Patents by Inventor Paparao Palacharla

Paparao Palacharla has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20130089317
    Abstract: In accordance with embodiments of the present disclosure, a method may include sorting potential optical layer link failures in a network in an increasing order of failed traffic amount. The method may further include, for each potential optical link failure in increasing order of failed traffic amount: determining the additional higher layer link capacity required on existing higher layer links associated with the potential optical link failure using higher layer restoration of the potential optical link failure; determining the additional optical layer capacity required for restoring the existing higher layer links associated with the potential optical link failure using optical layer restoration; and selecting one of the higher layer and the optical layer as a restoration layer for restoration of the existing higher layer links associated with the potential optical link failure based on the determined additional higher layer link capacity and the determined additional optical layer capacity.
    Type: Application
    Filed: January 12, 2012
    Publication date: April 11, 2013
    Inventors: Qiong Zhang, Xi Wang, Paparao Palacharla, Motoyoshi Sekiya
  • Publication number: 20130011138
    Abstract: In accordance with some embodiments of the present disclosure a method for receiving and processing an optical orthogonal frequency-division multiplexed signal containing a plurality of traffics comprises receiving the optical orthogonal frequency-division multiplexed signal.
    Type: Application
    Filed: July 5, 2011
    Publication date: January 10, 2013
    Applicant: FUJITSU LIMITED
    Inventors: Inwoong Kim, Paparao Palacharla, Xi Wang, Motoyoshi Sekiya
  • Patent number: 8347006
    Abstract: In certain embodiments, minimizing interconnections in a multi-shelf switching system includes receiving a map describing the switching system, where the switching system comprises shelves and input/output (I/O) points. The map is transformed to yield a graph comprising nodes and edges. A node represents an I/O point, and a node weight represents a number of interface cards of the I/O point represented by the node. An edge between a node pair represents traffic demand between the I/O points represented by the node pair, and an edge weight represents the amount of the traffic demand represented by the edge. The graph is partitioned to yield a groups that minimize interconnection traffic among the shelves, where each group represents a shelf of the multi-shelf switching system.
    Type: Grant
    Filed: January 7, 2010
    Date of Patent: January 1, 2013
    Assignee: Fujitsu Limited
    Inventors: Qiong Zhang, Paparao Palacharla, Xi Wang, Takao Naito
  • Patent number: 8346965
    Abstract: A method may include constructing an auxiliary graph for a network comprising a plurality of network elements, the network elements having an Internet Protocol layer, a lower layer, and a wavelength layer, the auxiliary graph including a plurality of directed edges, the plurality of directed edges indicative of connectivity of components of the plurality of network elements. The method may further include: (i) deleting directed edges from the auxiliary graph whose available bandwidth is lower than the required bandwidth of a selected demand; (ii) finding a path for the demand on the auxiliary graph via remaining directed edges; (iii) deleting at least one directed edge of the auxiliary graph on the wavelength layer along the path; (iv) adding lower layer lightpath edges to the auxiliary graph for a lower layer lightpath for the path; and (v) converting lower layer lightpaths to Internet Protocol lightpaths if a conversion condition is satisfied.
    Type: Grant
    Filed: November 9, 2010
    Date of Patent: January 1, 2013
    Assignee: Fujitsu Limited
    Inventors: Qiong Zhang, Paparao Palacharla, Qingya She, Xi Wang, Motoyoshi Sekiya
  • Publication number: 20120328286
    Abstract: A system and method are provided for monitoring traffic in a network comprising a plurality of links, wherein each of the plurality of links comprises a plurality of neighboring pairs of slots. The system and method may include identifying a first usage status and a second usage status, calculating a utilization entropy value based at least on the difference between the first and second usage status, iteratively calculating a set of utilization entropy values for a portion of the network, and calculating an overall utilization entropy value for the portion of the network under analysis based at least on a statistical analysis of the set of utilization entropy values.
