Sk Telecom Company, Ltd.

Snu Rdb Foundation

Sk Planet Co., Ltd.

Jae Hwang Yu

Min Seok Kim

Jong Tae Ihm

Moon Kee Kim

Keun Hwan Choi

Se Hyun Oh

Kyung Sik Han

Woo Jin Shim

Jae Yeon Noh

Cheol Ho Yim

Yong Gil Park

Dong Hahk Lee

Goon Seop Lee

Ku Ik Chung

Nam Soo Kim

Hwan Sik Yun

Ki Ho Cho

Sung Cheol Hong

Young Sik Shin

Dong Keon Kim

Ho In Jeon

Sung Hoon Lee

Seong Soo Park

Seung Ho Shin

Jun Mo Koo

Sang Shin Lee

Yong Woo Bae

Jin Hee Han

Byung Moo Kim

Kang Il Koh

Hak Soon Lee

Young Woo Kim

Jin Yong Han

Guk Chan Lim

An Na Choi

Dong Youb Sinn

Sun Joon In

Kyo Hoon Son

An image projection device includes: a panel unit configured to emit light rays; a projection optical system configured to receive the light rays emitted from the panel unit and to refract the light rays; a reflection unit having a reflection surface for receiving the light rays refracted by the projection optical system and reflecting the light rays; and a screen unit configured to display an image upon receiving the light rays reflected from the reflection surface. The panel unit, the projection optical system, the reflection unit, and the screen unit are arranged such that a distance of a shortest path among paths extending from the panel unit to the reflection unit through the projection optical system along a predetermined linear axis is longer than a distance of a longest path among paths extending from the reflection unit to the screen unit along the predetermined linear axis.

Image projection device

Provided is a system and method for a local area broadcast service, and a wireless transmission apparatus applied to them. In the system, contents to be broadcasted in a predetermined local area are transmitted from a broadcast server to a wireless transmission apparatus through a wired network based on an Internet Protocol and the contents are then broadcasted from the wireless transmission apparatus to one or more user terminal devices. Therefore, according to the present invention, a server of a wired network can easily provide particular contents for each particular local area to one or more user terminal devices in the local area. Moreover, it is possible to reduce the load of the server, when the server provides multiple types of contents or provides contents to a plurality of user terminal devices.

Local area broadcasting service system and method, and wireless transmission device applied therein

Disclosed is a multicast system and a multicast method using a shortened address and an apparatus applied to the same. The multicast system using the shortened address according to the present disclosure has a address configuration for supporting a multicast in an IEEE 802.15.4 MAC (Medium Access Control) layer. Accordingly, when a device processes a multicast through an address configuration of the MAC layer, the device receives the multicast through a simple scheduling such as receiving a beacon signal of a coordinator device only when there is a broadcast of a group including the device. As a result, the device can efficiently perform the multicast in a power managing process or a power processing process.

Multicast system and multicast method using shortened address and apparatus applied to the same

Provided is a synchronization system and method for acoustic communication in audible frequency range, and an apparatus applied thereto. The synchronization system for acoustic communication in audible frequency range is configured to prevent deterioration of a synchronization performance and to reduce an amount of calculation by calculating a correlation based on a few samples as opposed to calculating a correlation for each sample when a receiver of the acoustic communication performs synchronization while the acoustic communication is performed in the audible frequency range through modification of an audio signal or adding of a predetermined signal to an audio signal.

Synchronization system and method for transmission and reception in audible frequency range-based sound communication, and apparatus applied thereto

The present invention relates to a method and to a wireless personal area network (WPAN) device in which the device sets the beacon slot in the WPAN device and receives beacon slot information from neighbor devices, while setting the beacon table of the devices, to avoid the transmission time of the neighbor devices and the transmission time of the devices neighboring the neighbor devices in a WPAN. In the method, beacon message, including information about neighbors' transmission time and information about neighbors' neighbors' transmission time, is received from neighbor devices. The beacon message is combined, and the neighbors' transmission time information and the neighbors' neighbors' transmission time information are input into a beacon table. The neighbors' transmission time and the neighbors' neighbors' transmission time are input into a field for BTTSs to be avoided in the beacon table. The first beacon slot is set, as my beacon transmission slot, among beacon slots except for the transmission time input into the field for BTTSs to be avoided. Information about the set beacon transmission slot is input into a field for my BTTS in the beacon table.

Method for allocating a beacon slot using a beacon table in wireless personal area network (WPAN) and WPAN device

Disclosed is a network interworking system and method. That is, a header size is minimized through a fragment of an IPv4 packet based IP packet and a header compression and it is implemented such that the IPv4 is loaded in an IEEE 802.15.4 MAC/PHY packet having a small payload, so that it is possible to efficiently transmit an IPv4 packet by using an IEEE 802.15.4 based WPAN. Further, various applications can be executed using the IPv4 while using an IEEE 802.15.4 technology, which is a low power communication technology, in a mobile device.

Packet transmission system based on wireless personal area network and method thereof

Disclosed is a system and a method for minimizing signal interference for a broadcasting and communication convergence section within a local area, and an apparatus applied to the same. The system has a construction of mounting a plurality of multi RF (Radio Frequency) channels within a local area wireless communication apparatus located in a local area and minimizing signal interference between mutually adjacent RF channels within the local area wireless communication apparatus in a standard for providing a broadcasting and communication convergence service. Accordingly, it is possible to remove the mutual channel effects affecting a communication signal without signal interference for adjacent channels due to a broadcasting signal and it is not necessary to enhance a filtering characteristic for the adjacent channels of a chipset, which corresponds to a broadcasting and communication convergence standard structure in a local area, so that there is an advantage of reducing network investment costs.

