Abstract: Disclosed herein are a telephone, a switchboard, and a method for sending a message between the telephone and the switchboard using a Dual Tone Multiple Frequency (DTMF) signal. The telephone includes a sensor interface unit for collecting sensing signals by being connected to sensors, a transmission unit for generating a message using the sensing signals, converting the message into a DTMF signal, and transmitting the DTMF signal and a telephone signal, and a power distribution unit for being supplied with power from the switchboard and distributing the power to operation units.

Abstract: Disclosed herein are a telephone, a switchboard, and a method for sending a message between the telephone and the switchboard using a Dual Tone Multiple Frequency (DTMF) signal. The telephone includes a sensor interface unit for collecting sensing signals by being connected to sensors, a transmission unit for generating a message using the sensing signals, converting the message into a DTMF signal, and transmitting the DTMF signal and a telephone signal, and a power distribution unit for being supplied with power from the switchboard and distributing the power to operation units.

Abstract: Disclosed is a method of avoiding channel interference by a sensor node including a multi transmission and reception unit in a wireless sensor network. The method includes setting channel A in channel group A for a first wireless transmission and reception unit, and setting channel B in channel group B for a second wireless transmission and reception unit, checking interference for the channel A, detecting interference for the channel B if interference is detected in the channel A, and performing communication through a channel where interference has not been detected among the channel A and the channel B.

Abstract: Disclosed is a method of avoiding channel interference by a sensor node including a multi transmission and reception unit in a wireless sensor network. The method includes setting channel A in channel group A for a first wireless transmission and reception unit, and setting channel B in channel group B for a second wireless transmission and reception unit, checking interference for the channel A, detecting interference for the channel B if interference is detected in the channel A, and performing communication through a channel where interference has not been detected among the channel A and the channel B.

Abstract: A medium access control (MAC) technique of a multihop sensor network. In the multihop sensor network, the MAC technique may contribute to significantly reducing transmission delay, and allow real-time services to be provided to all nodes by extending a guaranteed time slot (GTS) restricted to one hop in a personal area network (PAN) coordinator (PNC) to all nodes. Furthermore, the MAC technique may allow the number of available GTSs to be significantly increased, by using all 16 frequency band channels instead of using only a single frequency band and setting a multi-superframe.

Abstract: Provided are a sensor node included in a sensor network, an update server updating the sensor node, and a method of updating a sensor node. The update server updating a sensor node included in a sensor network includes an execution code manager managing execution codes for a plurality of sensor nodes included in the sensor network, a rule generator generating an update rule based on a result of comparing an existing execution code managed by the execution code manager with an update execution code required for a new function update of the sensor node, and a downloader causing the sensor node to download the update rule generated by the rule generator. Accordingly, an execution code can be updated by a small amount of data transmission.

Abstract: A low-power method for media access control on a semi-linear sensor network with multiple sensor nodes, includes: sensing a channel after waking up from a sleep mode by an arbitrary transmission sensor node that has obtained data; and generating a long preamble including a number of element preambles and sending to a destination sensor node after said channel sensing. This method further includes: sending said data to said destination sensor node after completion of transmission of said long preamble; and identifying duty cycle information of said destination sensor node after completion of transmission of said data and adjusting the number of said element preambles according to said duty cycle information.

Abstract: Provided is a system and method for disseminating an accident. The accident dissemination system may include a sensor to sense the accident and to generate accident information; and a vehicle processor to open an S channel and thereby transmit the accident information to a vehicle at the rear entering an accident location where the accident has occurred, and to transmit the accident information to an oncoming vehicle, travelling in the opposite direction and being alienated from the accident location, via a first D channel opened by the oncoming vehicle.

Abstract: Provided is a method of supporting node portability in a sensor network, wherein data transmission to a portable node can be guaranteed since even when the portable node is assigned with a different address by being associated with another network, the newly assigned address is transmitted to a parent node or a sink node that was previously associated with the portable node.

Abstract: Provided is a method of minimizing power consumed by each node in a wireless network when communicating with neighboring nodes. Unlike a conventional synchronous media access control (MAC), the present invention suggests an asynchronous MAC. Thus, the active duration of a node extends only when transmitting a large quantity of data and the extended active duration returns to the minimum active duration again after completing the data transmission.

Abstract: A wakeup-on-demand apparatus includes: a wakeup radio receiver (WRR) receiving a first radio signal to detect an address; and a main radio transceiver (MRT) responding to the first radio signal, transmitting and receiving a second radio signal for data communication, when the detected address coincides with a preset address.

