Patent application number | Description | Published |
20080205443 | BANDWIDTH-ALLOCATING DEVICE AND METHOD - In the bandwidth-allocating method of the present invention for PON (: Passive Optical Network), a bandwidth is allocated from an optical line terminal to each optical network unit. The optical line terminal stores a bandwidth contract table for indicating a correspondence relationship between communication flow IDs and service quality parameters, each communication flow ID identifying each communication flow between the optical line terminal and each optical network unit. The bandwidth-allocating method includes a step of transmitting a service-quality request message including the communication flow IDs and the service quality parameters from each optical network unit to the optical line terminal, and a step of the optical line terminal's updating the bandwidth contract table based on the service quality parameters, and performing the bandwidth allocation to a communication flow specified by the corresponding communication flow ID based on the bandwidth contract table. | 08-28-2008 |
20080216143 | METHOD FOR RECEIVING IP BROADCAST AND A RECEIVING TERMINAL - An IP broadcast terminal | 09-04-2008 |
20090080888 | Optical line terminating apparatus and optical communication system - An optical access communication apparatus and an optical access communication system for the coexistence of two wideband PON systems without using an expensive optical device or module. A low-speed PON and a high-speed PON have a same upstream wavelength, and an OLT receives optical signals by a same optical receiver in the two systems, converts the optical signals into electric signals, amplifies the electric signals, branches the amplified electric signals, and processes the branched signals by clock and data recovery sections of bit rates corresponding to the two PON systems, thereby achieving an optical communication apparatus and an optical communication system for constructing a simple and low-cost triple-play service system of excellent transmission quality. | 03-26-2009 |
20090097861 | Passive optical network system and optical line terminating apparatus - A passive optical network (PON) system which enables plural types of ONUs having different signal transmission speeds to be connected to one OLT. An optical line terminating apparatus (OLT) connected to plural types of ONUs having different signal transmission speeds through an optical distribution network includes an optical transmitter-receiver connected to the optical distribution network, a transmission/reception line interface connected to a wide area network, a downstream frame processing section for converting a packet received by the transmission/reception line interface from the wide area network into a downstream frame containing identification information on a destination ONU in a header, and a downstream transmission controller for modulating the downstream frame at a speed corresponding to a signal transmission speed of the destination ONU and outputting the modulated frame to an electrical/optical converter connected to the optical transmitter-receiver. | 04-16-2009 |
20090162053 | PON system method for receiving optical signal and OLT - When a signal of weak optical power is received immediately after a signal of intense optical power, input of the signal of intense optical power readily causes saturation, and the influence interferes in the signal of weak optical power to deteriorate receiver sensitivity. Moreover, when a reverse-bias voltage of APD is changed, if a difference between the voltages is large, a next optical signal is received until the receiver sensitivity of the APD becomes stable, so that receiver sensitivity deteriorates. A DBA order is determined so that a difference in reverse-bias voltage is small, and reverse-bias voltage is controlled in line with reception timing from ONU. | 06-25-2009 |
20090162064 | NETWORK SYSTEM AND OPTICAL LINE TERMINAL - It is necessary to completely remove overlapping of signals between plural PONs in order to make the PONs coexist. Accordingly, it is required to share or intensively manage bandwidth use conditions over an optical fiber that serves as a common band between plural systems. Therefore, transmission clocks should be synchronized with high accuracy between plural systems. A reference clock is provided from an external device or a representative OLT to the entire systems to perform clock synchronization between plural systems, so that the overall systems are synchronized by synchronizing each OLT with the reference clock. A hierarchical management method is selected that manages ONUs under the control of each OLT by managing band use information arranged for each OLT with respect to an external device or a representative OLT for sharing of bandwidth use conditions between plural systems. | 06-25-2009 |
20090162065 | NETWORK SYSTEM AND OPTICAL LINE TERMINAL - It is necessary to completely remove overlapping of signals between plural PONs in order to make the PONs coexist. Accordingly, it is required to share or intensively manage bandwidth use conditions over an optical fiber that serves as a common band between plural systems. Therefore, transmission clocks should be synchronized with high accuracy between plural systems. A reference clock is provided from an external device or a representative OLT to the entire systems to perform clock synchronization between plural systems, so that the overall systems are synchronized by synchronizing each OLT with the reference clock. A hierarchical management method is selected that manages ONUs under the control of each OLT by managing band use information arranged for each OLT with respect to an external device or a representative OLT for sharing of bandwidth use conditions between plural systems. | 06-25-2009 |
