MA Yu, PEI Yu-kui, GE Ning. Design of WUSB system based on Nak-Only handshake protocol[J]. 2011, 30(12): 129-132. DOI: 10.13873/j.1000-97872011.12.028.
A Nak-Only handshake protocol is brought out to reduce the waste of bandwidth when short data packet such as ACK transmitting in a PHY-layer packet with specific length.It keeps the receiver negatively waiting instead of sending the ACK packet
so that the waste of bandwidth could be reduced.This program requires a stable TX-RX switching time in the PHY-layer.But if the switching time sometimes exceeds the limit
packet lost could also be avoided by buffering 3 data packets in the transmitter.It can be proved from the simulation that Nak-Only handshake protocol improves the throughput rate of WUSB
and the effect is close to the ideal case that packet length could be freely specified in PHY-layer.