A receiver-driven TCP flow control in CDMA2000 wireless networks with constrained mobile resources

Abstract

This paper presents a receiver-driven TCP flow control mechanism that is adaptive to the wireless condition in CDMA2000 networks. A receiver-driven TCP flow control is in general achieved by adjusting the size of the advertised window at the receiver. The proposed method continually measures, at the receiver, both the available wireless bandwidth and the round-trip packet delay. Depending on the measured values, the receiver appropriately adjusts the size of the advertised window. Constrained by the adjusted window which reflects the current state of the wireless network, the sender achieves an improved TCP throughput as well as reduced round-trip packet delay. The proposed method is specifically developed for handheld devices with limited memory resources. Its implementation only affects the protocol stack at the receiver and thus, neither the sender nor the routers need modifications. The experimental results obtained in CDMA2000 1x networks show that the TCP throughput of the proposed method improves about 5 times over the conventional method when the receiver's buffer size is limited to 2896 bytes. Also, with 64 Kbytes of buffer size, the round-trip packet delay of the proposed method has been reduced in half compared to the conventional method.