Abstract: In optical transmission schemes of the related art, there is a problem of delay dependency on an overhead or a flow size. In a DC network and a supercomputer network, an OCS scheme and an OPS scheme remain in an examination stage. A network of the electrical packet switching is still a main stream. In a scheme of sharing links using a dedicated wavelength, a considerable number of wavelengths is also necessary to provide full connectivity. The number of wavelengths cannot be realized and an unrealistic number considering the usable number of wavelengths such as current used C bands. In an optical network and an optical transmission system of the present invention, burst mode data transmission in which a label-based switching on an exclusively reserved dedicated wavelength is used is performed. Each node has a uniquely allocated wavelength, and thus traffics coexisting in all the network nodes do not collide.

Abstract: Embodiments of the present disclosure relate to a method and apparatus for optical communication. For example, there is provided a method implemented at a passive optical network device configured to perform high-rate communication via a bandwidth-limited link. The method comprises: receiving, via the bandwidth-limited link, a training signal from an optical network unit; obtaining a delay signal by delay-sampling the training signal; determining, based on the delay signal, a first channel response of the bandwidth-limited link, the first channel response characterizing change of the training signal caused by the bandwidth-limited link; and compensating, based on the first channel response, a communication signal received via the bandwidth-limited link from the optical network unit, to reduce distortion of the communication signal. A corresponding apparatus is also disclosed.

Abstract: This application provides a method and an apparatus for establishing an optical cable connection.

Abstract: The present disclosure relates to systems and method for deploying a fiber optic network. Distribution devices are used to index fibers within the system to ensure that live fibers are provided at output locations throughout the system. In an example, fibers can be indexed in multiple directions within the system. In an example, spare ports can be providing in a forward direction and reverse direction ports can also be provided.

Abstract: The present disclosure relates to systems and method for deploying a fiber optic network. Distribution devices are used to index fibers within the system to ensure that live fibers are provided at output locations throughout the system. In an example, fibers can be indexed in multiple directions within the system. In an example, spare ports can be providing in a forward direction and reverse direction ports can also be provided.

Abstract: Optical encoders for encoding signed, real numbers using optical fields are described. The optical fields may be detected using coherent detection, without the need for independent phase and amplitude control. This encoding technique enables the use of simple and non-ideal modulators (e.g., modulators that provide neither pure phase nor pure amplitude modulation) for high-precision encoding. A photonic system implementing optical encoding techniques may include a modulator configured to be driven by a single electrical modulating signal and a coherent receiver. An optical transformation unit optically coupled between the modulator and the coherent receiver may transform the phase and/or the intensity of the modulated optical field. The optical encoding techniques described herein may be used in a variety of contexts, including high-speed telecommunications, on chip-phase sensitive measurements for sensing, communications and computing, and optical machine learning.

Abstract: Systems and methods for providing transmission and reception of hybrid time and wavelength division multiplexed signals on passive optical networks are provided. Networks that use shared transmission media avoid interference between transmitters by restricting the times or wavelengths that given transmitters may use to transmit their messages. The hybrid broadcast WDM TDM PON architecture enables transmitters to use multiple fixed wavelengths for parallel optical transmission within given timeslots to avoid interference with other transmitters and make use of inexpensive fixed optical components to gain a speed advantage over existing architectures while making use of their deployed infrastructure. A single scheduling manager controls the timeslots of upstream and downstream transmissions, which make use of existing standards.

Abstract: The invention relates to a method for detecting collisions in an out-of-band communication channel, implemented by a master device of an optical communications network enabling in-band communications and further comprising slave devices. The out-of-band communication channel enables transmissions of signalling information with respect to the in-band communications in the form of modulation symbols over successive symbol periods. Collisions occur when plural slave devices access the out-of-band communication channel by using carrier wavelengths matching each other.

