Quality of service in third-generation IP-based radio access networks
Mooi Choo Chuah, Kamesh Medepalli, Seyong Park, Jiansong Wang · Bell Labs Technical Journal · 2002
Currently, the radio access network (RAN) in code division multiple access (CDMA)-based third-generation (3G) technologies (CDMA2000 and Universal Mobile Telecommunications Service [UMTS]) is based on asynchronous transfer mode (ATM). By using the quality-of-service (QoS) guarantees provided by ATM technology, these 3G systems can efficiently transport time-sensitive user traffic to different network elements. An effort is currently under way in several wireless standards bodies to convert this connection-oriented ATM-based RAN to a connectionless Internet protocol (IP) network. Such a migration would converge the core and radio access networks and hence yield cost savings and ease of maintenance. It is also apparent that such a migration imposes new challenges to be solved on the QoS front since IP is, predominantly, a best-effort transport mechanism. In this paper, we explore the QoS support provided by 3rd Generation Partnership Project 2 (3GPP2) standards and discuss several possibilities for using IP transport without degrading the QoS experienced by different traffic types. We provide a detailed description on the DiffServ approach and how it can be used together with multiprotocol label switching (MPLS) technology to provide the QoS guarantees in an IP-based RAN. Finally, we briefly describe how the QoS framework discussed for CDMA2000∗can be applied to UMTS based networks.