20090169209 | Network system, optical line terminating apparatus, and optical network apparatus - A general object of the present invention is to provide an optical communication system in which an optical transmission power of an optical communication apparatus is controlled to be a required minimum power that apparatuses of all subscribers in the optical communication system meet a prescribed error rate. An optical line terminating apparatus (OLT) transmits data to multiple optical network apparatuses (ONUs) at an optical intensity calculated based on information acquired from the multiple ONUs, which is related to optical intensities of signals that the multiple ONUs receive from the OLT, the optical intensity being calculated so that a minimum optical intensity of the optical intensities of the signals is greater than a predetermined value. | 07-02-2009 |
20090196606 | OPTICAL ACCESS NETWORK AND OPTICAL SWITCHING SYSTEMS - An optical access network and optical switching systems requiring no frame delay process on an optical switchboard are disclosed. Plural ONUs are connected to user terminals. An OLT communicates with an IP network through an access gateway. An optical switching unit (OSW) connects the ONUs and the OLT by switching the optical line. A control line connects the OLT and the OSW to control the optical switch change-over operation in the OSW. The optical switch port information required to generate the optical switch activation signal are concentrated in the OLT, which transmits the optical switch change-over control signal to the OSW through the control line before the transmission frame. | 08-06-2009 |
20090232495 | PASSIVE OPTICAL NETWORK SYSTEM WITH MODE-VARIABLE OPTICAL NETWORK UNIT - An optical line terminal connecting with numbers of optical network units comprises a control unit which controls each optical network unit to make it operate in a first mode in which transmission and reception of control messages and data are possible or in a second mode in which the transmission and reception of control messages are possible but the transmission of data is impossible, according to a communication permission request transmitted from an optical network unit and based on a preset maximum number of optical network units permitted to execute upstream communication from the optical network unit to the optical line terminal. | 09-17-2009 |
20100021160 | OPTICAL ACCESS SYSTEM, OPTICAL SWITCHING UNIT AND OPTICAL LINE TERMINAL - Provided is an optical access system, including: an optical line terminal, a plurality of optical network units and an optical switching unit. The optical line terminal sends to the optical switching unit a control frame including a switching time when the optical switching unit is to make a switch from one of the optical communication paths between the optical line terminal and the plurality of optical network units to another, and an identifier of an optical communication path to which the switch is made in order to switch the optical communication paths between the optical line terminal and the plurality of optical network units. The optical switching unit switches the optical communication paths between the optical line terminal and the plurality of optical network units based on the switching time and the identifier of the optical communication path after switching which are included in the control frame. | 01-28-2010 |
20100086302 | Channel switching system and method of IPTV service in passive optical network - Channel switching system and method of an IPTV service in a passive optical network (PON) are disclosed. To reduce a channel switching time of an IPTV system in the passive optical network, the system and the method use a channel switching control module and a channel list module in the passive optical network. In a case where a passive optical network system receives an IPTV channel switching request transmitted from a terminal user, the channel switching control module checks a recording of a channel list module and a recording of an authentication list module, and then updates a filter recording of an optical network unit to thereby directly transmit an image flow of a new channel in the passive optical network. When such system and method are applied to the passive optical network, high-speed switching of the IPTV service channel by the terminal user can be realized. | 04-08-2010 |
20100104286 | OPTICAL ACCESS SYSTEM AND OPTICAL LINE TERMINAL - Provided is an optical access system comprising: an optical line terminal connected to another network; a plurality of optical network units, each connected to a user terminal; and at least one of an optical switching unit and an optical splitter, which is installed between the optical line terminal and the plurality of optical network units. The optical line terminal allocates a length of time to a discovery phase for detecting the plurality of optical network units, and a length of time to data transmission phases for transferring data from the plurality of optical network units; and changes a ratio of the length of time of the discovery phase to the length of time of the data transmission phases so that the length of time of the discovery phase is shortened in the case where a number of the optical network units that are registered in the optical line terminal increase. | 04-29-2010 |
20100119227 | Storage function method and apparatus in a passive optical network - A method and an apparatus for implementing a storage function in a passive optical network (PON) system. On the basis of a LINK ID held by the data, data requiring storage, e.g. data making exclusive use of a wide bandwidth such as audiovisual data and large-volume data packages, are determined among all the data sent to an optical network unit. These data requiring storage are stored in a storage device installed in the optical network unit. In case the user requests data stored in the storage device, the stored data are transferred directly to the user, without any need to request and send these data for the second time via an IPTV server and the core network. It is possible to avoid duplicate transfers of data, and in particular to avoid duplicate transfers of data making exclusive use of a comparatively wide bandwidth such as audiovisual data and large-volume data packages, to improve the utilization factor of the downlink bandwidth, and to reduce flow congestion and data delays. | 05-13-2010 |
