A Cross-Layer Distributed Call Admission Control

A wireless mesh network (WMN) is a collection of wireless network nodes that communicate among themselves. Unlike wireless local area networks, WMNs are self configuring systems, where each node can relay messages on behalf of others. This allows coverage of a much larger geographical area than if all nodes needed to be able to communicate directly with a central node. WMNs promise to deliver wireless services for a large variety of applications in personal, local, campus, and metropolitan areas. To fulfill their potential, WMNs require fast, efficient & accurate admission control policy to allow connections access with minimal impact on existing connections & full consideration for network congestion. This paper presents a two part admission control mechanism for WMNs, a route admission control(RAC) and a connection admission control(CAC). The RAC part uses bandwidth estimates (BWEST) of the available traffic resources. This BWEST is driven from the measured traffic at the specific WMN node during a fixed period of time. The available bandwidth is calculated at each node and is updated regularly, and used by the admission controller to route new incoming connections. Connection acceptance during the CAC part is decided based on the call dropping probability. Numerical results show considerable improvement in the admission control responsiveness and network throughput. It also shows that BWEST becomes more accurate under heavy traffic conditions.