Abstract: The present invention relates to a method for fabricating an optical device integrated with a spot size converter to reduce defect and low reflectivity in a butt-joint portion, the method including the steps of: a) depositing a first clad layer, an active layer and a second clad layer sequentially on the (100) plane of a semiconductor substrate; b) forming on the second clad layer a double dielectric mask of which the lower layer has a relatively wider width than that of the upper layer, exposing one side of the second clad layer; c) wet-etching the first clad layer, the active layer and the second clad layer in a buried ridge structure by using the double dielectric mask, and exposing the (111)A plane of the active layer tilted towards the (100) plane by a predetermined angle; d) growing a spot size conversion region on the (111)A plane of the active layer; and e) removing the double dielectric mask.
Type:
Grant
Filed:
March 4, 2002
Date of Patent:
July 22, 2003
Assignees:
Electronics and Telecommunications Research Institute, Korea Telecom
Abstract: The present invention concerns a method of controlling the conformity of the transmission rate of data cells transmitted by a source terminal in communication with a destination terminal.
It consists essentially, when a backward-resource management cell (BW-RM) of order k arrives at the said interface unit (21), of determining the programming time (tp(k)) of the taking into account, by the said control process (21b), of the rate request (ER(k)) contained in the field of the said cell (BW-RM).
It also concerns a user-network interface unit which has means for being able to implement the steps of the said methods.
Abstract: Method and system for providing data communication through a port of a system, the port having at least two operating modes, each of which corresponding to a different data rate. Communication with the system is enabled by operating the port in one of the operating modes. The system is switched to operate in another operating mode and the communication with the system is continued in the another operating mode, whenever a predetermined mode switching code is received through the port.
Type:
Grant
Filed:
June 15, 2000
Date of Patent:
July 22, 2003
Assignee:
Tadiran Telecom Business Systems Ltd.
Inventors:
Yaron Agami, Marina Timchenko, Evald Markinzon
Abstract: The present invention relates to a hybrid component and method capable of simultaneously combining and depolarizing two pump laser diodes of different wavelengths with linear polarized output. The beam combiner is a Wellstone prism which is used to combine two linear-polarized pumping beams, and the depolarizer has three different embodiments: a single stage high birefringent waveplate; two stages high birefringent waveplates; a quarter waveplate or a three-quarter waveplate plus a single stage high birefringent waveplate. The Polarization Beam Combiner (PBC) and the depolarizer are integrated into one single hybrid component, in which two orthogonal pumping lights with different wavelengths are combined and depolarized simultaneously. Therefore, the hybrid component and method makes it simpler and cheaper to design a Raman amplifier and will propel Raman amplifier market penetration in optical communication systems.
Abstract: To support a changing volume of a voice-grade traffic in an access network having a local exchange with a limited capacity, there are proposed the following steps. The first step is to provide two or more access networks such that each having its subscribers and its associated local exchange with a limited capacity; each of the access networks is capable of dividing traffic, outgoing from its subscribers, into the voice-grade traffic portion and data traffic portion, and capable of directing the data traffic portion to a packet network while directing the voice-grade traffic portion to a PSTN network via the associated local exchange. The PSTN network and the packet network are respectively common for the access networks. There should be defined an overload condition of a local exchange as a condition when traffic there-through equals to a predetermined threshold, and a normal load condition of the local exchange when traffic there-through is below the predetermined threshold.
Abstract: A computerized lottery or wagering system includes a game generator and a plurality of vendor stations that permit players to select game parameters. The game is graphically portrayed in animation as one or more races (horse race, dog race, car race, motorcycle race, etc.). The game may entail win, place, show, quinella, exacta/perfecta, trifecta, or series bets. At a predetermined time for each game, selection of game parameters for that game is ended and a winning sequence of numbers is randomly generated. The game generator selects and seamlessly composes a plurality of video segments into an animated video sequence of the race(s) corresponding to the winning sequence of numbers, for broadcast via RF transmission, microwave transmission, fiber optic cabling or closed circuit television lines. The video segments are rendered directly to a compressed digital format to maintain the video image in the highest quality possible.
Abstract: Method and apparatus for sending and displaying short messages from data network users which are linked to a telephonic network. The telephonic network comprises telephones, each with a display for visually displaying short messages to subscribers of the telephonic network. The apparatus holds a dialogue between the data network users and a software agent embedded in the telephonic network. The dialogue provides the telephonic network the content, the sender ID and the address information of each short message, stores the content and address information in a database, and displays the content of the messages on the telephone display of each destined subscriber.
Abstract: A method and apparatus for detecting an error rate of a data stream. The data stream is divided into a sequence of blocks, and a detection interval is defined including a predetermined number of blocks in the sequence. For one or more of the blocks in the detection interval, respective error measures are computed responsive to the error rate of the data stream. The one or more blocks in the detection interval are classified as good or bad blocks by comparing the respective error measures to a first threshold. It is estimated that an error condition exists in the data stream by comparing a count of the bad blocks in the interval to a second threshold.
Abstract: A process for etching a PPMS layer that increases the etch selectivity of PPMS relative to PPMSO from an initial low etch selectivity to a higher etch selectivity at a later stage of the etching process. In some embodiments, the etch selectivity used during a first etching step of the process is less than 4:1 and the etch selectivity used during a second etching step, subsequent to the first step, is greater than 5:1. In some other embodiments, the etch selectivity of the first step is between 2-3:1 and the etch selectivity of the second step is greater than 8:1. Optionally, in still other embodiments a third etching step, performed between the first and second etching steps may be employed where the etch selectivity is between 3-8:1.
