Time Patents (Class 398/52)
  • Patent number: 7529483
    Abstract: A communication system for the mutual interconnection of a plurality of lower traffic level (5 Terabit) switch nodes via a relatively higher traffic level (Petabit) connection bus, which system comprises in operative association with each node, a two part TDM optical data management interface, wherein a first of the two parts comprises a time slot resequencer which serves to provide for the transmission of data from its associated node to the bus, and wherein a second of the two parts comprises a time slot specific combiner which serves for the transmission of data from the bus to its associated node, each node and the bus having independent data scheduling.
    Type: Grant
    Filed: March 18, 2002
    Date of Patent: May 5, 2009
    Assignee: Roke Manor Research Limited
    Inventors: Roderick Leonard Wallace Stevens, Michael John McTiffin, Paul Roderick Webb
  • Publication number: 20090110397
    Abstract: An apparatus for preventing collision of upstream signals is provided. The apparatus is suitable for a time division multiplexing (TDM) passive optical network (PON). The apparatus includes an optical coupler device, an optic-electron converter (O/E), a control system, and an optical signal switch module. The O/E is coupled to the optical coupler device, the control system is coupled to the O/E, and the optical signal switch module is coupled to the optical coupler device and the control system. The optical coupler device receives a first optical signal and splits the first optical signal into a second optical signal and a third optical signal. The O/E converts the second optical signal into a first electrical signal. The control system generates a control signal according to the first electrical signal. The optical signal switch module determines whether to stop the third optical signal from passing the apparatus according to the control signal.
    Type: Application
    Filed: December 25, 2007
    Publication date: April 30, 2009
    Applicant: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventors: Chien-Hung Yeh, Sien Chi
  • Publication number: 20090097848
    Abstract: A method includes storing a value of shared variables from an active member of a plurality of packet-to-tdm interfaces. Another member of the plurality of packet-to-tdm interfaces is selected to become active. The value of shared variables is provided to the selected member.
    Type: Application
    Filed: October 12, 2007
    Publication date: April 16, 2009
    Inventors: Anthony L. Sasak, Christopher V. O'Brien
  • Publication number: 20090080885
    Abstract: An optical network scheduling device (10) including a plurality of schedulers (16) each corresponding to a respective channel in the optical burst switch network and configured to maintain a transmission schedule for the respective channel; and a controller (12) configured to receive a burst transmission request and to select at least one of the schedulers as a selected scheduler schedule a burst transmission.
    Type: Application
    Filed: May 27, 2005
    Publication date: March 26, 2009
    Applicant: Research Triangel Institute
    Inventors: Pronita Mehrotra, Dan Stevenson, Mark Cassada, Wayne Dettloff
  • Publication number: 20090074410
    Abstract: A method for synchronous cross-connect switching in optical transport network, the method includes: receiving optical channel transport unit (OTU) signals; mapping the OTU signals into interim switching units, wherein the interim switching units match bit rates of the received OTU signals; performing a synchronous cross-connect switching for the interim switching units; and demapping the interim switching units obtained after the synchronous cross-connect switching to obtain the OTU signals.
    Type: Application
    Filed: September 12, 2008
    Publication date: March 19, 2009
    Inventors: Shimin Zou, Limin Dong, Qiuyou Wu
  • Patent number: 7480465
    Abstract: The receiver features a first splitter which divides a differential phase modulated signal into three signal components from which at least two signal components are routed via timers. The first timer has a delay of a half period of the carrier signal and thereby serves in a conventional way for phase comparison and thus for demodulation. The second timer is adjustable and is used to compensate for the dispersion.
    Type: Grant
    Filed: January 12, 2006
    Date of Patent: January 20, 2009
    Assignee: Nokia Siemens Networks GmbH & Co. KG
    Inventor: Mahesh U. Ajgaonkar
  • Publication number: 20080317465
    Abstract: A method for implementing transport layer service of NGN, wherein the NGN includes a service layer and a transport layer, the method including: establishing an independent transport-layer control device in the control plane of the transport layer in the NGN network; establishing a transport connection in the user plane of the transport layer under the control of the transport-layer control device; bearing the NGN service through the transport connection. The present invention also discloses a system for implementing transport layer service of NGN. According to the present invention, the network design of NGN may be simplified, the cost of the transport layer network may be reduced, and a strict QoS guarantee for NGN services may be provided.
    Type: Application
    Filed: September 5, 2005
    Publication date: December 25, 2008
    Applicant: Huawei Technologies, Co.,Ltd.
