Abstract: The present invention discloses a method for preparing a microporous polyolefin film comprising: a step of injecting a composition comprising polyolefin 30 to 60 wt % and a diluent, which can make liquid-liquid phase separation with the polyolefin thermodynamically 40 to 70 wt %, into an extruding machine, and melting and kneading thereof to prepare a single phase melt; and a step of extruding the melt while conducting liquid-liquid phase separation by passing through a section having the temperature below the liquid-liquid phase separation temperature and forming thereof in the form of a sheet, and a microporous polyolefin film prepared according to the method.

Abstract: The present invention discloses a method for preparing a microporous polyolefin film comprising: a step of injecting a composition comprising polyolefin 30 to 60 wt % and a diluent mixture comprising a diluent, which can make liquid-liquid phase separation with the polyolefin thermodynamically 40 to 70 wt %, into an extruding machine, and melting and kneading thereof to prepare a single phase melt; and a step of extruding the melt while conducting liquid-liquid phase separation by passing through a section having the temperature below the liquid-liquid phase separation temperature and forming thereof in the form of a sheet, and a microporous polyolefin film prepared according to the method.

Abstract: The present invention relates to a composition for preparing a separator for an electrochemical device, a method preparing a separator for an electrochemical device, and an electrochemical device having a separator prepared therefrom, more particularly, a composition for preparing a separator for an electrochemical device, comprising a polyolefin, a first diluent, and a second diluent, wherein an interaction energy between the first diluent and the second diluent is in the range of 2 to 3.5 cal/cm3, a method preparing a separator for an electrochemical device using the composition, and an electrochemical device having a separator prepared therefrom. In accordance with the present invention, the pore size of a polyolefin separator can be suitably controlled into a size desired by a user, and the high-temperature stability and mechanical property of the separator can be remarkably improved, thereby enhancing the life time and stability of an electrochemical device having the same.

Abstract: In a wireless optical communication system in which communication is performed based on a free space and a plurality of the communication apparatuses are arranged in a ring form around a central office terminal (COT), the communication apparatus monitors optical signals received in a first direction or in a second direction opposite to the first direction, and selects a first path through which the optical signals in the first direction are received and a second path through which the optical signals in the second direction are received. The communication apparatus converts an optical signal having a predetermined unique wavelength from among the optical signals received through the selected path into a signal of a frequency domain having a plurality of subcarriers, and obtains packet data mapped to each of the subcarriers.

Abstract: An optical backhaul network for a wireless broadband service is provided. The optical backhaul network for a wireless broadband service includes: a plurality of optical network units for outputting an uplink optical signal having a multiplexed wavelength; an optical line termination for outputting a downlink optical signal of a single mode in order to transmit the downlink optical signal to the plurality of the optical network units in a broadcasting form; and a plurality of remote nodes for outputting a part of the downlink optical signal to the plurality of the optical network units and for outputting the uplink optical signal to the optical line termination. Therefore, one center and a plurality of access points can be efficiently connected.

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 are a forced protection switching method and a forced protection switching clearing method in an Ethernet ring network. When an operator desires to block a port of a specific node for maintenance and repair, the operator gives a forced switching (FS) command to the specific node in order to block the port. When the operator desires to clear FS, the operator gives a clear command to the specific node in order to clear the blocked port. As a result, operation flexibility of the Ethernet ring network is provided.

Abstract: In a Wavelength-Division-Multiplexed Passive Optical Network (WDM-PON) utilizing a conventional downstream optical signal reusing method, there is an inventory problem that different optical transmitter types need to be provided for the operation, management, replacement, etc. of a system. A WDM-PON system according to the present invention, includes: a seed light (SL) unit generating a seed light whose wavelength intervals and center wavelengths are adjusted using at least one seed light source; an optical line terminal (OLT) receiving the wavelength-multiplexed seed light from the seed light unit, transmitting a downstream optical signal to a subscriber of the WDM-PON, and receiving a upstream optical signal from the subscriber; and an optical network unit (ONU) receiving the downstream optical signal from the OLT, flattening and modulating the downstream optical signal with upstream data so that the downstream optical signal is reused for carrying upstream data.

Abstract: The present invention relates to a composition for preparing a separator for an electrochemical device, a method preparing a separator for an electrochemical device, and an electrochemical device having a separator prepared therefrom, more particularly, a composition for preparing a separator for an electrochemical device, comprising a polyolefin, a first diluent, and a second diluent, wherein an interaction energy between the first diluent and the second diluent is in the range of 2 to 3.5 cal/cm3, a method preparing a separator for an electrochemical device using the composition, and an electrochemical device having a separator prepared therefrom. In accordance with the present invention, the pore size of a polyolefin separator can be suitably controlled into a size desired by a user, and the high-temperature stability and mechanical property of the separator can be remarkably improved, thereby enhancing the life time and stability of an electrochemical device having the same.

Abstract: A tunneling-based mobility support method and apparatus is provided which supports a mobility of a mobile node in a heterogeneous network regardless of IP versions (IPv4/IPv6). The mobility support apparatus includes a load balancer, a plurality of mobility support servers, and a plurality of end routers each being TCP connected to each of the mobility support servers. When receiving a tunnel establishment request message from the mobile node, the load balancer selects one mobility supports server from a plurality of mobility support servers to control a mobility service for the mobile node. The selected mobility support server selects a plurality of tunnel end addresses of one end router from the plurality of end routers to establish an IP tunnel with the mobile node according to a predetermined criterion, forwards the tunnel establishment request message to the end router, and sends the mobile node a tunnel establishment response message including the tunnel end address of the selected end router.

