Access nodes of a large-scale network are arranged into a number of groups. The groups are arranged into a number of bands. Each distributor of a pool of distributors interconnects each access node of a selected group to at least one channel from each group of a selected band. A discipline of allocating the selected group and the selected band to a distributor ensures that each access node has: a number, approximately equal to half the number of groups, of parallel single-hop paths to each other access node of a same group; a number, approximately equal to half the number of bands, of parallel single-hop paths to each access node of a different group within a same band; and one single-hop path to each other access node of a different access band. To eliminate the need for cross connectors, geographically-spread distributors are arranged into geographically-spread constellations of collocated distributors.

Provided are a state transition method and apparatus, a device, and a storage medium. The method comprises: an optical network unit verifies a received physical synchronization sequence field, and transitions the current state according to a verification result. As such, the probability of downstream synchronization detection can be effectively improved, and the probability of missed downstream synchronization detection can be reduced, thereby ensuring the normal operation of a PON system.

This application provides a training sequence determining method and a related device. The method in embodiments of this application includes: An ONU receives a first message sent by an OLT. Then, the ONU determines a target training sequence based on the first message, where the target training sequence is used to determine a working parameter of an equalizer in the OLT. Further, the ONU generates a first data frame including the target training sequence. In this application, the OLT may perform training based on the received target training sequence to determine the working parameter of the equalizer in the OLT.

A network system for a data center is described in which a switch fabric provides interconnectivity such that any servers may communicate packet data to any other of the servers using any of a number of parallel data paths. Moreover, according to the techniques described herein, edge-positioned access nodes, permutation devices and core switches of the switch fabric may be configured and arranged in a way such that the parallel data paths provide single L2/L3 hop, full mesh interconnections between any pairwise combination of the access nodes, even in massive data centers having tens of thousands of servers. The access nodes may be arranged within access node groups, and permutation devices may be used within the access node groups to spray packets across the access node groups prior to injection within the switch fabric, thereby increasing the fanout and scalability of the network system.

An optical module for use in an optical system is disclosed, the optical module implementing Precision Time Protocol (PTP) clock functionality therein. The optical module includes an electrical interface with the optical system; circuitry connected to the electrical interface and configured to implement a plurality of functions of functionality; an optical interface connected to the circuitry; and timing circuitry connected to the electrical interface and one or more of the plurality of functions, wherein the timing circuitry is configured to implement the PTP clock functionality.

An optical transmission device includes: a receiver configured to receive a signal including data; a generator configured to generate an output clock to output the data based on a signal clock synchronized with the signal; and a controller configured to control a frequency of the output clock based on a first amount of the data so that the output clock follows a clock of a transmission source of the data.

[PROBLEM TO BE SOLVED] To uninterruptedly change a band of an optical transmission path in a line IF section, which relays a signal transmitted to an optical transmission path in a client IF section to which a communication terminal is connected, to the same band as a changed band in the client IF section without suspending the communication in the line IF section. [SOLUTION] An optical transmission system 10A performs processing for changing a band of an optical fiber 15 in a line IF section (L section) that relays a signal from an optical fiber 12 in a client IF section (C section) to the same band as that in the C section. Line IF units 24A and 24B provided on both sides of the L section set a temporary evacuation lane p as an optical lane having a band different from those of a plurality of optical lanes 0 to n in the optical fiber 15 in the L section, selects either a change-target optical lane (for example, the optical lane 0) or the temporary evacuation lane p, the change-target optical lane being provided in the optical fiber 15 in the L section and having a band to be changed to a same band as a band in the C section, while causing a buffer unit 46 to absorb a delay difference between a signal received by the change-target optical lane and a signal received by the temporary evacuation lane p, and sets the optical lane not selected to have the same band as the band in the C section.

Provided are a method and a device for implementing timeslot synchronization. The method includes: a master node performing timeslot synchronization training of an OBTN according to a timeslot length of the OBTN. By adopting the solution provided by the embodiments of the present disclosure, an FDL does not need to be considered in node design, the node design is simplified, the time precision of synchronization is improved and no loss is caused to optical efficiency.

A large-scale switching system deployed as a global network or a large-scale data center includes a large number of access nodes (edge nodes) interconnected through optical or electronic rotators. The rotators are logically arranged in a matrix and each access node has a channel to each rotator in a respective row and a channel from each rotator of a respective column of the matrix. A dual timing circuit coupled to a diagonal rotator pair exchanges timing data with edge nodes connecting to the diagonal rotator pair to facilitate temporal alignment of data received at input ports of each rotator. Each access node has a path to each other access node traversing only one of the rotators. The rotators may be arranged into constellations of collocated rotators to facilitate connectivity of access nodes to rotators using wavelength-division-multiplexed links.

Systems, apparatus, and methods for a configurable gearbox with a variable number of input lanes and output lanes and a multiplexer for each output lane that can be configured to dynamically select any of the input lanes during each clock cycle.