    Inventor: Haoze Yu
  • Publication number: 20080292313
    Abstract: Methods, systems, and computer-readable media provide for ranging a device in a point-to-multipoint network. According to embodiments, a method for ranging a device in a point-to-multipoint network is provided. According to the method, a device identifier representing a drop in the point-to-multipoint network where the device is installed is received. The device identifier is associated with the device. The device identifier and a unique identifier associated with the device are transmitted over the point-to-multipoint network to a central unit for ranging the device in the point-to-multipoint network.
    Type: Application
    Filed: May 25, 2007
    Publication date: November 27, 2008
    Inventors: Glenn Mark Mahony, Mounire El Houmaidi, Homayoun Torab
  • Publication number: 20080247754
    Abstract: A method and apparatus for adjusting timeslot fragments of multiple links in an Automatically Switched Optical Network (ASON). The method includes the steps of: obtaining link information of multiple links necessary for timeslot fragment adjustment, calculating adjusted link information of each link according to the link information, and adjusting a timeslot allocation of each link according to the adjusted link information.
    Type: Application
    Filed: June 13, 2008
    Publication date: October 9, 2008
    Applicant: HUAWEI TECHNOLOGIES CO., LTD.
    Inventors: Junbai Sun, Huadong Li, Jianguo Zeng, Yanming Xiao, Hao Wu
  • Publication number: 20080181608
    Abstract: The present invention provides systems and methods to effectively combine layer one and layer two cross-connects in a hierarchical fashion. The present invention combines layer one and layer two cross-connects between a layer one (L1) line card and a layer two (L2) line card in a transport and aggregation platform. Advantageously, the present invention provides network operators increased flexibility and capability in transport and aggregation networks. Particularly, transport networks tend to contain only layer one capabilities. The present invention makes the introduction of layer two functionality into transport networks practical because an entire physical connection need not be dedicated to all layer one cross-connects or all layer two cross-connects.
    Type: Application
    Filed: January 29, 2007
    Publication date: July 31, 2008
    Inventors: Ronald M. Parker, John P. Jones, Chris Munford
  • Patent number: 7394824
    Abstract: In a system including a parent station and a plurality of child stations connected only to the parent station, which is unable to detect a response among the plurality of child stations, the parent station includes a transmission permission sequential allocation mechanism for giving transmission permission sequentially and a first timer for monitoring a first period which is a response detection time period. The child station includes a transmission permission detection mechanism for detecting that the identifier sent by the parent station is directed to the own station. Each of the child stations transmits data in a band period when the child station is permitted to communicate. When the parent station does not receive a response from the child station permitted to communicate within the first period, the parent station permits a next child station to communicate.
    Type: Grant
    Filed: May 16, 2002
    Date of Patent: July 1, 2008
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toshihisa Hane
  • Patent number: 7394983
    Abstract: Provided are a method and an apparatus for detecting the fault of an optical switch. The apparatus includes an optical monitoring signal generator, a coupler, a splitter, a plurality of optical detecting and output power transition sensing units, and a fault determiner. The optical monitoring signal generator generates optical monitoring signals having different wavelengths from optical signals including data to be transmitted. The coupler optically couples the optical monitoring signals to the optical signals including data to be transmitted and inputs the coupled optical signals to an optical switch. The splitter splits the optical monitoring signals from optical signals output from the optical switch. The plurality of optical detecting and output power transition sensing units detect output power transitions of the split optical monitoring signals.
    Type: Grant
    Filed: October 14, 2003
    Date of Patent: July 1, 2008
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Wang-joo Lee, Kwang-joon Kim, Sung-hoon Kwak
  • Patent number: 7380993
    Abstract: An optical transmitter for converting and coupling an information-containing electrical signal with an optical fiber having an electrical input for coupling with an external electrical cable or information system device having a plurality of parallel data lines, a modulator for converting between an information-containing electrical signal on each data line and a multi-level digital pulse amplitude modulated signal corresponding to the binary electrical signal; and a signal timing circuit coupled to said modulator for aligning the data signal to a predetermined clock signal. The transmitter is preferably wavelength division multiplexed, using an electro-optical subassembly coupled to each respective timer circuit for converting between the information-containing electrical signal and a modulated optical signal corresponding to the electrical signal at a predetermined wavelength. The transceiver is preferably implemented in a pluggable standardized form factor.
    Type: Grant
    Filed: September 15, 2006
    Date of Patent: June 3, 2008
    Assignee: Emcore Corporation
    Inventor: John Dallesasse
  • Patent number: 7366413
    Abstract: A modular cross connect system for optical telecommunication networks has the optical unit divided in at least two main bodies with one section for connection comprising the collimators and a main commutation section with MEMS devices. The first section is a fixed part while the second section is a readily removable section. The two sections face each other through a window and, in the first section, optics are provided for steering all or part of the optical signals from and to the main MEMS unit to a MEMS standby or protection plane to allow replacement of the main MEMS unit without interrupting service.