Abstract: A first transceiver and a method performed by the first transceiver for monitoring a fiber cable. The first transceiver is connectable to a second transceiver by the fiber cable. The transceivers employ SCM analog modulation where baseband is dedicated for monitoring and the subcarriers are dedicated for data transmission. The method comprises receiving, from a device, at least one electromagnetic data signal to be transmitted towards the second transceiver on the fiber cable, and shifting the at least one data signal in the frequency domain. The method further comprises generating an electromagnetic test signal in a base band, combining the at least one data signal and the generated test signal, and modulating the combined data signal and test signal to respective optical carrier. The method further comprises transmitting the modulated data signal and generated test signal on the fiber cable towards the second transceiver.

Abstract: Systems and methods for providing transmission and reception of hybrid time and wavelength division multiplexed signals on passive optical networks are provided. Networks that use shared transmission media avoid interference between transmitters by restricting the times or wavelengths that given transmitters may use to transmit their messages. The hybrid broadcast WDM TDM PON architecture enables transmitters to use multiple fixed wavelengths for parallel optical transmission within given timeslots to avoid interference with other transmitters and make use of inexpensive fixed optical components to gain a speed advantage over existing architectures while making use of their deployed infrastructure. A single scheduling manager controls the timeslots of upstream and downstream transmissions, which make use of existing standards.

Abstract: A method and apparatus for authentication in a passive optical network are disclosed. In the disclosure, a first terminal serial number of an ONU and a first logic registration code are transmitted from the ONU to an OLT; if the OLT determines that the first terminal serial number does not match a second terminal serial number stored on the OLT, the OLT judges whether the first logic registration code received from the ONU matches a second logic registration code stored on the OLT; the OLT stores the first terminal serial number received from the ONU on the OLT if the first logic registration code matches the second logic registration code.

Abstract: Optical transmitter apparatus 10 comprising a reflective optical amplifier 12, a driver 14, an optical splitter 16, polarisation compensation apparatus 18 and an optical router 20. The reflective optical amplifier is arranged to receive an optical seed signal. The driver is arranged to generate a drive signal arranged to cause the reflective optical amplifier to amplify the optical seed signal to form an optical signal. The optical splitter is arranged to receive the optical signal and to split off a part of the optical signal to form a further optical signal. The polarisation compensation apparatus is arranged to receive the further optical signal and to rotate a polarisation of the further optical signal by a pre-determined amount, to form a further optical seed signal. The optical router is arranged to receive the further optical seed signal and to direct the further optical seed signal to the reflective optical amplifier for amplification thereby.

Abstract: Methods, systems, and computer readable media for combining VoIP call data with geographical information are disclosed. According to one method, VoIP subscriber device call quality information and VoIP subscriber device status information are determined for a plurality of VoIP subscriber devices. Geographic information is obtained regarding a geographic area in which the VoIP subscriber devices are deployed. The VoIP subscriber device status and the call quality information are combined with the geographic information and, based on the combined VoIP subscriber device status and the geographic information, a map that illustrates the geographic locations of the VoIP subscriber devices and an indication of the current status and the call quality of each VoIP subscriber device is graphically displayed on a display device associated with a computer.

Abstract: A method of registering a coax network unit (CNU) in a network is performed at an optical-coax unit (OCU). In the method, a first discovery message is broadcasted to a plurality of CNUs. In response, a first registration request is received from a first CNU of the plurality of CNUs. In response to the first registration request, a proxy entity corresponding to the first CNU is implemented in the OCU. A second discovery message is received from an optical line terminal (OLT). In response to the second discovery message, a second registration request is transmitted to the OLT requesting registration of the proxy entity with the OLT.

Abstract: An optical line termination node has a first connection arrangement for connecting a working fiber, a second connection arrangement for connecting a protection fiber, a transceiver arrangement having first primary link and a first secondary link, and protection switching means configured for being switched either in a working operating state or in a protection operating state.

Abstract: A cable boot is mounted to a telecommunications module housing an optical component, wherein the cable boot extends outwardly from the module. The cable boot is mounted by axially passing the cable boot over a plurality of cables carrying fiber optic signals leading to the optical component, axially passing a portion of the cable boot through a cutout defined on a main housing of the telecommunications module, placing a boot retainer over the boot in a direction transverse to the axial direction to capture the flexible boot against movement both in the axial direction and the transverse direction, and mounting a cover on the main housing to capture the boot retainer against the main housing.

