Patent ID: 7881344
Filing Date: 2011-02-01
Classification: H04L,Y02D

Abstract:
1. A communication network system for performing time-division-multiplexing communication in a communication cycle including a data transfer period and an idle period, the communication network system comprising: a network including a plurality of nodes, a first node of the plurality of nodes configured to transmit a wakeup signal from the first node to at least two other nodes of the plurality of nodes and to start a communication cycle responsive to at least one of the plurality of nodes being woken up by the wakeup signal so as to be placed in a communication state, the communication cycle being a periodic cycle including the data transfer period and the idle period; an un-wakeup-node detecting unit connected to the network and configured to detect a second node of the plurality of nodes that remains in a sleep state following transmission of the wakeup signal; a pseudo-wakeup-signal transmitting unit connected to the network and configured to transmit a pseudo-wakeup signal to the network during at least one idle period of the communication cycle to wake up the second node from the sleep state after the un-wakeup-node detecting unit detects that the second node remains in the sleep state; and a network-idle-time detection circuit configured to detect the idle period by measuring a time elapsing after a start of the communication cycle to a predetermined start time of the idle period of the communication cycle.