Abstract: A low-power method for media access control on a semi-linear sensor network with multiple sensor nodes, includes: sensing a channel after waking up from a sleep mode by an arbitrary transmission sensor node that has obtained data; and generating a long preamble including a number of element preambles and sending to a destination sensor node after said channel sensing. This method further includes: sending said data to said destination sensor node after completion of transmission of said long preamble; and identifying duty cycle information of said destination sensor node after completion of transmission of said data and adjusting the number of said element preambles according to said duty cycle information.

Abstract: Provided is a method for transmitting sensing information in a wireless sensor network including a pair node. The method for transmitting sensing information in a wireless sensor network including a sink node, parent nodes, and sensor nodes set as pair nodes among sensor nodes connected to the parent nodes, includes the steps of: a) setting up predetermined sensor nodes in the same target area as pair nodes for transmitting and receiving sensing information to/from corresponding sensor nodes; b) at the pair nodes, transmitting first sensing information sensed by oneself to corresponding sensor nodes; c) at the sensor nodes, transmitting first sensing information sensed by oneself and second sensing information transmitted from corresponding pair nodes to the parent node; and d) at the parent node, transmitting the received first and second sensing information to the sink node at the same time.

Abstract: Provided are a sensor node included in a sensor network, an update server updating the sensor node, and a method of updating a sensor node. The update server updating a sensor node included in a sensor network includes an execution code manager managing execution codes for a plurality of sensor nodes included in the sensor network, a rule generator generating an update rule based on a result of comparing an existing execution code managed by the execution code manager with an update execution code required for a new function update of the sensor node, and a downloader causing the sensor node to download the update rule generated by the rule generator. Accordingly, an execution code can be updated by a small amount of data transmission.

Abstract: A medium access control (MAC) technique of a multihop sensor network. In the multihop sensor network, the MAC technique may contribute to significantly reducing transmission delay, and allow real-time services to be provided to all nodes by extending a guaranteed time slot (GTS) restricted to one hop in a personal area network (PAN) coordinator (PNC) to all nodes. Furthermore, the MAC technique may allow the number of available GTSs to be significantly increased, by using all 16 frequency band channels instead of using only a single frequency band and setting a multi-superframe.

Abstract: Provided are a communication method and apparatus of a wireless sensor network which uses at least one channel and has a tree structure. The method includes: generating windows, where a beacon interval is divided, according to each channel; selecting a window, which is not assigned to nodes that exist within a predetermined range from a certain node, from among the generated windows; and the certain node communicating with a child node of the certain node by using a channel to which the selected window belongs during a time corresponding to the selected window.

Abstract: Provided is a method of minimizing power consumed by each node in a wireless network when communicating with neighboring nodes. Unlike a conventional synchronous media access control (MAC), the present invention suggests an asynchronous MAC. Thus, the active duration of a node extends only when transmitting a large quantity of data and the extended active duration returns to the minimum active duration again after completing the data transmission.

Abstract: Provided is a method of supporting node portability in a sensor network, wherein data transmission to a portable node can be guaranteed since even when the portable node is assigned with a different address by being associated with another network, the newly assigned address is transmitted to a parent node or a sink node that was previously associated with the portable node.

Abstract: Provided are a method and apparatus for connecting a sensor network to a heterogeneous network, in which an external network connected to the sensor network functions as a virtual personal area network (PAN) so that the same PAN address system is used between the sensor network and the external network by using a concept of a ‘virtual PAN’. According to the method and apparatus for connecting the sensor network to the heterogeneous network, a node of the sensor network can efficiently communicate with a node of the external network including the heterogeneous network by assigning the virtual PAN address to the node of the external network including the heterogeneous network without inserting any additional layer into the node of the sensor network.

Abstract: Provided are a coordinator in a wireless sensor network (WSN) which can improve transmission performance and prevent data loss, and a method of operating the coordinator. The method includes: scanning a transmitted beacon and storing information on a channel included in the beacon; when it is determined that a home channel communicating with a parent node is in an inactive mode on the basis of the information on the channel, in synchronization with the activation of another channel of the same hierarchical level as that of the home channel, activating a home channel communicating with a child node and communicating with the child node; and communicating with the child node through an auxiliary channel that has a frequency band different from those of the home channel communicating with the child node and home channels of other nodes and is always in an active mode.