    Type: Grant
    Filed: June 24, 2002
    Date of Patent: April 29, 2008
    Assignee: Marconi Communications S.p.A.
    Inventor: Ugo Cerato
  • Patent number: 7356259
    Abstract: Optical bypass node upgrade configurations are disclosed: (1) a configuration where optical taps are pre-positioned in wavelength division multiplex (WDM) line systems terminating at optical-electrical-optical (OEO) core switching nodes to allow for future upgrade of the nodes to degree-two or higher optical bypass; (2) a configuration where the taps are pre-positioned in a degree-two optical bypass node to allow for future upgrade to a degree-N optical bypass node; and (3) a configuration and procedure for upgrading OEO core switching nodes to optical bypass when the taps have not been pre-positioned in the WDM line systems. These configurations do not introduce bit errors for non-upgraded optical paths.
    Type: Grant
    Filed: June 17, 2004
    Date of Patent: April 8, 2008
    Assignee: Ciena Corporation
    Inventor: Charles Haggans
  • Publication number: 20080069570
    Abstract: An optical transmitter for converting and coupling an information-containing electrical signal with an optical fiber having an electrical input for coupling with an external electrical cable or information system device having a plurality of parallel data lines, a modulator for converting between an information-containing electrical signal on each data line and a multi-level digital pulse amplitude modulated signal corresponding to the binary electrical signal; and a signal timing circuit coupled to said modulator for aligning the data signal to a predetermined clock signal. The transmitter is preferably wavelength division multiplexed, using an electro-optical subassembly coupled to each respective timer circuit for converting between the information-containing electrical signal and a modulated optical signal corresponding to the electrical signal at a predetermined wavelength. The transceiver is preferably implemented in a pluggable standardized form factor.
    Type: Application
    Filed: September 15, 2006
    Publication date: March 20, 2008
    Inventor: John Dallesasse
  • Publication number: 20080069562
    Abstract: In a communication system in which data is transferred by packets, a ranging method in which a receiver, in a given ranging window, periodically compares received data with expected data to find a match. The periodic comparison includes searching for known preamble and/or delimiter sequences of ranging packets and involves timeouts for each search period. In case a match between the known sequences and received sequences is not found and the respective timeout is exceeded, the search and comparison process is restarted and continues until a global timeout is exceeded.
    Type: Application
    Filed: September 18, 2007
    Publication date: March 20, 2008
    Applicant: PMC-SIERRA ISRAEL LTD.
    Inventor: Raanan Ivry
  • Patent number: 7332234
    Abstract: An optoelectronic device that has a network address (e.g., IF address) and participates in in-band traffic for purposes of performing functions (e.g., network diagnostics, network control, network provisioning, fault isolation, etc.) that are traditionally performed by host equipment. An embodiment of the invention may have a protocol engine and a status monitoring module. The protocol engine identifies data packets that are addressed to the optoelectronic device, and allows the optoelectronic device to insert packets of information generated by the device into in-band data. Logic of the optoelectronic device may modify the operating parameters of the device according to the control information included in the data packets. The status monitoring module detects the device's physical conditions and the conditions of its links.
    Type: Grant
    Filed: September 21, 2005
    Date of Patent: February 19, 2008
    Assignee: Finisar Corporation
    Inventors: Frank H. Levinson, Mark Farley
  • Publication number: 20070223922
    Abstract: An optical transmission device includes an input interface unit, a cross-connecting unit, and an output interface unit, and a bandwidth switching control unit, and switches bandwidths allocated to paths in a transmission channel that connects to an adjoining optical transmission device synchronously with the adjoining optical transmission device. When the bandwidths are not continuous in the transmission channel, the bandwidth switching control unit controls the input interface unit, the cross-connecting unit and the output interface unit to rearrange the non-continuous bandwidths into continuous ones.
    Type: Application
    Filed: August 3, 2006
    Publication date: September 27, 2007
    Inventor: Nobuki Nakata
  • Patent number: 7272310
    Abstract: An architecture and method for performing coarse-grain reservation of lightpaths within wavelength-division-multiplexed (WDM) based photonic burst switched (PBS) networks with variable time slot provisioning. The method employs a generalized multi-protocol label switched (GMPLS)-based PBS label that includes information identifying each lightpath segment in a selected lightpath route. A resource reservation request is passed between nodes during a forward traversal of the route, wherein each node is queried to determine whether it has transmission resources (i.e., a route lightpath segment) available during a future timeframe. Soft reservations are made for each lightpath segment that is available using information contained in a corresponding label. If all lightpath segments for a selected route are available, the soft reservations turn into hard reservations. The stored reservations enable quick routing of control burst that are employed for routing data during scheduled use of the lightpaths.