Abstract: A method provides advertisements to optical network units (ONUs) by an optical line terminal (OLT), wherein the advertisements enable the ONUs to identify free channels from a plurality of wavelength-division multiplexing (WDM) channels in a passive optical network (PON). The method includes: transmitting from the OLT to the ONUs an advertisement identifying a free channel for each of a plurality of incompatible channel (ICH) groups, receiving a request from an ONU for the advertised free channel of an ICH group, authenticating the requesting ONU via the advertised free channel, allocating the advertised free channel to the requesting ONU upon successful authentication of the requesting ONU, and transmitting an updated advertisement from the OLT to the ONUs.

Abstract: An optical network unit according to the present invention is provided as comprising a configuration that component units built therein are grouped for at least two sheets of substrate modules and arranged thereat. There are provided individual embodiments: (a) arranging an L2 layer and a part of the component unit of an L1 layer at a first substrate module, meanwhile, arranging the left part of the component unit of the L1 layer at a second substrate module; (b) arranging the component units of the L1 layer and of the L2 layer at the first substrate module and the second substrate module individually by grouping therefor; and (c) arranging the component units of the L2 layer and of the L1 layer at the first substrate module and the second substrate module respectively.

Abstract: An OLT that receives a signal in which transmission signals having a plurality of transmission rates are time-division multiplexed, as a received signal, and performs data reproduction by selecting reproduction data to be reproduced, among oversampled signals obtained by oversampling the received signal. The OLT includes a data-signal-information acquisition unit that acquires a transmission rate of a received signal targeted for a process of the data reproduction, a sampling frequency control unit that determines a sampling frequency to be used for the oversampling based on the transmission rate, and a sampling-clock generation unit that generates a clock signal having the sampling frequency determined by the sampling-frequency control unit, and performs the oversampling based on the clock signal.

Abstract: An arrangement at a Remote Node, a Remote Node, a Central Office, a WDM-PON and a method in an arrangement at a Remote Node, and a method in a Central Office are provided for supervision of the WDM-PON. The arrangement comprises at least one filter connected to the feeder fiber links and adapted to separate a data signal and an original OTDR signal received on either of the feeder fiber links. Further, the arrangement comprises a first splitter adapted to receive, from the at least one filter, the original OTDR signal, to split the original OTDR signal into a plurality of OTDR sub-signals and to output, to an N*M AWG, the plurality of OTDR sub-signals. The at least one filter is further adapted to output the original OTDR signal to the first splitter and to output the data signal to the AWG, thereby enabling supervision of the WDM-PON.

Abstract: A method and system for upgrading service to an optical network terminal among a plurality of optical network terminals on a passive optical network. The upgrade enables bidirectional communications between a central office and the optical network terminal over dedicated downstream and upstream wavelength channels outside the downstream and upstream wavelength bands associated with the passive optical network. The optical network terminal to receive upgraded service is disconnected from a passive optical splitter at a remote node serving the optical network terminal, and optically coupled to a port of the multi-port arrayed waveguide grating at the remote node. Wavelength taps are provided at the central office and the remote node to facilitate multiplexing and demultiplexing the dedicated downstream and upstream channels with the downstream and upstream wavelength bands associated with the passive optical network.

Abstract: A Wavelength Division Multiplexed Orthogonal Frequency Division Multiple Access Passive Optical Network (WDM-OFDMA-PON) includes a passive last-mile optical split terminated by optical network units (ONUs) with OFDMA transceivers; a standard single mode fiber (SSMF) link; a central office optical line terminal (CO-OLT) coupled to SSMF link and the passive last-mile optical split, wherein the CO-OLT comprises an OFDMA transceiver, burst-mode-free operation, inline optical dispersion compensation free operation, and WDM-enabled operation.

