Electronics and Telecommunications Research Institute

Jin-Soo Han

Moo-jung Chu

Wan-Ki Park

Jong-Hyun Lee

Seung-Il Myong

Je-Soo Ko

Sun-Hyok Chang

Hyun-Woo Oh

Jyung-Chan Lee

Jong-Hyun Jang

Won-Kyoung Lee

Chang-Sic Choi

In-Tark Han

Dong-Won Han

Hee-Sang Chung

Seung-Kwan Kim

The network configuration technology for controlling an electric power sensor node is disclosed. The method for controlling electric power includes transmitting an an Ethernet packet type command message to at least one electric power sensor node through an LRWPAN-Ethernet bridge in accordance with profile information related to an electric power control, the profile information being set by a user; receiving LR-WPAN packet type response messages transmitted from the at least one electric power sensor node in response to the Ethernet package type command message as Ethernet packet type response messages through the LRWPAN-Ethernet bridge; and providing a control result of an electric power equipment corresponding to the at least one electric power sensor node to the user based on the Ethernet packet type response messages.

Method for controlling electric power of electric power controller, LRWPAN-ethernet bridge and sensor node

Provided are an apparatus and method for controlling home appliances using zigbee wireless communication. The apparatus, includes: a memory for storing a control profile and an operation program, and operating the stored operation program; a display means for supporting interface with a user; a display input/output control means for controlling input/output of the display means; a first wireless network interface for transmitting/receiving wireless data to/from home appliances based on zigbee wireless communication; and a control means for forming Wireless Personal Area Network (WPAN) with the home appliances based on the first wireless network interface, displaying a list of controllable home appliances based on device product information transferred from the home appliances through the WPAN, reading a control profile in the memory upon home appliances control request of the user, and transferring the control profile through the first wireless network interface.

Apparatus and method for controlling home appliances using zigbee wireless communication

An optical receiver in an optical communication system, and more particularly, to a method and an apparatus for optimizing a decision level of a signal output from an optical receiver to obtain a minimum bit error rate (BER) by measuring output characteristics of the optical receiver and adjusting a reference voltage of the optical receiver based on a measurement result. The provided method includes measuring the strength of an electric signal at a modulated frequency out of the frequency elements of the output electric signal in the optical receiver, generating a reference voltage based on the strength data of the electric signal, inputting the reference voltage to the optical receiver and re-measuring the strength of the electric signal output from the optical receiver to determine whether the strength of the signal is minimum, and maintaining the reference voltage when the strength of the signal is minimum and adjusting the reference voltage in other cases. Thus, the provided method optimizes the distribution of level one and level zero, i.e., a decision level, of the electric signal output from the optical receiver, so the efficiency and the performance of the transferred optical signal are maximized.

Method and apparatus for optimizing decision level of signal output from optical receiver

A method for realizing, in a fiber amplifier with three stages of amplifiers, automatic gain control in which a constant gain is obtained when channels are varied, and automatic level control in which a constant output per channel is obtained when a light power is varied because of variations in span loss. A light power or another light power of a specific wavelength is monitored to determine when variations in these light powers take place, current values of pump laser diodes appropriate for an input is read from a lookup table, and pump laser diodes are driven. During this operation, a pump power of the first stage amplifier is constantly maintained, and those of the second or third stage amplifier are controlled.

Fiber amplifier and control method thereof

Provided are an optical signal receiving apparatus whose optimum receiving performance is maintained regardless of a change in the power of an optical signal, and a method using the same. The apparatus includes an optical coupler for dividing an input optical signal at a predetermined ratio to produce first and second divided signals, a photoelectric converter for converting the first divided signal into an electric signal, an amplifier for amplifying the electric signal within a predetermined range centering on a reference voltage, a reference voltage controlling unit for detecting the power of the second divided signal, predicting the power of the first divided signal, and controlling the amplitude of the reference voltage in accordance with the predicted power, and a clock & data recovery unit for recovering a clock signal and data from a signal output from the amplifier. Even if the power of an optical signal changes, the reference voltage of a limiting amplifier, which is best suitable for optimum performance with respect to the power of an input optical signal, can be detected and adjusted using the method and apparatus, thereby maintaining the optimum receiving performance of the optical signal receiving apparatus.

Optical signal receiving apparatus and method using the same

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Daejeon, South Korea

Jin-Soo Han