    Type: Grant
    Filed: June 24, 2003
    Date of Patent: September 18, 2007
    Assignee: Intel Corporation
    Inventors: Christian Maciocco, Shlomo Ovadia
  • Patent number: 7266295
    Abstract: A modular reconfigurable multi-server system with hybrid optical and electrical switching fabrics for high-speed networking within a wavelength-division-multiplexed based photonic burst-switched (PBS) network with variable time slot provisioning. An optical high-speed I/O module within the multi-server system includes an optical switch with the control interface unit. A server module of the multi-server system statistically multiplexes IP packets and/or Ethernet frames to be transmitted over the PBS network, generate control and data bursts and schedule their transmission. Then, the server E-O converts the bursts, and then transmits the optical bursts to the optical I/O module. The optical I/O module then optically transmits the bursts to the next hop in the optical path after processing the optical control burst to configure the optical switch, which then optically switches the optical data burst without performing an O-E-O conversion.
    Type: Grant
    Filed: April 17, 2003
    Date of Patent: September 4, 2007
    Assignee: Intel Corporation
    Inventors: Shiomo Ovadia, Mario Paniccia, Kirk R. Hayden
  • Patent number: 7260329
    Abstract: Optical apparatus that uses optically-actuated optical switches in conjunction with an optical codeword addressing scheme to provide for time division multiplexing and demultiplexing of high data rate optical data. Optical codewords traveling simultaneously with the data on a separate wavelength, in conjunction with the optical switches, enable all-optical multiplexing and demultiplexing. The present invention can also switch packets of data while keeping the data entirely in the optical domain, and no optical to electrical conversions are necessary.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: August 21, 2007
    Assignee: Lockheed Martin Corporation
    Inventors: Thomas C. Fall, Ralph Spickermann, Daniel A. Tauber
  • Patent number: 7242867
    Abstract: A synchronization architecture for a cross connect switch having an ingress stage, a center stage, and an egress stage utilizes optical interfaces and media to distribute a system clock and frame sync to the I/O modules and switch fabric so that system can reassign the source/destination of the numerous STS-1 streams. A main synchronization module encodes the frame sync within the system clock. An optical interface converts the encoded sync signal to an optical sync signal which is sent over optical media to a secondary synchronization module which extracts the encoded frame sync from the optical sync signal and recovers the system clock. The system clock may be frequency multiplied or divided as necessary for distribution to the ingress and egress switch fabrics as well as the I/O modules. The sync reference may be externally provided or derived from an optical input data signal and forwarded to the main sync module using an optical pathway.
    Type: Grant
    Filed: October 31, 2002
    Date of Patent: July 10, 2007
    Assignee: CIENA Corporation
    Inventor: Michel Clouinard
  • Patent number: 7209658
    Abstract: The invention relates to a time division and wavelength division multiplex optical switching node for use in an optical communications network (2), which node combines a set of time division multiplex packets (8-1, 8-2, . . . , 8-i) into a wavelength division multiplex packet (18) to form a composite wavelength division multiplex packet, in particular by conferring on each time division multiplex packet (8-1, 8-2, . . . , 8-I) a respective appropriate multiplexing wavelength (?1, ?2, . . . , ?i), for example a wavelength specific to each time division multiplex packet. The invention has applications in high bit rate optical networks in particular, in which it offers versatility and transparent use of the different multiplexing modes.
    Type: Grant
    Filed: December 30, 2002
    Date of Patent: April 24, 2007
    Assignee: Alcatel
    Inventors: Denis Penninckx, Ludovic Noirie
  • Patent number: 7206509
    Abstract: A method and apparatus are disclosed for temporally shifting one or more packets using wavelength selective delays. The header information associated with each packet, together with a routing algorithm, routing topology information and internal OPTR state, is used to route each packet to the appropriate destination channel and to make timing decisions. A wavelength server generates optical control wavelengths in response to the timing decisions. A generated optical control wavelength is used to adjust the wavelength of a given packet tray and thereby introduce a wavelength selective delay to the packet tray to align packet trays or to shift one or more packet trays to avoid a collision. The wavelength of the packet tray is converted to a control wavelength corresponding to an identified delay, irrespective of the initial channel upon which the packet tray was received. At the output stage of the packet tray router, the packet tray wavelength can be converted to any desired output channel wavelength.
