Link quality aware local repair in AODV-based ad-hoc networks

The Ad Hoc On-Demand Distance Vector (AODV) protocol is an on-demand protocol specialized for mobile ad hoc network. Because of node's mobility and limited transmission range, the routes created by original AODV become invalid frequently leading to larger control overhead. In this paper, we propose a new scheme to improve AODV protocol by the concept of reliable distance. The reliable distance, which is always smaller than transmission range, is depended on the node's velocity and direction information attained from Global Positioning System (GPS). By the new mechanism, the routes are more reliable. Performance comparison of optimized AODV with conventional AODV by NS-2 simulator in various conditions shows the performance improvement.

Openly available communication signals, in wireless adhoc network poses high security risk. The adhoc networks are very much vulnerable to Dos attacks on the network layer. Blackhole and Grayhole attacks are the widespread attacks on adhoc networks. Here the malicious nodes interrupt data transmission in the network by transmitting false routing information. A realization of these enabled us to approach the subject of data security in wireless adhoc networks with a different perspective so as to have a communication route, free from all previously mentioned security threats. The purpose of this paper is to present an efficient Adhoc On-demand Distance Vector (AODV) protocol that removes the malicious node by isolating it, thereby ensuring secure communication. In order to achieve this goal, the intermediate nodes receiving false routing information from its neighbour node is programmed to consider that neighbour node as malicious. In adhoc network, nodes can join or leave at any time. So, an efficient security mechanism is needed. So, the nodes are arranged in spanning tree fashion. An RSA key exchange and two encryption techniques are used among authenticated neighbours in the adhoc network to provide more security and thus avoid group rekeying problems.

A Mobile Ad Hoc Network (MANET) protocol requires proper settings to perform data transmission optimally. To overcome this problem, it is necessary to select the correct routing protocol and use the routing protocol’s default parameter values. This study examined the effect of route request parameters, such as RREQ_RETRIES and MAX_RREQ_TIMOUT, on the Ad Hoc On-demand Distance Vector (AODV) protocol, which was then compared with the default AODV performance Optimized Link State Routing (OLSR) protocols. The performance metrics used for measuring performance were Packet Delivery Ratio (PDR), throughput, delay, packet loss, energy consumption, and routing overhead. The results show that the OLSR protocol has a smaller delay than the AODV protocol, while in other measurements, the AODV protocol is better than OLSR. By reducing the combination value of RREQ_RETRIES, MAX_RREQ_TIMEOUT in AODV routing to (2, 10 s) and (3, 5 s), the protocol’s performance can be improved. The two combinations result in an average increase in throughput performance of 3.09%, a decrease in delay of 17.7%, a decrease in packet loss of 27.15%, and an increase in PDR of 4.8%. For variations in the speed of movement of nodes, 20 m/s has the best performance, while 5 m/s has the worst performance.

An innovative method is proposed to analyze the nodes and its packets, in order to identify the malicious nodes which are created by the single or black hole attacks in the mobile ad hoc networks, by timeout period analysis. Timeout period acts as an imperative function to avoid the false alarms and predicts the misbehaving nodes accurately. The proposed method is dependent on the ad hoc on-demand distance vector (AODV) routing protocol and IEEE 802.11 MAC protocol. This paper proposed modified AODV with timeout period analysis for each transmitted packets from the nodes with queuing analysis for computing the average, minimum and maximum delay of packet transmission. The existing AODV protocol was modified to adopt the timeout period analysis, detect the malicious nodes which are to be changed as single or cooperative black hole nodes and remove the nodes from the network. The network simulator is used to simulate the modified AODV protocol to analyze the performance of the obtained results and correlate the results.

Hybrid Wireless Mesh Networks (HWMNs) based on the IEEE 802.11 are being increasingly deployed as a varied network of Mobile Ad-hoc Network (MANET) to provide users with extended coverage for wireless Internet access. HWAN, however, has a problem of too wide broadcasting of the Route Request (RREQ) in the route discovery of the Ad hoc Ondemand Distance Vector (AODV) protocol. In this paper, to enhance the performance of the AODV protocol, we have transformed it into a multipath protocol and proposed a new protocol that overcomes disadvantage of AODV by composing the neighbor table for overloaded RREQ. The neighbor table is provided in the form of metric using several items including the bandwidth. This can bring the localization effect of the nodes and we can expect a performance improvement by preventing an overloaded RREQ. Through the simulation, we could confirm better performance in packet loss rate, throughput, packet delivery ratio and routing overhead than the DSR protocol and AODV protocol.

