POWER-SAVING CONTROL SYSTEM, MASTER STATION DEVICE, SLAVE STATION DEVICE, AND POWER-SAVING CONTROL PROGRAM

PROBLEM TO BE SOLVED: To prevent power supply to a common component of an ONU including a plurality of LLIDs from being stopped even when one of the LLIDs is in a sleep state.SOLUTION: There is provided a communication system for performing communications between a plurality of slave station devices including a plurality of logic link identifiers and a master station device using a plurality of logic link identifiers. The communications are performed for each of the plurality of logic link identifiers. When all of the plurality of logic link identifiers are in a sleep state, the slave station devices stop power supply to a common component of the slave station devices only during a period of time in which the sleep states of all the logic link identifiers overlap with one another.