| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve such a problem that, when performing communication between a master unit and a slave unit, time synchronization between the master unit and the slave unit is required, but when the slave unit is battery-driven, when requesting a command using polling from the slave unit to the master unit for time synchronization, since the number of times of communication by polling is added in addition to a time setting command, processing for causing the master unit to have the command is required and the communication time of the slave unit is elongated by that amount, and battery consumption is progressed, to construct a radio sensor network for radio communication between a plurality of battery-driven slave units and a single master unit, and to elongate a service life of a battery by suppressing the power consumption of the battery by reducing excessive communication for the time synchronization. <P>SOLUTION: In a radio sensor network for performing radio communication between the plurality of battery-driven slave units and the single master unit, the master unit does not issue a time synchronizing instruction. When the master unit receives measurement data from the slave unit, the master unit embeds the present time in acknowledgement (ACK) which is returned to the slave unit of a transmission source and transmits the acknowledgement. <P>COPYRIGHT: (C)2011,JPO&INPIT |
