Abstract: An embodiment of the invention provides communications services to Optical Network Terminals (ONTs) in a Passive Optical Network (PON) with at least two Optical Line Terminals (OLTs). The role of these OLTs is autonomously governed based on characteristics of upstream signals from the ONTs. When an OLT in a standby mode determines that upstream signal power is below a power threshold, the OLT in standby mode changes its mode and operates in the active mode. An OLT in active mode monitors the upstream signals and determines the number of upstream signals that are misaligned to a respective downstream command sent from the active OLT. When the number of misaligned signals is greater than a counts threshold, the active OLT switches its operation and operates in standby mode. Through autonomous operation, the OLTs provide redundancy for the PON without added control channel complexity.

Abstract: Disclosed herein are optical distribution networks and corresponding methods for providing physical-layer redundancy. Example embodiments include a head-end passive optical splitter-combiner (OSC) to split optical signals from an Optical Line Terminal (OLT) onto primary and secondary optical paths for redundant distribution to optical network terminal(s) (ONTs), a passive access OSC for tapping the redundant signals, and an optical switch for selecting between the redundant signals and providing an ONT access to the selected signal. Example optical distribution networks and corresponding methods provide multiple drop points, a fully cyclical path, and autonomous protection switching, all at low cost. A further advantage of these networks and methods is that where faults may occur, maintenance may not be required for a certain time.

Abstract: Typical passive optical networks (PONs) employ several optical network terminals (ONTs) connected to an optical line terminal (OLT) via an optical splitter/combiner (OSC). Due to the passive nature of the OSC, determining a port assignment of an ONT may be difficult or impossible. Methods described herein provide for identifying a port in a passive optical network, optionally as corresponding to an ONT. A first subset of the ONTs is caused to transmit a first signal, such as a status signal, with a respective attribute having a first value, and a second subset of the ONTs is caused to transmit a second signal with the respective attribute having a second value. At the OSC, the signals are detected as a function of the attribute and the first and second values. Results of this detection are reported, from which an identification of a port and associated ONT can be determined.

Abstract: An embodiment of the invention provides communications services to Optical Network Terminals (ONTs) in a Passive Optical Network (PON) with at least two Optical Line Terminals (OLTs). The role of these OLTs is autonomously governed based on characteristics of upstream signals from the ONTs. When an OLT in a standby mode determines that upstream signal power is below a power threshold, the OLT in standby mode changes its mode and operates in the active mode. An OLT in active mode monitors the upstream signals and determines the number of upstream signals that are misaligned to a respective downstream command sent from the active OLT. When the number of misaligned signals is greater than a counts threshold, the active OLT switches its operation and operates in standby mode. Through autonomous operation, the OLTs provide redundancy for the PON without added control channel complexity.

Abstract: Typical passive optical networks (PONs) employ several optical network terminals (ONTs) connected to an optical line terminal (OLT) via an optical splitter/combiner (OSC). Due to the passive nature of the OSC, determining a port assignment of an ONT may be difficult or impossible. Methods described herein provide for identifying a port in a passive optical network, optionally as corresponding to an ONT. A first subset of the ONTs is caused to transmit a first signal, such as a status signal, with a respective attribute having a first value, and a second subset of the ONTs is caused to transmit a second signal with the respective attribute having a second value. At the OSC, the signals are detected as a function of the attribute and the first and second values. Results of this detection are reported, from which an identification of a port and associated ONT can be determined.

Abstract: Disclosed herein are optical distribution networks and corresponding methods for providing physical-layer redundancy. Example embodiments include a head-end passive optical splitter-combiner (OSC) to split optical signals from an Optical Line Terminal (OLT) onto primary and secondary optical paths for redundant distribution to optical network terminal(s) (ONTs), a passive access OSC for tapping the redundant signals, and an optical switch for selecting between the redundant signals and providing an ONT access to the selected signal. Example optical distribution networks and corresponding methods provide multiple drop points, a fully cyclical path, and autonomous protection switching, all at low cost. A further advantage of these networks and methods is that where faults may occur, maintenance may not be required for a certain time.

Abstract: A method for managing data congestion and/or contention occurring at a point-of-traffic concentration. The method includes reading a time value associated with a data packet, the time value being representative of when the data packet entered the network. The time value is within the header of the data packet. The age of the data packet is determined from the time value. The data packet is discarded if the age of the data packet is above a threshold value. Alternatively, a first time value determined from a time reference is associated with a data packet at a first node. The data packet is transmitted to a second node and the first time value is compared to a second time value to provide a result. The second time value is also determined from the time reference. The data packet is discarded if the result exceeds a threshold value.

Abstract: A method for managing data congestion and/or contention occurring at a point-of-traffic concentration. The method includes reading a time value associated with a data packet, the time value being representative of when the data packet entered the network. The time value is within the header of the data packet. The age of the data packet is determined from the time value. The data packet is discarded if the age of the data packet is above a threshold value. Alternatively, a first time value determined from a time reference is associated with, a data packet at a first node. The data packet is transmitted to a second node and the first time value is compared to a second time value to provide a result. The second time value is also determined from the time reference. The data packet is discarded if the result exceeds a threshold value.