COMMUNICATION SYSTEM, SUBSCRIBER-SIDE DEVICE, AND EXTERNAL POWER SUPPLY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a communication system capable of reducing power consumption when including a communication device constituted by a plurality of devices.SOLUTION: A communication system comprises: a subscriber-side device 4 that relays communication between a host network 1 and a terminal; and a USB device 6 that is connected with the subscriber-side device 4. The subscriber-side device 4 includes: an ONU unit 100 that receives power supply from either a commercial power supply 5 or the USB device 6 and supplies power to an HGW unit 200 in the subscriber-side device 4; and the HGW unit 200 that receives power supply from the ONU unit 100. The USB device 6 includes a battery that can supply power to the subscriber-side device 4. The ONU unit 100 sets its own operation mode to a power-saving mode when receiving power supply from the USB device 6. The HGW unit 200 sets its own operation mode to a power-saving mode when the ONU unit 100 receives power supply from the USB device 6.