Abstract: A fault in a telecommunication line can be identified and located using line test data for that telecommunication line. A series of line tests can be performed on a selected telecommunication line experiencing problems. The results from the series of line tests can be analyzed to identify differences in the results between the line tests. The identified differences can then be used to determine if a fluctuation is present in the telecommunication line. If a fluctuation is determined to be present in the telecommunication line, the identified differences can also be used to determine a location of the fluctuation relative to reference location such as the distribution point where the telecommunication line originates.

Abstract: A coupling module can be used to communicate high speed signals between an optical transceiver and a processing module of an optical communication device, such as an optical line termination (OLT) or an optical network unit (ONU). The coupling module can adjust the common mode voltage level of a differential signal output by the optical transceiver to the common mode voltage level required by the processing module. In addition, the coupling module splits each of the differential output signals from the optical transceiver and passes the split signals to both a high-pass filter and a low-pass filter that are connected in parallel. The outputs of the high-pass filter and the low-pass filter from different paths of the differential signal are cross-coupled and combined to provide a differential signal to the processing module.

Abstract: Methods, systems, and apparatus for payload compression are disclosed. In one aspect, a determination is made that one or more fields of a packet to be transmitted are compressible based on a compression table. Prior to transmitting the packet and in response to the determination, the one or more fields of the packet are compressed based on the compression table. Compressing the one or more fields of the packet includes removing the one or more fields from the packet to generate a compressed packet. One or more bits in a header of the compressed packet are modified to indicate at least one compression entry in the compression table associated with the compression performed on the compressed packet.

Abstract: A system identifies rogue optical network units (ONUs) on a passive optical network that uses time and wavelength division multiplexing. An optical line terminal (OLT) is configured to recognize the occurrence of errors on the upstream transmission over the network. When those errors reach a predetermined threshold, the OLT attempts to identify potential rogue ONUs by controlling the ONUs to tune to different wavelengths. The OLT first controls the ONUs to transmit on a first wavelength. The OLT then iteratively divides the ONUs into multiple groups, each group being assigned a different wavelength for upstream transmission. The OLT them monitors upstream transmission to determine which group of ONUs is exhibiting rogue behavior. This process is repeated until a small group of ONUs is isolated as a potential rogue. The potentially rogue ONUs are individually analyzed and one or more ONUs is positively identified.

Abstract: An optical transmission system includes a laser module generating a modulated optical waveform, including both amplitude and frequency modulation, at center frequencies corresponding to different operating temperatures; and an optical shaping filter, with passbands corresponding to the different center frequencies, that converts at least part of the frequency modulation to additional amplitude modulation.

Abstract: Methods, systems, and apparatus for provisioning a network device are disclosed. In one aspect, a message is received by a translation device from a controller. A determination is made, by the translation device, that the received message includes data that is destined for multiple different downstream network devices. A determination is made that a first downstream network device among the multiple different downstream network devices is incapable of being provisioned using a communications protocol of the received message. Data from the received message, that is destined for the first downstream network device, is translated, by the translation device, from the communications protocol of the received message to a translated message defined in a different protocol that is required to provision the first downstream network device. The translated message is transmitted, by the translation device, to the first downstream network device according to the different protocol.

Abstract: Methods, systems, and apparatus for hosting an optical line terminal (OLT) bonding engine are disclosed. In one aspect, packet data for transmission over a passive optical (PON) is selected. A transmission wavelength assigned to the packet data is identified. A particular OLT is selected from among the additional OLTs to transmit the packet data over the PON based on the corresponding wavelength of the particular OLT matching the identified transmission wavelength assigned to the packet. The packet data is formatted based on the particular OLT. The formatted packet data is transmitted to the particular OLT for transmission over the communications interface.

Abstract: Methods, systems, and apparatus for Internet Protocol security (IPsec) selector coalescing for per-host Security Associations (SAs) are disclosed. In one aspect, separate per-host SAs are assigned, by a network communications device including one or more processors, to each of two or more different source communication devices that each communicates with corresponding destination devices. While the separate per-host SAs are assigned to each of the two or more different source communication devices, a group SA is generated. The group SA is assigned, by the network communications device, to all of the two or more different source communication devices. The assignment of the separate per-host SAs is removed from each of the two or more different source communication devices.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for optimizing PON efficiency using a variable FEC. In one aspect, an OLT broadcasts a message over an optical network, and receives, from an ONU, a response to the message. The OLT transmits activation parameters specifying that the OLT supports multiple different FEC code lengths when FEC is activated, and receives from the ONU, a set of FEC code lengths supported by the ONU. The OLT also receives performance measures collected by the ONU. The OLT selects, from among the FEC code lengths supported by the ONU, one or more appropriate FEC code lengths for communications between the ONU and the OLT based on the performance measures collected by the ONU and performance measures collected by the OLT. The OLT configures the ONU to utilize the appropriate FEC code length.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for telecommunications network troubleshooting. In one aspect, a method includes obtaining multiple current observations characterizing current operation of a telecommunications network, the multiple observations including performance monitoring data for the network and quality of service data for the network. One or more prior network states for the network are obtained. A current state of the network is determined, by a machine learning model, based on the current observations and the one or more prior network states. One or more actions are performed based on the current state of the network, including, when the current state of the network is an abnormal state, taking an action that is mapped to the abnormal state.

Abstract: Multiple ports of a vectored digital subscriber line (DSL) system can be automatically reconfigured to respond to a fault or defect associated with another one of the ports of the system. Information regarding retrain events for the ports of the system can be examined to identify the “bad” port with the associated fault or defect and the corresponding group of ports affected by the bad port. The affected group of ports can be identified as a group of ports that all were retrained within a predetermined time period and for common retrain reasons (e.g., 1 or 2 different retrain reasons). Once the affected group of ports is identified, the affected group of ports and the bad port can receive corresponding repair profiles to reconfigure the ports to respond to the fault or defect.