Abstract: Provided is a time division multiple access over wavelength division multiplexed passive optical network (TDM-over-WDM-PON) system. According to the TDM-over-WDM-PON system, a downstream optical signal is separated according to a wavelength in a remote node, transmitted to an optical amplifying device located in subscriber equipment, amplified in the optical amplifying device, transmitted back to the remote node, and then transmitted to the subscriber equipment. Also, an upstream optical signal is transmitted to a wavelength converting device located in the subscriber equipment from the remote node, wavelength-converted in the wavelength converting device, returned back to the remote node, and then transmitted to a central office.

Abstract: Disclosed are a method and apparatus for recommending personalized content in an Internet Protocol Television (IPTV) service environment. The content recommending method includes: acquiring a user's viewing history information regarding broadcasting content; analyzing the user's preference for each content item based on the user's viewing history information; creating a list of recommended content items based on the analysis of the user's preference; and providing the list of recommended content items to the user's terminal. Accordingly, it is possible to recommend personalized content according to users' preference.

Abstract: Provided are a user authentication apparatus and method for supporting PMIPv6 (Proxy Mobile Internet Protocol version 6) in next generation networks. Authentication and mobility signaling protocol can be performed without having an additional signaling process when a mobile terminal moves by extending user profiles of the next generations to support the PMIPv6.

Abstract: There is provided a interactive IPTV broadcasting service system of user participation, the system including: a broadcast controller reserving time of IPTV broadcast channels to perform an IPTV broadcast according to the reserved time, notifying user participation to accept the user participation during the broadcasting service, and controlling so that video of the user making a request for participation in broadcasting is included in video of the broadcast in progress, and then broadcast, a plurality of clients each notifying the broadcast controller of the request of the corresponding user when the participation in broadcasting is requested according to a selection of the IPTV broadcasting user and generating video and audio traffic of the corresponding user, and a media server relaying the users' participation in broadcasting between the broadcast controller and the clients, and receiving and mixing video and audio traffic of a broadcaster and the video and audio traffic of each of the users making the req

Abstract: Provided are a network resource control method and apparatus for guaranteeing an admission rate of a high-priority service. In the method and apparatus, the admission rate of the high-priority service is increased by differentiating between the high-priority service and a low-priority service by either rejecting the low-priority service or reducing a bandwidth allocated to the low-priority service when the low-priority service has already been accepted.

Abstract: Provided is an automatic optical power control method for an optical line terminal (OLT) of a passive optical network (PON). The automatic optical power control method includes at the OLT, measuring an allowable range of the optical power allowing a normal network operation on the PON, at the OLT, setting an optimum optical signal level within the measured allowable range of the optical power, and at the OLT, adjusting a power level of a transmitter to the set optimum optical signal level. Accordingly, an appropriate power level can be selected depending on an optical distribution network (ODN) structure to drive the transmitter. Also, when the entire optical network units are deactivated, a laser of the transmitter is turned off to thereby minimize unnecessary power consumption at the OLT.

Abstract: Provided are an optical output power control method that provides optical communication without harming the human body even when a transmission line is cut or no optical network unit (ONU) accesses a communication system, and a passive optical network (PON) system using the method. In the method, an optical signal having a predetermined period is transmitted when an optical communication system is in an abnormal state, wherein the predetermined period includes a laser-on time interval in which the optical signal has a normal power level and a laser-off time interval in which the optical signal is off or has a power level lower than the normal power level, so that the optical communication system performs optical communication without harming the human body even during the abnormal state.

Abstract: Provided is a method for setting a security channel between an OLT and at least one ONU in an EPON. In detail, a channel is generated by which the OLT makes a reciprocal security capability agreement with the ONU that wants to set a security channel in a discovery interval and then automatically registers the ONU with the security capability agreement. The security channel is set by which the OLT distributes an encryption key for the security with the ONU completed with the security capability agreement. A renewal point of the encryption key is shared by transmitting a message indicative of a time to change the encryption key between the OLT and the ONU both completed with the encryption key distribution.

Abstract: A dynamic bandwidth allocation (DBA) device and a method thereof are provided. In the DBA method, the band allocation periods according to class queues and allocable bands with respect to each class queue are calculated on the basis of the service level agreement information and stored according to the service types in separate tables. The bandwidth allocation amount is calculated with respect to class queues which have the allocation periods by concurrently checking all the tables at each frame. The upward bandwidth usage efficiency is improved by calculating the final bandwidth allocation information from the service with a high priority order on the basis of the total allocable bandwidth of the corresponding frame. The upward bandwidth allocation amount can be calculated at each frame by reducing the processing speed in calculating the bandwidth allocation amount of each class queue. Accordingly, it is possible to effectively use the network.

Abstract: A time division multiplex (TDM)/wavelength division multiple access (WDMA) passive optical network (PON) device includes a base station terminal, a wavelength splitter, and a subscriber terminal optical transceiver. The base station terminal includes a transmitter, an optical circulator transmitting the optical signals output from the transmitter to an optical distribution network, and a receiver demultiplexing wavelength division multiplexed upstream signals from the optical distribution network through the optical circulator. The wavelength splitter splits the downstream signals from the base station terminal to subscriber ports corresponding to wavelengths and multiplexes the optical signals received from each of the subscriber ports to the base station terminal. The subscriber terminal optical transceiver receives the downstream signals from the wavelength splitter and reuses the received downstream signals as optical sources for upstream signals.