The objective of this study is to enhance the Ad hoc On-demand Distance Vector (AODV) routing protocol, a representative mobile ad hoc network environment routing protocol. In the existing AODV protocol, dynamic topology changes due to node mobility cause frequent route failures and network instability. We herein propose a local repair scheme to re-establish routes when links are broken and a dual-path routing scheme to improve network stability by employing alternate routes. After comparing the total data processing volumes, average packet end-to-end delays, numbers of connection pairs, energy consumptions, and numbers of generated packets of the enhanced AODV protocols, we discuss the optimal operating conditions for each scheme. We also investigated the performance variations resulting from changing the number of nodes and node mobility, using an NS-2 simulator. The results revealed that the dual-path protocol generally performs the best and improves the packet end-to-end delay by up to 45 %.

Routing protocols are fundamental in establishing linkages and communication amongst nodes in Mobile Ad-hoc Networks (MANET). Since Ad-hoc On-demand Distance Vector (AODV) protocol shuns loops and minimizes route broadcasts its predominantly utilized in MANET. This systematic review sought to uncover approaches employed in extending AODV for performance improvement in MANET, their limitations, and AODV characteristics that are extendable. Barbara Kitchenham's original guidelines (2007) guided the research, while studies were retrieved from IEEE, Science Direct, Wiley, Semantic Scholar, ACM Digital Library, EBSCOhost, and Google Scholar databases. The common approaches employed are consideration of parameters to improve quality of service, artificial intelligence and machine learning, and use of the signal strength. The limitations of the approaches can be optimized for improved performance in terms of reduced control traffic and packet loss, efficient bandwidth and memory utilization, reduced processing costs, and energy consumption. The AODV characteristics commonly extended are route discovery, selection, and maintenance. Future work could investigate clustering and zoning, and caching mechanisms approaches to enrich the reliability, performance, and efficiency of AODV protocol.

<p>In the scenario of node failure in mobile multi-agent, Ad hoc On-demand Distance Vector (AODV) rout-ing protocol fails in network information transmission due to the damage of communication link. In addi-tion, the existing AODV multipath routing protocol node load balancing mechanism is imperfect. In order to solve the low network survivability caused by the above problems, an improved responsive multipath routing protocol MD_AODV (Multipath Destroy-resistance AODV) is proposed. The protocol is opti-mized in three aspects: multi-channel concurrency mechanism, node load balancing mechanism and shortest path maintenance mechanism. The simulation analysis of the modified AODV multipath routing protocol is realized on OPNENT simulation platform. The simulation results show that compared with AODV protocol, the improved multipath routing protocol can enhance the utilization of network re-sources and has better link redundancy. Moreover, the modified routing protocol not only enhances the reliability and fault tolerance of the path, but also increases the network aggregation bandwidth. </p> <p> </p>

Recently, the study of multicast routing attracts more attentions in MANET. Multicast Ad Hoc On-Demand Distance Vector (MAODV) protocol, which is multicast operation of the Ad hoc On-Demand Distance Vector (AODV) routing protocol, enables dynamic, self-starting, multihop routing between participating mobile nodes wishing to join or participate in a multicast group within an Ad Hoc network. Through analyzing its operation mechanism, we present a probability based multicast routing protocol with energy constrained (PBMR),in which a hybrid probability forwarding strategy is adopted. When a node wants to join a multicast tree, it floods a RREQ-Join message to its neighbors, when the neighbors receive this message, the neighbor with much energy left has a high probability to forward the message, and so on. By making correctness proof and complexity analysis of PBMR, this paper evaluates MAODV and PBMR with extensive simulations, the results show that PBMR has a better jitter than MAODV and a more balance in energy consumption. On the one hand, it saves the energy of the network system; on the other hand, it has a longer network lifetime and a more stable routing than MAODV and successfully solves the inconsistent problem of energy and scalability.

