UMTS to GSM handover based on compressed mode technique

Handover from UMTS to GSM is a key feature of third generation wireless systems. It is usually based on measurements on GSM cells performed using compressed mode. The aim of this paper is first to present an evaluation of compressed mode impact on performance, in particular in terms of required E_b/N_o and measurement delays. We propose then to use these results in a dynamic system simulation tool to perform an accurate evaluation of UMTS to GSM handover algorithm. This simulation tool allows to find optimal choice of the handover criteria and effective parameters setting. First results are presented here.