Mobility and connection management in a wireless ATM LAN

This paper proposes algorithms for handoff, location, and connection management in a wireless asynchronous transfer mode (ATM) local-area network (LAN). Fast handoffs while maintaining cell sequence and quality-of-service (QoS) guarantees are achieved by distributing switching functionality to base stations, and using a networking scheme based on provisioned virtual trees. A new distributed location management scheme using a minimal registration procedure and broadcasts on wired links is proposed for this LAN. The detailed signaling procedures that support the algorithms for mobility and connection management are described. Finally, an implementation of these procedures and an analysis of the measured data is presented. Measurements of service times obtained from this implementation indicate that over 100 calls/s. can be handled by each node in 50-node network with a high-percentage of mobiles (75%) relative to fixed endpoints. This is comparable to current wired ATM switch call handling throughputs, in spite of the fact that these nodes perform additional handoff and location management functions. The data also indicates handoff latency times of 1.3 ms. This validates our proposal for maintaining cell sequence while performing handoffs.