Combined speech and video scalable coding: a UMTS case study

All-IP UMTS cell capacity evaluation, considering two real-time services: telephony and video telephony is considered in this paper. For each service, we introduce two levels of quality: standard and premium. This differentiation is achieved by using the two-layers SNR scalability featured by H.263 video coder and two different bit-rate modes for adaptive multirate (AMR) speech coder. First, we show how to map the above services into the radio bearers of the UMTS terrestrial radio access (UTRA). Then, we describe a methodology to evaluate the uplink channel capacity of the cell when loaded with the above services. To this end for both services, and for each quality level within each service, we define a target QoS through subjective and objective quality assessments. These QoS are met by squeezing out the available CDMA resources of the cell. Results are given in terms of admission regions for different scenarios.