MULTIPLE CALL HAND-OFF PROBLEM WITH QUEUED HAND-OFFS AND MIXED PLATFORM TYPES

Cellular communication systems that support a mixture of platform types and queuing of hand-off calls are considered. In pure loss systems, if there are no channels available at the target gateway, the hand-off attempt fails and the call is forced to terminate. In delay systems however, hand-off calls can be held in queue while the supporting mobile is within a transition region where acceptable performance can be provided by at least two different gateways (base stations). When only a finite number of hand-off calls can be queued, mixed delay/loss configurations arise. An analytically tractable model is developed to predict communications traffic performance for such systems. Theoretical performance characteristics obtained show trade-offs among blocking and forced termination probabilities and carried traffic.