Elastic Routing in Ad Hoc Networks with Directional Antennas

This article presents a hybrid genetic algorithm (GA) with two-optimization algorithm, to find a solution to the problem routing in Ad Hoc network big map, the objective is to find the shortest possible distance between a transmitter head (cluster, node, intermediate or advanced) and the base station. From studies and remarks, it has been proved that in the topologies of the large Ad Hoc network, the node responsible for transmitting to the base station sometimes used up its total energy and became inactive. So, there are many techniques to solve the problem routing in Ad Hoc networks, like GA (Genetic Algorithm), SA (Simulated Annealing), and BA (Bat Algorithm). In this article, we are focus on the (GA) that are present in the basic approaches of our work. We propose an analysis of these metaheuristics by identifying the fundamental ideas and propose ways to guide the choice of a metaheuristic in practice, particularly in Ad Hoc big map network, to find the best path between two nodes in communication. Thereafter, we try to more optimizer our algorithm by using a 2-optimizer algorithm, and we compare between two method GA and GA-2opt, the result show much better quality of our solution to adjust the problem of routing in big map Ad Hoc network.KeywordsArtificial intelligenceGenetic algorithmTwo-optimization algorithmAd Hoc network

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.

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.

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.

In this paper, we address the problem of multicast routing in mobile ad-hoc networks from the viewpoint of energy efficiency. In an ad-hoc wireless network, each node runs on a local energy source which has a limited energy life span. Thus, energy conservation is a critical issue in mobile ad-hoc networks. One approach for energy conservation is to establish routes that require lowest total energy consumption. This optimization problem is referred as the minimum-energy multicast routing problem (MEMRP). In this paper, propose new efficient heuristic algorithms for the construction of energy-efficient multicast routes in mobile ad-hoc networks. These algorithms exploit the broadcast nature of the wireless channel, and address the need for energy-efficient operations. Empirical studies show that our algorithms are able to achieve better performance than algorithms that have been developed for MEMRP.

Ad Hoc wireless network consists of mobile nodes that do not rely on any fixed network infrastructure. The dynamic route is allocated for a pair of nodes by Ad Hoc on-demand routing protocol (AODV), that establishes a route only when a source node want to transmit data. Routes in Ad Hoc network can be broken caused by a node in the route may move out of their neighbor's signal range or node's battery may be ran out. Many algorithms have been developed to solve the problem [1],[6], one of them is break avoidance algorithm (AODV-BA [1]). However, using AODV-BA protocol, an upstream node of the broken link has to buffer packets during the route maintenance process. In case that the route maintenance is unsuccessful, the source node must re-establish a new route. In this paper, we propose AODV Backup Route Discovery with 2 Levels of Threshold (AODV-2T). The protocol tests for the power of its own battery power and its neighbors' RF signal. And it would cooperate with the neighbors to find a backup route as to fix the weak link problem where the first threshold is met. Consequently, if the power of signal or battery is fallen below the second threshold level, AODV-2T node could switch the data packet transmission to the new route without any delay. AODV-2T can reduce connection tear-off that causes packets lost and more routing control overhead by 15-18 percent compared to the original AODV and AODV-BA.

Mobile Ad hoc Network is an emerging research area with practical applications. Due to its fundamental nature, however, a malicious attack may disrupt the route discovery process and significantly affect the Quality of Service delivered by the network In this paper, we introduce a new secure routing protocol, Secure On-demand Source Routing (SOSR), which follows a number of basic techniques of ad hoc on-demand routing protocols. Our protocol is based on promiscuous receive mode, successfully defeats different types of identified attacks and detects misbehaviors of abnormal nodes. The only requirement of the protocol is a shared key between the communication end nodes. In particular, the scheme offers low processing overhead for intermediate nodes of the network.

In this paper, first we introduce the basic principle of network coding and the present research situation. Then, in allusion to the limitation that traditional wireless Ad Hoc routing protocol can't support network coding well and that network coding system COPE passively waits for coding opportunity, an improved CA-DSR(Coding Aware-DSR) protocol is presented. This protocol considers the factors: utilizing the coding opportunity, finding the shortest path and neatly avoiding long route delay comprehensively as the route selection criteria. The simulation results on NS2 Simulation platform show that the improved routing protocol can discover the code opportunity and improve the network throughput effectively.

When a jamming attack occurs, existing ad hoc routing protocols can experience significant throughput degradation and unnecessary control overhead due to the inclusion of unreliable links into routing paths. In this work, we identify which factors hinder establishment of reliable routing paths by the existing routing protocols in the face of jamming attacks. Our solution is Jamming-Aware Routing (JAR) based on OLSR protocol, which provides explicit route recovery procedures to counteract jamming attack. By establishing a reliable routing path, the proposed scheme achieves significant throughput gains as well as control overhead reduction.

