Fujitsu Corporation

Martin Bouda

Takao Naito

Paparao Palacharla

Motoyoshi Sekiya

Inwoong Kim

Olga I Vassilieva

Xi Wang

Qiong Zhang

Stephen A Smith

Hiroshi Onaka

Tadashi Ikeuchi

Stephen Joseph Brolin

Tadao Nakazawa

Kazumasa Takabayashi

Naoki Hashimoto

Ken Morito

Yuji Kotaki

Yoichi Akasaka

Chengyi Gao

A system and method for generating, based on optical network topology information, an optical model to represent an optical network; provisioning a new optical connection within the optical network: determining, using the optical model, a first bit error rate (BER) of the new optical connection; determining, using the optical network providing the new optical connection, a second BER of the new optical connection; determining, based on the first and the second BER, a BER excursion parameter of the new optical connection; training a margin allocator based on the BER excursion parameter of the new optical connection, and the first BER of the new optical connection; comparing the first BER of the new connection and a required optical margin to a threshold to determine a reliability of the new optical connection; and allocating, using the margin allocator, the required optical margin for additional optical connections of the optical network.

System and method for optical system margin allocation

A method for VON service with guaranteed availability may use probability density functions (PDF) of Q-factor to determine availability of physical links assigned to a virtual link in the VON. Then, a VON mapping may be performed based on the determined availabilities, among other factors.

Virtual optical network service with guaranteed availability

Methods and systems are provided for monitoring a network link in an optical transport network. The method includes injecting a first level of added noise to the data stream at the receiver for a first period. The method further includes calculating a first bit error rate (BER) for the first period. The method also includes injecting a second level of added noise to the data stream at the receiver for a second period, the second level of added noise different than the first level of added noise, wherein the first and second periods do not overlap. The method further includes calculating a second BER for the second period. In addition, the method includes determining a characteristic of the network link based on the first BER and the second BER.

Noise margin monitor and control method

A matrix M indicating a minimum number of all optical paths between pairs of nodes may be generated in one embodiment using an algorithm for transitive closure. In various embodiments, different algorithms and methods may be used to generate matrix M. Once a convergent matrix M has been generated that attains transitive closure, any corresponding reachability matrix RM^a may be obtained from matrix M in a computationally efficient manner. Matrix M may be used to determine groups of potential regenerator placements and obtain end-to-end optical paths by selecting desired sequences of regenerators.

Memory-efficient matrix-based optical path computation

Methods and systems are provided for optical signal transmission using span-wise spectrum management. The method includes transmitting a first optical signal at a first wavelength by a control system. The first optical signal has a first optical path distance. The method further includes determining a first guard band requirement for the first optical signal, and transmitting a second optical signal by the control system. The second optical signal has a second optical path distance. The method includes determining a second guard band requirement for the second optical signal, and placing the second optical signal spectrally adjacent to the first optical signal by selecting a second wavelength. The second wavelength is selected to satisfy the first and second guard band requirements.

Span-wise spectrum management system and method

A matrix M is used to determine groups of potential regenerator placements and obtain potential end-to-end optical paths by selecting desired sequences of regenerators. Then, a hierarchical guided search may be employed to efficiently select desired N-tuple disjoint optical paths from the potential optical paths. The hierarchical guided search may employ a search graph and a search tree to guide the search and to eliminate candidate nodes and optical paths early in the search process.

Hierarchical guided search for N-tuple disjoint optical paths

Methods and systems for optical path computation based on a reachability matrix may rely on matrix multiplication to determine a number and respective network locations of regenerators for establishing an end-to-end reachable path in an optical network between a source node and a destination node. The reachability matrix may specify directly reachable optical paths between nodes in the optical network.

Optical path computation based on a reachability matrix

An opto-electronic module used in optical networking may be implemented using two different thermal zones. A first thermal zone at a first temperature may be used for an optical module. A second thermal zone at a second temperature may be used for an electronic module. The first temperature may be different from the second temperature. As a result, a physical dimension of the electronic module may be reduced in comparison to using a single thermal zone for the opto-electronic module.

