Abstract: Provided are an apparatus and method of transmitting and receiving a wake-up signal. The method of receiving a wake-up signal includes the following: operating a radio frequency (RF) receiving unit that receives a wireless signal through an antenna during an SFD detecting time, wherein the SFD detecting time is shorter than a predetermined SFD detecting time period, according to the predetermined SFD detecting time period and detecting a start of frame delimiter (SFD) to indicate that the received wireless signal is a wake-up signal to wake-up a node in a sleep mode; and detecting the wake-up signal by continuously operating the RF receiving unit when the SFD is detected. Power consumption that is used to receive the wake-up signal can be reduced.

Abstract: A transimpedance amplifier for a burst mode optical communication converts a burst current signal into differential output voltage signals. Using a multi-level digital AGC mechanism, the transimpedance amplifier is rapidly adapted to a burst signal whose amplitude varies in a wide range. By using an adaptive level detection method, a multi-level digital AGC can be implemented without using ADC. In addition, because the transimpedance amplifier uses a selective reset generation scheme that performs a reset operation for itself after a high power burst, a burst mode operation can be performed without external reset signals. Accordingly, the transimpedance amplifier can be integrated with an optical detector within a TO-can. Furthermore, the transimpedance amplifier can have the burst mode capability and the best sensitivity.

Abstract: Disclosed are an apparatus and method for constant amplitude encoding of a transmission signal in a CDM (Code Division Multiplexing) communication system. The apparatus for constant amplitude encoding of a transmission signal includes: an encoding module sequentially performing horizontal encoding and vertical encoding on an input signal; and a spreading and multiplexing module spreading the signal which has been encoded by the encoding module and multiplexing the spread signal in a vertical direction to output a data stream having a constant amplitude.

Abstract: Provided are an apparatus and method for charging an internal battery in a wireless sensor network. A method for a slave sensor node to charge an internal battery in a sensor network includes estimating an hourly chargeable electric energy rate in a scan phase with a master sensor node, transmitting the estimated hourly chargeable electric energy rate using an association request message requesting association with the master sensor node after recognizing the master sensor node, requesting charging from the master sensor node and performing wireless charging when a power level of an internal battery requires charging, reporting the power level of the internal battery varied by the wireless charging to the master sensor node by predetermined time periods during the wireless charging, and stopping the wireless charging when the power level reported to the master sensor node reaches a predetermined power level.

Abstract: Provided is a low-power wake-up receiver that is sensitive to electric waves, by which power consumed by a radio frequency (RF) transceiver of a sensor node in a ubiquitous sensor network (USN) is minimized. A wake-up receiver waking up a main transceiver includes a duty cycle signal generation unit controlling a duty cycle of a duty cycle signal; a burst signal detection unit receiving an input signal including a burst signal and a data signal based on the duty cycle signal, amplifying the input signal, and, if the amplified input signal is the burst signal, outputting a control signal; and a data signal detection unit re-amplifying the amplified input signal based on the control signal, and, if the re-amplified input signal is the data signal, outputting a wake-up signal. Power supplied to the duty cycle signal generation unit is interrupted based on the control signal and power is re-supplied to the duty cycle signal generation unit based on the wake-up signal.

Abstract: Provided is a general-purpose interface port that may interface with a sensor board including multiple types of sensor device drivers and download a sensor device driver from the sensor board, and a sensor node that may recognize a type of sensor included in the sensor board using the downloaded sensor device driver, the sensor node including a micro control unit that may process sensing data received from the sensor board, thereby providing a plug and play function between a micro control unit of a sensor node and a sensing unit including a sensor board in a Ubiquitous Sensor Network (USN) or a Wireless Sensor Network (WSN).

Abstract: Provided are an apparatus and method for charging an internal battery in a wireless sensor network. A method for a slave sensor node to charge an internal battery in a sensor network includes estimating an hourly chargeable electric energy rate in a scan phase with a master sensor node, transmitting the estimated hourly chargeable electric energy rate using an association request message requesting association with the master sensor node after recognizing the master sensor node, requesting charging from the master sensor node and performing wireless charging when a power level of an internal battery requires charging, reporting the power level of the internal battery varied by the wireless charging to the master sensor node by predetermined time periods during the wireless charging, and stopping the wireless charging when the power level reported to the master sensor node reaches a predetermined power level.

Abstract: Provided is a low-power wake-up receiver that is sensitive to electric waves, by which power consumed by a radio frequency (RF) transceiver of a sensor node in a ubiquitous sensor network (USN) is minimized. A wake-up receiver waking up a main transceiver includes a duty cycle signal generation unit controlling a duty cycle of a duty cycle signal; a burst signal detection unit receiving an input signal including a burst signal and a data signal based on the duty cycle signal, amplifying the input signal, and, if the amplified input signal is the burst signal, outputting a control signal; and a data signal detection unit re-amplifying the amplified input signal based on the control signal, and, if the re-amplified input signal is the data signal, outputting a wake-up signal. Power supplied to the duty cycle signal generation unit is interrupted based on the control signal and power is re-supplied to the duty cycle signal generation unit based on the wake-up signal.

Abstract: Disclosed are an apparatus and method for constant amplitude encoding of a transmission signal in a CDM (Code Division Multiplexing) communication system. The apparatus for constant amplitude encoding of a transmission signal includes: an encoding module sequentially performing horizontal encoding and vertical encoding on an input signal; and a spreading and multiplexing module spreading the signal which has been encoded by the encoding module and multiplexing the spread signal in a vertical direction to output a data stream having a constant amplitude.