System and method for minimizing signal interference between broadcasting signals and communication signals within local area and apparatus applied to the same

A local wireless signal receiving apparatus using digital RF processing technology including: a receiving digital RF processor receiving an RF signal and detecting an IF signal from the received RF signal; a zero-crossing signal detector detecting a zero-crossing signal from the detected IF signal, and converting the detected zero-crossing signal into a digital signal; and a receiving signal processor converting the digital signal into a local wireless signal.

Local wireless signal transmitting/receiving apparatus and method using digital radio frequency processing technology

The present invention relates to a system and to a method for QoS (Quality of Service) support in a ubiquitous sensor network. The system for QoS support in a ubiquitous sensor network includes a mesh coordinator and nodes. The mesh coordinator organizes a super frame containing a dedicated QoS data transmission period, and synchronizes each of the nodes constituted into one network with the abovementioned super frame. The nodes create a beacon frame containing information on whether or not to set QoS, to broadcast the beacon frame in a dedicated beacon period of the super frame if QoS data transmission is needed, to create a QoS data frame with a set priority, and to transmit the QoS data frame to the dedicated QoS data transmission period of the super frame in the case of transmitting QoS data. The present invention divides QoS data from general data to improve the quality of data transmission and ensure stability, and prioritizes QoS data to transmit the most important data among QoS data in a quick and stable manner.

System and method for QoS support in ubiquitous sensor

Provided is a data reception error reduction system and method in acoustic communication in audible frequency range, and an apparatus applied thereto. The data reception error reduction system in the acoustic communication in audible frequency range may be configured to reduce a data reception error in a receiver by taking into consideration that a sound signal is noisy and is significantly affected by a change in the ambient environment when the acoustic communication is performed in the audio frequency band through modification of an audio signal or adding of a predetermined signal to an audio signal. Accordingly, the data reception error may be reduced in the receiver even in an environment where a sound signal is noisy and is significantly affected by a change in the ambient environment, and reliability of data transmission may increase.

System and method for reducing data reception error in acoustic communication in audible frequency range, and apparatus applied thereto

Disclosed are an apparatus and a method for voice processing in a mobile communication terminal. A plurality of microphones are used to remove environmental noise at the time of voice communication, so that it is possible to perform high-quality voice communication and video telephony. Moreover, it is possible to perform voice recording even when a user does not open a mobile communication terminal. Furthermore, when voice is recorded or sound is recorded during moving image photographing, a plurality of microphones are effectively utilized to achieve good-quality recording and to perform recording conveniently even when the folder or the slider of the mobile communication terminal is closed. Therefore, it is possible to provide improved convenience in using the mobile communication terminal.

Apparatus and method for voice processing in mobile communication terminal

A chip equalization apparatus and method for selecting cluster signals from broadcast signals being continuously received in multi-path channels for extracting a plurality of cluster signals from among the received broadcast signals and using a plurality of chip equalizers each having a tap coefficient update part for updating the tap coefficients of the selected cluster signals when the equalization outputs are combined to compensate the broadcast signals and provide low power consumption and efficient equalization for use in a satellite broadcasting receiving system.

Chip equalization apparatus and method thereof

The present invention relates to a system and method for providing a supplementary information service related to broadcast content. The system for providing a supplementary information service related to broadcast content being broadcasted to user terminal comprises a Time Information Creating Server for Identifying a start time information of the broadcast content; and a Supplementary Information Service Providing Server for receiving the start time information of the broadcast content from the Time Information Creating Server, calculating elapsed time for a specific scene based on the start time information, and providing a user terminal with an supplementary information corresponding to the scene based on the elapsed time, through a communication network. And the method for providing a supplementary information related to broadcast content being broadcasted to user terminal comprises steps of identifying a start time information of the broadcast content; calculating elapsed time for a specific scene based on the start time information; and providing a user terminal with an supplementary information corresponding to the scene based on the elapsed time, through a communication network.

System, server and method for providing supplementary information service related to broadcast content

Disclosed herein is a system and method for providing a supplementary information associated with a broadcast content. The system provides a supplementary information associated with a specific broadcast program in the broadcast content by means of a supplementary information server, wherein the supplementary information server comprises a broadcasting receiving unit for receiving the broadcast content; a synchronization information unit for storing a synchronization information of the supplementary information associated with the specific broadcast program; a video comparison unit for comparing screens of the broadcast content with a previously stored scene change screen of the specific broadcast program and setting a start time of the specific broadcast program; a supplementary information extracting unit for calculating an elapsed time from the start time of the specific broadcast program to a specific screen and extracting the supplementary information corresponding to the elapsed time. The supplementary information associated with the specific broadcast program in the broadcast content is provided through the steps of receiving a synchronization information of the supplementary information associated with the specific broadcast program; setting a start time of the specific broadcast program by comparing screens of the broadcast content with a previously stored scene change screen of the specific broadcast program; calculating an elapsed time corresponding to a specific screen based on the start time; extracting the supplementary information corresponding to the elapsed time.

System and method for synchroning broadcast content with supplementary information

The present invention relates to a method of efficiently assigning addresses in a WPAN and a WPAN device. The address assignment method of the present invention is performed by a higher device. Address assignment information for determining an address to be assigned to a lower device, is managed. An address is assigned to a lower device that requests connection from the higher device based on the address assignment information. The address assignment information is updated to a address value as the address value is assigned, and the updated address assignment information is transmitted to lower devices. If an update of address assignment information is requested by the lower device that assigned an address value to a device lower thereto, the address assignment information is updated and the updated address assignment information is transmitted to lower devices.

Growing community of inventors

Seoul, South Korea

Jae Hwang Yu