Abstract
UMTS access networks can provide a wide range of bearer services with different levels of quality of service suitable for multimedia applications with bit rates of up to 2 Mbit/s. These multiple services are managed by use of composite transport channels, each having static and semi-static transport channel parameters such as transport block size, CRC code length, channel coding schemes, RLC mode, MAC type, transport time interval, rate matching and spreading factor. The perceived quality of the application seen by the end user is greatly affected by the settings of these radio access parameters. The paper examines the effects of these network parameter settings on the performance of real-time video communications by simulating MPEG-4 coded video transmission over a UMTS multimedia evaluation test bed. It investigates the optimal radio bearer design for real-time video transmission over UTRAN (UMTS terrestrial radio access network).