摘要:
The present invention is to provide an optical access network in which a remote unit receives an optical burst signal. A central unit (OLT) transmits a DC-balanced optical continuous signal including packets having identification information for identifying each remote unit (ONU) to an optical switching module (OSM). The optical switching module (OSM) receives the DC-balanced optical continuous signal from the central unit (OLT), optically switches the packets based on the identification information, and transmits a DC-balanced optical burst signal including the packets to the remote unit (ONU). The remote unit (ONU) receives the DC-balanced optical burst signal and acquires the packets transmitted to the remote unit (ONU).
摘要:
The present invention is to provide an optical access network in which a remote unit receives an optical burst signal. A central unit (OLT) transmits a DC-balanced optical continuous signal including packets having identification information for identifying each remote unit (ONU) to an optical switching module (OSM). The optical switching module (OSM) receives the DC-balanced optical continuous signal from the central unit (OLT), optically switches the packets based on the identification information, and transmits a DC-balanced optical burst signal including the packets to the remote unit (ONU). The remote unit (ONU) receives the DC-balanced optical burst signal and acquires the packets transmitted to the remote unit (ONU).
摘要:
In an optical access network using an optical switching device, a 2×1 optical splitter in the uplink and downlink directions is eliminated to extend the transmission distance between the OLT and the ONU. An optical switching device includes a downlink optical switch element for switching a downlink optical signal sent by an OLT, an uplink optical switch element for switching an uplink optical signal sent by a plurality of ONU, an O/E for converting a downlink optical signal to a first electrical signal, an E/O for converting the first electrical signal to a downlink optical signal and inputting the downlink optical signal to the downlink optical element, an O/E for converting an uplink optical signal output from the uplink optical switch element to a second electrical signal, and an E/O for converting the second electrical signal to an uplink optical signal and sending the uplink optical signal to the OLT.
摘要:
In an optical access network using an optical switching device, a 2×1 optical splitter in the uplink and downlink directions is eliminated to extend the transmission distance between the OLT and the ONU. An optical switching device includes a downlink optical switch element for switching a downlink optical signal sent by an OLT, an uplink optical switch element for switching an uplink optical signal sent by a plurality of ONU, an O/E for converting a downlink optical signal to a first electrical signal, an E/O for converting the first electrical signal to a downlink optical signal and inputting the downlink optical signal to the downlink optical element, an O/E for converting an uplink optical signal output from the uplink optical switch element to a second electrical signal, and an E/O for converting the second electrical signal to an uplink optical signal and sending the uplink optical signal to the OLT.
摘要:
To provide synchronizing methods, optical switch modules, center devices, remote devices, optical access systems, optical access networks, programs, and recording media in the optical access network which can give the connection start time of the upstream optical switching element of the optical switch module. To the optical switch module, ranging functions are provided and the center device OLU carries out ranging of the optical switch module OSM as is the case of ranging of the remote device ONU. The center device OLU transmits the difference between roundtrip time of the remote device ONU and roundtrip time of optical switch module OSM, which is the result of these rangings, to the optical switch module OSM, and the optical switch module OSM can obtain the contact start time of the upstream optical switching element by calculating the contact start time using the difference.
摘要:
An optical access network method, an optical access network and an optical switch for an optical access network, capable of solving all the three problems in the conventional GE-PON: transmission distance problem, security problem and communication interference problem. The optical access network comprises an OLT, a plurality of ONUs and one or more stages of optical switches, which are connected one another. In the direction from the OLT to the ONU, each frame (packet) transmitted from the OLT to one of the ONUs is checked so that only the destination ONU specified in the frame (packet) is connected to the OLT. In the direction from the ONU to the OLT, a control message transmitted from the OLT to one of the ONUs is checked so that only one ONU which has been given a transmission allowance from the OLT is connected to the OLT with respect to each frame (packet).
摘要:
An optical access network method, an optical access network and an optical switch for an optical access network, capable of solving all the three problems in the conventional GE-PON: transmission distance problem, security problem and communication interference problem. The optical access network comprises an OLT, a plurality of ONUs and one or more stages of optical switches, which are connected one another. In the direction from the OLT to the ONU, each frame (packet) transmitted from the OLT to one of the ONUs is checked so that only the destination ONU specified in the frame (packet) is connected to the OLT. In the direction from the ONU to the OLT, a control message transmitted from the OLT to one of the ONUs is checked so that only one ONU which has been given a transmission allowance from the OLT is connected to the OLT with respect to each frame (packet).
摘要:
To provide synchronizing methods, optical switch modules, center devices, remote devices, optical access systems, optical access networks, programs, and recording media in the optical access network which can give the connection start time of the upstream optical switching element of the optical switch module. To the optical switch module, ranging functions are provided and the center device OLU carries out ranging of the optical switch module OSM as is the case of ranging of the remote device ONU. The center device OLU transmits the difference between roundtrip time of the remote device ONU and roundtrip time of optical switch module OSM, which is the result of these rangings, to the optical switch module OSM, and the optical switch module OSM can obtain the contact start time of the upstream optical switching element by calculating the contact start time using the difference.
摘要:
The present invention provides an automatic identification level control circuit, an identification level control method, an automatic identification phase control circuit, an identification phase control method, and an optical receiver, capable of stably setting an optimal identification level or identification phase. An automatic identification level control circuit of the present invention includes a coupling capacitor, an identification circuit, a level fluctuation detection circuit, an identification voltage control circuit, and a low-pass filter. The identification circuit includes limiter amplifiers and flip flops. The level fluctuation detection circuit includes exclusive OR circuits.
摘要:
A control device configured with a torque/current computation section, an actual current computation section, a current feedback control section, and a voltage control section. A two-axis rotating coordinate system has a first axis defined in a direction of field magnetic flux of a magnet provided in the rotor, and a second axis defined in a direction that is shifted by an electrical angle of 90 degrees with respect to the first axis. In the case where a torque command includes periodic torque vibration, the torque/current computation section executes first-axis command fixation control in which a first-axis current command, which is a first-axis component of the two-phase current command, is fixed at a predetermined value and a second-axis current command, which is a second-axis component of the two-phase current command, is vibrated in accordance with the torque vibration.