An adaptive call admission policy for broadband wireless multimedia networks using stochastic control

One of the key techniques in ensuring the quality of service in wireless networks is call admission control. The traditional well-known guard channel (GC) scheme and its numerous variants give preferential treatment to the handoff calls over new arrivals by reserving a number of radio channels exclusively for handoffs. However, this scheme is not able to adapt to changes in traffic pattern due to the static nature. The SDCA (stable dynamic call admission) control mechanism proposed by S. Wu (2002) can overcome that shortcoming, and improve the control precision and stability greatly because of its stochastic nature. Unfortunately, it is only suitable for single-service. In this paper, call admission control mechanism is extended by setting up a fictitious stochastic model to study the actual system so as to void meeting the complicated multiple dimensions stochastic problem and propose a new scheme called multiservices dynamic call admission (MDCA) to adapt for multiservices in the broadband wireless networks. Numerical results of simulation show that our scheme steadily satisfies the hard constraint on call dropping probability of multiservices while maintaining a high channel throughput.