Electronics and Telecommunications Research Institute

In Hwan Lee

Cheol Sig Pyo

Tae Joon Park

Chang Sub Shin

Ho Yong Kang

Hoyong Kang

Se Han Kim

Wun-Cheol Jeong

Byung Bog Lee

Ju Derk Park

Byeong Cheol Choi

Eun Hee Kim

Jae Heum Lee

Myung Nam Bae

Nae Soo Kim

Wun Cheol Jeong

Jong-Arm Jun

Dong-Hwan Park

Hyochan Bang

Jae Hong Ruy

Dong Hyun Ahn

Hyung Seok Chung

Cheo Sig Pyo

Nguyen Trung Kien

Wu Cheol Jeong

A synchronization method performed by a first communication node may include: receiving, from a second communication node of the communication system, a first synchronization information signal including information on a first synchronization reference time and information on a first offset; identifying information on a first time at which the first synchronization information signal is transmitted and information on a target synchronization time configured by the second communication node, based on the information included in the first synchronization information signal; setting a synchronization timer based on the information on the first offset; and when the synchronization timer expires, determining that time synchronization with the second communication node is acquired.

Method and apparatus for synchronization in wireless communication system

Provided is a method of improving a bandwidth of an antenna using a transmission line stub to enable long-range communication together with broadband matching. According to the method, it is possible to combine a transmission line stub in series or parallel with a feeding point, which is an antenna signal input/output point of a body serving as an antenna, and apply the transmission line stub to an antenna for wide use.

Method of improving bandwidth of antenna using transmission line stub

Disclosed is a manhole type omnidirectional antenna having a relatively small angle between a main beam direction and the Earth's surface and exhibiting omnidirectional characteristics to allow long-range communication, wherein the manhole type omnidirectional antenna includes a manhole cover installed in a manhole in the Earth's surface; a main body installed in a cavity of an upper surface of the manhole cover and configured to convert an electrical signal into an electromagnetic wave to wirelessly communicate with a gateway separated from the manhole cover; and a radome inserted into the cavity to cover the main body.

Manhole cover type omnidirectional antenna

A method of configuring a multi-superframe is provided. The method includes setting at least one parameter for configuring the multi-superframe, and configuring the multi-superframe corresponding to the at least one parameter, wherein the at least one parameter includes a superframe order (SO), a beacon order (BO), and a multi-superframe order (MO), in a form of positive integers, and the setting includes setting the MO to have a value higher than the BO.

Extended DSME MAC for low power utility monitoring service

A method and apparatus for encoding a constant amplitude that is applied to a code division multiplexing communication system are provided. By dividing a data bit into a block unit, the receiving side can easily determine an error, and by reducing power consumption in outdoor wide area communication using a bit string of a small length in a basic unit of an input frame, efficiency can be improved, and thus a physical layer of a ubiquitous sensor network can be optimized.

Apparatus and method for encoding constant amplitude in code division multiplexing communication system

A multi-channel wireless network acquires reference time information that is commonly applied to all multi-channels and acquires packet receiving time information of a received packet on each channel basis based on the reference time information by spreading and applying the reference time information to each channel.

Method and apparatus for processing packet in multi-channel wireless network

Disclosed is a wireless communication system. The wireless communication system includes an embedded-type antenna embedded in a base, and a wireless communication unit including a communication unit that is connected to the embedded-type antenna and exchanges information with an external device, and a housing that is arranged to surround the communication unit, wherein at least one of the communication unit and the housing performs transmission and reception of electric waves as a substitute of the embedded-type antenna.

Wireless communication system

An IP packet forwarding server forwards an IP data packet between a user terminal and a machine-type communications (MTC) device allocated with a private internet protocol (IP). Such an IP packet forwarding server allocates a call identifier for connection between the user terminal and the MTC device, sets up a packet call to the MTC device and the user terminal using the call identifier, obtains packet forwarding information while setting up the packet call to the MTC device and the user terminal, and forwards an IP data packet between the MTC device and the user terminal using the packet forwarding information.

Method and apparatus for packet call setup

A received signal strength indicator is provided. The received signal strength indicator includes a plurality of differential amplifiers forming an amplifier chain for amplifying differential signals and a plurality of rectifiers for rectifying signals output from the plurality of differential amplifiers and the differential signals, and a low pass filter for combining the signals rectified by the plurality of rectifiers to output received signal strength. Each rectifier includes a class AB voltage-current converter for converting a differential voltage into a current, and two triode transistors.

Rectifier, received signal strength indicator, and receiver

Provided are a node device of a beacon-enabled Wireless Personal Area Network (WPAN) managing a channel resource and a method thereof. The node device may generate a pseudo random binary sequence (PRBS) and generate a hopping sequence based on a number of available channels using the PRBS, thereby generating a hopping sequence having a characteristic of pseudo randomness and selecting a channel to be hopped, using the hopping sequence.

Apparatus and method for managing channel resource in beacon-enabled wireless personal area network (WPAN)

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.

Low-power method for media access control in semi-linear sensor network

Provided are a method and apparatus for controlling a shared memory, and a method of accessing the shared memory. The apparatus includes a processing unit configured to process an application program, a user program unit configured to execute a program written by a user based on the application program of the processing unit, a shared memory unit connected to each of the processing unit and the user program unit through a system bus and configured to store data interchanged between the processing unit and the user program unit, and a control unit configured to relay a control signal indicating whether the system bus, by which the data is interchanged between the processing unit and the user program unit, is occupied, and control connection of each of the processing unit and the user program unit with the system bus in response to the control signal. In the apparatus, the processing unit and the user program unit can easily interchange a large amount of messages through the shared memory unit having an abundant memory space.

Growing community of inventors

Daejeon, South Korea

In Hwan Lee