Joint admission/congestion control for wireless CDMA systemssupporting integrated services

摘要

A new data traffic control scheme is developed for maintaining thenpacket error rate (PER) of real-time voice traffic while allowingnnonreal-time data traffic to utilize the residual channel capacity ofnthe multi-access link in an integrated service wireless CDMA network.nDue to the delay constraint of the voice service, voice users transmitntheir packets without incurring further delay once they are admitted tonthe system according to the admission control policy. Data traffic,nhowever, is regulated at both the call level (i.e., admission control)nand at the burst level (i.e., congestion control). The admission controlnrejects the data calls that will otherwise experience unduly long delay,nwhereas the congestion control ensures the PER of voice traffic beingnlower than a specified quality of service (QoS) requirement (e.g., 10n-2). System performance such as voice PER, voice-blockingnprobability, data throughput, delay, and blocking probability isnevaluated by a Markovian model. Numerical results for a system with anRician fading channel and DPSK modulation are presented to show theninterplay between admission and congestion control, as well as how onencan engineer the control parameters. The tradeoff of using multiple CDMAncodes to reduce the transmission time of data messages is alsoninvestigated