    Type: Application
    Filed: June 21, 2011
    Publication date: December 27, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Xi Wang, Inwoong Kim, Qiong Zhang, Paparao Palacharla, Motoyoshi Sekiya
  • Publication number: 20120301140
    Abstract: In accordance with some embodiments of the present disclosure a method for shared mesh protection in an optical transport network comprises provisioning a route for each of a plurality of working demands through the optical transport network. The method further comprises provisioning a route for backup demands corresponding to each of the plurality of working demands. The method additionally comprises packing into a single optical data unit a first backup demand corresponding to a first of the plurality of working demands and a second backup demand corresponding to a second of the plurality of working demands, wherein the first and second of the plurality of working demands share at least one common link in the optical transport network. The method also comprises unpacking the first and second backup demands from the optical data unit.
    Type: Application
    Filed: May 26, 2011
    Publication date: November 29, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Qiong Zhang, Paparao Palacharla, Motoyoshi Sekiya
  • Publication number: 20120263455
    Abstract: In accordance with embodiments of the present disclosure, a method may include determining individual spectrum requirements for each of a plurality of signals to be communicated in an optical network, wherein a first signal of the plurality of signals has a first spectrum requirement and a second signal of the plurality of signals has a second spectrum requirement. The method may also include calculating a minimum spectrum granularity based on the individual spectrum requirements. The method may further include assigning each particular signal a channel spectrum equal to an integer multiple of the minimum spectrum granularity.
    Type: Application
    Filed: July 1, 2011
    Publication date: October 18, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Xi Wang, Qiong Zhang, Inwoong Kim, Paparao Palacharla, Motoyoshi Sekiya
  • Publication number: 20120237200
    Abstract: In accordance with embodiments of the present disclosure, a method may include for each particular working demand in a communication network, calculating a dedicated backup path for a working path of the particular working demand such that each particular backup path does not include links present in the working path. The method may also include, for each particular working demand: (i) assigning to the backup path a wavelength associated with the particular working demand; and (ii) assign to the backup path a transponder at each of the source and destination of the backup path associated with the wavelength; such that the backup path for at least one particular working demand is assigned a transponder that is also assigned to the backup path for at least one other particular working demand.
    Type: Application
    Filed: June 2, 2011
    Publication date: September 20, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Xi Wang, Paparao Palacharla
  • Publication number: 20120117269
    Abstract: A method may include constructing an auxiliary graph for a network comprising a plurality of network elements, the network elements having an Internet Protocol layer, a lower layer, and a wavelength layer, the auxiliary graph including a plurality of directed edges, the plurality of directed edges indicative of connectivity of components of the plurality of network elements. The method may further include: (i) deleting directed edges from the auxiliary graph whose available bandwidth is lower than the required bandwidth of a selected demand; (ii) finding a path for the demand on the auxiliary graph via remaining directed edges; (iii) deleting at least one directed edge of the auxiliary graph on the wavelength layer along the path; (iv) adding lower layer lightpath edges to the auxiliary graph for a lower layer lightpath for the path; and (v) converting lower layer lightpaths to Internet Protocol lightpaths if a conversion condition is satisfied.
    Type: Application
    Filed: November 9, 2010
    Publication date: May 10, 2012
    Inventors: Qiong Zhang, Paparao Palacharla, Qingya She, Xi Wang, Motoyoshi Sekiya
  • Publication number: 20120093507
    Abstract: A system and method are provided for dynamically reconfiguring an optical circuit between a first node and a second node of a communication network. The system and method may include establishing a scheduling window for receiving a plurality of optical traffic demands, classifying the plurality of optical traffic demands into at least a set of bandwidth adjustable demands and a set of fixed bandwidth demands, provisioning a first set of provisioned wavelengths from the plurality of wavelengths to carry the set of fixed bandwidth demands during the scheduling window, allocating the bandwidth remaining on the first set of provisioned wavelengths to the set of bandwidth adjustable demands, and if necessary, provisioning a second set of provisioned wavelengths from the plurality of wavelengths to carry the bandwidth required by the set of bandwidth adjustable demands that could not be allocated to the first set of provisioned wavelengths.
