Pulsed ACK: Improving Robustness of TCP for Asymmetric Bandwidth

The transmission control protocol (TCP) proves degraded performance at the environment which has bandwidth asymmetry, since the uplink is filled with ACK packets. In order to solve the issue, we propose a TCP option, Pulsed ACK. To apply this option, TCP brings down the number of ACKs and allows the receiver to send ACKs at intervals. We consider the number of data packets acknowledged by an ACK, d, to achieve these effects, and using this value, the receiver adjusts the interval of sending them. The sender also controls the increment of cwnd at the receipt of an ACK packet so that it increases by 1 every RTT. The simulation results show that TCP with the Pulsed ACK option gains 1.85 times higher throughput compared to TCP without the option.