    Type: Grant
    Filed: November 29, 2002
    Date of Patent: April 17, 2007
    Assignee: Lucent Technologies Inc.
    Inventor: Marc J. Beacken
  • Patent number: 7177546
    Abstract: A system for time-dividing an optical signal is provided. The system time-divides a signal and reflects and/or refracts the signal using a time-dividing device to multiple receivers. By using time-division, the full signal is sent to each receiver designated to receive the signal during a certain time period. A cost effective and efficient system is provided by time-dividing the optical signal.
    Type: Grant
    Filed: December 12, 2001
    Date of Patent: February 13, 2007
    Assignee: Qwest Communications International Inc.
    Inventor: Thomas Schwengler
  • Patent number: 7164858
    Abstract: An optical transmission system is provided with a broadband optical transmitter including a broadband light source and a broadband optical modulator, an optical filter, an optical modulator, a transmission path, a wavelength router, and an optical receiver. The broadband optical transmitter outputs a broadband optical signal to the optical filter. The optical filter uses a branch wavelength bandwidth of the wavelength router as a basis for transmittance therethrough, and outputs only an applicable optical signal to the optical amplifier. The wavelength router simultaneously distributes the optical signal coming via the transmission path to each corresponding output port. In optical receivers, the optical signals penetrated through the wavelength router are converted into electrical signals.
    Type: Grant
    Filed: April 24, 2002
    Date of Patent: January 16, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toru Shiozaki, Masaru Fuse
  • Patent number: 7149432
    Abstract: Optical equalization across N (an integer, N>1) channels of a multi-channel link of a communications network, is accomplished by averaging effects of optical performance variations within each of the M (an integer, M>1) parallel data signals. At a transmitting end node of the link, each one of the M data signals are distributed across the N channels of the link. Thus a substantially equal portion of each data signal is conveyed through the link in each one of the N channels. At a receiving end node of the link, respective bit-streams received over the N channels to are processed recover the M data signals. As a result, bit error rates of the bit-streams received through each channel are averaged across the M data signals, all of which therefore have a substantially equal aggregate bit error rate.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: December 12, 2006
    Assignee: Nortel Networks Limited
    Inventors: Roland A. Smith, Kim B. Roberts
  • Patent number: 7149427
    Abstract: A micromirror array assembly (10, 20) for use in optical modules (5, 17) in a wireless network system is disclosed. The micromirror array assembly (10, 20) includes a plurality of mirrors (29) monolithically formed with a frame (43), attached by way of hinges (55) and gimbal portions (45). Permanent magnets (53) are attached to each of the gimbal portions (45) associated with the mirrors (29). The resulting frame (43) is then mounted to a coil driver assembly (50) so that coil drivers (34) can control the rotation of each mirror (29), under separate control from control circuitry (14, 24). The micromirror array assembly (10, 20) is thus able to support higher signal energy at larger spot sizes, and also enables multiplexed transmission and receipt, as well as sampling of the received beam for quality sensing.
    Type: Grant
    Filed: December 14, 2001
    Date of Patent: December 12, 2006
    Assignee: Texas Instruments Incorporated
    Inventors: Andrew S. Dewa, Robert C. Keller
  • Patent number: 7136587
    Abstract: A system and method for efficiently and effectively simulating hardware-in-the-loop testing of a wireless communications network. The system and method employs an optical matrix-vector multiplier (MVM) for performing optical signal processing to simulate radio frequency (RF) signal propagation characteristics in a mobile wireless communications network. Specifically, the system and method employs an optical modulator, which is adapted to modulate optical energy with signal energy, such as radio frequency (RF) signal energy, propagating from a first group of transceivers of the network to form a vector of optical signals. The optical matrix-vector multiplier (MVM) receives the vector of optical signals, and has a matrix of optical channel weights which are modifiable in accordance with desired parameters to represent at least on parameter of the wireless network. The optical MVM is further adapted to output signals based on the received vector of optical signals and the optical channel weights.
    Type: Grant
    Filed: November 15, 2001
    Date of Patent: November 14, 2006
    Assignee: MeshNetworks, Inc.
    Inventors: Dennis W. Davis, Phillip D. Neumiller
  • Patent number: 7133616
    Abstract: A wavelength-selective routing capability is provided in a single network element by configuring the network element using a combination of add/drop network elements to route individual optical channels of WDM signals among a plurality of optical transmission paths coupled to the network element. Any optical channel of any WDM signal received at the network element can be selectively added, dropped, or routed among the multiple optical transmission paths within and external to the node.
    Type: Grant
    Filed: September 1, 2001
    Date of Patent: November 7, 2006
    Assignee: Lucent Technologies Inc.
