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.

Aspects of the subject disclosure may include, for example, receiving a first optical signal from a first optical network via a first port of the wavelength converter, receiving a second optical signal from a second optical network via a second port of the wavelength converter, modulating the first optical signal with the second light signal to generate a third optical signal, eliminating the first light signal from the third optical signal to generate a fourth optical signal, and transmitting the fourth optical signal through the second optical network. The first optical signal can include a first digital signal modulated onto a first light signal of a first wavelength, the second optical signal can include a second light signal can include a second wavelength different from the first wavelength, and the fourth optical signal can include the first digital signal modulated onto the second light signal. Other embodiments are disclosed.

According to various aspects of the present disclosure, an apparatus is provided. In an aspect, the apparatus includes an optical transceiver having a first port, a second port and an optical switch coupled to the first port and the second port. The optical switch is switchable between a unidirectional port operation mode and a bidirectional port operation mode. When the optical switch is in the unidirectional port operation mode, the first port is configured to send a first optical signal, and the second port configured to receive a second optical signal. When the optical switch is in the bidirectional port operation mode, the first port configured to send the first optical signal and receive the second optical signal, and the second port configured to receive a third optical signal and not send the first signal. Furthermore, a second bidirectional port operation mode is supported with the second port configured to send the first optical signal and receive the second optical signal, and the first port configured to receive a third optical signal and not send the first signal.

An optical transport network (OTN) node including a plurality of optical circuit switches (OCSs), each OCS being a respective degree of the OTN node, at least two of the OCSs including an input port configured to be connected to a respective optical transport fiber outside of the OTN node, at least one first output port connected to a first switching layer, and at least one second output port connected to a second switching layer. The first and second switching layers have different levels of granularity, such as but not limited to a wavelength switched layer, a band switched layer or a fiber switched layer.

Provided is a monitoring apparatus capable of efficiently optimizing the transmission efficiency of an entire network. The monitoring apparatus (1) includes a variable parameter changing unit (2), a monitoring information acquisition unit (4), and an estimation unit (6). The variable parameter changing unit (2) changes a variable parameter for at least one of multiple network apparatuses that constitute an optical communication network transmitting an optical signal by wavelength division multiplexing. The monitoring information acquisition unit (4) acquires monitoring information related to a state of optical communication from at least one of the multiple network apparatuses. The estimation unit (6) estimates at least one penalty for a receiving side, using the monitoring information.

This disclosure describes devices and methods related to multiplexing optical data signals. A method may be disclosed for multiplexing one or more optical data signals. The method may comprise receiving, by a dense wave division multiplexer (DWDM), one or more optical data signals. The method may comprise combining, by the DWDM, the one or more optical data signals. The method may comprise outputting, by the DWDM, the combined one or more optical data signals to one or more wave division multiplexer (WDM). The method may comprise combining, by the one or more WDM, the combined one or more optical data signals and one or more second optical data signals, and outputting an egress optical data signal comprising the combined one or more optical data signals and one or more second optical data signals.

A method to select a number of fibers for ROADM-equipped nodes of an optical network by which a controller is operative to determine which links are utilized as well as their usage frequencies and then partition a scale of usage frequencies into a number of intervals. By assigning a number of fibers to each one of the intervals, a number of fibers is assigned to each link, according to their usage frequencies, setting the degree for ROADMs at the nodes. Simulations can evaluate the network's performance in terms of a blocking rate representing an overall signal blocking rate by the ROADMs at network nodes. The number of intervals, their ranges, and the number of fibers associated with each interval can be iterated until an improved or satisfactory network performance is achieved.

The present disclosure relates to an NE (90) in a WDM transmission system. The NE (90) according to the present disclosure includes a WSS (901) which allows, in accordance with configurations allocated to a plurality of respective slots, optical signals of the plurality of respective slots to pass, and a WSS control unit (902) which allocates a configuration to each of the plurality of slots. The WSS control unit (902) additionally allocates, if an adjacent slot adjacent to a desired one of the plurality of slots is unused, a configuration for allowing an optical signal to pass through a path the same as that of the desired slot to the adjacent slot.

An optical transmission apparatus includes a first transmitter configured to transmit a first optical signal in a first wavelength band and a second optical signal in a second wavelength band located next to the first wavelength band; a second transmitter configured to transmit a third optical signal in a third wavelength band located next to the second wavelength band and a fourth optical signal in a fourth wavelength band located next to the third wavelength band; and a processor coupled to the first transmitter and the second transmitter and configured to select the third wavelength band among the first wavelength band, the second wavelength band, the third wavelength band and the fourth wavelength band, and control the first wavelength band, the second wavelength band, and the fourth wavelength band based on the third wavelength band.

An optical transmission device includes: a selector configured to select a wavelength of a signal to be transmitted to an optical transmission line and output a wavelength-multiplexed signal; an adjustor configured to control a power level of the wavelength-multiplexed signal; and a controller configured to control the adjustor or the selector, wherein the selector selects a wavelength of an optical signal in a second wavelength band different from an existing first wavelength band, and when the second wavelength band is added to or removed from the optical transmission line, the controller controls power of the wavelength-multiplexed signal in the second wavelength band at a slower speed than power control in the first wavelength band.