A Distributed Architecture for Future CDMA Wireless IP Networks

The migration of the radio access network to an all-IP network provides significant advantages in terms of cost savings, scalability, and simplified network management for providing a variety of IP-based services in wireless networks. As code division multiple access (CDMA) has been widely adopted as the air-interface standard of future wireless networks, this paper proposes a novel, distributed radio network architecture to support all- IP services using CDMA shared access. Specifically, the architecture distributes the so-called fast cell-site selection (FCSS) functionality among base-station routers (BSRs) so that data transmission for a call can be switched quickly from one base station with a weak radio link to another with a better link, as a means to enhance system capacity. A key objective of the new architecture with distributed radio resource management functions is to provide a unified approach to supporting multimedia IP applications in CDMA networks. We present a distributed architecture for radio network control that specifically supports signaling message exchanges among network elements for FCSS in the presence of terminal mobility. We study the design and quality-of-service requirements of the backhaul network for supporting FCSS. We also propose distributed paging and registration algorithms for the new architecture. Using VoIP as a prime example of real-time services, we show by simulations significant improvement of VoIP capacity for FCSS at low mobility when compared to standard cell-site selection techniques. For typical network and radio link parameters, our results reveal the feasibility and merits of the proposed architecture for CDMA all-IP wireless networks.