationship-zone activation, and relationship-zone inactivation. The simulation results are compared with LSR, ZRP and ZHLS protocols, and DRZRP greatly reduces the communication overhead of routing control messages and significantly improves the average delay of routing requests. The new protocol matches the service relationship among nodes in the network, and has comprehensive performance advantage in communication overhead and routing request delay, which improves the quality of network service.

     

Performance Analysis of P-GEDIR Protocol for Vehicular Ad Hoc Network in Urban Traffic Environments

A Vehicular Ad hoc Network (VANET) is a wireless ad hoc network that is formed between vehicles on an on demand basis. In VANETs all the vehicles (nodes) are used as routers and these routers are free to move randomly and organized themselves arbitrarily. A lot of research work around the world is being conducted to design an efficient routing protocol for VANETs. In this paper, we propose a new routing method known as Peripheral node based GEographic DIstance Routing (P-GEDIR), a position-based routing protocol that takes advantage of GEographic DIstance Routing (GEDIR). It may not be possible to find node at the extreme end of the transmission range. Therefore, we have considered an area around the extreme end of the transmission range. Further a mathematical model for the protocol has been designed to determine expected number of successful hops, expected distance to the next-hop node, and expected one-hop progress. The protocol has been simulated using MATLAB. In this work, results clearly show that using the peripheral node is an advantage to maximize the performance of routing protocol in terms of average number of successful hops and expected one-hop progress. The result of P-GEDIR is compared with the existing GEDIR protocol.     

Checkerboard-Like Routing Protocol for Ad Hoc Mobile Wireless Networks

The main purposes of this article are to relieve broadcast problem, to immunize to some prerequisites, and to reduce the number of transmitted control packets. Broadcasting control packets network-wide is the most direct and common method for finding the required destination node in ad hoc mobile wireless networks; however, this causes a lot of waste of wireless bandwidth. To remedy the problem, routing protocols demanding some prerequisites are proposed; nonetheless, hardly can they be used if these prerequisites are missed or become stale. To efficiently reduce the number of transmitted control packets, our routing protocol partitions the network into interlaced gray districts and white districts by the aid of GPS and inhibits an intermediate node residing in a white district from re-transmitting the received control packets. However, a mobile node residing in a gray district is responsible for re-transmitting them till they reach the destination node. Our routing protocol does not demand any prerequisite except the use of GPS. Each mobile node can always obtain its own location information; furthermore, the information may neither be missed nor become stale. Our routing protocol is easy to be implemented, saves precious wireless bandwidth, and reduces almost half a number of control packets as compared with pure flooding routing protocols.Ying-Kwei Ho received the B.S. degree and M.S. degree in applied mathematics and in electrical engineering from the Chung-Cheng Institute of Technology in 1987 and 1993 respectively and the Ph.D. degree in computer engineering and science from the Yuan-Ze University, Taiwan, R.O.C. He joined the Army of Taiwan, R.O.C. in 1987 and worked as a software engineer. From 1993 to 1997, he was an instructor in the War Game Center of Armed Forces University, Taiwan, R.O.C. He is currently an assistant professor of the Department of Computer Science at Chung-Cheng Institute of Technology. His research interests include mobile computing, wireless network performance simulation and evaluation, and modeling and simulation.Ru-Sheng Liu received the B.S. degree in electrical engineering from the National Cheng-Kung University, Taiwan, in 1972 and the M.S. and Ph.D. degrees in computer science from the University of Texas at Dallas, Richardson, Texas, in 1981 and1985, respectively. He is currently an associate professor in the Department of Computer Engineering and Science at Yuan-Ze University, Chungli, Taiwan. His research interests are in the areas of mobile computing, internet technology, and computer algorithms.     

一种无线自组织网络动态路由协议

介绍了一种基于稀疏树的无线自组织网络动态路由协议,该协议采用了稀疏树路径生成算法来减少路由更新的数据量并减少网络链路的冗余,采用增量更新来降低路由协议开销并降低对传输带宽的占用,支持单向信道,采用快速路径查找算法消除网络拓扑动态变化过程中的环路与无穷计数问题。仿真结果显示它具有收敛快,开销小等特性,能够较好地适应窄带无线通信环境的需要。     

SDR: A Stable Direction-Based Routing for Vehicular Ad Hoc Networks

A stable and reliable routing mechanism for vehicular ad hoc networks (VANETs) is an important step toward the provision of long data transmission applications, such as file sharing and music download. Traditional mobile ad hoc network (MANET) routing protocols are not suitable for VANET because the mobility model and environment of VANET are different from those of traditional MANET. To solve this problem, we proposed a new stable routing algorithm, called stable directional forward routing. The novelty of the proposed routing protocol is its combining direction broadcast and path duration prediction into ad hoc on-demand distance vector routing protocols, which including: (1) Nodes in VANET are grouped based on the position, only nodes in a given direction range participating in the route discovery process to reduce the frequency of flood requests, (2) Route selection is based on the link duration while not the hops or other metrics to increase the path duration, (3) Route discovery is executed before the path expiration in order to decrease the end to end delay. The performance of the new scheme is evaluated through extensive simulations with Qualnet. Simulation results indicate the benefits of the proposed routing strategy in terms of decreasing routing control packet, reducing the number of link-breakage events, improving the packet delivery ratio and decreasing the end-to-end delay.     

