Connectivity, Performance, and Resiliency of IP-Based CDMA Radio Access Networks

IP-based Radio Access Networks (RAN) are expected to be the next generation access networks in UMTS and CDMA networks. There are several benefits of IP-based RAN including lower costs, flexibility of merging wired and wireless networks, and network scalability and reliability. While Quality of Service issues in IP-based RAN have been addressed by a number of researchers, the question of connectivity, i.e., how best to connect base stations to the Radio Network Controllers (RNC) in an IP-based RAN, has not been addressed by any research literature. Furthermore, given a connection configuration, an RNC selection algorithm that assigns an incoming call to an RNC is also necessary. This paper examines Radio Access Network (RAN) connectivity and its impact on the performance and resiliency of the wireless network using different RNC selection algorithms. The proposed Min-Load-1 algorithm, which allows at most one hard handoff in order to accommodate each incoming request, delivers performance close to the standard Min-Load algorithm using a RAN of much higher connectivity and is close to the optimal algorithm using the same RAN. We also find that using Min-Load-1 algorithm and allowing the base stations to connect to two RNCs result in resiliency to RNC failures that is similar to having full-mesh connectivity between base stations and RNCs