Theoretical and experimental analysis of the new soft handoff algorithm for CDMA systems

The IS-95B soft handoff is analyzed, which is likely to be incorporated in all CDMA-based 3G standards. A simple semi-empirical model for evaluation of various handoff strategies is developed. Based on the model, we show that a part of the capacity improvement predicted for 3G systems that is expected to come from a new soft handoff algorithm might not be achievable. This corroborates the conclusion published in Chedda (1999). However, we found that the new algorithm can still significantly improve the utilization of the network resources, and reduce operator costs. Experimental results for several comparative IS-95A vs. IS-95B field tests are presented, which compare favorably with our simulations. As opposed to Chedda, no significant increase in the messaging was observed, nor any problems with either the forward or the reverse link.