Abstract: Provided are an apparatus and method of transmitting and receiving a wake-up signal. The method of receiving a wake-up signal includes the following: operating a radio frequency (RF) receiving unit that receives a wireless signal through an antenna during an SFD detecting time, wherein the SFD detecting time is shorter than a predetermined SFD detecting time period, according to the predetermined SFD detecting time period and detecting a start of frame delimiter (SFD) to indicate that the received wireless signal is a wake-up signal to wake-up a node in a sleep mode; and detecting the wake-up signal by continuously operating the RF receiving unit when the SFD is detected. Power consumption that is used to receive the wake-up signal can be reduced.

Abstract: A wireless sensor node is provided which is divided into functional modules on a function basis and operates the functional modules to cooperatively perform its individual functions. The wireless sensor node includes a wireless transceiver to wirelessly communicate with a control node; a primary configuration unit to set a node identification address in communication with a control node; a secondary configuration unit to use the node identification address to register with the control node and set an address for communication which is assigned by the control node; a basic power supply to supply power to modules for communication and sensor control; functional modules to perform data processing and sensor control; and a functional module activator to activate the functional modules according to a type of received data or an operation for data transmission.

Abstract: A transimpedance amplifier for a burst mode optical communication converts a burst current signal into differential output voltage signals. Using a multi-level digital AGC mechanism, the transimpedance amplifier is rapidly adapted to a burst signal whose amplitude varies in a wide range. By using an adaptive level detection method, a multi-level digital AGC can be implemented without using ADC. In addition, because the transimpedance amplifier uses a selective reset generation scheme that performs a reset operation for itself after a high power burst, a burst mode operation can be performed without external reset signals. Accordingly, the transimpedance amplifier can be integrated with an optical detector within a TO-can. Furthermore, the transimpedance amplifier can have the burst mode capability and the best sensitivity.

Abstract: Provided is a burst mode optical receiver capable of accurately detecting an optical signal of minimum amplitude, by automatically controlling a gain of a pre-amplifier according to an amplitude of an input optical signal. The burst mode optical receiver can automatically control a gain of a pre-amplifier according to the amplitude of an input optical signal using an output signal of a first peak detector. In other words, when the input optical signal has a small amplitude that meets the receiving sensitivity of the burst mode optical receiver, the gain of the pre-amplifier automatically increases, thereby improving the receiving sensitivity of the burst mode optical receiver.

Abstract: Provided is a communication apparatus in a PON bridge sublayer, which supports point-to-point communications between optical network units (ONU) in an Ethernet passive optical network (EPON). To support point-to-point communications between ONUs in the EPON, the communication apparatus in the PON bridge sublayer includes a second processing portion, a second input queue, a second lookup and learning portion, a second output queue, a first input queue, a first lookup and learning portion, a filtering database table a VLAN ID table, a table control portion, a first output queue, and a first processing portion.

Abstract: A communication node system for an Ethernet-PON includes: an LLID register for storing an LLID being an allocated identifier; a preamble generator for generating a PON preamble; a CRC generator for generating a CRC for the preamble; a transmission connector for combining transport data with the CRC-including preamble to generate a transport frame, and forwarding the transport frame; a reception connector for receiving the frame and dividing the frame into a preamble and received data; a filter for extracting an LLID from the preamble, comparing the extracted LLID with the LLID stored in the register, and selectively filtering the extracted LLID; and a received frame generator for discarding the received data, or combining the received data with the preamble to generate a received frame.

Abstract: Provided is a burst mode optical receiver considering a characteristic of an extinction ratio of a received optical signal is provided. By using a peak detector considering a characteristic of an extinction ratio, top and bottom peak voltages of actual burst packets can be precisely detected while not being affected by a DC offset corresponding to an extinction ratio even though burst packets having a DC offset corresponding to the extinction ratio are received. Accordingly, waveform distortion of a signal output from the burst mode optical receiver can be minimized.

Abstract: An apparatus for and a method of generating pointers for identifying structure boundaries of data for leased lines such as T1/E1 in an asynchronous transfer mode (ATM) adaptation layer Type 1 (AAL1) through an ATM layer.

Abstract: Provided is a burst mode optical receiver considering a characteristic of an extinction ratio of a received optical signal is provided. By using a peak detector considering a characteristic of an extinction ratio, top and bottom peak voltages of actual burst packets can be precisely detected while not being affected by a DC offset corresponding to an extinction ratio even though burst packets having a DC offset corresponding to the extinction ratio are received. Accordingly, waveform distortion of a signal output from the burst mode optical receiver can be minimized.

Abstract: A burst mode optical receiver includes: a photodiode which converts an input optical signal into a current signal; a pre-amplifier which converts the current signal into a voltage signal; a single-to-differential converter which converts the single voltage signal output from the pre-amplifier into differential signals; a post amplifier which amplifies the differential signals and cancels an offset occurring during the amplification or offsets inherited from the differential signals; and a discriminator which discriminates data from the differential signals.

Abstract: Provided is a burst mode optical receiver capable of accurately detecting an optical signal of minimum amplitude, by automatically controlling a gain of a pre-amplifier according to an amplitude of an input optical signal. The burst mode optical receiver can automatically control a gain of a pre-amplifier according to the amplitude of an input optical signal using an output signal of a first peak detector. In other words, when the input optical signal has a small amplitude that meets the receiving sensitivity of the burst mode optical receiver, the gain of the pre-amplifier automatically increases, thereby improving the receiving sensitivity of the burst mode optical receiver.