Patent ID: 9420624
Filing Date: 2016-08-16
CPC Classification: H04W

Claim Text:
1. A terminal node device communicatable with an external sink node device and another terminal node device, comprising: a communication module which communicates with the external sink node device and another terminal node device; sensor modules; and a control unit which controls the terminal node device so as to transition from an initial state into one of a synchronous state and a leave state and allows the terminal node device to be operated while transitioning into one of the initial state, the synchronous state, and the leave state, wherein in the case of the initial state, the control unit scans a message received from an external portion by using the communication module; if a beacon message is received from a sink node device, the control unit transitions into the synchronous state; and if a beacon message is not received from the sink node device for a predetermined time, the control unit transitions into the leave state, wherein in the case of the synchronous state, if a beacon message is received from the sink node device by using the communication module, the control unit synchronizes the terminal node device with the sink node device according to the beacon message received from the sink node device, performs sensing by using the sensor module, generates a sensing message including the sensed information, and transmits the sensing message to the sink node device by using the communication module; and if a beacon message is not received from the sink node device for a predetermined time, the control unit transitions into the leave state, wherein in the case of the leave state, the control unit performs sensing by using the sensor module and broadcasts a sensing message including the sensed information; and if the leave state has been maintained for a preset time, the control unit transitions into the initial state, wherein in the case of the leave state, the control unit allows one frame for message communication to include a transmitting duration, a sensing duration, and a sleep duration, and wherein the transmitting duration is a duration where a sensing message is broadcasted by using the communication module, the sensing duration is a duration where sensing is performed by using the sensor module, and the sleep duration is a duration excluding the transmitting duration and the sensing duration.