Abstract: An ONU includes a CDR that regenerates a clock based on a signal from an OLT, an oscillator that generates an internal clock, a time stamp counter that manages a time of the ONU based on the clock in a period in which the CDR regenerates the clock and manages the time of the ONU based on the internal clock in a period in which the CDR does not regenerate the clock, an MPCP control unit that decides, when a Cyclic Sleep mode is set, a receiver-time synchronization time that is a period in which the receiver is normally operated within a sleep time, based on a difference between a time stamp value included in the signal transmitted from the OLT and a time stamp managed by the time stamp counter, and a power-saving control unit that controls the receiver to be normally operated in the receiver-time synchronization time.

Abstract: A wavelength division multiplexing passive optical network (WPON) comprising an optical line terminal (OLT) and a plurality of optical network units (ONUs) coupled to the OLT via a power optical splitter. The OLT is configured to monitor wavelengths in use by the ONUs and to divide upstream traffic from the ONUs into multiple channels using tunable filters. Also disclosed is an OLT for a PON, the OLT comprising a plurality of receivers and a plurality of tunable filters corresponding to each of the receivers. The OLT also comprises channel control logic coupled to the tunable filters, wherein the channel control logic is configured to detect a plurality of wavelengths in use for upstream traffic in the PON and to divide the upstream traffic into multiple channels using the tunable filters. Included is a method for managing upstream traffic in a PON, the method comprising monitoring, by a processor, wavelengths in use for upstream traffic in the PON.

Abstract: An ONU includes a power-interruption detecting unit configured to detect power interruption of the ONU, a transmitting and receiving unit capable of being set in a power saving state, and a PON-side control unit configured to notify an OLT of, as power saving return information, a power holding time during occurrence of the power interruption of the ONU and a startup time, which is time until the transmitting and receiving unit returns from the power saving state, and, when the power-interruption detecting unit detects the power interruption, transmit a power interruption notification to the OLT. The OLT includes the PON control unit configured to determine, based on the power saving return information, whether the ONU can transmit the power interruption notification when the power interruption occurs in the power saving state.

Abstract: The disclosure provides a long-distance box and a method for processing uplink light and downlink light of the long-distance box, uplink light and downlink light from different Passive Optical Network (PON) systems are split, the uplink light from the different PON systems is transmitted through a first optical path, and the downlink light from the different PON systems is transmitted through a second optical path; wherein the uplink light from the different PON systems is amplified by an Optical Amplifier (OA) and then output to Optical Line Terminals (OLT) of respective systems; the downlink light from different PON systems with the different wavelengths is transmitted through different optical sub-paths of the second optical path according to the wavelengths of the downlink light, and the downlink light is amplified by different Optical-Electrical-Optical (OEO) conversion devices on the different optical sub-paths and then output to Optical Network Units (ONUs) of the respective systems.

Abstract: The inventive concept relates to an optical line terminal registering optical network terminals having overlapping serial numbers. The optical line terminal may include a memory storing serial number information of optical network terminals of which a registration is completed in a storage region; and a control part that if a serial number by a serial number request is received from optical network terminals, the received serial number is compared with the serial number information of the memory and if they overlap each other, a previously set preliminary identifier is allocated to the optical network terminal having an overlapping serial number.

Abstract: The present disclosure relates to an optical line terminal, the disclosure includes: an optical transmitter for generating a low speed downstream optical signal; a wavelength-multiplexer for wavelength-multiplexing the downstream optical signal; a first optical power branching tap coupler for allowing wavelength-multiplexed downstream optical signal to branch off; a wavelength band separator/coupler for separating between the wavelength-multiplexed downstream optical signal and a wavelength-multiplexed upstream optical signal; a circulation type wavelength-demultiplexer for wavelength-demultiplexing a downstream optical signal branched off by the first optical power branching tap coupler and an upstream optical signal separated by the wavelength band separator/coupler; an optical receiver for outputting a downstream electrical signal by using the wavelength-demultiplexed optical signal; and a signal processing module for controlling an optical power and a wavelength of the optical transmitter according to a s

Abstract: One or more overlay wavelengths are applied to a GPON architecture to provide sufficient, cost-effective forward bandwidth per home for targeted, unique narrowcast services to allow traditional HFC operators to use a PON architecture with their existing HFC equipment. A separate return path capability using a separate coaxial cable with RF signals to the GPON may also be used. This return capability may be provided either by a fiber optic link or coaxial link from the home.

