MeshScan: Performance of Passive Handoff and Active Handoff

Abstract

A core problem of fast handoff is when handoff should perform and which Mesh Node (MN) should associated with. We have developed a fast handoff management scheme called MeshScan to provide a novel use of channel scanning latency, by employing open system authentication in both Passive Handoff and Active Handoff. This scheme comprises three steps: firstly a client device takes advantage of the Wireless Mesh Network (WMN) architecture to maintain a list of active MNs. Secondly MeshScan Handoff Sensor performs handoff when it receives a disassociation management frame from the serving MN or when the measured signal strength from the serving MN exceeds a given threshold. Thirdly when handoff is required, a client transmits Authentication Request frames to all MNs from the list instead of broadcasting Probe Request frames, as in an active scan to discover the available MNs. The handoff delay is used as criteria for system performance. Numerical results are presented to demonstrate the feasibility of MeshScan with Active Handoff algorithm. This fast handoff scheme is feasible by upgrading the software only on the client side. This paper compares the theoretical handoff latency of MeshScan with other approaches and we demonstrate the effectiveness of our scheme through experiment.