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

Abstract

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.