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: A method for time synchronization on a passive optical network is disclosed, including: an optical line terminal (OLT) receives clock information sent by a first optical network unit (ONU); the OLT adjusts local time of the OLT according to the clock information, to implement clock synchronization between the OLT and the first ONU; the OLT sends the clock information to a second ONU, to implement clock synchronization between the second ONU and the OLT. The OLT in an embodiment of the present invention does not need to obtain clock signals from an upper network and the clock information does not need to be transmitted in a multi-level mode over a packet network; therefore, the precision of ToD can be greatly increased.

Abstract: A method for communicating in a passive optical network (PON), includes receiving traffic from a plurality of optical network units (ONUs) transmitting in an upstream transmission channel, wherein each of the ONUs may transmit at any wavelength within a wavelength band associated with the upstream transmission channel. The method also includes dividing the upstream transmission channel into a plurality of sub-channels, that each include a subset of the wavelength band associated with the upstream transmission channel. The method further includes determining the identity of each of the plurality of ONUs transmitting in each of the sub-channels, assigning a plurality of ONUs transmitting in the upstream transmission channel to each of at least two of the sub-channels based on the determination of the ONUs transmitting in that sub-channel, and allocating transmission timeslots for time-shared transmission by the ONUs in one or more of the sub-channels.

Abstract: In general, techniques are described for monitoring downstream traffic in order to schedule delivery of upstream traffic in a computer network. The techniques may be implemented by an optical line terminal (OLT) comprising a control unit and an interface. The control unit determines an amount of upstream data that is waiting at one of a plurality of ONTs to be transmitted upstream to the OLT, and determines an amount of downstream data that is transmitted by the OLT to this ONT. The control unit increases the determined amount of upstream data based on the determined amount of downstream data transmitted by the OLT to the ONTs and, after increasing the determined amount of upstream data, generates an upstream grant map that grants time slots to the ONTs based on the determined amount of upstream data. The interface transmits the upstream grant map downstream to the ONTs.

Abstract: The present invention relates to a method and devices for fast protection of an optical network system, in particular for a Passive Optical Network (PON), such as a Gigabit-capable Passive Optical Network (GPON). In the method, it is detected that the communication from a first optical network device is lost. Switching of functionality is initiated from a first optical line termination device to a second optical line termination device, and a control message is sent from the second optical line termination device to the first optical network device such that the first optical network device is prevented from moving into initial state. Furthermore, the method comprises determining and setting timing settings for the first optical network device.

Abstract: Embodiments of the present invention relate to a bi-direction optical sub-assembly and an optical transceiver. A transmitter in the bi-direction optical sub-assembly is configured to transmit a first communication signal or a detection signal, where the first communication signal or the detection signal is input from a first end of a first optical path and output from a second end of the first optical path, enters a second end of a third optical path through reflection of a WDM optical filter, and is input from a first end of the third optical path to an optical fiber. A second communication signal received by the optical fiber is input from the first end of the third optical path and output from the second end of the third optical path, and the second signal is received by a BOSA receiver through transmission of the WDM optical filter.

Abstract: 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.

Abstract: The disclosure provides an optical network system, an Optical Line Terminal (OLT), an Optical Network Unit (ONU) and an Optical Distribution Network (ODN) apparatus. The system includes: an OLT configured to modulate and encode at least one line of time-division-multiplexed downlink signals, synthesize the downlink signals encoded into one line and then output it, receive uplink signals, and decode the uplink signals received and then output them; an ODN configured to separate the downlink signals received into multiple lines and then output them, synthesize the uplink signals received into one line, and then output it to the OLT; and ONUs configured to receive the downlink signals output from the ODN, decode the downlink signals received and output them, encode one line of time-division-multiplexed uplink signals, and output the uplink signals encoded to the ODN. Decoding of the downlink signals and encoding of the uplink signals can further be implemented by the ODN.

