| 摘要 |
Each of a plurality of sensor nodes (102) alternately switches, during the same time, between a first state (St1) in which, if a prescribed trouble occurs in the local sensor node (102), the local sensor node (102) would transmit, to a collection apparatus (101), a trouble notification signal notifying that the trouble has occurred in the local sensor node (102) and a second state (St2) in which the local sensor node (102) transmits, to a communication apparatus, data signals different from the trouble notification signal. During a partial interval (i) included in each of a plurality of intervals (I) of the first state (St1), the local sensor node (102) exhibits a third state (St3) in which the local sensor node (102) would receive a trouble notification signal transmitted from one of the plurality of sensor nodes (102) other than the local sensor node (102) and transfer the received trouble notification signal. During an interval different from the partial interval (i) and included in each of the plurality of intervals (I) of the first state (St1), the local sensor node (102) exhibits a fourth state (St4) in which the local sensor node (102) receives no trouble notification signal. |
