Dynamic Source Routing Protocol Based on Link Stability Arithmetic

An ad-hoc wireless network is formed by a number of mobile nodes having limited communication range. The dynamic source routing (DSR) protocol is frequently used to extend the effective range of these nodes through mutual cooperation. The accurate execution of the DSR protocol demands sustained benevolent behaviour by all participating nodes. However, as ad-hoc networks are created in improvised environments, the realization of such altruistic behaviour is virtually impossible to achieve. In fixed networks, trust infrastructures like certification authorities and key distribution centres are generally used to provide default trust relationships. However, the creation of such an entity in an ad-hoc network is considered neither feasible nor pragmatic. In this paper, we propose a novel mechanism for establishing trust based routing in ad-hoc networks without necessitating a trust infrastructure. We accentuate, that the proposed mechanism is most suitable for ad-hoc networks that can be created on the fly without making any suppositions or imposing pre-configuration requirements.

Enabling transmission over ad-hoc networks is more challenging than over conventional mobile networks because a connection path in an ad-hoc network is highly error-prone and the path can go down frequently. Although it is well-known that wireless channels are time varying because of user mobility and multi-path propagation effects, experiments for various types of channels show that the basic channel parameters can be stable for short time intervals. Therefore, a wireless channel can be adequately represented by a set of stationary channel models. There are number of wireless channel models proposed in literature. For simplicity, we used a two state Markov model known as a Gilbert-Elliot model and then in order to model more appropriately a real communication channel, a three state Markov model is analyzed here. We demonstrate our concept by applying it to the dynamic source routing protocol (DSR). In our proposed modified DSR, both the route discovery and route selection are based on physical layer parameter and the link monitoring function located at each node. Since routing selection based on the link quality is implemented, the minimum transfer delay from source to destination and the maximal throughput may be obtained. Simulation results show that according to the channel quality, the delay and throughput performance show remarkable performance when compared to traditional DSR.

Ad hoc networks are useful for providing communication support where no fixed infrastructure exists or the deployment of a fixed infrastructure is not economically profitable, and movement of communicating parties are allowed. Due to the dynamic topology, developing better routing protocol became a challenging task. The Dynamic Source Routing (DSR) protocol is a simple and efficient routing protocol designed specifically for use in multi-hop wireless ad hoc networks of mobile nodes. Multi-path routing protocol is one of the approaches used to have less overhead, better bandwidth cost by distributing the load among a set of paths . However, due to interfering in the channels of the paths, multi-path increases the end to end delay and do not work well in highly congested networks. In this paper we propose a congestion aware multi-path Dynamic Source Routing Protocol. we generate a set of disjoint multi-paths and handle the problem of end to end delay using the correlation factor measurement. A set of path selection criteria have been used to improve the end to end delay. The simulation experiments are conducted using ns-2 network simulator. We will compare the performance of the suggested algorithm to the performance of the conventional Dynamic Source Routing Protocol (DSR).

Wireless Ad Hoc network routing algorithm is one of the core technologies of wireless Ad Hoc networks. Ad Hoc network is dynamic topology on characteristic, mainly reflected on the network node number and node movement, which lead to network topology changes, in order to study the Ad Hoc network size and topology changes influence on packet delivery, time delay and routing control, through experiment it is concluded that, the dynamic source routing protocol is an ideal choice.

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.

Power-aware routing has proven to be effective in maximizing the life time of ad-hoc networks. However, all the previous research focused on the power-aware routing algorithms in a cooperative network, where all the nodes honestly report battery usage. However, selfish nodes in ad-hoc networks have incentives to misreport lower residual energy to maximize their own usage. In this paper, we first show that it is a dominant strategy for a selfish node to report lower residual energy in a power-aware ad-hoc network, which diminishes the benefits of power-aware routing algorithms. We then propose a novel power-aware reputation system (PARS), to stimulate cooperation on power-aware routing in ad-hoc networks. Analysis and simulation results show that PARS is effective in supporting power-aware routing in selfish ad-hoc networks.

Ad-hoc 네트워크 환경에서의 많은 라우팅 알고리즘들은 소스 라우팅 기법을 기초로 설계되었으며 밀집된 ad-hoc 환경에서의 최단경로설정은 짧은 기간동안만 유지되는 제약사항이 존재한다 때문에 SSA와 ABR과 같은 라우팅 프로토콜은 링크 안정성을 고려하여 좀더 안정적인 경로를 탐색한다. 본 논문은 Ad-Hoc network 환경에 현실적으로 적합한 SSA 라우팅 알고리즘을 바탕으로 utilization 메트릭을 고려한 새로운 라우팅 기법에 대해 제안한다. 제안된 방식에서는 SSA의 특정 메트릭에 의한 병목현상을 해결하기 위해 연결을 위한 여러 경로들을 누적 utilization에 따라 분산시키도록 하여 네트워크상의 로드 밸런싱을 추구하였다. 성능 분석을 위해 기존의 라우팅 기법인 AODV와 SSA를 참고 비교 대상으로 하였다. ns-2 네트워크 시뮬레이션 결과 선택되어질 수 있는 안정적인 route가 많은 경우 전체 트래픽이 여러 경로들로 분산되어 경로 재설정(route reconstruction) 횟수를 현저히 줄이는 좋은 성능을 보였다 Many routing algorithms, proposed for ad-hoc wireless networks, we based on source routing scheme and shortest path route has short lifetime especially in highly dense ad-hoc wireless networks. So some routing protocols such as SSA and ABR are considering the link stability and try finding more stable route. In this paper we propose a new routing algorithm considering utilization metric based on SSA routing algerian in Ad-Hoc networks. To reduce the bottleneck by specific metric of SSA, proposed scheme makes load balancing in networks by distributing the connections to several routes. For the evaluation of the performance we compare our scheme with existent routing protocol AODV and SSA. And the results, obtained using the ns-2 network simulation platform, show good performance that reduced the number of reconstructions remarkably by distributing the whole traffic to several routes when there are several stable routes.

