tailieunhanh - Wireless Mesh Networks part 12

Tham khảo tài liệu 'wireless mesh networks part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 264 Wireless Mesh Networks detection accuracy is increased. In the following sub-sections the two protocols are discussed in detail. A secure and efficient routing protocol for WMNs A secure and efficient routing protocol for WMNs has been proposed in Sen 2010a that can handle stringent quality of service QoS requirements of real-time applications. There are several key contributions of the work i It provides an accurate estimation of the end-to-end delay in a routing path the estimated value is then used to check whether the routing can guarantee the application QoS. ii It computes a link quality estimator and utilizes it in route selection. iii It provides a framework for reliable estimation of available bandwidth in a routing path so that flow admission with guaranteed QoS can be made. iv It helps in identifying and isolating selfish nodes. The protocol is a reactive routing protocol in which during the routing discovery phase each intermediate node uses an admission control scheme to check whether the flow can be admitted or not. If a flow is admitted an entry is created for the flow in a table called the flow table maintained locally by the node. The important components of the protocol are described below i. Estimating reliability of routing paths every node estimates the reliability of each of its wireless links to its one-hop neighbor nodes. For computing the reliability of a link the number of control packets that a node receives in a given time window is used as a base parameter. An exponentially weighted moving average EWMA method is used to update the link reliability estimate. If the percentage of control packets received by a node over a link in the last interval of measurement of link reliability is Nt and if Nt-1 is the historical value of the link reliability before the last measurement interval a is the weighting parameter the updated link reliability R is computed using 8 R a Nt 1 -a Nt-1 8 Every node maintains estimates of the .