Patents Assigned to Korea Telecom
  • Patent number: 6411600
    Abstract: An asynchronous transfer mode (ATM) protection triggering method using “received-AIS” flag determines whether the failure generation position is generated within a protected domain or not, by determining whether the “received-AIS” flag is “0” in case that a node detecting a failure link transmits an end-to-end AIS cell to a downstream side node, and a source point passing the end-to-end AIS cell sets the “received-AIS” flag to “1” and then receives “AIS cell receiving” signal from a sink point of the protected domain, thereby obviating a CRC-10 calculation problem and a backward compatibility.
    Type: Grant
    Filed: August 6, 1998
    Date of Patent: June 25, 2002
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Dong Yong Kwak, Yool Kwon
  • Patent number: 6406932
    Abstract: A 0.98 &mgr;m semiconductor laser of a ridge waveguide (RWG) structure includes: to be lengthen the durability of a semiconductor laser by increasing a catastrophic optical damage (COD) level, a ridge having a fixed width and length so that the strip may stop in the position of 30 &mgr;m on the basic of end portion of an output facet along length direction of a resonator; and a non-waveguide region in the end portion of both sides of a resonator.
    Type: Grant
    Filed: April 12, 2001
    Date of Patent: June 18, 2002
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Jung Kee Lee, Kyung Hyun Park, Dong Hoon Jang, Chul Soon Park
  • Patent number: 6390139
    Abstract: A conduit pipe is installed within a cable tunnel and telecommunication cables are disposed in the conduit pipe. The conduit pipe is divided longitudinally into a plurality of divided bodies. Each divided body is equipped at one longitudinal side with a retaining part and at the other longitudinal side with a protruded part. A single conduit pipe is formed when the divided bodies are connected to each other along the longitudinal side. Since the divided bodies can be wound around a small-diameter bobbin to be carried, the space for their custody is reduced and the carriage thereof is easier. Further, since connection parts on surfaces of the conduit pipes can be arranged such that they occupy empty spaces between conduit pipes, the space occupied by the connection parts can be minimized, thereby comparatively larger number of telecommunication cables being able to be disposed within the cable tunnel.
    Type: Grant
    Filed: February 8, 2001
    Date of Patent: May 21, 2002
    Assignee: Korea Telecom
    Inventors: Young-Sug Kang, Geu-Bok Kim, Yong-Kun Noh, Myung-Woo Seo, Jeong-Kwen Park
  • Patent number: 6393024
    Abstract: An ATM switch network with an expansible optical ring, in which each switch forms several paths with a vertical ring, a horizontal ring and an expansible ring. The network has a large-capacity and a small switching interval, minimizing cell delay deviation and rendering the network suitable for high-speed multimedia service. A group switch node is formed by grouping the switches forming the vertical and horizontal rings, thereby enhancing reliability within a transmission interval by bisecting the wavelength division multiplexed logical paths and by using two optical lines. The network discriminates between I/O terminals for matching data having a low-speed small capacity and wavelength division I/O terminals for matching data having a high-speed large capacity. By using a node's I/O terminals, the network interconnects nodes via wavelength division multiplexing optical lines, thereby forming an automatic adaptive network.
    Type: Grant
    Filed: August 25, 1998
    Date of Patent: May 21, 2002
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Seung Kyun Park, Jun Kyun Choi
  • Patent number: 6393188
    Abstract: A dispersion compensation device and an optical transmission system are capable of simultaneously compensating a dispersion value and dispersion slope in a single-mode optical fiber in a high-speed long-distance optical transmission system and a wavelength division optical transmission system. The dispersion compensation device includes N number of component optical fibers arranged in a serial fashion, N being a positive integer more than one, wherein each of the component optical fiber has a different dispersion value per a unit length, a dispersion slope per a unit length, and a different length.
    Type: Grant
    Filed: September 2, 1999
    Date of Patent: May 21, 2002
    Assignees: Korea Telecom, Daewoo Telecom Ltd.
