Modeling soft handoffs' performance in a realistic CDMA network

Abstract

The advent of code division multiple access (CDMA) technology has offered solution to the incessant termination of ongoing calls experienced in second generation networks. Seamless connectivity is now made possible as these networks provide an uninterrupted-transfer loop known as the overlap region, which must be effectively managed to ensure efficient handoffs. This contribution adopts a practical approach to the soft handoff problem, with concrete experimental solution that will benefit network operators and the wireless research community. We achieve this by studying an existing CDMA cellular network over a period of two months. Under ideal conditions, we adapt the existing data to the COST-231 Hata pathloss model and derive a soft handoff (SHO) probability model, peculiar to the study environment and generic to similar environments. In order to draw effective conclusions and advise on best practices, the model was simulated for various coverage areas and propagation exponents. Simulation results confirm that SHO thresholds should be carefully chosen in order to minimize network defects. © 2012 Springer-Verlag GmbH.