PREAMBLE ADDITION CIRCUIT AND OPTICAL TRANSMITTER- RECEIVER

摘要

PROBLEM TO BE SOLVED: To provide an optical transmitter-receiver where a preamble is generated by hardware so as to reduce software development man-hours and that is applicable to an optical fiber communication network provided with a passive optical multiplexing path. SOLUTION: The preamble addition circuit of this invention is provided with 1st and 2nd delay circuits that delay both a transmission request signal and data to be sent by a prescribed time and with a device that generates a synchronizing signal for the prescribed delay time and also with a device that is triggered by the transmission request signal to continue transmission for a 2nd prescribed time and with a mechanism that transmits an idle signal as its control when the transmission request signal goes to a low level within the 2nd prescribed time.