Ad Hoc Routing with Distributed Ordered Sequences

In this paper, we analyze the advantages and disadvantages of the proactive QoS routing in ad-hoc networks. We discuss how to support bandwidth QoS routing in OLSR (Optimized Link State Protocol), a best-effort proactive MANET routing protocol. Using OPNET, we simulate the algorithm, exploring both traditional routing protocol performance metrics and QoS-specific metrics. Our analysis of the simulation results shows that the additional message overhead generated by the proactive QoS routing have a negative impact on the performance of the routing protocol. Given the negative results, we identified research areas that would be worthwhile investigating in order to obtain better performance results.KeywordsIdle TimePacket Delivery RatioOptimize Link State RoutGood BandwidthBandwidth ConditionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

An ad hoc network, a self-organizing wireless network is made up of mobile nodes, each node act as relay for providing data communication. The topology of the ad hoc networks changes often and needs large and frequent exchange of data among the network nodes for efficient routing. Existing routing protocols are distance vector method and link state routing protocols. The location information of the adhoc network nodes are broadcasted within the transmission range. The enemy can receive the location information of the nodes. Current position aided routing protocols were not designed for use in high risk environment. We have proposed a method for secured routing in adhoc network. It is a hierarchical method to solve the above problem. This method need not maintain the route information explicitly. This reduces the number of query control messages and suits well in dynamic environment. This method is better adaptive to dynamic environment than the present proactive, reactive and zone routing protocol methods (ZRP) and improves the security, efficiency and performance in ad-hoc routing.

We introduce WRP-Lite, which is a table-driven routing protocol that uses non-optimal routes, and compare its performance with the performance of the dynamic source routing (DSR) protocol, which is an on-demand routing protocol for wireless ad-hoc networks. We evaluate the performance of WRP-Lite and DSR for varying degree of mobility and traffic in a 20-node network. The performance parameters are end-to-end delay, control overhead, percentage of packets delivered, and hop distribution. We show that WRP-Lite has much better delay and hop performance while having comparable overhead to DSR.

A mobile ad-hoc network comprises of a number of low power wireless nodes. Each of these participating nodes endeavours to pass packets for other nodes based upon a preagreed protocol. The dynamic source routing (DSR) protocol is one of the most commonly used protocols in ad-hoc wireless networks. In a DSR based network, each transmitted data packet contains the complete list of node addresses that the packet has to traverse in order to reach its final destination. Intermediate nodes blindly forward these packets as per the attached list without taking into consideration the behavioural pattern of the subsequent nodes. In this paper, we present a variant of the DSR protocol in which intermediary nodes act as trust gateways. These gateways take into account the contemporary trust levels of the network nodes and thus facilitate in detecting and evading malicious nodes. With the help of extensive simulations, we demonstrate that the proposed DSR protocol augments the performance of the standard DSR protocol by up to 30% in a network where 40% of the nodes act maliciously. The proposed scheme is also independent of cryptographic mechanisms and does not impose any superfluous conditions upon the network establishment and operation phase.

Link stability poses an important role on the efficiency of routing in vehicular ad hoc networks (VANETs). Due to several reasons, it is very challenging to predict and improve link stability in vehicular networks. First of all, the mobility of nodes are very high, which frequently disconnects communicating nodes and creates links unstable. Secondly, the topology will change dynamically as nodes can join and leave that makes cluster maintenance a non-trivial challenge to solve. In this paper, we provide a stable clustering architecture that considers link stability and mobility in vehicular networks to reduce overhead for cluster formation and maintenance. The proposed architecture improves routing efficiency by using least number of hops from source to destination. To validate the proposed clustering architecture extensive simulation has been done using SUMO and NS3 environment. We have done some detailed comparison with some other clustering algorithms from the recent literature and results show the efficacy of our proposed architecture and algorithm.

Link state has been the dominating IGP routing technology in IP networks for more than a decade. With the advent of wireless ad-hoc networking, the need for light, efficient and robust routing makes it a good candidate to be also used in this constrained environment. One of the key issue in ad-hoc networking is the lack of bandwidth. Thus, in this paper we examine the overhead due to link state routing in an ad-hoc network. More precisely we study the classic link-state protocol OSPF and OLSR, a link state protocol that was developed specifically for ad-hoc networks. Further, we study how this overhead evolves when the node density increases. The last part of the paper presents directions towards extending OSPF for wireless and ad-hoc networks, which would make it a favorite to seamlessly unify wired and mobile IP networks.

The presence of asymmetric links is a common and non-negligible phenomenon in many ad-hoc networks, including MANETs and sensor networks. Asymmetry is caused by node mobility, heterogeneous radio technologies, and irregularities in radio ranges and packet loss patterns. Most existing ad-hoc routing protocols either assume fully symmetric networks or simply ignore any asymmetric links. In the first case, route discovery can fail when the symmetry assumption does not hold true, e.g., many reactive routing protocols rely on a two-phase communication process, where the same path is used to communicate between a sender and a receiver. If a single link on this path is asymmetric, the route establishment may fail. In the second case, asymmetric links are identified and explicitly ignored in the route establishment phase. This can lead to route discovery failure if there is no symmetric path between a sender and a receiver or it can lead to less than optimal routes. This document provides an overview of routing protocols that explicitly consider asymmetric links in the route discovery phase and introduces robust mechanisms that bypass asymmetric links to ensure successful route establishment.