Abstract: The present invention discloses a method and a system for scheduling an uplink message based on a Gigabit-capable Passive Optical Network (GPON). The method includes the following steps of: configuring a private managed entity for an 802.1p entity, and defining a mapping relationship between a priority queue and a priority of an uplink message in the private managed entity (S100); the 802.1p entity scheduling an uplink message from an optical network unit, mapping the uplink message to a corresponding GEM PORT, and creating a corresponding priority queue according to the mapping relationship between the priority queue and the priority of the uplink message defined in the private managed entity (S101). In the present invention, the uplink messages mapped to the GEM PORTs in the GPON system can be flexibly scheduled under the N:M bridge-mapping service model of the GPON system, and it is a beneficial extension to the existing mode for scheduling an uplink message based on the GPON system.

Abstract: A method and apparatus for controlling traffic in an optical network having a plurality of OLTs for communicating with a plurality of PONs. A traffic controller receives traffic information concerning current traffic volume and, preferably with reference to a rules database, calculates the number of OLTs required to support the current traffic volume. A separate determination may be made whether a network reconfiguration is permitted at this time. If a reconfiguration is permitted, the traffic controller configures a traffic control switch to route the PON traffic to an from only the calculated number of OLTs. The traffic control switch may be implemented using a voltage-controlled optical fiber coupling or electronically, routing the traffic as electrical signals to and from electro-optical converters associated with each PON. The OLTs to be used may be selected by the traffic controller.

Abstract: A bandwidth control method used in a case where, for example, a first communication device (OLT) allocates a bandwidth for signal transmission to each of a plurality of second communication devices (ONUs) connected to the OLT in a communication system having the OLT and the ONUs includes a sleep controlling of shifting devices among the ONUs that satisfy a predetermined condition into a power saving state, a control-target selecting of selecting control target devices among the ONUs based on a result of performing the sleep controlling, and a bandwidth determining of determining a bandwidth to be allocated to the selected control target devices.

Abstract: A method for small scale time increased bandwidth assignment to increase optical network unit ONU downstream energy efficiency includes splitting of downstream scheduling cycles into multiple rounds, using selective ones of the multiple rounds as probing rounds and other than said selective ones of the multiple rounds as fixed rounds, the probing rounds and fixed rounds being cooperatively selected for energy efficiency without limitations in length of the downstream scheduling cycles.

Abstract: A method for detecting faults and their locations in an optical path between an optical line terminal (OLT) of and optical network units (ONUs) of a passive optical network (PON). The method comprises forming a maintenance optical link through the PON between the OLT and a collocated ONU, the OLT and its collocated ONU are each connected to an optical splitter; sending a ranging request from the OLT to the collocated ONU; in response to the ranging request, receiving, over the maintenance optical line, a ranging burst signal including at least a fault analysis detection pattern (FADP); and analyzing the FADP in the received signal by auto-correlating the FADP signal with an expected FADP signal, an uncorrelated event measured through the auto-correlation is indicative of a fault in the optical path of the PON and occurrence times of such events are indicative of the fault's location in the optical path.

Abstract: A method for enabling alternating current (AC) coupling of high-speed burst data signals transmitted by an optical network unit (ONU). The method comprises generating a first data pattern to be sent to an optical transceiver through an AC coupling circuit, wherein the first data pattern is a direct current (DC) balanced pattern; generating a second data pattern to be sent to the optical transceiver through the AC coupling circuit, wherein the second data pattern is output prior to transmission of a high-speed burst data signal; and generating a third data pattern to be sent to the optical transceiver through the AC coupling circuit, wherein the third data pattern is output posterior to the transmission of the high-speed burst data signal.

