Designing IP-based heterogeneous Radio Access Network

The next generation access networks in UMTS and CDMA networks are expected to be IP-based Radio Access Networks (RAN). There are several benefits of IP-based RAN including lower costs, flexibility of merging wired and wireless networks, network scalability and reliability. In addition to the quality of service issues in IP-based RAN, the issue of connectivity and assignment of calls to radio network controllers is also addressed. Optimum RAN connectivity and optimum Radio Network Controller (RNC) utilisation is an important problem in the design of IP-based RAN and is solved for IPbased homogeneous radio access networks. In this paper, we solve it for IP-based heterogeneous RAN which is a NP-hard problem. We present a systematic and comprehensive formulation for this problem using Integer Linear Programming (ILP) and implementation for the same. Also we propose a simple greedy based heuristic and compare its performance.