Patent ID: 8184975

Claim:
A passive optical network system comprising: a master station to time-division multiplex signals of a first transmission speed and a second transmission speed and to perform communication; plural slave stations including a first slave station to communicate with the master station at the first transmission speed and a second slave station to communicate with the master station at the second transmission speed; and an optical fiber network in which the signals from the master station are transmitted to the respective slave stations through a splitter, wherein each of the plural slave stations includes an automatic gain adjustment circuit to adjust signal level of a received signal from the master station, the signal level varying according to a change of transmission speed of the received signal, and wherein the master station time-division multiplexes payload and/or overhead information of the first transmission speed, payload and/or overhead information of the second transmission speed, and a dummy signal inserted at a place where the transmission speed is changed, and transmits multiplexed information and signal to the slave stations.