Abstract: An optical power distributor is coupled to a high-intensity broadband light source to distribute in a shared manner an output of the high-intensity broadband light source to a plurality of optical line terminals. A depolarizer is also described having an input coupled to an output of a polarized broadband light source. A first integrated module has optical transmitters and an optical wavelength router for a first band. A second integrated module has optical receivers and an optical wavelength router for a second band.

Abstract: A method for performing a protection in passive optical networks. The method comprises forming a protection maintenance link between an active optical line terminal (OLT) and a standby OLT; forming a synchronization link between the active OLT and the standby OLT; computing a base differential distance value; continuously measuring round trip time (RTT) values by the active OLT using the protection maintenance link; periodically sending at least RTT values calculated by the active OLT to the standby OLT over the synchronization link; and computing, by the standby OLT, a new RTT value based on at least a RTT value measured by the active OLT and a standby differential distance value, when a switch-over action is triggered, thereby allowing the standby OLT to serve optical network units (ONUs) in the PON without performing a ranging process.

Abstract: An optical routing scheme in which an optical network having a mesh topology is configured to route optical packets through an optical routing layout superimposable with the mesh topology, but having a star-like topology. Using this routing layout, the optical network can be configured to transport optical packets from respective ingress nodes, through the hub node located at the star center, to respective egress nodes in a manner that enables a data throughput that approaches the theoretical capacity. No special hardware is required for implementing the hub functionality, and any node of the optical network can be configured to serve as the hub node. The latter feature enables relatively straightforward optimization of the optical routing layout and transmission schedule, e.g., by changing the identity of the hub node and adjusting the transmission schedule at the ingress nodes to synchronize packet arrivals to the hub node.

Abstract: A Data Over Cable Service Interface Specifications (DOCSIS) Passive Optical Network (PON) system (DPON) makes optical subscribers appear as cable subscribers. In one embodiment, a Cable Modem (CM) proxy is located in an Optical Line Termination (OLT). The OLT implements a cable modem protocol stack that operates as the CM proxy and communicates with a back office system. The OLT translates the data retrieved by the CM proxy into Optical Network Unit (ONU) recognizable commands, and sends the translated data to the ONU. In a second embodiment, the CM proxy is located in the ONU. The ONU implements the cable modem protocol stack that operates as the CM proxy and communicates with the back office system. The ONU translates the data retrieved by the CM proxy into ONU recognizable commands and sends the translated data to the ONU.

Abstract: A method removes signal interference in a passive optical network. The passive optical network includes an optical line terminal, a splitting unit coupled with the optical line terminal, an optical network unit coupled with the splitting unit, and an identification signal uniquely associated with the optical network unit. The method includes the steps of sending a first signal, detecting the first signal, comparing the detected first signal with an identification signal and decoupling the optical network unit from the splitting unit if the comparing step results in a mismatch.

Abstract: A temperature controlled multi-channel transmitter optical subassembly (TOSA) may be used in a multi-channel optical transceiver. The temperature controlled multi-channel TOSA generally includes an array of lasers optically coupled to an optical multiplexer, such as an arrayed waveguide grating (AWG), to combine multiple optical signals at different channel wavelengths. The lasers may be thermally tuned to the channel wavelengths by establishing a global temperature for the array of lasers and separately raising local temperatures of individual lasers in response to monitored wavelengths associated with the lasers. A temperature control device, such as a TEC cooler coupled to the laser array, may provide the global temperature and individual heaters, such as resistors adjacent respective lasers, may provide the local temperatures. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: Methods and apparatus for line coding in a communications network are described. According to one embodiment of the invention, downstream communications traffic bits are received and mapped into downstream bit positions of a transmission structure. A pre-selected bit in each upstream bit positions of the transmission structure is provided to form a downstream transmission structure. A downstream optical signal carrying the downstream transmission structure is generated for transmission. Upstream communications traffic bits are also received and mapped into the upstream bit positions of the transmission structure to form an upstream transmission structure. An upstream optical signal carrying the upstream transmission structure is generated for transmission.