End-to-end TCP performance in W-CDMA / UMTS

In this work, we focus on modeling of TCP in an end-to-end path where both wired and wireless, mobile sections of the network are present. The former is governed by loss and is subject to TCP retransmission. The latter is governed by error and path loss and is under data link layer control error detection/retransmission mechanism as well as UMTS-oriented error correction and power control. We first investigate the end-to-end performance of TCP in the outer-loop, with bit error ratio (BER) as a QoS metric. Second, we consider the inner-loop control case, and relate TCP performance to the signal-to-interference ratio (SIR) and the despread bit energy to interference density ratio E_b/N₀. Third, we review the power control algorithm and propose a novel one basing it on end-to-end TCP performance rather than UMTS channel measurements.