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

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

Attacks and countermeasures on routing protocols in wireless networks

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

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

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

An enhanced bridged-based multi-hop wireless network implementation

Proceedings of: 5th Annual ICST Wireless Internet Conference (WICON 2010), 1-3 March 2010, SingaporeIn this paper an enhanced Layer-2 multi-hop wireless network implementation for Infrastructure based Wireless Mesh Networks is presented. This work combines the flexibility of Layer-2 Wireless Bridging with the dynamic self-configuring capabilities of MANET routing. The main contribution of this paper is an investigation of the issues encountered when applying a pure bridging based solution to wireless multi-hop networks and the development of several mechanisms to overcome these problems. This work was implemented and deployed in a real testbed environment using Routerboard hardware and utilising a number of open-source network tools in accordance with the needs of our platform. The developed testbed incorporates self-healing and self-configuration features without requiring a traditional MANET routing protocol. Instead the 802.11 beacon frames sent by the Access Points were extended with link information to allow optimal construction of the mesh topology. Results are presented which demonstrate the automated topology construction mechanism. Further results also show the enhancements made to the normal 802.11 Layer-2 mobility mechanism.European Community's Seventh Framework ProgramPublicad

A STUDY OF ZIGBEE TECHNOLOGY

The zigbee communication is a communication technology to connect local wireless nodes and provides high stability and transfer rate due to data communication with low power. In the nodes away from coordinator in one PAN, the signal strength is weak causing the network a shortage of low performance and inefficient use of resources due to transferring delay and increasing delay time and thus cannot conduct seamless communication. This study suggests the grouping method, that makes it possible to perform wide range data transferring depending on the node signal strength in zigbee node and analyzes the suggested algorithm through simulation. Based on IEEE 802.15.4 Low Rate-Wireless Personal Area Network (LR-WPAN) standard, the Zigbee standard has been proposed to interconnect simple, low rate and battery powered wireless devices. The de-ployment of Zigbee networks is expected to facilitate numerous applications such as Home-appliance net-works, home healthcare, medical monitoring and environmental sensors. An effective routing scheme is more important for Zigbee mesh networks. In order to achieve effective routing in Zigbee Mesh networks, a Zigbee protocol module is realized using NS-2. The suitable routing for different data services in the Zigbee application layer and a best routing strategy for Zigbee mesh network are proposed. The ZigBee standard provides network, security, and application support services operating on top of the IEEE 802.15.4 Medium AccessControl (MAC) and Physical Layer wireless standard. It employs a group of technologies to enable scalable, self-organizing, self-healing networks that can manage various data traffic patterns. ZigBee is a low-cost, low-power, wireless mesh networking standard. The low costal lows the technologyto be widely deployed in wireless control and monitoring applications, the low power-usage allows longerlife with smaller batteries, and the mesh networking which promises high reliability and larger range. ZigBee has-been developed to meet the growing demand for capable wireless networking between numerous low power devices. The aims of this network are to reduce the energy consumption and latency by enhancing routing algorithm. In a traditional tree routing when a node wants to transmit a packet to the destination, the packet has to follow child/parent relationship and go along tree topology, even if the destination is lying at nearby source. In order to solve this problem, an Enhanced Tree Routing Algorithm is introduced using ZigBee network. This algorithm can find the shortest path by computing the routing cost for all of router that stored in neighbor table, and transmit the packet to the neighbor router that can reduce the hop count of transmission. The enhanced tree routing algorithm can achieve more stable and better efficiency then the previous traditional tree routing algorithm

Coefficient of Restitution based Cross Layer Interference Aware Routing Protocol in Wireless Mesh Networks

In Multi-Radio Multi-Channel (MRMC) Wireless Mesh Networks (WMN), Partially Overlapped Channels (POC) has been used to increase the parallel transmission. But adjacent channel interference is very severe in MRMC environment; it decreases the network throughput very badly. In this paper, we propose a Coefficient of Restitution based cross layer interference aware routing protocol (CoRCiaR) to improve TCP performance in Wireless Mesh Networks. This approach comprises of two-steps: Initially, the interference detection algorithm is developed at MAC layer by enhancing the RTS/CTS method. Based on the channel interference, congestion is identified by Round Trip Time (RTT) measurements, and subsequently the route discovery module selects the alternative path to send the data packet. The packets are transmitted to the congestion free path seamlessly by the source. The performance of the proposed CoRCiaR protocol is measured by Coefficient of Restitution (COR) parameter. The impact of the rerouting is experienced on the network throughput performance. The simulation results show that the proposed cross layer interference aware dynamic routing enhances the TCP performance on WMN