Sensor network MAC system for multihop communication

PURPOSE: An MAC(Media Access Control) system of a multi-hop sensor network is provided to prevent transmission delay caused by relatively long inactive duration for energy saving and the convenience of scheduling. CONSTITUTION: In the higher layer of a source device, MLME-EGTSinfo.request primitive is transmitted to MLME(MAC sub Layer Management Entity)(601). The MLME transmits an EGTS information request command to a destination device(602). The destination device confirms the reception of the EGTS(Extended Guaranteed Time Slot) information request command by transmission of an ACK(Acknowledgement) frame(603). The MLME of the destination device transmits a time stamp and an EGTS parameter to the source device(604). The source device transmits an ACK frame to the destination device(605). The MLME of the source device notifies a higher layer next to itself that the EGTS information request succeeds(606).