An optical reception apparatus includes an equalization processor, an extraction unit, a first ratio calculator, and an instruction transmitter. The equalization processor suppresses fluctuations in amplitude of an electrical signal obtained by converting an optical signal including a plurality of pilot symbols subjected to BPSK modulation by an optical transmission apparatus. The extraction unit extracts the pilot symbols from the electrical signal with suppressed fluctuations in amplitude. The first ratio calculator calculates a ratio of an amplitude component to a phase component of each of the pilot symbols extracted by the extraction unit. The instruction transmitter transmits information relating to skew adjustment based on the ratio of the amplitude component to the phase component calculated by the first ratio calculator for each of different control values to the optical transmission apparatus.

A multilane transmission device that transmits data frames by using a plurality of lanes, comprising: a data frame allocating unit that allocates data frames based on a transmission destination; a flow group information sequence information adding unit that adds flow group information indicating a flow group corresponding to a transmission source and transmission destinations and sequence information indicating a sequence of the data frames to the data frames allocated based on each transmission destination by the data frame allocating unit; and a lane selecting/outputting unit that transmits the data frames having the respective flow group information and the respective sequence information added thereto by the flow group information sequence information adding unit to the transmission destinations by using one or more lanes corresponding to the respective flow group information.

A method for bandwidth management in an optical broadcast network includes signaling, for a new optical broadcast service, from an originating node to all nodes in the optical broadcast network, wherein the signaling identifies a wavelength or portion of spectrum associated with the new optical broadcast service; at each of the nodes, checking for contention by the new optical broadcast service; responsive to identifying contention at one of the nodes, signaling the identified contention back to the originating node; and responsive to no contention at any of the nodes, processing the signaling, storing an update of the new optical broadcast service, and either forwarding the signaling to peer nodes or terminating the signaling.

An optical reception apparatus includes an equalization processor, an extraction unit, a first ratio calculator, and an instruction transmitter. The equalization processor suppresses fluctuations in amplitude of an electrical signal obtained by converting an optical signal including a plurality of pilot symbols subjected to BPSK modulation by an optical transmission apparatus. The extraction unit extracts the pilot symbols from the electrical signal with suppressed fluctuations in amplitude. The first ratio calculator calculates a ratio of an amplitude component to a phase component of each of the pilot symbols extracted by the extraction unit. The instruction transmitter transmits information relating to skew adjustment based on the ratio of the amplitude component to the phase component calculated by the first ratio calculator for each of different control values to the optical transmission apparatus.

A method and apparatus is proposed for performing the ONU activation process in a PON having a standard line rate of 50 G or higher. The method and apparatus are based upon having the OLT instruct any activating ONUs to transmit at a line rate that is less than 50 G, which allows for an OLT receiver without any particular equalization configuration to accurately recover the upstream burst-mode transmissions from the activating ONUs. Once the activation process is completed, the OLT may instruct the new ONUs to reset their transmitters to operate at the higher line rate of the PON. Alternatively, at the end of the activation process, the new ONUs may be configured to automatically reset their transmitters to higher line rate.

Embodiments of the present invention disclose a method for switching a modulation format of a passive optical network, an apparatus, and a system. The method includes: separately delivering, by an OLT, a registration message to an optical network unit in all supported upstream modulation formats and/or downstream modulation formats; receiving, by the OLT, a first message reported by the optical network unit, where the first message includes an upstream modulation format capability and/or a downstream modulation format capability; and determining, by the OLT, a target upstream modulation format and/or a target downstream modulation format of the optical network unit according to the first message, and instructing the optical network unit to switch to the target upstream modulation format and/or the target downstream modulation format. Therefore, in a PON system that supports a plurality of modulation formats, a modulation format reporting capability of the ONU is improved.

A photonic frame switching system may include a main controller and at least one photonic frame wrapper line card. The main controller may determine a point in time at which a photonic frame wrapper line card transmits a photonic frame by allocating a time slot to the photonic frame wrapper line card. When the photonic frame switching system includes a plurality of photonic frame wrapper line cards, points in times at which the plurality of photonic frame wrapper line cards transmits the photonic frames may be synchronized. In particular, when a portion of the plurality of photonic frame wrapper line cards transmit a plurality of photonic frames having different destinations, points in times at which all of the plurality of photonic frame wrapper line cards transmits the photonic frames may be adjusted based on a latency by a destination change.

A network system for a data center is described in which a switch fabric provides full mesh 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.

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.

An apparatus comprises: a first clock; a receiver configured to: receive a first packet via a first channel corresponding to a first wavelength, and receive a third packet via a third channel corresponding to a third wavelength; and a processor coupled to the receiver and configured to: implement channel bonding using the first channel and the third channel, synchronize the first clock based on the first packet, and calculate a channel skew between the first channel and the third channel based on the first clock.