Predictive schemes for handoff prioritization in cellular networksbased on mobile positioning

摘要

We propose and evaluate new schemes for channel reservationnmotivated by the rapidly evolving technology of mobile positioning. Thenschemes, called predictive channel reservation (PCR), work by sendingnreservation requests to neighboring cells based on extrapolating thenmotion of mobile stations (MSs). A number of design enhancements arenincorporated to minimize the effect of false reservations and to improventhe throughput of the cellular system. These enhancements include: (1)nreservation pooling; (2) queuing of reservation requests; (3) hybridnapproach for integrating guard channels (GCs); and (4) using a thresholdndistance (TD) to control the timing of reservation requests. The designnenhancements have produced a set of highly efficient schemes thatnachieve significant reduction in handoff blocking rates while onlynincurring remarkably small increases in the new call blocking rates. ThenPCR approach has also been used to solve the MINBLOCK optimizationnproblem and has given significant improvement over the fractional guardnchannel (FGC) protocol. Detailed performance results of the differentnvariations of the PCR scheme and comparisons with conventional channelnreservation schemes are presented. An analytical Markov model for thenhybrid predictive version of the scheme is developed and itsnapplicability and numerical results are discussed