    Inventors: Ki-Tae Jeong, Young-Tark Lee, Ho-Jin Jeong, Han-Kyo Seo, Jeong-U Jeon, Tae-Sang Park, Seok-Bong Ko, Yun-Hee Cho, Seong-Il Choi, Sang-Woork Park
  • Patent number: 6389020
    Abstract: A customer premise network equipment and a data communication method based on a single ring configuration are disclosed. The equipment includes a plurality of subscriber terminals connected one-to-one or one-to-multiple or a broadcasting type between a network and a subscriber by a single ring, and a customer premise network terminal equipment connected by a single ring for receiving an one-to-one protocol and implementing a communication between the subscriber terminals and an access between the subscriber terminal and the network.
    Type: Grant
    Filed: August 13, 1998
    Date of Patent: May 14, 2002
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Jong Oh Kim, Kyu Ho Lee, Bong Tae Kim
  • Patent number: 6389554
    Abstract: A concurrent write duplexing device with extension of memory bus according to the present invention includes: a primary memory having a first memory in which changed information is stored and a first memory controller for controlling the first memory; a secondary memory having a second memory in which the operating system is loaded to change an operation mode from the standby module to the active module upon failure of duplexing separation and a second memory controller for controlling the second memory; a bus transceiver part for exchanging data with a CPU through a system bus and having a bus transceiver in the first memory controller and a bus transceiver in the second memory controller, to thereby determine as to whether the first and second memory controller operate; and a memory switch part for exchanging data between the active module and the standby module and having memory switches which set direction of memory bus in accordance with an operation mode of module, so that write operation performed in t
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: May 14, 2002
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Woo Sug Jung, Kwang Sug Song, Bo Sub Kwon
  • Publication number: 20020056039
    Abstract: Disclosed is a system for providing a sender certification service based on an end-to-end (EtoE) message security and public key infrastructure (PKI) between mobile terminals. The system performs by proxy a verification work of the user's certificate that is difficult to be performed by the mobile terminal having a limited capacity. The system performs by proxy a certification removal list (CRL) check and a certificate validity check with respect to the certificate sent by a sender, and thus the mobile terminal having the limited capacity can directly use the certificate without any CRC check or validity check of the sender's certificate, and effectively perform the PKI based electronic certification service. The system can be usefully applied to all fields that require a PKI based certification security service in the radio network environment in that messages are transmitted/received between the mobile terminals.
    Type: Application
    Filed: December 28, 2000
    Publication date: May 9, 2002
    Applicant: Korea Telecom
    Inventors: Young Sook Lim, Seung-Jae Lee, Kyung Hee Kang
  • Patent number: 6381278
    Abstract: A high accurate and real-time gradual scene change detector and method thereof. The gradual scene change detector can enhance the automatic video analysis device to develop more efficient video library and multi-media service. Also, the detector can accomplish more convenient development and maintenance of the multi-media service.
    Type: Grant
    Filed: November 15, 1999
    Date of Patent: April 30, 2002
    Assignee: Korea Telecom
    Inventors: Eui-Seob Shin, Hyeok-Man Kim, Min Gyo Chung, Woon-Kyung Kim, Byung-Woong Kwon, Sun-Geun Kim
  • Patent number: 6377673
    Abstract: An intelligent peripheral system and a call processing method thereof are disclosed. The system includes an apparatus storing and maintaining a special resource information for providing an intelligent network system to a user in accordance with a request of the user, and an apparatus performing a protocol matching function and a call processing function between a service switching point (SSP) and a service control point (SCP) of the advanced intelligent network system, wherein said both apparatuses are separately installed for thereby implementing a direct connection to another intelligent network system through a common line signal network and easily expanding a resource channel, for thereby directly being connected with another IP system and implementing an easier expandability of a resource channel by separately connecting an apparatus processing a protocol matching function between a user and an IP network and an apparatus processing a call processing function.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: April 23, 2002
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Min Su Cho, Tae Il Kim
  • Patent number: 6369926
    Abstract: A multichannel light source wavelength and strength stabilizing apparatus and a method thereof are disclosed.
