FIELD: radio engineering, communications.
SUBSTANCE: invention relates to a system of a passive optical network (PON). OLT (2) sends a frame with a request for inspection of a communication line and inspection of a volume of accumulated data from ONU (4). ONU (4) returns a frame of a response to a request as a response. When ONU (4) detects a condition, in which there is no traffic of an ascending flow, ONU (4) accordingly makes a record into a response frame and sends a response frame into OLT (2). OLT (2) tracks traffic of a descending flow. When OLT (2) recognises, on the basis of tracking result or a frame of a response to a request, a condition, in which there is no traffic of an ascending or a descending flow, OLT (2) instructs ONU (4) to change into the mode of low consumed power. Having received the instruction, ONU (4) carries out transition of a functional module in accordance with the instruction content, into the mode of low consumed power. When ONU (4) does not receive a frame with a response within predetermined time, ONU (4) carries out transition of functional modules different from the functional module, which performs communication control, into the mode of low consumed power. OLT (2) stops transfer of a frame with a request, when the device at the side of a subscriber changes into the mode of low consumed power.
EFFECT: reduced consumed power of ONU while maintaining a communication line between OLT and ONU.
18 cl, 4 dwg
