Call Admission Control (CAC) protocols play a very important role in the performance of wireless networks. In this paper, we present a call admission control protocol for cellular wireless networks. Our protocol depends on degrading the existing calls by reducing the bandwidth allocated to them in order to admit "important" calls. Our protocol assign priorities for the incoming calls, and in the same time assign priorities to the existing calls, both admitted calls are admitted according to their priorities and the existing calls are degraded according to their priorities. We show simulation results for the relation between network utilization, call-blocking probability, and average assigned bandwidth during the life of the call.

The performance of any cellular wireless network, as well as its revenue (number of customers using the network, and their degree of satisfaction) is determined to a great extent by its call admission control (CAC) protocol. As its name implies, the CAC determine if a new call request is granted, or rejected. In this paper, we propose a call admission control protocol for cellular multimedia wireless networks. Multimedia networks are characterized by a wide variety of bandwidth requests, priorities, and drop-off/rejection requirements by different customers. Our protocol depends on degrading the existing calls, according to their degradation priority, by reducing the bandwidth allocated to them in order to admit new calls according to their admission priority. Our protocol is too complicated for an analytical solution. However we present a Markov Model of a simplified version of our protocol for completeness, a Markov representation of the protocol is too complicated to be of any real value. Extensive simulation results show how our proposed protocol can improve the drop-off/rejection ratio for large bandwidth calls and at the same time maintain the quality of service requested by important calls.