It is well known that TCP does not fully utilize the available bandwidth in fast long-distance networks. This paper proposes S-shaped TCP (SS-TCP). The window growth function of SS-TCP is, in the steady state condition, S-shaped, and it can be divided into three regions. In region I, the window growth rate of SS-TCP is the same as that of standard TCP (STD-TCP). In region II, the window of SS-T...