Type:
Grant
Filed:
March 15, 2001
Date of Patent:
July 8, 2003
Assignees:
France Telecom, Applied Materials, Inc.
Inventors:
Olivier Joubert, Cedric Monget, Timothy Weidman, Dian Sugiarto, David Mui
Abstract: A method and a device for compensation of nonlinearity appearing in optical fiber links due to the positive Kerr effect created by optical fibers, the method comprises conveying an optical signal via one or more such compensating devices, each being capable of creating the negative Kerr effect for one or more optical wavelengths.
Abstract: The invention relates to a method for configuring a telecommunication system comprising at least one sending entity and one receiving entity between which one and the same link ensures the transmission of several transport channels of different qualities of service. The sending entity performs a rate matching between the various qualities of service, on completion of which the various qualities of service are multiplexed.
Abstract: A method of generating a weight vector based on the maximum signal-to-interference-plus-noise output power ratio (SINR0) criteria without an eigenvector finding technique, is provided for use in a smart antenna system. The weight vector is applied after pseudo noise (PN) dispreading rather than in front of a receiver for channel estimation and data symbol demodulation. The method includes setting an initial weight vector w(0) and a convergence parameter or an initial eigenvalue. New post-PN processing vectors y(i) and new pre-PN processing vectors x(i) are received. The weight vector w(k) at a snapshot k is then updated and optimized.
Abstract: Method and apparatus for the alignment of optical interconnections between at least one optical data transmission point and at least one corresponding optical data receiving point. A collimated beam of data carrying light is polarized through an electrically-controlled light polarizer, such as a spatial light modulator or a liquid crystal, which comprises an array of pixels. A focused beam of the data-carrying light, emitted from the light polarizer, is obtained on the receiving point, by individually controlling the polarization of each pixel, and deflecting the direction of the collimated beam when emitted from the light polarizer, until a predetermined value of an electrical signal (current and/or voltage) representing the level of alignment is obtained. The collimated beam is further continuously and/or adaptively aligned by determining a desired current and a threshold current and/or voltage produced by an optical sensor at the receiving point.
Abstract: The securing of a telephone link between the two subscriber sets is established on the basis of encryption keys transmitted over the service channel (D) of the ISDN network whether the link be established on the switched telephone network (PSTN) or on the Internet network (NSTN).
A server verifies the identifiers of the subscriber taps (PA1, PA2) and stores the encryption keys.
Abstract: A video teleconferencing system uses digital transcoding to obtain algorithm transcoding, transmission rate matching, and spatial mixing. The video teleconferencing system comprises a multipoint control unit (MCU) for allowing multiple audiovisual terminals, which send and receive compressed digital data signals, to communicate with each other in a conference. The MCU has a video processing unit (VPU) that performs algorithm transcoding, rate matching, and spatial mixing among the terminals within a conference. The VPU includes a time division multiplex pixel bus and a plurality of processors. Each processor is assignable to an audiovisual terminal in the conference and is coupled to the pixel bus. In a receive mode, each processor receives and decodes compressed video signals from its assigned terminal and puts the decoded signal onto the pixel bus. In a transmit mode, each processor receives from the pixel bus uncompressed video signals from any terminal in the conference.
Abstract: A flow control system and methodology controls and avoids congestion in an Asynchronous Transfer Mode (ATM) network. The congestion state of a network switch is determined based on incoming Available Bit Rate (ABR) traffic, Constant Bit Rate (CBR) traffic, and Variable Bit Rate (VBR) traffic. High-frequency fluctuations due to VBR traffic are filtered out of the CBR/VBR traffic to determine the underlying trend of network traffic. A filtering mechanism is based on wavelet transforms. The switch congestion state is determined based on the current ABR traffic, the filtered CBR/VBR traffic, and the current status of buffers in the switch. The congestion state can then be used to adjust the ABR rate according to a feedback scheme such as Explicit Forward Congestion Indication (EFCI).
Abstract: This invention concerns a multicarrier signal designed to be transmitted to digital receivers, especially in a non-stationary transmission channel. The multicarrier signal corresponds to the frequency multiplexing of several elementary carriers. Each of the several elementary carriers corresponds to a series of symbols. The multicarrier signal is built on a non-orthogonal time-frequency lattice with a density two.
Abstract: In order to process communications between a base station comprising an N separate antennae network, N being a whole number greater than 1, and at least one mobile phone, the method consists of the following steps: estimating the incoming direction and the path power to the base station; determining a main incoming direction of those paths to the base station; selecting antennae, M being a whole number less than N, whereof the individual receiver, respectively transmitter, lobes have directions contained in an angular sector centred on the main incoming direction; processing only the signals received by the M selected main antennae coming from the mobile phone, respectively synthesising only the signals to be transmitted by the M selected antennae.
Abstract: An automated prefix dialing system is disclosed to allow a subscriber/user to automatically insert a predetermined prefix dialing code in certain outgoing telephone call situations. The system is electrically disposed between the telephone company's central office circuit and the subscriber's circuit. The system preferably comprises six sub-circuits: DC power path circuit (off-hook sensor circuit), shadow-ring detector circuit, isolation circuit, DTMF receiver circuit, DTMF generator circuit, and micro controller circuit. When not in use, no power is used by the system. The DC power path circuit, provides power received from the central office line to the various circuits and components of the system when the subscriber's phone is taken off-hook. Off-hook sensor circuitry detects when the telephone has been lifted either in response to an incoming call or to initiate an outgoing call.
Type:
Grant
Filed:
January 18, 2000
Date of Patent:
June 17, 2003
Assignee:
Immix Telecom, Inc.
Inventors:
Claude O. Simpson, Mark O. Gerwig, David G. Storm, Rong Zeng