    Type: Application
    Filed: October 15, 2010
    Publication date: April 19, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Xi Wang, Qiong Zhang, Paparao Palacharla, Takao Naito
  • Patent number: 8144626
    Abstract: According to particular embodiments, determining disjoint paths includes receiving a graph representing a network comprising nodes and links. The graph is transformed such that the number of intermediate nodes of a path indicates the number of regenerators for the path. A set of seed paths from a source node to a destination node of the transformed graph is generated. For each seed path, a shortest path from the source node to the destination node is determined to yield one or more pairs of disjoint paths from the source node to the destination node. An optimized pair of disjoint paths is selected, where the optimized pair of disjoint paths has an optimized number of regenerators.
    Type: Grant
    Filed: June 30, 2009
    Date of Patent: March 27, 2012
    Assignee: Fujitsu Limited
    Inventors: Qiong Zhang, Xi Wang, Paparao Palacharla, Takao Naito
  • Patent number: 8131151
    Abstract: An optical node may include a plurality of optical input components operable to receive a plurality of signals communicated in an optical network and a plurality of optical output components operable to transmit a plurality of signals to be communicated in the optical network.
    Type: Grant
    Filed: October 9, 2009
    Date of Patent: March 6, 2012
    Assignee: Fujitsu Limited
    Inventor: Paparao Palacharla
  • Patent number: 8055140
    Abstract: According to particular embodiments, reducing cross-phase modulation includes sending instructions to a phase modulation array comprising channel pixel sets that modulate phases of channels. The channel pixel sets comprise a first channel pixel set that modulates a first phase of a first channel and a second channel pixel set that modulates a second phase of a second channel that uses a phase modulation format. The first channel pixel set is instructed to modulate the first phase at a first constant phase. The second channel pixel set is instructed to modulate the second phase at a second constant phase different from the first constant phase in order to create a group delay between the first channel and the second channel.
    Type: Grant
    Filed: November 10, 2009
    Date of Patent: November 8, 2011
    Assignee: Fujitsu Limited
    Inventors: Olga I. Vassilieva, Richard L. Colter, Daniel Bihon, Paparao Palacharla
  • Publication number: 20110243030
    Abstract: Systems and methods for determining multiple paths in a multi-domain network are provided. In some embodiment, a method for determining multiple paths in a network is provided. The method may include determining a first path between a source node and a destination node and determining a second path disjoint from the first path. In some embodiments, to determine the second path includes determining which ingress nodes are available in a domain that includes the destination node, where the available ingress nodes are not part of the first path, and implementing a disjoint path algorithm for each of the available ingress nodes. To determine the first path includes implementing forward path calculations.
    Type: Application
    Filed: March 31, 2010
    Publication date: October 6, 2011
    Applicant: FUJITSU LIMITED
    Inventors: Qiong Zhang, Mohammad Masud Hasan, Xi Wang, Paparao Palacharla, Takao Naito, Fredrick S. Gruman
  • Publication number: 20110242995
    Abstract: Systems and methods for multi-domain routing are provided. In some embodiments, a method for determining a path calculation from a source node to a destination node over a multi-domain network is provided. The method may include steps for receiving a predetermined sequence of domains for communicating information from the source node to the destination node, determining a link type for each of a plurality of links in the predetermined sequence of domains, modifying the link type of one or more of the plurality of links such that the plurality of links are unidirectional links towards a destination node, and determining a path along the predetermined sequence of domains based on the modified plurality of links.
