8,398 research outputs found

    Performance Evaluation Cross Layer Routing Metric in Protocol Routing OLSR Wi-Fi Wireless Mesh Networks

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    Wireless Mesh network is a wireless communications and allows multiple nodes work together to deliver message to the destination. Mesh topology improve the reliability of the entire network. Investment is needed in wireless mesh networks less than the cellular network. Wireless Mesh Network is a technology solution to increase the coverage, reliability and ease of implementation that have the nature of multi-hop, self-reconfigurable, self-healing and self-organized. WMN performance depends on the routing protocol used. Routing metrics used by routing protocols decides which route to use between pair of nodes. Various routing metrics have been developed to increase throughput, load balancing and choose the path that is reliable in Wireless Mesh Network. Some cross-layer routing metrics have been developed to improve network performance. This study aims to improve the throughput received by the network, by evaluating the performance of the simulation results cross layer routing metrics Expected Forwarded Counter (EFW) using routing protocols OLSR at 802.11 Wi-Fi Wireless Mesh Network. EFW is routing based on cross-layer metrics to overcome the problems caused by the drop packet selfish behavior on a mesh router. Simulations carried out by using Network Simulator 2. An optimal routing metric has a potential to improve performance of a wireless mesh network. For better performance Improvement can be done by designing efficient routing metrics that can support adaptive mesh routers and mesh clients. The simulation results were evaluated with a modified routing metric EFW with protocol routing OLSR in Wi-FI Wireless Mesh Network. Routing metric EFW is an improvement of ETX by adding the estimated probability of dropping relaying node. The propose routing metric is a combination of EFW metric with routing metric ETT that consider packet size and bandwidth of the link to improve overall routing performance. From the simulation result , routing metric EFW modification has better performance fo throughput,PDR, Packet loss, and end to end delay than routing metrix etx or routing metric EFW, when the number of nodes used is smaller and using high data rate scenario

    Performance Analysis of On-Demand Routing Protocols in Wireless Mesh Networks

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    Wireless Mesh Networks (WMNs) have recently gained a lot of popularity due to their rapid deployment and instant communication capabilities. WMNs are dynamically self-organizing, self-configuring and self-healing with the nodes in the network automatically establishing an adiej hoc network and preserving the mesh connectivity. Designing a routing protocol for WMNs requires several aspects to consider, such as wireless networks, fixed applications, mobile applications, scalability, better performance metrics, efficient routing within infrastructure, load balancing, throughput enhancement, interference, robustness etc. To support communication, various routing protocols are designed for various networks (e.g. ad hoc, sensor, wired etc.). However, all these protocols are not suitable for WMNs, because of the architectural differences among the networks. In this paper, a detailed simulation based performance study and analysis is performed on the reactive routing protocols to verify the suitability of these protocols over such kind of networks. Ad Hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR) and Dynamic MANET On-demand (DYMO) routing protocol are considered as the representative of reactive routing protocols. The performance differentials are investigated using varying traffic load and number of source. Based on the simulation results, how the performance of each protocol can be improved is also recommended.Wireless Mesh Networks (WMNs), IEEE 802.11s, AODV, DSR, DYMO

    Performance analysis of on-demand routing protocols in wireless mesh networks

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    Wireless Mesh Networks (WMNs) have recently gained a lot of popularity due to their rapid deployment and instant communication capabilities. WMNs are dynamically self-organizing, self-configuring and self-healing with the nodes in the network automatically establishing an adiej hoc network and preserving the mesh connectivity. Designing a routing protocol for WMNs requires several aspects to consider, such as wireless networks, fixed applications, mobile applications, scalability, better performance metrics, efficient routing within infrastructure, load balancing, throughput enhancement, interference, robustness etc. To support communication, various routing protocols are designed for various networks (e.g. ad hoc, sensor, wired etc.). However, all these protocols are not suitable for WMNs, because of the architectural differences among the networks. In this paper, a detailed simulation based performance study and analysis is performed on the reactive routing protocols to verify the suitability of these protocols over such kind of networks. Ad Hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR) and Dynamic MANET On-demand (DYMO) routing protocol are considered as the representative of reactive routing protocols. The performance differentials are investigated using varying traffic load and number of source. Based on the simulation results, how the performance of each protocol can be improved is also recommended