Abstract: A connection system has a high-density, high-speed connector that is electrically connected to a plurality of cables by a tiered circuit board. Edges of the circuit board are offset in order to form steps on which conductive pads may be formed. Each set of pads on a given step may be electrically connected to one or more conductors of a cable, such as a twinax ribbon cable. Thus, each of the cables may be coupled to one or more conductive pads on a respective step of the circuit board such that a large number of conductors may be electrically interfaced with the connector in a relatively small space, unencumbered by the bend radius of the cable. In addition, the cables may be coupled to the circuit board in a manner that does not require significant bending at the ends of the cables helping to preserve signal integrity. That is, conductive paths turn at high angles (e.g., close to 90 degrees) within the circuit board rather than at the ends of the cables connected to the circuit board.

Abstract: A system for performing failover switches in an optical network, such as a time and wavelength division passive optical networks (TWDM PON) like NG-PON2, includes a backup optical line terminal (OLT) for backing up communications of a primary OLT. The backup OLT is configured to allocate small upstream time slots, referred to herein as “de minimis” time slots, to at least one optical network terminal (ONT) communicating with the primary OLT during normal operation. When a failure occurs that prevents communication between the ONT and the primary OLT, the ONT autonomously tunes to the upstream and downstream wavelength pairs of the backup OLT and begins to transmit data to the backup OLT in the de minimis time slot allocated to it. The presence of data in the de minimis time slot indicates the occurrence of a failover switch to the backup OLT, and the backup OLT then begins to allocate time slots to this ONT, which is normally serviced by the primary OLT according to its normal TDM algorithm.

Abstract: A telecommunication system uses a dynamic bandwidth allocation (DBA) algorithm based on current load conditions for controlling transmissions to a plurality of access modules of an access node in order to achieve a fair allocation of network bandwidth at the access node. As an example, access modules at an access node communicate via a control channel with dynamic bandwidth allocation (DBA) logic that receives load information from each of the access modules. Using such load information, the DBA logic dynamically controls the upstream data rates so that a fair allocation of network bandwidth is achieved across all of the access modules. Specifically, the data rates are controlled such that packet flows for services of the same class achieve the same or similar performance (e.g., average data rate) regardless of which access module is receiving each respective packet flow.

Abstract: An electronic system may include a housing and one or more electronic modules. The housing and electronic modules may be configured to allow different numbers and types of electronic modules to be attached to the exterior of the housing.

Abstract: Methods, systems, and apparatus for configuring a network device are disclosed. In one aspect, a network address that is assigned to the network device by a network address server is detected by an equipment configuration device. The network address server differs from the network device. In response to detecting the network address, a set of connection parameters that connect the network device to a controller device is transmitted by the equipment configuration device and to the network device. The set of connection parameters is transmitted outside of communications, transmitted by the network address server, that assigned the network address to the network device.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for reducing jitter and latency in a PON. In one aspect, an optical network unit includes a downstream optical receiver configured to receive downstream traffic over a first wavelength; a first upstream optical transmitter having a first data rate; a second upstream optical transmitter having a second data rate that is higher than the first data rate; and a controller configured to direct upstream traffic to one of the first upstream optical transmitter or the second upstream optical transmitter depending on a traffic type of the traffic. Traffic having a control plane traffic type is directed to the first upstream optical transmitter and traffic having a data plane traffic type is directed to the second upstream optical transmitter.

Abstract: In a vectored Discrete Multi-Tone (DMT) system that employs trellis encoding, tones of a DMT signal are paired by a trellis encoder, and parity information is shared between the paired tones. In accordance with some embodiments, the tones are paired based on an interpolation pattern that is used to calculate vectoring coefficients in an effort to mitigate interpolation error. Specifically, a tone having a vectoring coefficient with a relatively large interpolation error may be paired with a tone having a vectoring coefficient with a relatively small interpolation error thereby reducing the peak interpolation error among paired tones within the system. By reducing the peak interpolation error in the paired tones, the number of communication lines included in a vectoring group can be increased without significantly degrading signal quality.

Abstract: An optical transmission system includes a laser module that generates a modulated optical waveform including both amplitude and frequency modulation; and an optical shaping filter that converts at least part of the frequency modulation to additional amplitude modulation. The optical transmission system is tuned by: measuring, based on the amplitude modulation of a filtered waveform output from the optical shaping filter, an average output power of the optical shaping filter; and adjusting a temperature of the laser module to a first temperature at which a target output condition is achieved, including: adjusting the temperature of the laser module to a first target temperature at which the average output power of the filtered waveform satisfies a first output criteria, or adjusting the temperature of the laser module to a second target temperature at which the output power and extinction ratio of the filtered waveform satisfy a second output criteria.

Abstract: A driver circuit for a transmitter includes a main path in parallel with an error correction path used for feed-forward error correction. The main path has an amplifier for amplifying a data signal to be transmitted from the transceiver. In parallel with the amplifier is a feedforward error correction circuit that provides an error correction signal that compensates for distortion introduced by the amplifier when the error correction signal is combined with the amplifier's output. The error correction circuit is designed to have a high impedance output so that voltage swings in the data signal do not create a demand for significant current from the feedforward error correction circuit, thereby reducing the current of the error correction signal. As an example, it is possible for the current of the error correction signal to substantially match that which is required to cancel the amplifier distortion, thereby minimizing distortion of the signal.