    Inventor: Carl A Caroli
  • Patent number: 7099587
    Abstract: A delayed optical signal is generated from an inputted optical signal by cyclically transmitting the inputted optical signal between at least two ends of an optical medium and outputting the inputted optical signal from one of the ends of the optical medium after at least one transmission cycle via the optical medium. Each transmission of the inputted optical signal in a direction via the optical medium is carried out over a wavelength resource that is different from a wavelength resource used in a preceding transmission of the inputted optical signal in a direction via the optical medium. Interference among repeated transmissions of the inputted optical signal via the optical medium is therefore minimized or even avoided. Related apparatus and method are also described.
    Type: Grant
    Filed: May 22, 2002
    Date of Patent: August 29, 2006
    Inventor: Doron Handelman
  • Patent number: 7088495
    Abstract: The present invention generally provides systems and methods for distribution of radiation among a plurality of optical channels, each of which can include a non-linear optical element. An optical system of the invention can include a source for generating radiation and an optical time-division multiplexer that can deflect, at any given time interval, the radiation into one of a plurality of optical channels.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: August 8, 2006
    Assignees: Sparta, Inc., Lumen Laboratories, Inc.
    Inventors: Pierre C. Trepagnier, Philip D. Henshaw, Robert F. Dillon
  • Patent number: 7068934
    Abstract: An optical interconnect comprises an input configured to receive light of a plurality of light wavelengths and a plurality of holographic optical elements. Each element configured to reflect one out of the plurality of light wavelengths and allowing others of the plurality of wavelengths to not be reflected. Each of a plurality of prisms is configured to rotate received light at a different angle than any of the other prisms. For each holographic optical element, one of the plurality of prisms is positioned to receive and rotate light reflected by that holographic element. Each of a plurality of beam splitters is positioned to receive light rotated by a respective one of the plurality of prisms and all the plurality of beam splitters direct light to an output of the optical interconnect.
    Type: Grant
    Filed: March 17, 2004
    Date of Patent: June 27, 2006
    Assignee: InterDigital-Technology Corporation
    Inventors: Emmanuel Kanterakis, Jian-Ming Wang
  • Patent number: 7068936
    Abstract: Methods and apparatus for providing a time slot switch which performs switching in the optical domain without the need for O-E-O conversion is described. The time slot switching device of the present invention may be part of a large switching device capable of performing switching and other function on WDM, TDM and WDM signals which are time division multiplexed. An optical time slot switch implemented using a time slot demultiplexer, optical cross-connect, variable delay lines and time slot multiplexer are described. Frequency conversion may be performed on a per time slot basis in cases where time slot signals are switched between lines using different wavelengths. Wave division demultiplexers and multiplexers can be added to the basic time slot switch to provide support for WDM switching and switching of TDM signals which are transmitted using wave division multiplexing.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: June 27, 2006
    Assignee: Agere Systems Inc.
    Inventors: Stanley Pau, Jianjun Yu, Keisuke Kojima, Naresh Chand
  • Patent number: 7054557
    Abstract: A technique for routing data within an optical network having a plurality of network nodes is disclosed. In one embodiment, the technique is realized by receiving data at a first network node via a first optical signal having a first wavelength. The first wavelength corresponds to a first optical frequency, and the first optical frequency is mapped to a first binary representation. The first binary representation is divided into a first plurality of fields, wherein at least one of the first plurality of fields corresponds to a routing label in a first label stack. A top routing label in the first label stack indicates a second network node. Based at least partially upon the top routing label, the data is transmitted from the first network node to the second network node via a second optical signal having a second wavelength. The first wavelength may be either the same as or different from the second wavelength.
    Type: Grant
    Filed: October 11, 2000
    Date of Patent: May 30, 2006
    Assignee: Nortel Networks Limited
    Inventors: Abel C. Dasylva, Delfin Y. Montuno, Yanhe Fan
  • Patent number: 7035542
    Abstract: The present invention propose to use an optical multiplexer associated with an optical clock as a wavelength converter. Each RZ coded tributary will be carried by a single wavelength (channel) passively interleaved with the others without interferometric interaction hence achieving a not necessarily perfect OTDM. This input data stream as optical data signal composed of different wavelengths is then launched on at least one data access of said optical multiplexer used as a wavelength converter. An optical clock at the desired bit-rate is launched on the probe access of said optical multiplexer synchronously to the multi-wavelength data stream. At the output, the initial clock wavelength is converted on data signal using the gain conversion property of the optical multiplexer. In such a way, a data stream of substantially higher bit-rate is obtained while due to a very precise synchronization a lost of data is minimized.
