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

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

Security and Privacy Issues in Wireless Mesh Networks: A Survey

This book chapter identifies various security threats in wireless mesh network (WMN). Keeping in mind the critical requirement of security and user privacy in WMNs, this chapter provides a comprehensive overview of various possible attacks on different layers of the communication protocol stack for WMNs and their corresponding defense mechanisms. First, it identifies the security vulnerabilities in the physical, link, network, transport, application layers. Furthermore, various possible attacks on the key management protocols, user authentication and access control protocols, and user privacy preservation protocols are presented. After enumerating various possible attacks, the chapter provides a detailed discussion on various existing security mechanisms and protocols to defend against and wherever possible prevent the possible attacks. Comparative analyses are also presented on the security schemes with regards to the cryptographic schemes used, key management strategies deployed, use of any trusted third party, computation and communication overhead involved etc. The chapter then presents a brief discussion on various trust management approaches for WMNs since trust and reputation-based schemes are increasingly becoming popular for enforcing security in wireless networks. A number of open problems in security and privacy issues for WMNs are subsequently discussed before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the author's previous submission in arXiv submission: arXiv:1102.1226. There are some text overlaps with the previous submissio

RECOMAC: a cross-layer cooperative network protocol for wireless ad hoc networks

A novel decentralized cross-layer multi-hop cooperative protocol, namely, Routing Enabled Cooperative Medium Access Control (RECOMAC) is proposed for wireless ad hoc networks. The protocol architecture makes use of cooperative forwarding methods, in which coded packets are forwarded via opportunistically formed cooperative sets within a region, as RECOMAC spans the physical, medium access control (MAC) and routing layers. Randomized coding is exploited at the physical layer to realize cooperative transmissions, and cooperative forwarding is implemented for routing functionality, which is submerged into the MAC layer, while the overhead for MAC and route set up is minimized. RECOMAC is shown to provide dramatic performance improvements of eight times higher throughput and one tenth of end-to-end delay than that of the conventional architecture in practical wireless mesh networks

Secure Routing in Wireless Mesh Networks

Wireless mesh networks (WMNs) have emerged as a promising concept to meet the challenges in next-generation networks such as providing flexible, adaptive, and reconfigurable architecture while offering cost-effective solutions to the service providers. Unlike traditional Wi-Fi networks, with each access point (AP) connected to the wired network, in WMNs only a subset of the APs are required to be connected to the wired network. The APs that are connected to the wired network are called the Internet gateways (IGWs), while the APs that do not have wired connections are called the mesh routers (MRs). The MRs are connected to the IGWs using multi-hop communication. The IGWs provide access to conventional clients and interconnect ad hoc, sensor, cellular, and other networks to the Internet. However, most of the existing routing protocols for WMNs are extensions of protocols originally designed for mobile ad hoc networks (MANETs) and thus they perform sub-optimally. Moreover, most routing protocols for WMNs are designed without security issues in mind, where the nodes are all assumed to be honest. In practical deployment scenarios, this assumption does not hold. This chapter provides a comprehensive overview of security issues in WMNs and then particularly focuses on secure routing in these networks. First, it identifies security vulnerabilities in the medium access control (MAC) and the network layers. Various possibilities of compromising data confidentiality, data integrity, replay attacks and offline cryptanalysis are also discussed. Then various types of attacks in the MAC and the network layers are discussed. After enumerating the various types of attacks on the MAC and the network layer, the chapter briefly discusses on some of the preventive mechanisms for these attacks.Comment: 44 pages, 17 figures, 5 table