On the Tradeoff Between Blocking and Dropping Probabilities in Multi-cell CDMA Networks

This paper is a sequel of previous work, in which we proposed a model and computational technique to calculate the Erlang capacity of a single CDMA cell that supports elastic services. The present paper extends that base model by taking into account two important aspects of CDMA. First, we describe a simple and a refined multicell CDMA model that are able to capture the impact of the neighbor cells on important performance measures of the cell under study. These performance measures include the class-wise blocking probabilities and the mean time that elastic sessions spend in the system. Secondly, we model the impact of the outage by taking into account that in-progress sessions can be dropped with a probability that depends on the current load in the serving and neighbor cells. We then consider a system with elastic and rigid service classes and analyze the trade-off between the total (soft and hard) blocking probabilities on the one hand and the throughput and the session drop probabilities on the other.