20100129072 | OPTICAL LINE TERMINAL AND OPTICAL LINE TRANSMISSION AND RECEPTION SYSTEM - An optical line terminal includes an optical network interface having an optical receiver unit to convert an optical signal received from an optical network unit into an electrical signal and output a direct current bias monitoring signal and an error code detector to detect an error code in the electrical signal to output an error code indication signal, a storage to store therein a direct current bias table indicating a direct current bias corresponding to a direct current bias control parameter of the optical network units and a dynamic band allocation information table indicating communication time slot information allotted to each optical network unit and a control unit to receive the direct current bias monitoring signal and the error code indication signal and supply the direct current bias control signal to the optical receiver unit to thereby form one feedback circuit together with the optical network interface. | 05-27-2010 |
20100183107 | BURST MODE RECEIVER - A burst mode receiver including a CDR circuit that does not perform bit synchronization determination at a wrong position even when a burst signal waveform containing a distortion is input is provided. The burst mode receiver includes a CDR circuit for reproducing clock and data from a received signal, a bit synchronization determination circuit for determining whether the CDR circuit is in an optimum phase, a waveform distortion determination circuit for determining from the received signal whether there is waveform distortion, and a CDR output enable determination circuit for determining whether an output of the CDR circuit is valid or invalid. The CDR output enable determination circuit performs CDR output enable determination based on a bit synchronization determination result and a waveform distortion determination result. | 07-22-2010 |
20100239255 | OPTICAL LINE TERMINAL, PASSIVE OPTICAL NETWORK SYSTEM, AND BANDWIDTH ASSIGNMENT METHOD - An OLT of a station-side device in a PON system, the OLT including: an MPCP control unit for receiving bandwidth requirements from each of a plurality of ONUs of home-side devices; a bandwidth assignment period calculation unit for calculating the following bandwidth assignment period for each request source based on the received bandwidth requirements for each request source; a dynamic bandwidth assignment calculation unit for calculating the following bandwidth assignment for each request source based on the received bandwidth requirements for each request source; and the MPCP control unit for transmitting transmission allowance based on the calculated bandwidth assignment to each of the plurality of ONUs. | 09-23-2010 |
20110211837 | Method of Recovery From Sleep State of an Onu in a Pon System Capable of Power Saving - There is a need to recover an ONU from a sleep state for communication with the PON before a specified sleep cancel time in a short period of time without degrading the band use efficiency. An OLT manages an electric state of each ONU connected to a PON. When at least one ONU is in sleep mode, the OLT transmits a grant to allocate a band for a sleep cancel report to the ONU. When the sleep-mode ONU requires communication, the ONU transmits the sleep cancel report to the OLT using the band for the sleep cancel report. When receiving the sleep cancel report, the OLT changes the managed ONU to a normal state and resumes the communication with the PON. | 09-01-2011 |
20110222866 | Multirate Burst Mode Receiver - There is a need to provide a multirate burst mode receiver for an OLT to be capable of receiving a high-speed burst signal without the need for a special capability of an ONU in a PON system including a mix of ONUs at different transmission bit rates. A multirate burst mode receiver according to the invention includes a signal input discrimination section and a bit rate discrimination section. The signal input discrimination section detects an average amplitude to discriminate signal input. The bit rate discrimination section detects an envelope curve for a high-frequency component to discriminate a signal bit rate. Based on a discrimination result from the signal input discrimination section and the bit rate discrimination section, the multirate burst mode receiver switches a setting for an optical signal reception section and a serial-parallel converter corresponding to the reception bit rate. | 09-15-2011 |
20110291766 | Transimpedance Amplifier and Pon System - In a gain-switching-type transimpedance amplifier, in order to provide a technique capable of preventing unnecessary gain switching caused when noise is received, and preventing decrease in sensitivity caused when noise with a large input level is received, and then, a burst signal with a small input level is received, a transimpedance amplifier | 12-01-2011 |
20120163809 | Burst-Mode Receiver Equipped with Optical Amplifier, Method for Controlling Optical Amplifier, and System - To, even when a transmission wavelength varies in each ONU and an optical amplifier gain depends on the wavelength in an OLT equipped with an optical amplifier, prevent the optical amplifier gain from varying in every ONU and thus prevent deterioration of a dynamic range. The OLT estimates a transmission wavelength of each ONU at the time of ONU registration, and retains a correspondence between an ONU identifier and the transmission wavelength. Moreover, for every burst, an injection current to the optical amplifier is adjusted based on a wavelength and optical amplifier characteristic database. | 06-28-2012 |
20130004172 | Optical Line Terminal and Optical Network System - Technology to provide linked control of bandwidth allocation to a plurality of optical network units among the plural wavelengths by a bandwidth allocation section coupled to the plural optical network units. | 01-03-2013 |