Location management for efficient bandwidth allocation and call admission control

Wireless mobile networks require efficient bandwidth utilization and reliable link connectivity regardless of terminal mobility. Solutions proposed for bandwidth and location management tend to impose two conflicting requirements on network design, namely (1) maintain maximum resource (bandwidth) utilization and (2) reserve enough bandwidth so that the maximum rate of forced call termination rate due to bandwidth unavailability is kept below an acceptable level. To resolve this conflict, we proposed a predictive guard bandwidth scheme that adapts the resources´ access priority via guard bandwidth adjustments, in response to changes in instantaneous traffic load, predicted from terminal mobility tracking. A mathematical formulation has been derived to predict a mobile user´s movement behavior in terms of boundary crossing probability and cell residence probability, based on which active mobile probability is obtained to estimate instantaneous traffic load in terms of handoff call arrival rate and call departure rate. For given traffic situation, a dynamic programming approach has been further developed to determine the necessary amount of guard bandwidth to achieve the objective of congestion-related performance. The effectiveness of the proposed predictive guard bandwidth scheme is demonstrated through simulation studies in comparison with fixed guard bandwidth scheme. Simulation results indicate that the proposed scheme is insensitive to traffic load fluctuations caused by changes of user movement behavior, and that it maintains reliable connectivity without sacrificing bandwidth utilization efficiency