In general, MIMO systems are associated with high scattering isotropic propagation while the use of directive antennas is associated with free space or narrow angular spread conditions. We found outdoor-indoor channels to be in between these two extremes, in the sense that we observed directivity - and - MIMO gain, for the same ensemble of channels. Our observation is based on measurements with directive (8 dB gain) and dipole antennas. Median MIMO capacities were found to be 80% of the ideal (Rayleigh i.i.d.), at 5 dB signal to noise ratio (SNR), with no significant difference resulting from the choice of antenna. On the other hand, using properly aimed directive antennas, the SNR was found on average to be 5.4 dB above that obtainable with dipoles, somewhat less than the 7 dB antenna gain difference. Thus, isotropic propagation, which would have negated directivity gains, cannot be justified in general. The combination of MIMO processing and angular search with directive antennas resulted on average in gains of 69% over the median capacities obtained with dipoles. Since MIMO and directivity can combine effectively, it may in some cases be convenient to arrange subgroups of antennas for beamforming, and then process the thus reduced number of radio channels for MIMO gain.

Ad hoc networks were created to provide communication between peers without any network infrastructure. They could help in a hostile environment for military and rescue entities, and also for commercial applications such as gaming or facilities for networking. To improve the provided services on those networks, many quality of service (QoS) frameworks have been proposed to improve the performance of ad hoc networks, and to offer many possibilities for important applications to use priorities, admission control, or quasi guarantees. The dynamicity of ad hoc networks introduces complexity for such QoS schemes. In this chapter, we offer a summary of all existing ad hoc protocols at different levels of the network architecture and the proposed QoS frameworks.

Routing for ad-hoc wireless network is challenging, and there is no single routing strategy to deal with the complex and dynamic nature of the ad-hoc network. Given the availability of the low cost of location-aware devices, geographic forwarding and routing provided opportunity for improving existing ad-hoc routing strategies. In this paper, geographic forwarding strategies and geographic routing protocols are reviewed; challenges of implementing geographic routing in ad-hoc network are identified and discussed. More research effort is called for improving the basic forwarding strategy to increase the efficiency of the geographic routing protocol to provide a practical solution addressing the issues related to routing around local minima.

Ad Hoc network is one of the popular wireless multi-hop networks. Nodes or Users in Ad Hoc network can move randomly and freely to maintain communication without the control of the fixed infrastructure. Due to the limited transmission power and wireless coverage of the terminal, if two terminals that are beyond their respective transmission radius need communicate, they must use other intermediate or relay nodes for packet forwarding, so that a wireless Ad Hoc network is formed among these nodes. In this paper, the current state-of-the-art multipath routing protocols for Ad Hoc networks are reviewed. Particularly, the pros and cons of them are analyzed. Finally, they are summarized and compared.

The next generation mobile communication systems will be based on infrastructure wired/ wireless LAN technologies and ad hoc networks. Such hybrid networks benefit the extension of infrastructure network coverage using ad hoc connectivity apart from offering the ad hoc nodes access to the resources of the wired/infrastructure networks. In most of the integration strategies Mobile IP is integrated with the ad hoc network routing protocol to provide Internet access and in few of the strategies the routing protocol has been enhanced to provide the connectivity without using Mobile IP.Few strategies use fixed gateways, others use mobile gateways. In this paper, we proposed two different approaches of integrating ad hoc network and the wired network using two different protocols. In the first part of this paper, an extended DSDV protocol, named as Efficient DSDV (Eff-DSDV) protocol is used to provide bi-directional connectivity between exclusive ad hoc hosts and the hosts on the Internet (wired network). The proposed framework uses one of the ad hoc hosts known as Mobile Gateway Node (MGN) to act as a bridge between ad hoc network and the Internet. The performance comparison is made between the proposed approach and one of the leading strategies based on packet delivery ratio, end-end delay, and control overhead. The experimental results indicate that the performance of the proposed strategy is better than the existing strategies.Later in the paper, we propose a framework for integrating mobile ad hoc network and the Internet using both fixed and mobile gateways. The ad hoc hosts can access the Internet using either fixed or mobile gateway, based on criteria of distance, load on the gateway. An extended version of AODV routing protocol is used in the framework. The objective behind using both fixed and mobile gateways is to increase the reliability of the Internet access, scalability, providing transparent Internet access to the ad hoc hosts and in general improve the performance of the integrated framework. The proposed framework is a hybrid architecture involving two-layer and three-layer approaches of integration. The performance comparison of the two proposed strategies has been done under common metrics. KeywordsMobile Ad Hoc Network (MANET)Integration StrategyMobile Gateway Node (MGN)Routing ProtocolEff-DSDVFixed GatewaysMobile Gateways

In this paper, Ad hoc on-demand distance vector (AOMDV) routing protocol has been analysed based on different performance parameters in different network scenarios. Performance parameters like normalized routing load, throughput, dropped packets, receiving packets, average delay. At different values of network connections, pause times, simulation times, and speed rates, we compared performance of AOMDV with Ad hoc on-demand distance vector, Destination-Sequenced Distance Vector, and Dynamic Source Routing routing protocols. For simulation work, network-simulator 2.35 has been used.