TRANSMISSION LINE LOSS TESTING METHOD, SLAVE STATION USING THE METHOD, MASTER STATION, AND COMMUNICATION SYSTEM

摘要

The present invention relates to a method for measuring transmission loss between in an optical transmission line between a master station and a slave station, when an additional slave station is installed to a star network communication system, and a slave station, a master station and an optical communication system using this method.

In this optical communication system, power of an optical signal is measured at a second end of an optical transmission line which is connected with an added slave station and at a first end other than the second end, by a second measuring unit and a first measuring unit respectively. The measurement result at the first end is stored in a storing unit, or alternatively, is sent to an incorporating unit by a transferring unit. In the incorporating unit, the measurement result at the first end is incorporated into a downstream optical signal, which is transmitted to the slave station. Then, in the slave station an information extracting unit extracts the measurement result at the first end from the downstream optical signal, and a processing unit calculates a difference between the measurement results of the first end and of the second end to obtain a transmission loss in the optical transmission line between the first end and the second end.