Mobile Ad Hoc Networks (MANETs) pose challenges in terms of power control, due to their fixed transmission power, the mobility of nodes and a constantly changing topology. High levels of power are needed in wireless networks, particularly for routing. In order to address this problem, power aware routing protocols have been proposed, with the aim of maximising the lifetime of the network. This paper presents an enhancement to the Ad Hoc On Demand Distance Vector (AODV) protocol, by reducing transmission power, when a large number of other radios are within range. This protocol, called DP-AODV (Dynamic Power AODV) combines the hello packet mechanism and the power control mechanism in order to reduce interference between nodes and increase the throughput in the network, thus reducing the overall power consumption. A performance evaluation of this enhanced protocol is carried out in comparison with three standard routing protocols, Ad Hoc On Demand Distance Vector (AODV), Ad Hoc On Demand Multipath Distance Vector (AOMDV) and Dynamic Source Routing (DSR), using network simulator 2 (NS2). Keywords-MANET; Dynamic Power; Density; Mobility; Interference.

The security of wireless networks has been a constant topic in the recent years. With the advance of wireless networks, building reliable and secured communication is becoming extremely important. Wireless security is a mechanism of preventing unauthorized access or damage to computers using wireless networks. A mobile ad-hoc network (MANET) is a self-organizing system of mobile nodes that communicate with each other through wireless links with no fixed infrastructure or centralized administration. This paper presents potential security attacks on Ad-hoc On-demand Distance Vector (AODV) routing protocol and their countermeasure. IETF standardized AODV and considered as one of the most popular and promising on-demand routing protocols because of its lower network overhead and algorithm complexity. AODV protocol does not store all the routing information in its routing table and this causes potential security threat to the wireless networks. In this paper, we consider various known security attacks and in- specific blackhole attack on AODV and propose a countermeasure to thwart blackhole attack.

This paper proposes a new function for the Ad Hoc On-Demand Distance Vector (AODV) algorithm using the connectivity concept to decide between source and local repair when a link break occurs. Besides, we used a Computational Intelligence algorithm, called Particle Swarm Optimization (PSO), which enables to find candidate solutions in all considered search space in order to reduce average data packet delivery delay sent over the network. The performance of the original AODV protocol, according to its Request for Comments (RFC), is compared with this new implemented approach, called here as AODVPSO. Three metrics were used to evaluate the performance of the algorithm: throughput (as data packet delivery fraction), routing overhead and average data packet delivery delay. We observed that the AODV-PSO outperformed the original AODV protocol in the scenarios studied in this paper.

Within this paper we planned a routing presentation of AODV and AOMDV protocols in MANET. The AODV (Ad hoc on demand Distance Vector) protocol is the unipath routing protocol and forming established the route in on require manner. With the help of AOMDV routing approach average end-to-end delay and routing above your head minimized and increased the presentation of the system. The multipath protocol has ability to ward balance the load of the network efficiently. The AOMDV (Ad hoc On demand Multipath Distance Vector) is the multipath routing protocol and established the more than two routes as the back-up route or alternative routes for data transmission and receiving in MANET. The performance of both the protocols are measured through maximum load handling, average load handling capability of nodes and routing performance is based on top of the packet deliverance part, throughput and end-to-end delay. The presentation of AOMDV protocol is superior to the unipath AODV and also handle the load through distributed to alternative paths.

Mobile ad-hoc networks are commonly known as MANETs. This type of network consists of nodes which are independent, mobile and also able to exchange messages between themselves. These nodes rely on limited battery; a common challenge in MANETs. As soon as battery power of node is used up, that node becomes a dead node. This node is not able to send or receive data. When all network nodes have used up their energy, then whole network becomes down. In this paper, energy consumption analysis of Ad-hoc on-demand distance vector (AODV) protocol is performed. Other parameters such as packet delivery ratio (PDR) and throughput are also analyzed using network simulator (NS2).

Ad hoc is a kind of self organized network which is different from traditional communication system. In recent years, ad hoc network has been well developed. AODV (ad hoc on-demand distance vector) is an important protocol of ad hoc network which is recommended by IETF by its simple operation and outstanding performance. However, AODV protocol is not perfect so far, which still has some issues needed to be amended. In this contribution, a unidirectional link problem in AODV protocol is discussed and several effective solutions are proposed, and some theoretical analysis is referred for performance comparison.