Abstract: Provided is a terminal node device including: a communication module communicating with an external sink node device and another terminal node device; sensor modules; and a control unit allowing the terminal node device to be operated while allowing the terminal node device to transition into one of the initial, synchronous, and leave states. In the initial state, the control unit scans a received message; if a beacon message is received from a sink node device, the control unit transitions into the synchronous state; and if not for a predetermined time, the control unit transitions into the leave state. Accordingly, if a beacon message is received from the sink node device, the terminal node device transitions into the synchronous state to constitute a server-based wireless sensor network; and if not, the terminal node device transitions into the leave state to constitute an independent sensor network.

Abstract: Provided is a terminal node device including: a communication module communicating with an external sink node device and another terminal node device; sensor modules; and a control unit allowing the terminal node device to be operated while allowing the terminal node device to transition into one of the initial, synchronous, and leave states. In the initial state, the control unit scans a received message; if a beacon message is received from a sink node device, the control unit transitions into the synchronous state; and if not for a predetermined time, the control unit transitions into the leave state. Accordingly, if a beacon message is received from the sink node device, the terminal node device transitions into the synchronous state to constitute a server-based wireless sensor network; and if not, the terminal node device transitions into the leave state to constitute an independent sensor network.

Abstract: A communication method for a mobile sensor node in a wireless sensor network includes: in a state that the mobile sensor node performs synchronization by a message reception interrupt from a parent sensor node and determines an uplink active duration and a downlink active duration, transmitting a message to the parent sensor node in the transmitting duration of the uplink active duration, receiving and processing messages from the parent sensor node and sensor nodes linearly connected around the parent sensor node in the receiving duration of the uplink active duration, and resetting a new parent sensor node using the received signal strength indications RSSIs of the received messages; and transmitting a message to the parent sensor node in the transmitting duration of the downlink active duration, checking whether or not a message is received from the parent sensor node in the receiving duration of the downlink active duration, if the message is not received from the parent sensor node, determining that time

Abstract: Provided are a double linked wireless sensor network capable of performing bidirectional communication and a method of transmitting and receiving data. In each of nodes constituting the wireless sensor network, an active duration and an inactive duration are alternately repeated, and the active duration is configured to include an upstream duration, an intermission duration, and a downstream duration. Each of the downstream duration and the upstream duration is configured to sequentially include a second receive slot, a second receive processing slot, a first receive slot, a first receive processing slot, a transmit slot, a transmit processing slot, a first acknowledge slot, a first acknowledge processing slot, a second acknowledge slot, and a second acknowledge processing slot, and wherein bidirectional communication can be performed between the sink node and the terminal node in a single period of the active duration.

Abstract: Disclosed is a wireless sensor network with a linear structure capable of bidirectional communication. The wireless sensor network includes a plurality of nodes linearly connected from a sink node to a terminal node by connecting each node to a single upper-level node and a single lower-level node, each node has an active period for transmitting/receiving data to/from its upper-level node and lower-level node, the active period includes a downstream duration for transmitting data/commands from the sink node to the terminal node and an upstream duration for transmitting data/commands from the terminal node to the sink node, and each of the upstream and downstream durations sequentially includes RX, TX, and ACK intervals, so that bidirectional communication between the sink node and the terminal node can be performed within a single active period.

Abstract: Provided are a double linked wireless sensor network capable of performing bidirectional communication and a method of transmitting and receiving data. In each of nodes constituting the wireless sensor network, an active duration and an inactive duration are alternately repeated, and the active duration is configured to include an upstream duration, an intermission duration, and a downstream duration. Each of the downstream duration and the upstream duration is configured to sequentially include a second receive slot, a second receive processing slot, a first receive slot, a first receive processing slot, a transmit slot, a transmit processing slot, a first acknowledge slot, a first acknowledge processing slot, a second acknowledge slot, and a second acknowledge processing slot, and wherein bidirectional communication can be performed between the sink node and the terminal node in a single period of the active duration.

Abstract: A communication method for a mobile sensor node in a wireless sensor network includes: in a state that the mobile sensor node performs synchronization by a message reception interrupt from a parent sensor node and determines an uplink active duration and a downlink active duration, transmitting a message to the parent sensor node in the transmitting duration of the uplink active duration, receiving and processing messages from the parent sensor node and sensor nodes linearly connected around the parent sensor node in the receiving duration of the uplink active duration, and resetting a new parent sensor node using the received signal strength indications RSSIs of the received messages; and transmitting a message to the parent sensor node in the transmitting duration of the downlink active duration, checking whether or not a message is received from the parent sensor node in the receiving duration of the downlink active duration, if the message is not received from the parent sensor node, determining that time

Abstract: Disclosed is a wireless sensor network with a linear structure capable of bidirectional communication. The wireless sensor network includes a plurality of nodes linearly connected from a sink node to a terminal node by connecting each node to a single upper-level node and a single lower-level node, each node has an active period for transmitting/receiving data to/from its upper-level node and lower-level node, the active period includes a downstream duration for transmitting data/commands from the sink node to the terminal node and an upstream duration for transmitting data/commands from the terminal node to the sink node, and each of the upstream and downstream durations sequentially includes RX, TX, and ACK intervals, so that bidirectional communication between the sink node and the terminal node can be performed within a single active period.