Receiving apparatus

An optical line terminal located on the side of a local exchange of an optical fiber subscriber network, the optical line terminal comprising:

• an optical-electrical conversion block for receiving optical packets sent in a burst from the subscriber side and converting the packets to packets of an electrical signal;
• and
• a packet reception processing block comprising:
• a peak voltage detection block for detecting a peak voltage of the packet;
• a bottom voltage detection block for detecting a bottom voltage of the packet;
• a stop control block for generating a stop signal for stopping the operation to detect the peak voltage and the operation to detect the bottom voltage;
• and
• a threshold value specification block for specifying a threshold voltage derived from the peak voltage and the bottom voltage;
• wherein the peak voltage detection block stops the operation to detect the peak voltage at the reception of the stop signal, and retains the peak voltage detected before the reception of the stop signal while the same packet is being received;
• the bottom voltage detection block stops the operation to detect the bottom voltage at the reception of the stop signal, and retains the bottom voltage detected before the reception of the stop signal while the same packet is being received;
• and
• the threshold value specification block specifies the threshold voltage derived from the peak voltage and the bottom voltage kept constant while the same packet is being received.