Performance Evaluation of TCP over UMTS Transport Channels

Universal Mobile Telecommunications System (UMTS) is a third-generation cellular network that enables high-speed wireless Internet access. It can provide maximum data-rates ranging from 64kb/s to 2Mb/s in different environmental types. UMTS is designed to provide access to the existing Internet services as well as to UMTS specific services. It will augment the existing capabilities of 2G mobile networks and GPRS, and one often envisaged strategy is to offer a richer set of multimedia services. It is widely known that TCP does not perform efficiently in wireless links where the bit error rate is high enough. This paper has as main target to evaluate the performance of TCP data transfer over the UMTS air interface, by means of a rather detailed simulation model. We examine the performance of TCP over UMTS Dedicated Channels (DCHs) with different bit rates and Transmission Time Intervals (TTIs) and we represent some simulation experiments for UMTS High Speed Downlink Packet Access (HSDPA) transmissions.