Quality of service scheduling for UMTS

The goal of the Universal Mobile Telecommunication System (UMTS) is the delivery of multimedia services to the mobile user. Each different service requires its specific quality of service (QoS) to satisfy the mobile user. In this paper, a scheduling algorithm for the medium access control (MAC) is presented that satisfies these QoS requirements. The main task of a scheduler is the of logical channels to appropriate transport in accordance to service requirements. Considering packet based services, the traffic characteristic is very dynamic due to its interactive and bursty nature. In consequence, a highly dynamic and flexible scheduling is required since the scarce radio resource should be used most efficient. The paper introduces a scheduler with dynamic channel type switching and transport format (TF) selection in accordance to the service QoS requirements. To validate the scheduling concept a typical mobile user application mix is examined for performance analysis by simulations.