An On-Demand Routing Protocol with Backtracking for Mobile Ad Hoc Networks

A mobile ad hoc network (MANET) is characterized by multi-hop wireless links and frequent node mobility. Communication between non-neighboring nodes requires a multi-hop routing protocol to establish a route. But, the route often breaks due to mobility. The source must rediscover a new route for delivering the data packets. This wastes the resources that are limited in MANET. In this paper, a new on-demand routing protocol is proposed, named on-demand routing protocol with backtracking (ORB), for multi-hop mobile ad hoc networks. We use the multiple routes and cache data technique to reduce the rediscovery times and overhead. After executing the route discovery phase, we find out a set of nodes, named checkpoint, which has the multiple routes to the destination. When a checkpoint node receives a data packet, it caches this data packet in its buffer within a specific time period. When a node detects a broken route during the data packets delivery or receives an error packet, it will either recover the broken route or reply the error packet to the source. If a node can not forward the data packet to the next node, it replies an error packet to the source. This packet is backtracking to search a checkpoint to redeliver the data packet to the destination along other alternate routes. The main advantage of ORB is to reduce the flooding search times, maybe just delay and cost while a route has broken. The experimental results show that the proposed scheme can increase the performance of delivery but reduce the overhead efficiently comparing with that of AODV based routing protocols. Hua-Wen Tsai received the B.S. degree in Information Management from Chang Jung Christian University, Taiwan, in June 1998 and the M.B.A. degree in Business and Operations Management from Chang Jung Christian University, Taiwan, in June 2001. Since September 2001, he has been working towards the Ph.D. degree and currently is a doctoral candidate in the Department of Computer Science and Information Engineering, National Cheng Kung University, Taiwan. His research interests include wireless communication, ad hoc networks, and sensor networks. Tzung-Shi Chen received the B.S. degree in Computer Science and Information Engineering from Tamkang University, Taiwan, in June 1989 and the Ph.D. degree in Computer Science and Information Engineering from National Central University, Taiwan, in June 1994. He joined the faculty of the Department of Information Management, Chung Jung University, Tainan, Taiwan, as an Associate Professor in June 1996. Since November 2002, he has become a Full Professor at the Department of Information Management, Chung Jung University, Tainan, Taiwan. He was a visiting scholar at the Department of Computer Science, University of Illinois at Urbana-Champaign, USA, from June to September 2001. He was the chairman of the Department of Information Management at Chung Jung University from August 2000 to July 2003. Since August 2004, he has become a Full Professor at the Department of Information and Learning Technology, National University of Tainan, Tainan, Taiwan. Currently, he is the chairman of the Department of Information and Learning Technology, National University of Tainan. He co-received the best paper award of 2001 IEEE ICOIN-15. His current research interests include mobile computing and wireless networks, mobile learning, data mining, and pervasive computing. Dr. Chen is a member of the IEEE Computer Society. Chih-Ping Chu received the B.S. degree in agricultural chemistry from National Chung Hsing University, Taiwan, the M.S. degree in computer science from the University of California, Riverside, and the Ph.D. degree in computer science from Louisiana State University. He is currently a Professor in the Department of Computer Science and Information Engineering of National Cheng Kung University, Taiwan. His current research interests include parallel computing, parallel processing, component-based software development, and internet computing.     

一种新的隐私保护型车载网络切换认证协议

该文针对现有车载网络切换认证协议存在的安全性、隐私等方面的不足,在LIAP协议的基础上提出改进方案。首先将随机数与伪标识串联,再用二次模运算对串联的信息进行加密,以生成动态身份标识保护用户位置隐私;与此同时,在移动终端切换过程中,新路侧单元重新生成新会话秘密序列,并与终端伪标识进行异或加密,对LIAP协议中存在的平行会话攻击进行安全防护。理论分析及实验表明,改进协议不仅满足终端匿名性和抵御各种攻击的安全需求,也实现了较快的切换速度,与同类切换认证协议相比,实用中具明显优越性。     

Collaboration of Trusted Node and QoS Based Energy Multi Path Routing Protocol for Vehicular Ad Hoc Networks

In the recent past information transmission through the vehicular ad hoc network (VANET) playing a vital role due to increase in accident statistics. There are numerous networking and VANET protocols helpful to control the trust while transmitting the data from source to destination nodes in traffic environment. In spite of many existing protocols for analyzing the trust in the network, the challenge of routing overhead, high energy consumption and malicious attacks issues still continue in the communication. This research introduces the trust collaboration nodes and Quality of Service (QoS) with energy multipath routing protocol for transmitting the information through VANET. Initially, the trusted nodes have been collected for analyzing the neighbouring nodes and the information are transmitted using the proposed QoS based energy efficient multipath routing protocol. During this transmission, the multi path protocol eliminates the intermediate attacks effectively when compared with the other existing protocols. The Proposed protocol maintains the QoS while routing the information from source to destination and further the efficiency has been analyzed through simulation experiments and Montgomery multiplier based Elliptic Curve Cryptography (ECC) will be used in future for better security and privacy.     

基于路径稳定性的Ad Hoc网络按需路由算法设计

鉴于Ad Hoc网络的高移动性,选择一条稳定的路径进行通信尤为重要.文章借鉴AODV按需路由的思想,提出了基于路径稳定性的路由算法PSR(Path Stable based on-demand Routing),通过引入路径有效因子PEF(Path Efficieney Factor)来考虑可行路径的稳定性问题,增强了所选路径的稳定性,减少了由于节点运动引起的链路断裂次数.性能分析和仿真结果表明,与AODV相比,PSR减少了开销,提高了效率,使得算法的性能得到了提升.     

移动Ad Hoc网络的一种跨层功率控制路由协议

移动ad hoe网络中通信终端能量有限,但在许多应用场景,尤其是战场环境下,节点能量消耗较大,因此采用有效的功率控制策略非常重要.利用信道增益的对称性,在AODV协议的基础上提出了一种不依赖于地理位置信息的跨层功率控制路由协议PBAODV,仿真表明该协议在不影响其他网络性能指标的前提下,有效的降低了系统整体功耗.