Abstract: Techniques for unified optical network unit power management in a passive optical network include operating an optical network unit (ONU) in a first state in which a transmitter of the ONU is turned off and a receiver of the ONU is turned on, operating the ONU in a second state in which both the transmitter and the receiver are turned off, and transitioning the ONU directly between the first state and the second state, based on a power management rule.

Abstract: A multi-wavelength passive optical network (MW-PON) includes an optical distribution network (ODN), a plurality of optical line terminations (OLTs) and an optical network unit (ONU). The ODN includes a trunk fiber, one or more branching elements, and a plurality of distribution fibers. Each OLT is associated with an individual bi-directional wavelength channel using a corresponding single downstream wavelength and a corresponding single upstream wavelength, and supporting a specific downstream line rate and one or more distinct upstream line rates. The ONU is communicatively coupled to a respective distribution fiber, being tunable over a specific range of downstream wavelengths and a specific range of upstream wavelengths, and supporting a specific downstream line rate and a specific upstream line rate.

Abstract: A method of Noisy Window and associated management messages to support set splitting if activating ONUs with uncalibrated transmitter, offering a power grant for unmodulated upstream transmission, measuring the average received optical power in all upstream wavelength channels and providing downstream indication of the upstream wavelength channel with abnormally high average received power.

Abstract: Techniques for unified optical network unit power management in a passive optical network include operating an optical network unit (ONU) in a first state in which a transmitter of the ONU is turned off and a receiver of the ONU is turned on, operating the ONU in a second state in which both the transmitter and the receiver are turned off, and transitioning the ONU directly between the first state and the second state, based on a power management rule.

Abstract: A method and an apparatus for self-calibration of an ONU receiver in a multi-wavelength PON system, said method including the initial physical layer scan of the receiver tuning range, distributed estimation of the down-stream wavelength channel drift with respect to the nominal standard-based wavelengths, and reporting the estimated downstream wavelength channel drift in the downstream Channel_Map message.

Abstract: Techniques for unified optical network unit power management in a passive optical network include operating an optical network unit (ONU) in a first state in which a transmitter of the ONU is turned off and a receiver of the ONU is turned on, operating the ONU in a second state in which both the transmitter and the receiver are turned off, and transitioning the ONU directly between the first state and the second state, based on a power management rule.

Abstract: Techniques, apparatus and systems are described for accommodating the optical network units (ONUs) having different nominal upstream bitrates on the same passive optical network (PON) system by making the specified burst preamble and the bandwidth map allocation record format invariant with respect to the nominal upstream bitrate of a target ONU. The disclosed techniques, apparatus and systems allow seamless evolution of the lower-bitrate services to higher-bitrate services offered to an end-user without need to upgrade the central office equipment. In addition they can avoid the adverse consequences of inadvertently connecting a high-upstream-bitrate ONU to a lower-upstream-bitrate network.

Abstract: A device determines a zero-distance equalization delay and an order for optical line terminal (OLT) channel terminations (CTs), and determines a round-trip propagation time between a first OLT CT, based on the order, and an optical network unit (ONU). The device determines an equalization delay based on the round-trip propagation time, and hands over the ONU to a next OLT CT. The device calculates a round-trip delay for the next OLT CT based on a propagation time between the next OLT CT and the ONU, a processing time of the ONU, and the equalization delay. The device compares the round-trip delay, for the next OLT CT, with the zero-distance equalization delay to obtain a comparison result, and alters the zero-distance equalization delay based on the comparison result. The device repeats the performing, the calculating, the comparing, and the altering for remaining OLT CTs.

Abstract: Techniques, apparatus and systems are described for an optical line terminal (OLT) operable in a passive optical network (PON) system to isolate and mitigate the behavior of a rogue optical network unit (ONU) that transmits optical power up the optical distribution network (ODN). In one aspect, a method of mitigating the behavior of rogue ONUs can include detecting the presence of a rogue ONU on the PON system, and transmitting, based on the detection, a message addressed exclusively to the ONUs that have not yet been discovered or identified by the OLT.

Abstract: A method of Noisy Window and associated management messages to support set splitting if activating ONUs with uncalibrated transmitter, offering a power grant for unmodulated upstream transmission, measuring the average received optical power in all upstream wavelength channels and providing downstream indication of the upstream activation in the optical communication network wavelength channel with abnormally high average received power.

Abstract: A method and an apparatus for self-calibration of an ONU receiver in a multi-wavelength PON system, said method including the initial physical layer scan of the receiver tuning range, distributed estimation of the down-stream wavelength channel drift with respect to the nominal standard-based wavelengths, and reporting the estimated downstream wavelength channel drift in the downstream Channel_Map message.