    Type: Grant
    Filed: August 19, 1998
    Date of Patent: April 9, 2002
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Gap Youl Lyu, Hyun Jae Lee, Seo Yeon Park, Jong Hyun Lee
  • Patent number: 6370138
    Abstract: The user cell is received from the FRIA (Frame Relay Interface Apparatus) for thereby performing a connection identifier-based usage parameter control function, and the user cell which follows the permitted traffic and the IPC cell received from the FRIA through the IPC bus are multiplexed and synchronized to the module clock of the clock generator. The thusly synchronized user cell and IPC cell are transmitted to the ATM switch which is away by a few meters. The head data of the ATM cell received from the ATM switch is analyzed. In the case of the user cell, the frame relay interface apparatus identifier is analyzed, and the cell is transmitted to a corresponding FRIA in accordance with a corresponding virtual path identifier and virtual channel identifier value, and in the case of the IPC cell and OAM cell, the processor processes the cell using the AAL5 reassembling unit, so that it is possible to provide a cell transmission function between the frame relay interface apparatus and the ATM switching system.
    Type: Grant
    Filed: July 30, 1998
    Date of Patent: April 9, 2002
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Do Yeon Kim, Won Sik Park, Jung Sik Kim
  • Patent number: 6356566
    Abstract: A clock signal generating apparatus for a data communication channel is disclosed which includes a first clock signal generating unit for receiving an external input clock signal and a frame position informing signal and outputting a predetermined cycle first clock signal and a first timing signal, a second clock signal generating unit for receiving the first clock signal and the first timing signal and externally outputting a first offset signal, a second timing signal, and a predetermined cycle second clock signal, respectively, and a third clock signal generating unit for receiving the first clock signal and the first timing signal and externally outputting a second offset signal, a third timing signal and a predetermined cycle third clock signal, respectively, for thereby implementing a reliable serial/parallel conversion, extraction and insertion of a data by generating a stable clock and timing signal using a simple circuit and supplying a stable clock signal for matching with an external apparatus for
    Type: Grant
    Filed: July 7, 1998
    Date of Patent: March 12, 2002
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Tae Hee Lee, Jong Ho Kim, Jeong Hoon Ko, Yoo Kyoung Lee
  • Patent number: 6346895
    Abstract: A method for using a nibble(partial bits of word) inversion code in a network system includes the steps of: a) adding 1 redundancy bit to n bit source data and generating a pre-code, n being an even number of 2 or over; b) deciding the number of transitions in the generated pre-code; c) determining the pre-code as a code word if the number of transitions in the pre-code is greater than or equal to 1+n/2 in a deciding result; d) inverting alternate bits including the redundancy bit among bits constructing the pre-code and generating the code word, if the number of transitions in the pre-code is less than n/2 in the deciding result; e) determining the pre-code as the code word in case that the number of transitions in the pre-code is equal to n/2 and simultaneously the source data is not an in-band signaling and not a special word in the deciding result; and f) inverting the nibble among the bits constructing the pre-code and generating the code word, in case that the number of transitions in the pre-code
    Type: Grant
    Filed: January 24, 2001
    Date of Patent: February 12, 2002
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Bhum-Cheol Lee, Jong-Moo Sohn, Eun-Chang Choi, Kwon-Chul Park
  • Patent number: 6344148
    Abstract: An easy method proposes a passive alignment by using an alignment mark. That is, V-shaped grooves are utilized as alignment marks in place of a metal pattern of the prior art in observing an optical contrast. Also, in order to adjust a height of an optical device, the support made of a metal is formed in the conventional method, whereas in the present invention a height of an optical device is adjusted by etching the silicon substrate and clamped through the use of solder bumps formed in the V-shaped grooves. And also, in this invention, it is possible that V-shaped grooves can be facilely formed on a non-planarized substrate by using a method of burying a mask material during the formation of the V-shaped grooves. By applying the above principle, the present invention proposes a process capable of passive aligning an optical device, a planar lightwave circuit (PLC) and an optical fiber, simultaneously.