    Type: Grant
    Filed: February 8, 2002
    Date of Patent: April 25, 2006
    Assignee: Avanex Corporation
    Inventors: Patrick Brindel, Bruno Lavigne, Olivier Leclerc
  • Patent number: 7024118
    Abstract: An optical time-division multiplexer branches input light into a plurality of optical paths with different optical lengths. At least one path includes a section of optical fiber with an optical length that is adjustable by physical stretching. The input light is separately modulated on each optical path, and the modulated light signals are recombined into a multiplexed output light signal. Adjustment of the optical length of the optical fiber can compensate for changes in input wavelength and adjust the phase of successive pulses in the multiplexed output signal to provide a ?-radian shift that enables long-haul optical transmission.
    Type: Grant
    Filed: March 18, 2002
    Date of Patent: April 4, 2006
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Kozo Fujii
  • Patent number: 7024114
    Abstract: A photonic switching device for switching without contention data in the form of optical packets includes a space switching matrix with a plurality of input ports and a plurality of output ports. A unit external to the space switching matrix includes a buffer memory common to all the output ports of the matrix. Each of the output ports provides access to the buffer memory via a space switching stage consisting of switches having a 1-to-2 switching function.
    Type: Grant
    Filed: November 14, 2001
    Date of Patent: April 4, 2006
    Assignee: Alcatel
    Inventors: Emmanuel Dotaro, Nicolas Le Sauze
  • Patent number: 6961521
    Abstract: A method and apparatus for transmitting a bit interleaved optical data stream on an optical network is disclosed. In one embodiment, the network includes multiple transmitters that are enabled to transmit an optical bit during established time slots that correspond to each transmitter. This allows those transmitters to create a bit interleaved optical data stream.
    Type: Grant
    Filed: March 27, 2001
    Date of Patent: November 1, 2005
    Assignee: Turin Networks
    Inventor: Lawrence E. Foltzer
  • Patent number: 6961523
    Abstract: In an optical multiplexing interconnection module, first and second NRZ input signals synchronous by clock signal are inputted to its input section. The first NRZ input signal is converted to a first RZ signal according to a logical product with a clock signal CLK by a drive circuit and the second NRZ input signal is converted to a second RZ signal according to a logical product with an inversion clock signal by a drive circuit. Then, light emitting devices are driven according to the first and second RZ signals from these drive circuits and two optical signals from the light emitting devices are inputted to an optical channel and multiplexed therein and then, a multiplexed optical signal is transmitted through an optical channel.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: November 1, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hideto Furuyama
  • Patent number: 6959151
    Abstract: A node in an optical communications network receives optical packets at its input. It determines a priority assigned to each optical packet. When the optical packet is a transit packet destined for another node then, if the packet is determined to have a relatively higher priority, it is output from the node via a continuous-flow transmission path. Other transmit packets having relatively lower priorities are sent via an alternative transmission path that may include queues or buffers resulting in a variable delay.
    Type: Grant
    Filed: May 5, 2000
    Date of Patent: October 25, 2005
    Assignee: British Telecommunications public limited company
    Inventors: David Cotter, Julian K Lucek
  • Patent number: 6925220
    Abstract: A first multimode interferometer has a first input port to which an optical signal is applied, a first output port, and a second output port. A first optical waveguide is connected to the first output port of the first multimode interferometer. The first optical waveguide has a refractive index changed in response to a trigger signal externally applied. A second optical waveguide is connected to the second output port. A triggering unit supplies, to the first optical waveguide, the trigger signal for changing the refractive index of the first optical waveguide. An optical switch is provided which can increase the processing speed, can reduce the device size, and is free from dependency on the polarization state of an optical signal.
    Type: Grant
    Filed: January 13, 2004
    Date of Patent: August 2, 2005
    Assignee: Fujitsu Limited
    Inventor: Kohki Mukai
  • Patent number: 6826368
    Abstract: The present invention relates to an optical switching device for WDM systems based on multi-frequency lasers and optical couplers. A router/switch mapping of IP (or other protocols) subnets or addresses to an optical channel instead of a physical interface. Another embodiment of the invention implements the mapping directly at the source where the data transmission originates. The invention allows integration of WDM in the routers and switches, and ultimately in the information source. As a result, unnecessary opto-electrical conversion steps and physical interfaces are eliminated.
    Type: Grant
    Filed: October 20, 1998
    Date of Patent: November 30, 2004
    Assignee: Lucent Technologies Inc.
