Wireless network performance analysis for adaptive bandwidth resource allocations.

摘要

With the rapid development in mobile communications and the emergence of various multimedia applications, it becomes more important that wireless networks satisfy appropriate quality-of-service (QoS) requirements. Call admission control (CAC) is an essential network management tool in wireless communications networks. It is used to provide improved network utilization and to guarantee QoS. The fundamental problem is how to allocate network resources to different users within QoS constraints.; Adaptive bandwidth call admission control can be used to improve network utilization and maintain the QoS requirements. In this dissertation we propose adaptive bandwidth call admission control with dynamic recourse allocation schemes which can be implemented in wireless multimedia network. The proposed schemes differentiate the QoS requirements of each call and prioritize handoff call requests over new call requests. Buffering call requests (handoff or new call) using a multi-queue mechanism has been also proposed to reduce blocking and dropping probabilities when the system is fully utilized (all channel are occupied). The performance analyses of the proposed schemes shows significant enhancements in comparison with the well known handoff prioritization scheme (guard channel scheme). The adaptation problem is also formulated as a three-dimension Markov chains under general adaptability conditions with different service times. The steady state transition probability, the new call blocking probability and the handoff dropping probability formulas are presented.