Data Plane Performance Issues Concerning MBMS in UMTS Release 6

Inhalt:
Third generation (3G) wireless networks, such as UMTS, should offer broadband broadcast and multicast services enabling several mobile users to receive the same downlink data stream using minimum possible network resources. It appeared that CBS (Cell Broadcast Service), used in current 2G and 3G networks, is insufficient to provide such services in terms of offered throughput and QoS. Therefore a new functionality, MBMS (Multimedia Broadcast/Multicast Service), has been introduced in UMTS release 6. The goal of this paper is to briefly describe MBMS, analyze the impact of MBMS on performance of the radio interface protocol stack and propose some performance improvements. We introduce a 2-stage MAC-c/sh/m scheduler, which allows several MBMS services to be efficiently multiplexed on existing transport (FACH) and physical (S-CCPCH) channels, taking into consideration their QoS requirements. We also discuss the impact of different configuration options on MBMS performance. The results of our work can be treated as a useful reference for designers and developers of MBMS and the UMTS radio interface protocol stack.