In one example, a first Provider Edge (PE) node is configured to communicate with a second PE node through a packet-switched network and with a third PE node through the packet-switched network. The first PE node communicates with a fourth PE node via the second PE node. The fourth PE node is configured to communicate with the second PE node over a working path through a time-division multiplexing transport network. The first PE node exchanges, with the fourth PE node, protection information. Based on exchanging the protection information, the first PE node communicates with the fourth PE node via the third PE node. The fourth PE node is further configured to communicate with the third PE node over a protection path through the time-division multiplexing transport network.

An optical beamforming device includes an RF front-end transmitting or receiving RF signals and an optical beamformer forming or compensating for a time delay for each of the plurality of channels based on the RF signals. The optical beamformer includes E/O converters converting the RF signals into optical signals, respectively, a linear modulator generating an optical modulation signal based on an RF input signal, a TTD array outputting an optical combined signal obtained by compensating for a time delay degree of the input optical signals or outputting output optical signals, in each of which a time delay is formed for each channel, by distributing the optical modulation signal, a photo detector generating an RF output signal to an RF back-end based on the optical combined signal, and O/E converters converting the output optical signals into RF signals, respectively.

An optical buffer and a method for storing an optical signal using the optical buffer, where the optical buffer includes a first waveguide, a first optical delay waveguide loop and a controller. The first waveguide includes a first arm and a second arm, where a first end of the first arm is an input end of the optical buffer, and a second end of the second arm is an output end of the optical buffer. A second end of the first arm connects to a first end of the second arm. The first optical delay waveguide loop connects to the first arm at a first end using a first optical switch, and a second part of the first optical delay waveguide loop connects to the second arm at a second end using a second optical switch. The controller connects to the first optical switch and the second optical switch respectively.

The invention relates to an optoelectronic transceiver device comprising a first optical connector (OC1) capable of connection to a first bidirectional optical fibre (OF1), and a second optical connector (OC2) capable of connection to a second bidirectional optical fibre (OF2), the device further comprising: an insertion-extraction module (ADM) capable of: extracting a wave-length (λ.sub.Rx) from a plurality of wavelengths constituting a first optical signal received by the first optical connector (OC1) and transmitting the first optical signal without the extracted wavelength to the second optical connector (OC2); inserting a wavelength (λ.sub.Tx) into a second optical signal received by the second optical connector (OC2) and transmitting the second optical signal with the inserted wavelength to the first optical connector (OC1); an electric-optical conversion module (EC1) capable of providing the insertion-extraction module with the wavelength (λ.sub.Tx) inserted into the second optical signal from an incoming electric signal (Data Tx); and an optical-electric conversion module (EC2) capable of converting the wavelength (λ.sub.Rx) extracted from the first optical signal by the insertion-extraction module into an outgoing electric signal (Data Rx).

The present invention provides a receiving device and an optical switching fabric apparatus, where the receiving device includes: multiple selecting modules, a fast optical switch connecting to each selecting module, an output module connecting to all the fast optical switches, and a receiver connecting to the output module, where the selecting module is configured to receive a multiwavelength optical signal, select and filter a first optical signal of a preset time segment in the multiwavelength optical signal; the fast optical switch is configured to select a second optical signal from the first optical signal filtered by the selecting module; the output module is configured to combine optical signals separately selected by all the fast optical switches into one optical burst signal; and the receiver is configured to perform optical-to-electrical conversion on the optical burst signal, and extract service data from an electrical signal.

An optical circuit switching matrix includes a plurality of optical ports, each optical port being optically coupled to a respective one of a plurality of user nodes and an optical coupler having at least one input port optically coupled to the plurality of optical ports, and an output port. The optical circuit switching matrix also includes a wavelength demultiplexer having an input optically coupled to the output port of the optical coupler, and a plurality of output ports, each output port being optically coupled to a respective one of the plurality of optical ports.

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.

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.

A network element (36) includes circuitry and at least one port (72). The at least one port is coupled to an optical fabric (32) including one or more optical switches (40) that provide optical paths between the at least one port and multiple destination nodes, at predefined time slots. The circuitry is configured to hold a schedule plan (84) that specifies which of the destination nodes are accessible via the optical fabric at which of the time slots, to queue packets that are destined to the destination nodes, and to transmit the queued packets via the at least one port in accordance with the schedule plan.

An optical beamforming device includes an RF front-end transmitting or receiving RF signals and an optical beamformer forming or compensating for a time delay for each of the plurality of channels based on the RF signals. The optical beamformer includes E/O converters converting the RF signals into optical signals, respectively, a linear modulator generating an optical modulation signal based on an RF input signal, a TTD array outputting an optical combined signal obtained by compensating for a time delay degree of the input optical signals or outputting output optical signals, in each of which a time delay is formed for each channel, by distributing the optical modulation signal, a photo detector generating an RF output signal to an RF back-end based on the optical combined signal, and O/E converters converting the output optical signals into RF signals, respectively.