QoS performance measure and system design in wireless ATM

This paper presents a model to estimate the quality of service (QoS) in wireless ATM. Wireless ATM should inherit the ATM feature of efficiently transporting highly diverse multimedia traffic with QoS guarantees. A challenge in guaranteeing QoS in wireless ATM is to coordinate the wireless ATM quality with the end-to-end QoS. The system analysis shows that an independent wireless ATM network architecture design facilitates the system design and segregates an end-to-end performance measure into two independent measures of the wireless and fixed networks. Advantages of independent measures are independent sets of traffic and QoS parameters and performance target for spectral efficiency, isolating perturbation of the performance measure caused by user mobility in the wireless domain, and facilitating the system provisioning for QoS guarantee. The delay analysis shows that the deterministic delay, such as the packetization delay, and the processing delay for interleaving and deinterleaving to reduce the signal correlation of the fading channel, occupy a great fraction of the delay budget. To achieve the minimal QoS target, the random delay factors, such as queueing delay and handoff latency should be limited.