    Type: Grant
    Filed: November 5, 1999
    Date of Patent: February 5, 2002
    Assignee: Korea Telecom
    Inventors: Soo-Jin Park, Ki-Tae Jeong, Tae-Seok Suh, Young-Bok Choi, Sang-Pil Han
  • Patent number: 6330439
    Abstract: A method for predicting radio-wave propagation loss values of points located in a service area of a base station, includes the steps of: (a) calculating radio-wave propagation loss values of points located along with initial and next radial lines based on parameters defined by a user; (b) designating one of initial missed points as a target point; (c) searching first and second mapping points; (d) calculating radio-wave propagation loss values of the first and second mapping points; (e) calculating radio-wave propagation loss value of the target point by using the radio-wave propagation loss values of the first and second mapping points; (f) designating another initial missed point as the target point and repeating said steps (c) to (f) until radio-wave propagation loss values for all the initial missed points are calculated; and (g) designating the next radial line as an initial line and repeating said steps (a) to (g) to calculate the radio-wave propagation loss values of the radial points located on the ra
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: December 11, 2001
    Assignee: Korea Telecom
    Inventors: Young-Hee Shin, Hyun-Meen Jung
  • Patent number: 6327359
    Abstract: A method for providing personal information which can overcome the duplication and redundancy of personal information and regional limitation, includes building a Computer Telephony Integration (CTI) information database, a personal information database, and a destination information database in a Service Control Point (SCP), to provide the personal information to CTI destination terminals in an intelligent network; transferring, by a Service Exchange Point (SSP), a calling line identification (CLI) and a dialing number (DN) to the SCP when an originating subscriber dials, retrieving a personal information and a destination information from said databases, and transferring the CLI and the retrieved personal information and destination information to the SSP; and providing, by the SSP, the CLI and the personal information to the destination terminals.
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: December 4, 2001
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Tae Gyu Kang, Seong Yong Bae, Se Hyeong Cho, Kyung Pyo Jun
  • Patent number: 6317247
    Abstract: A bias voltage stabilizing method for an electricity-optical modulator based on an off-level sampling is disclosed.
    Type: Grant
    Filed: December 2, 1998
    Date of Patent: November 13, 2001
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Choong Reul Yang, Wol Yon Hwang, Hyun Hah Hong, Sun Gyu Han, Heuk Park
  • Patent number: 6289007
    Abstract: A group code and a cell code are multiplexed and then used as a pilot code for discriminating a base station in asynchronous cellular CDMA (Code Division Multiple Access) communication systems. Using the multiplexed code, interferences are reduced in case of using two pilot codes. A method for acquiring a cell site station in asynchronous CDMA (Code Division Multiple Access) communication systems including a base station controller, a plurality of mobile stations and base stations, and discriminating the base stations by using different sequences, the method including the steps of: a) assigning a group code of the cell as a pilot code of an inphase channel of the base stations; b) assigning a cell code of the cell as a pilot code of a quadrature channel of the base stations; and c) multiplexing the pilot codes of inphase channel and the quadrature channel, and generating an inphase/quadrature pilot code.
    Type: Grant
    Filed: August 20, 1998
    Date of Patent: September 11, 2001
    Assignee: Korea Telecom
    Inventors: Dong In Kim, Yu Ro Lee, Yeon Soo Kim, Heung Ryel You
  • Patent number: 6278720
    Abstract: A 0.98 &mgr;m semiconductor laser of a ridge waveguide (RWG) structure includes: to be lengthen the durability of a semiconductor laser by increasing a catastrophic optical damage (COD) level, a ridge having a fixed width and length so that the strip may stop in the position of 30 &mgr;m on the basic of end portion of an output facet along length direction of a resonator; and a non-waveguide region in the end portion of both sides of a resonator.
    Type: Grant
    Filed: July 21, 1998
    Date of Patent: August 21, 2001
    Assignees: Electronics and Telecommunications Research Institute, Korea Telecom
    Inventors: Jung Kee Lee, Kyung Hyun Park, Dong Hoon Jang, Chul Soon Park