Different thermal zones in an opto-electronic module

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.

System and method for increasing upstream capacity in an optical network

In accordance with an embodiment of the present disclosure a method for adaptively spacing channels of an optical network comprises determining a first desired power level of a first channel of an optical network. The method further comprises determining a second desired power level of a second channel of the optical network, the second desired power level being less than the first desired power level. Additionally, the method comprises determining a first spectral space between the first channel and one or more channels neighboring the first channel based at least on the first desired power level. The method also comprises determining a second spectral space between the second channel and one or more channels neighboring the second channel based at least on the second desired power level, the second spectral space less than the first spectral space.

Method and system for an adaptive channel grid of an optical network

In accordance with some embodiments of the present disclosure, a method for spectrally spacing carrier waves comprises determining a frequency offset between a first frequency of a first optical carrier wave and a second frequency of a second optical carrier wave. The method further comprises adjusting the second frequency of the second optical carrier wave according to the frequency offset. The method additionally comprises combining a first optical signal associated with the first carrier wave and a second optical signal associated with he second carrier wave into a multi-frequency signal.

Method and system for flexible optical signal aggregation and transmission

In accordance with the teachings of the present invention, a system and method for transmitting optical markers in a passive optical network (PON) system is provided. In a particular embodiment, a method for transmitting optical markers in a PON system includes transmitting a first optical marker signal, the first optical marker signal used to identify at least one of the first optical marker signal, an upstream wavelength corresponding to the first optical marker signal, and an optical network unit (ONU) type transmitting at the upstream wavelength corresponding to the first optical marker signal. The method also includes transmitting a second optical marker signal, the second optical marker signal used to identify at least one of the second optical marker signal, an upstream wavelength corresponding to the second optical marker signal, and an ONU type transmitting at the upstream wavelength corresponding to the second optical marker signal. The method further includes, at a distribution node of the PON, routing the first optical marker signal to a first set of one or more optical fibers in a PON each corresponding to a first upstream wavelength and routing the second optical marker signal to a second set of one or more optical fibers in the PON each corresponding to a second upstream wavelength.

System and method for transmitting optical markers in a passive optical network system

According to one embodiment, a system for transmitting an optical signal comprises a traffic distribution circuit configured to distribute traffic to a plurality of wavelength division multiplexer (WDM) modules. The system further comprises a first WDM module and a second WDM module. The first and second WDM modules each comprise a plurality of tunable optical transmitters, with each transmitter associated with a different wavelength band of a plurality of wavelength bands. Each transmitter in the first and second WDM modules is also tuned to transmit optical signals in channels included within the associated wavelength band of the transmitter. The first and second WDM modules each comprise a multiplexer configured to combine the optical signals transmitted from the plurality of transmitters into optical signals. The system further comprises a cyclic multiplexer configured to combine the optical signals from the first and second WDM modules into an optical output signal.

Multi-wavelength transponder with wavelength division multiplexing modules

A method for logging system characteristic data of a system is provided. The method includes receiving a plurality of system characteristic data points associated with a first time period of predetermined length, and generating a one or more first power sums from the plurality of system characteristic data points.

Method and apparatus for logging system characteristic data

In accordance with the teachings of the present invention, a system and method for extending reach in a passive optical network (PON) is provided. In a particular embodiment, a method for extending reach in a PON includes transmitting traffic at a first wavelength from a transmitter at a first optical network unit (ONU) in a PON and transmitting traffic at a second wavelength from a transmitter at a second ONU in the PON. The method also includes receiving the traffic in the first wavelength at a first input port of a multiplexer at a distribution node in the PON and receiving the traffic in the second wavelength at a second input port of the multiplexer at the distribution node. The method further includes forwarding the traffic in the first wavelength and the traffic in the second wavelength to an optical line terminal (OLT) in the PON.

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Plano, TX, United States of America

Martin Bouda