Enhanced TCP with end-to-end bandwidth and loss differentiation estimate over heterogeneous networks

The TCP performance degradation over heterogeneous networks is caused by not only network congestion, but also random errors of wireless links. We propose an end-to-end stable accurate rapid bandwidth estimate (SARBE) algorithm reacting appropriately to the end-to-end loss differentiation estimate algorithm (LDED), which can improve the TCP performance over heterogeneous networks without the incipient congestion notifications of the intermediate routers. LDED detects the signal of incipient congestion to lead the sender to enter the congestion avoidance phase opportunely before router's queue overflows. As well as relying distinguishing ability the causes of loss, our algorithm adjusts the packet transmission rate precisely according to the estimated bandwidth after new ACK receiving, fast retransmit or transmission timeout events.