Measurement device, transmission device, and network system

A first transmission device connected to a second transmission device via a transmission line, the first transmission device comprising:

• signal processing circuitry configured to add first time stamp information to a first frame in time synchronization with the second transmission device;
• a transmitter configured to transmit the first frame to which the first time stamp information is added to the second transmission device via the transmission line;
• a receiver configured to receive, from the second transmission device, a second frame including second time stamp information added by the second transmission device in time synchronization with the first transmission device;
• and
• an interface configured to, in a case where an error has occurred in the second frame, make notification of the second time stamp information added to the second frame in which the error has occurred.

A network system comprising:

• a first transmission device;
• a second transmission device connected to the first transmission device via a transmission line;
• and
• a measurement device that specifies a position at which an error has occurred in a frame transmitted in the transmission line, wherein
• the first transmission device is configured to:
• add first time stamp information to a first frame in time synchronization with the second transmission device;
• transmit the first frame to which the first time stamp information is added to the second transmission device via the transmission line;
• add second time stamp information to a second frame in time synchronization with the first transmission device;
• and
• transmit the second frame to which the second time stamp information is added to the first transmission device via the transmission line,
• the first transmission device is further configured to:
• receive the second frame from the second transmission device via the transmission line;
• and
• in a case where an error has occurred in the received second frame, notify the measurement device of the second time stamp information included in the second frame in which the error has occurred,
• the second transmission device is configured to:
• receive the first frame from the first transmission device via the transmission line;
• and
• in a case where an error has occurred in the received first frame, notify the measurement device of the first time stamp information included in the first frame in which the error has occurred, and
• the measurement device is configured to specify the position at which the error has occurred on the basis of the second time stamp information notified from the first transmission device, the first time stamp information notified from the second transmission device, and a light speed.

A network system comprising:

• a first transmission device;
• and
• a second transmission device connected to the first transmission device via a transmission line, wherein
• the first transmission device is configured to:
• add first time stamp information to a first frame in time synchronization with the second transmission device;
• transmit the first frame to which the first time stamp information is added to the second transmission device via the transmission line;
• add second time stamp information to a second frame in time synchronization with the first transmission device;
• and
• transmit the second frame to which the second time stamp information is added to the first transmission device via the transmission line,
• the first transmission device is further configured to:
• receive the second frame from the second transmission device via the transmission line;
• and
• in a case where an error has occurred in the received second frame, notify the second transmission device of the second time stamp information included in the second frame in which the error has occurred, and
• the second transmission device is configured to:
• receive the first frame from the first transmission device via the transmission line;
• and
• on the basis of the first time stamp information included in the first frame in which an error has occurred in a case where the error has occurred in the received first frame, the second time stamp information notified from the first transmission device, and a light speed, specify a position at which the error has occurred.