    Inventors: Uziel Koren, Francis R. Waldman
  • Patent number: 6804428
    Abstract: This invention provides a method and apparatus for spectral power monitoring by use of a polarization diversity scheme. In the present invention, a multi-wavelength optical signal is first decomposed into first and second polarization components, and the second polarization component is subsequently rotated by 90-degrees, prior to impinging onto a diffraction grating that provides a higher diffraction efficiency for the first polarization component. The diffraction grating separates the first and second polarization components by wavelength respectively into first and second sets of optical beams, impinging onto an array of optical power sensors. The inventive optical spectral power monitoring apparatus thus is able to minimize the insertion loss, while providing enhanced spectral resolution.
    Type: Grant
    Filed: December 14, 2001
    Date of Patent: October 12, 2004
    Assignee: Capella Photonics, Inc.
    Inventors: Mark H. Garrett, Jeffrey P. Wilde, Pavel G. Polynkin
  • Patent number: 6798992
    Abstract: A device and method for detecting rotational drift of mirror elements in a MEMS tilt mirror array used in an optical crossconnect. The optical crossconnect directs optical signals from an input fiber to an output fiber along an optical path by rotatably positioning mirror elements in desired positions. A monitoring device disposed outside of the optical path is used to obtain images of the MEMS array or to transmit and receive a test signal through the crossconnect for detecting the presence of mirror element drift.
    Type: Grant
    Filed: March 2, 2000
    Date of Patent: September 28, 2004
    Assignees: Agere Systems Inc., Lucent Technologies Inc.
    Inventors: David John Bishop, Randy Clinton Giles
  • Patent number: 6792208
    Abstract: One embodiment of the present invention provides a system that facilitates optical switching. The system starts by receiving a plurality of optical input signals. The system then divides each of the plurality of optical input signals into a plurality of wavebands that can be carried on a single optical fiber, wherein each waveband includes a predetermined subset of the wavelengths in the optical signal. Once the optical input signals have been divided into wavebands, the wavebands are then routed through a waveband switch. After being routed through the waveband switch, the wavebands are combined to form a plurality of optical output signals, where each optical output signal can possible include wavebands from different optical input signals. Additionally, some of the wavebands can be divided into wavelengths, and the wavelengths can be routed through a wavelength switch or a traffic grooming switch.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: September 14, 2004
    Assignee: The Regents of the University of California
    Inventors: Biswanath Mukherjee, Shun Yao
  • Patent number: 6788839
    Abstract: A fully “time tunable” all-optical switch routes/switches digital bits (packets) in an all-optical format for transmission, or for further processing, in an all-optical communication network. The all-optical switch is implemented in either a semiconductor hybrid or in a completely monolithic form. Variable time delay elements adjust the time delay of a clocking signal input and a data packet input. The clocking signal determines the state of two nonlinear optical elements, such as semiconductor optical amplifiers, incorporated in the upper and lower arms of a Mach-Zehnder configuration. An optical coupler is connected to the output of the all-optical switch. The output of data from selected ports of the optical coupler is controlled using the variable time delay elements.
    Type: Grant
    Filed: March 19, 2001
    Date of Patent: September 7, 2004
    Assignee: General Instrument Corporation
    Inventor: Kerry I. Litvin
  • Patent number: 6771908
    Abstract: An optical network has an optical splitter connected to (1) a working optical subscriber unit (OSU) of a working circuit, (2) a protection OSU of a protection circuit, and (3) one or more optical network terminals (ONTs), where an ONT has (i) a working line termination (LT) unit of the working circuit and connected to the optical splitter via a working optical fiber and (ii) a protection LT unit of the protection circuit and connected to the optical splitter via a protection optical fiber. The present invention enables fast protection switching from the working circuit to the protection circuit. The arrival times of corresponding downstream cells are measured at both the working and protection LT units of the ONT, and information related to the arrival times is transmitted from the ONT to the protection OSU.
    Type: Grant
    Filed: February 12, 2001
    Date of Patent: August 3, 2004
    Assignee: Lucent Technologies Inc.
    Inventors: Peter Van Eijk, Reed K. Even, Piet Van Heyningen, Song Jiang, Kyeong-Soo Kim, Woojune Kim, Fengkun Liu, Yong-Kwan Park
  • Patent number: 6760512
    Abstract: A programmable electro-optically controlled optical delay device providing multiple optical outputs. The optical delay device provides multiple output ports where the optical propagation delay increases at each port. An incident optical beam is propagated within electro-optically active material within the device, so that the propagation delay at each output port may be varied according to an applied voltage. In an optical beam steering system, the present invention provides true-time delay for multiple optical beams, allowing the beams radiated by the beam steering system to be time-coincident. The present invention provides for one or two dimensional beam steering.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: July 6, 2004
    Assignee: HRL Laboratories, LLC
    Inventor: David M. Pepper