    SURVEY ON ROUTING METRICS AND ROUTING PROTOCOLS IN WIRELESS MESH NETWORKS

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    Today, Internet has become an indispensable part of our daily lives. It has a growing user community in many fields from banking transactions to online entertainment. It will be very efficient for users, as the next generation internet access becomes wireless like frequently used services such as cellular phones. But for providing this, a new network is needed to be designed or an existing network must be improved as well as making changes on infrastructure. At this point, mesh network infrastructure arises and offers more sophisticated internet access with less need. The most important advantage of mesh networks is the capability of working without infrastructure. Mesh networks are an additional access technology more than being a renewed one in the next generation wireless networks called 4G. In this study, wireless mesh networks base architecture and design factors are emphasized, current routing protocols that are used on wireless mesh networks and routing metrics on which these protocols are based, are explained. Finally, the performance effects of these protocols and metrics on different network topologies are referred.

    Feasibility of Using Passive Monitoring Techniques in Mesh Networks for the Support of Routing

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    In recent years, Wireless Mesh Networks (WMNs) have emerged as a promising solution to provide low cost access networks that extend Internet access and other networking services. Mesh routers form the backbone connectivity through cooperative routing in an often unstable wireless medium. Therefore, the techniques used to monitor and manage the performance of the wireless network are expected to play a significant role in providing the necessary performance metrics to help optimize the link performance in WMNs. This thesis initially presents an assessment of the correlation between passive monitoring and active probing techniques used for link performance measurement in single radio WMNs. The study reveals that by combining multiple performance metrics obtained by using passive monitoring, a high correlation with active probing can be achieved. The thesis then addresses the problem of the system performance degradation associated with simultaneous activation of multiple radios within a mesh node in a multi-radio environment. The experiments results suggest that the finite computing resource seems to be the limiting factor in the performance of a multi-radio mesh network. Having studied this characteristic of multi-radio networks, a similar approach as used in single radio mesh network analysis was taken to investigate the feasibility of passive monitoring in a multi-radio environment. The accuracy of the passive monitoring technique was compared with that of the active probing technique and the conclusion reached is that passive monitoring is a viable alternative to active probing technique in multi-radio mesh networks

    Attacks and countermeasures on routing protocols in wireless networks

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    Routing in wireless networks is not an easy task as they are highly vulnerable to attacks. The main goal of this work is to study the routing performance and security aspects of wireless ad hoc and mesh networks. Most of the routing protocols use hop-count as the routing metric. Hop count metric may not be appropriate for routing in wireless networks as this does not account for the link qualities, advantages of multi-radio paradigm etc. There are several metrics designed for link quality based source routing protocols for multi-radio wireless ad hoc and mesh networks. For example Weighted Cumulative Expected Transmission Time (WCETT), Adjusted Expected Transfer Delay(AETD) etc. But these metrics do not consider the effect of individual link qualities on the total route quality and route selection. This lack of ability from WCETT or AETD would allow them to select suboptimal paths when actually an optimal path is available. In another point of view, this inability can create a routing disruption attack named as delay-variation attack (a variant of black hole attack). It can be launched by a couple of colluding attackers attracting packets at one point by showing very good link qualities and dropping packets at another point by decreasing the link quality. To select an optimal route and prevent the above mentioned attack, a new routing metric known as Variance Based Path Quality metric (VBPQ) is proposed. VBPQ metric provides a robust, reliable and secure edge to the routing mechanism. Another major contribution of this study is to provide a detection mechanism for wormhole attacks in wireless ad hoc networks operating on link quality based source routing protocols. There have been several detection techniques designed for hop count based routing protocols but not for link quality based source routing protocols. In this work, a data mining approach called Cross feature analysis is used in an algorithm to detect wormhole attacks

    Identifying Design Requirements for Wireless Routing Link Metrics

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    In this paper, we identify and analyze the requirements to design a new routing link metric for wireless multihop networks. Considering these requirements, when a link metric is proposed, then both the design and implementation of the link metric with a routing protocol become easy. Secondly, the underlying network issues can easily be tackled. Thirdly, an appreciable performance of the network is guaranteed. Along with the existing implementation of three link metrics Expected Transmission Count (ETX), Minimum Delay (MD), and Minimum Loss (ML), we implement inverse ETX; invETX with Optimized Link State Routing (OLSR) using NS-2.34. The simulation results show that how the computational burden of a metric degrades the performance of the respective protocol and how a metric has to trade-off between different performance parameters
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