A hand-off scheme for wireless ATM networks

The integration of the wireless and the wireline networks continues to present several challenging research issues. As ATM is the choice for the backbone of wireline broadband network, it is natural to extend the ATM protocol to the wireless environment. However, the current ATM signaling does not handle the issue of host mobility, especially the connection handoff problem. In this paper, we investigate the issue of extending the ATM protocol to support connection handoffs. A VP_based hierarchical handoff scheme is proposed to support the ATM protocol over the integration of the wireless and wireline networks. This scheme provides a fast and efficient handoff connection processing mechanism. It also provides (1) a distributed connection admission control, (2) a reduction of the connection disruption time during a connection handoff session, and (3) a minimal buffer requirement from the mobile host and base stations. During a connection handoff, misrouted ATM cells can be re_routed to their destinations. Hence, ATM cells of a connection are kept in order when the connection handoff occurs. This substantially reduces the overhead due to end_to_end retransmissions invoked at the higher layer. An analytical model is used to present the handoff algorithm. This model provides a mechanism for calculating performance metrics such as, the connection disruption time and the buffer requirement of the mobile host and base stations.