METHOD FOR DECIDING SWITCHING TIME, LINE TERMINATOR REALIZING THE METHOD, CONTROL NETWORK UNIT AND NETWORK UNIT, AND LINE TERMINATOR FOR THEM AND TREE SHAPE OPTICAL NETWORK INCLUDING CONTROL NETWORK UNIT FOR THE PURPOSE

摘要

PROBLEM TO BE SOLVED: To provide a method for deciding a switching time of a switch. ;SOLUTION: A switch passes an information signal INi that is present at an approximated switching time APP-Ti and shuts a branch when no information signal is present. This method has a step where a control network unit CTRL-NU captures permission information, a step where an approximated switching time is decided and a step where a network unit transmits a prescribed bit pattern PAT. When the prescribed bit pattern passes through the switch, this method includes a step where a bit pattern whose edge is cut off is provided and the reception of the bit pattern is detected, a step where a degree of cut TR of the prescribed bit pattern is provided, a step where a calibrated value CAL-SWi is calculated and a step where a calibrated value is given to the control network unit to decide the switching time.;COPYRIGHT: (C)2000,JPO