Abstract: A device determines a zero-distance equalization delay and an order for optical line terminal (OLT) channel terminations (CTs), and determines a round-trip propagation time between a first OLT CT, based on the order, and an optical network unit (ONU). The device determines an equalization delay based on the round-trip propagation time, and hands over the ONU to a next OLT CT. The device calculates a round-trip delay for the next OLT CT based on a propagation time between the next OLT CT and the ONU, a processing time of the ONU, and the equalization delay. The device compares the round-trip delay, for the next OLT CT, with the zero-distance equalization delay to obtain a comparison result, and alters the zero-distance equalization delay based on the comparison result. The device repeats the performing, the calculating, the comparing, and the altering for remaining OLT CTs.

Abstract: A multi-wavelength passive optical network (MW-PON) includes an optical distribution network (ODN), a plurality of optical line terminations (OLTs) and an optical network unit (ONU). The ODN includes a trunk fiber, one or more branching elements, and a plurality of distribution fibers. Each OLT is associated with an individual bi-directional wavelength channel using a corresponding single downstream wavelength and a corresponding single upstream wavelength, and supporting a specific downstream line rate and one or more distinct upstream line rates. The ONU is communicatively coupled to a respective distribution fiber, being tunable over a specific range of downstream wavelengths and a specific range of upstream wavelengths, and supporting a specific downstream line rate and a specific upstream line rate.

Abstract: Techniques, apparatus and systems are described for accommodating the optical network units (ONUs) having different nominal upstream bitrates on the same passive optical network (PON) system by making the specified burst preamble and the bandwidth map allocation record format invariant with respect to the nominal upstream bitrate of a target ONU. The disclosed techniques, apparatus and systems allow seamless evolution of the lower-bitrate services to higher-bitrate services offered to an end-user without need to upgrade the central office equipment. In addition they can avoid the adverse consequences of inadvertently connecting a high-upstream-bitrate ONU to a lower-upstream-bitrate network.

Abstract: Techniques for unified optical network unit power management in a passive optical network include operating an optical network unit (ONU) in a first state in which a transmitter of the ONU is turned off and a receiver of the ONU is turned on, operating the ONU in a second state in which both the transmitter and the receiver are turned off, and transitioning the ONU directly between the first state and the second state, based on a power management rule.

Abstract: Systems, methods and apparatus for operating an optical network terminal (ONT) in a passive optical network include maintaining an operational state in the passive optical network, estimating an upstream channel, adjusting equalization delay and physical layer frame offset values and switching from a backup mode to a primary mode of operation upon detecting a failure condition.

Abstract: Techniques, apparatus and systems are described for an optical line terminal (OLT) operable in a passive optical network (PON) system to isolate and mitigate the behavior of a rogue optical network unit (ONU) that transmits optical power up the optical distribution network (ODN). In one aspect, a method of mitigating the behavior of rogue ONUs can include detecting the presence of a rogue ONU on the PON system, and transmitting, based on the detection, a message addressed exclusively to the ONUs that have not yet been discovered or identified by the OLT.

Abstract: The present invention focuses on the aggregation of flows belonging to different classes of non-guaranteed-delay traffic into a single FIFO queue in a downstream stage of the multi-stage switch. These include the guaranteed flows requiring bandwidth reservation, the best-effort flows that require a fair share of the excess bandwidth, and the flows that require both types of guarantee. We disclose a credit-based backpressure scheme which selectively controls the traffic originating from the previous stage of the system while achieving the goal of meeting the requirements of the individual flows. The credit function is maintained for each controlled traffic component in the aggregate session, and its objective is to balance the actual arrival rate of the component with the service rate dynamically granted by the downstream scheduler. The number of flows that can be aggregated is related to the complexity of maintaining the credit functions for the different traffic components.

Abstract: A method to restore the original order of packets in an end-to-end data flow after the flow has been multiplexed over a set of communication or switching paths whose available bandwidth varies significantly over time. To convey the relative path ordering, the method considers all possible path pairs. For each such path pair it enumerates the packet block transmissions, i.e., the sequences of packets transmitted on a selected path of the given path pair which are not interleaved by the packets transmitted on the other path of the same pair. Packet block enumeration for each path pair is performed independently and does not take into account any packets transmitted on the other paths. A packet transmitted on a given path carries a set of packet block identifications for each path pair the given path belongs to. Increasing the range of the packet block enumeration, the robustness of the method can be adjusted to an arbitrary level of packet loss tolerance.

Abstract: A hierarchial vector clock (HVC) providing a logical time system to a collection of distributed systems. HVC is not restricted to any fixed number of hierarchy levels and scals naturally when the number of levels increases. Unlike constant-size clocks, its storage and processing requirements grow gracefully at approximately a logarithmic rate with the number of distributed sites within the distributed system. HVC is well suited for modern, message-passing distributed systems which make use of highly hierarchical communication networks.