| 摘要 |
PROBLEM TO BE SOLVED: To control periodic sleep so as to ensure power saving and a real time property.SOLUTION: An ONU 2 comprises: a buffer situation acquisition unit 25 for acquiring a buffer situation of a transmission buffer 21; a first determination unit 43 for performing determination on a connection state on first communication in a lower layer; a second determination unit 44 for performing determination on a connection state on second communication in a higher layer; and a sleep control unit 45 for making an optical reception unit 42 sleep periodically depending on the buffer situation. The sleep control unit 45 makes, depending on the buffer situation, a sleep time be equal to or shorter than a first sleep time when the first communication is in a connection state and the second communication is not in a connection state; makes the sleep time be a second sleep time shorter than the first sleep time when the second communication is in a connection state; and makes the sleep time be a third sleep time longer than the first sleep time when neither the first nor the second communication is in a connection state.SELECTED DRAWING: Figure 3 |