    Type: Application
    Filed: March 31, 2010
    Publication date: October 6, 2011
    Applicant: FUJITSU LIMITED
    Inventors: Qiong Zhang, Mohammad Masud Hasan, Xi Wang, Paparao Palacharla, Takao Naito, Fredrick S. Gruman
  • Publication number: 20110206374
    Abstract: In accordance with embodiments of the present disclosure, a method for demand aggregation is provided. The method may include routing demands in a ring network such that a length for each routed demand does not exceed a route length maximum, and a load imbalance at each node in the ring network is minimized. The method may also include maximizing optical line card sharing by assigning routed demands sharing common ends to the same wavelength.
    Type: Application
    Filed: February 7, 2011
    Publication date: August 25, 2011
    Inventors: Xi Wang, Qiong Zhang, Paparao Palacharla, Takao Naito
  • Publication number: 20110176813
    Abstract: A system is provided for electrical domain optical spectrum shaping. The system may include a laser, a modulator, a first electrical filter, and a second electrical filter. The laser may be configured to output an optical carrier signal. The modulator may be configured to modulate the optical carrier signal to output a modulated optical signal based on a first filtered input signal and a second filtered input signal received by the modulator. The first electrical filter may be configured to filter a first input signal to produce the first filtered input signal. The second electrical filter may be configured to filter a second input signal to produce the second filtered input signal.
    Type: Application
    Filed: January 20, 2010
    Publication date: July 21, 2011
    Inventors: Inwoong Kim, Paparao Palacharla, Takao Naito
  • Publication number: 20110167183
    Abstract: In certain embodiments, minimizing interconnections in a multi-shelf switching system includes receiving a map describing the switching system, where the switching system comprises shelves and input/output (I/O) points. The map is transformed to yield a graph comprising nodes and edges. A node represents an I/O point, and a node weight represents a number of interface cards of the I/O point represented by the node. An edge between a node pair represents traffic demand between the I/O points represented by the node pair, and an edge weight represents the amount of the traffic demand represented by the edge. The graph is partitioned to yield a groups that minimize interconnection traffic among the shelves, where each group represents a shelf of the multi-shelf switching system.
    Type: Application
    Filed: January 7, 2010
    Publication date: July 7, 2011
    Applicant: Fujitsu Limited
    Inventors: Qiong Zhang, Paparao Palacharla, Xi Wang, Takao Naito
  • Publication number: 20110109953
    Abstract: According to particular embodiments, reducing cross-phase modulation includes sending instructions to a phase modulation array comprising channel pixel sets that modulate phases of channels. The channel pixel sets comprise a first channel pixel set that modulates a first phase of a first channel and a second channel pixel set that modulates a second phase of a second channel that uses a phase modulation format. The first channel pixel set is instructed to modulate the first phase at a first constant phase. The second channel pixel set is instructed to modulate the second phase at a second constant phase different from the first constant phase in order to create a group delay between the first channel and the second channel.
    Type: Application
    Filed: November 10, 2009
    Publication date: May 12, 2011
    Applicant: Fujitsu Limited
    Inventors: Olga I. Vassilieva, Richard L. Colter, Daniel Bihon, Paparao Palacharla
  • Publication number: 20110103790
    Abstract: Methods and systems are provided for compensating impairment of a signal in an optical network. A method may include: (i) recording, for each node of a plurality nodes of the network, traffic management information specific to such node; (ii) communicating, by each node, its associated traffic management information to one or more other nodes; (iii) receiving, at a particular node of the plurality of nodes, the traffic management information communicated from the one or more nodes; (iv) determining, by the particular node, digital signal processor tap coefficients for a digital coherent receiver integral to the particular node based on at least a portion of the traffic management information; and (v) compensating, by the digital coherent receiver, optical impairment of the optical signal based on at least the determined digital signal processor tap coefficients and processing of the optical signal by a digital signal processor integral to the digital coherent receiver.
    Type: Application
    Filed: November 3, 2009
    Publication date: May 5, 2011
    Applicant: Fujitsu Limited
    Inventors: Paparao Palacharla, Daniel Bihon