System-Level Performance Evaluation of HSDPA/HSUPA with TCP-based Application

We assess the system-level performance of 3GPP Release 5 and Release 6 systems with a downlink-oriented TCP-based application (FTP). We first investigate whether the traffic due to the TCP acknowledgments sent to the server can overload the capacity of the Release 5 uplink when a set of high performance UEs simultaneously download. Next we investigate the download performance with realistic uplink scheduling delays in Release 5 and the benefit due to the uplink enhancements brought by HSUPA (Release 6). It is found that, although the TCP acknowledgments do not overload the capacity of the uplink in Release 5, significant improvements will be obtained with Release 6 thanks to the faster uplink scheduling.