<title>Performance evaluation of TCP under dynamic allocation scheme for down link transmission rate in W-CDMA systems</title>

Abstract

IMT-2000 has attracted strong attention as the Next Generation Mobile Communication System. That can provide high-bit-rate data communication service, so that a great number of packets conveyed by TCP will be transmitted over a wireless link. W-CDMA standardized in 3GPP (standardizing IMT-2000) allows dynamic allocation of transmission rates to flows over a wireless link in response to changing link condition for each flow, which is thought to be essential for next generation mobile communication system. Therefore, in this paper, we study the characteristics of the dynamic allocation scheme when TCP flows share a wireless link, in particular by focusing on the throughput performance of those TCP flows. First, we examine the effectiveness of the dynamic allocation of down link transmission rate for TCP flows in response to changing FER by means of simulations. Through simulation results, we will show how it can improve the total throughput performance of TCP flows. Furthermore, we can obtain an effective way to allocate transmission rates to flows with different FERs in order to achieve high total throughput. Finally, we will deal with a case of multiple flows from a fixed host to a mobile host. In actual networks, it will very often happen. In this case, we will show that the total throughput of TCP flows less degrades than in the above single flow case even when FER becomes high.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.