Abstract:
Provided are a method and apparatus for controlling media access in a sensor network and a method of managing traffic information. Since traffic information is exchanged between nodes and data is transmitted by using a dynamic long preamble according to receiver nodes, data transmission efficiency can be improved, energy consumed to transmit the long preamble can be reduced, and data transmission delay can be reduced as well.
Abstract:
A media access control device of a medium access control method in a sensor network reducing delay generated between a hop and a sensor node are provided to process data quickly by using a check interval of short length. A first node performs an LPL(Low Power Listening) which is the check interval which is most short among the usable check interval(S510). A first node receiving the downward traffic information determines the check interval by summing the traffic volume which periodically reports to the sink node by summing upward traffic and downward traffic which receives from its own lower nodes(S525). The first node transmits the upward traffic binding update message by using the long preamble of the type '2 fitted to the check interval of the node having the most small traffic(S540).
Abstract:
Provided is a method of transmitting/receiving data in a sensor node for reducing overhearing of sensor nodes, and a sensor network which implements the method. A sender node having transmission data from among a plurality of nodes which perform a low power listening (LPL) operation in an asynchronous manner at predetermined time intervals, generates a long preamble including short preambles, each having information including a destination address of the transmission data, a remainder of the long preamble, and a length of the transmission data, and sequentially transmits the second preamble and the transmission data. A receiver node from among the plurality of nodes determines whether a valid signal is sensed during an active state in the LPL operation. If it is determined that the valid signal is sensed, the receiver node receives the short preamble transmitted from the sender node. The receiver node determines a duration time of a deactivated state of the receiver node based on the received first preamble, thereby reducing overhearing in the sensor network.
Abstract:
A method of transmitting/receiving data in a sensor network for reducing overhearing of sensor nodes is provided to minimize the power consumption of sensor nodes by minimizing the overhearing of the sensor nodes in a sensor network environment using an MAC(Media Access Control). A transmission node having transmission data generates a long preamble including at least short preamble for reducing the overhearing of other nodes(S510). The transmission node transmits the long preamble and the transmission data(S520). At least one first preamble includes the information as to the destination address of the transmission data, the residual amount of the second preamble at its time position and the length of the data to be transmitted.
Abstract:
수직 빔 폭을 조정하여 복수의 방사 패턴을 제공하는 안테나 및 안테나 구성 방법이 제공된다. 안테나는, 복수의 방사 패턴을 제공하는 집중 회로 소자부, 및 제어데이터에 기초하여 복수의 방사 패턴들 중 어느 하나를 선택적으로 제공하는 스위칭부를 포함할 수 있다.
Abstract:
Disclosed is a sensor terminal capable of personalizing an external physical device and a method thereof. The sensor terminal includes a control unit which recognizes an external physical device as a built-in device. The control unit includes the device object of at least one physical device, a device object driver which manages the profile of the device object, and a device service module which generates the device object of the physical device and registers the generated device object and the profile of the device object in the device object driver. Thereby, the sensor terminal recognizes an external physical device as a built-in device and can use it identically.
Abstract:
Disclosed are a sensor node for reducing traffic in a sensor network and an adaptive sensing data reporting method. The sensor node according to an embodiment of the present invention compares the difference between a previously reported sensing value and a current sensing value with a threshold value, and reports the current sensing value when the difference is greater than the threshold value. The sensor node adaptively varies a period of a timer according to whether the current sensing value is transmitted based on a sensing value comparison result. When a current sensing value transmission occurs based on the sensing value comparison result, the sensor node additionally reports the current sensing value within the period of the timer.
Abstract:
A direction control antenna turns on or off a plurality of switches based on external control commands from the outside and comprises a plurality of impedance devices connected to a space between a grounding body and a radiator and the switches connected to a space between each impedance device and the grounding body. The radial directions and patterns of the antenna are determined based on the position and number of the radiators which are short-circuited from the grounding body by a switch turned on. [Reference numerals] (110) Grounding body; (120) Radiator
Abstract:
링크 품질 지표(Link Quality Indicator; LQI) 에 기초하여 전송 프레임의 길이를 결정하는 방법 및 장치가 제공된다. 대상 송신기는 LQI를 대상 수신기에게 요청하고, 대상 수신기는 LQI에 대한 정보를 대상 송신기로 전송한다. 대상 송신기는 LQI를 기초로 전송 프레임의 길이를 결정한다. 대상 송신기는 LQI 값에 비례하도록 전송 프레임의 길이를 결정할 수 있다.
Abstract:
PURPOSE: A system and method for monitoring a road slope collision are provided to take prior measures before a section is collided by predicting possibilities of a road slope collision based on underground information of the road slope. CONSTITUTION: A method for monitoring a road slope collision is as follows. Underground information of a road slope is measured. Whether the measured underground information is exceeded a critical value of the underground information based on possibilities of a road slope collision or not is confirmed. If the measured underground information is exceeded the critical value, an inclination of the road slope is measured by driving a sensor. If the measured inclination of the road slope is exceeded a critical inclination value, the road slope is decided to be collided.