73 results about "Optical IP Switching" patented technology

An optical signaling header technique applicable to optical networks wherein packet routing information is embedded in the same channel or wavelength as the data payload so that both the header and data payload propagate through network elements with the same path and the associated delays. The header routing information has sufficiently different characteristics from the data payload so that the signaling header can be detected without being affected by the data payload, and that the signaling header can also be removed without affecting the data payload. The signal routing technique can overlaid onto the conventional network elements in a modular manner using two types of applique modules. The first type effects header encoding and decoding at the entry and exit points of the data payload into and out of the network; the second type effects header detection at each of the network elements.

An optical signaling header technique applicable to optical networks wherein packet routing information is embedded in the same channel or wavelength as the data payload so that both the header and data payload propagate through network elements with the same path and the associated delays. The header routing information has sufficiently different characteristics from the data payload so that the signaling header can be detected without being affected by the data payload, and that the signaling header can also be removed without affecting the data payload. The signal routing technique can overlaid onto the conventional network elements in a modular manner using two types of applique modules. The first type effects header encoding and decoding at the entry and exit points of the data payload into and out of the network; the second type effects header detection at each of the network elements.

The invention requests to protect a photoelectric hybrid conflict device and a method for conflict control and cache dispatching of optical grouping, and relates to the technical field of fiber-optical communication. Aiming at the defects of low cache utilization factor, huge volume and high cost in fiber-optical delay lines of the conventional optical switch, the invention adopts a technical scheme that: the fiber-optical delay lines are used as main sharing output cache, N output terminals share B limited fiber-optical delay lines, an electronic storage is used as a photoelectric hybrid cache structure for an assisted cache, and an output channel of conflict optical grouping is dispatched by an improved first-fit-void-filling algorithm. When the optical grouping fails to be dispatched to an output port, the shortest available FDL cache is searched first, and if the shortest available FDL cache is not found, the optical grouping is cached in the electronic storage; and when the output port is idle or the outputted FDL line is available, the stored grouping is dispatched to the output port. The method reduces the packet loss rate of the optical grouping and achieves the aim of improving the performance of optical switching.

Asynchronous optical data is aligned with synchronous convergence points in an optical packet switching system. The convergence points can be any place where data enters an optical packet switching element, buffer stage, switch fabric, etc. The arrival time for data approaching the convergence point is compared with a reference signal associated with the upcoming convergence point. The comparison is used to identify the amount of time-shift required to align the approaching data with the reference signal. Control information is derived according to the comparison and used to control an optical data aligner that synchronizes the data with the convergence point.

An optical packet switching apparatus includes an optical packet switching apparatus, an optical transmitting apparatus, and an optical packet receiving apparatus. The optical packet transmitting apparatus includes a packet generator for generating a packet signal by adding the routing information to a received client signal, a BIP adding unit for adding BIP to the generated packet signal, and an electrical-to-optical converter for converting the packet signal, to which the BIP has been added, into an optical packet signal so as to be sent out. The optical packet receiving apparatus includes an electrical-to-optical converter for converting the received optical packet signal into an electrical packet signal, and a BIP comparison unit for detecting the error occurrence in the packet signal, based on the BIP added to the packet signal.

An optical packet transmitter device includes: a detection unit for detecting packet-length information and priority information from a received Ether signal; a setting unit for setting, according to the degree of priority, a division factor by which the Ether signal is divided and a wavelength used for an optical packet signal to be transmitted; a header generation unit for generating a header containing destination information, the packet-length information, the priority information, and information of wavelength in use of the Ether signal; a transmission processing unit for dividing the Ether signal according to the set division factor and generating a plurality of packet signals; a header insertion unit for inserting the generated header in at least one packet signal; and an electrical/optical converter unit for converting the plurality of packet signals into optical packet signals of a plurality of wavelengths according to the set wavelength in use.

An optical network, having an optical communication link and first and second routers. The first router receives and classifies data, then forms a data burst based on destination. The first router sends an encrypted header and the data burst via the optical link. The second router, at least one hop from the first router, receives, decrypts and authenticates the header. Then, the second router extracts data burst information from the header and determines whether the address of the second router is the destination address for the data burst. If so, the second router receives the data burst and sends data to an appropriate line interface. If not, the second router selects and reserves a wavelength on a second optical link for the data burst. The second router selects an encryption key for the header, encrypts and sends the header, and then routes the data burst to the selected wavelength.

The invention discloses an optical fiber communication network monitoring protecting system and a method thereof. The optical fiber communication network monitoring protecting system comprises optical path transmission equipment and monitoring protecting equipment. The improvement of the optical fiber communication network monitoring protecting system is characterized in that the optical path transmission equipment comprises an optical switching unit; the optical switching unit monitors optical power data in real time, determines optical fault state and performs corresponding optical path switching; and a monitoring center receives monitoring data and information of an optical power acquiring unit and the optical switching unit and performs comprehensive analysis on the line state. The method comprises the steps of: A. performing real-time monitoring on the optical power by the optical power acquiring unit and the optical switching unit respectively, when a fault of the optical path occurs, finishing corresponding switching by the optical switching unit, and reporting the monitoring data and information to the monitoring center through a network; B. analyzing by the monitoring center for determining whether switching of the optical switching unit is correct, and then performing the following operations: B1, if switching is incorrect, transmitting an original state returning command by the monitoring center to the optical switching unit, and B2, if switching is correct, starting fault point testing for determining the geographical position of the fault point. The optical fiber communication network monitoring protecting system has high reliability and high stability.

An exemplary method and optical network that provide optical network restoration using refreshed state tables are disclosed. The exemplary method for recovering from a failure in an optical network using refreshed switch state tables includes generating and storing connection information in switch state tables of associated optical switches that define optical link connections to be made in the event of a failure, monitoring whether a failure has occurred, and refreshing the switch state tables by continuing to generate and store connection information in the plurality of switch state tables that are associated with the plurality of optical switches of the optical network until the failure in the optical network is detected. Once the failure is detected, optical switching is automatically performed in the optical switches based on the lookup table connection information in the switch state tables that are associated with the optical switches. The exemplary method may then include determining whether any of the telecommunications traffic in the optical links of the optical network was not restored due to the optical switching that was automatically performed.

An optical packet switching device is provided with: a first input unit and a second input unit for receiving an optical packet signal having destination information and priority information; a first demultiplexer and a second demultiplexer for branching the optical packet signal; an optical switch unit for routing one of branched optical packet signals; a first analyzer unit and a second analyzer unit for analyzing the header of the other branched optical packet signal so as to detect the destination information and the priority information; and an output competition determination unit for checking for temporal competition of a plurality of optical packet signals based on destination information and for determining whether the optical packet signals should be transmitted or discarded based on priority information when there is competition.

An optical packet switching system includes: an optical packet switching device configured to route and output an input optical packet signal; an optical amplifier device provided in a stage subsequent to the optical packet switching device; and a control signal generation unit configured to superimpose a noise component on the optical packet signal by inducing cross talk in the optical packet switch.

A method and apparatus are provided for low latency loss-free burst switching. Burst schedules are initiated by controllers of bufferless core nodes and distributed to respective edge nodes. In a composite-star network, the burst schedules are initiated by any of a plurality of bufferless core nodes and distributed to respective edge nodes. Burst formation takes place at source nodes and a burst size is determined according to an allocated bitrate of a burst stream to which the burst belongs. An allocated bitrate of a burst stream may be modified according to observed usage of scheduled bursts of a burst stream. A method of control-burst exchange between each of a plurality of edge nodes and each of a plurality of bufferless core nodes enables burst scheduling, time coordination, and loss-free burst switching. Both the payload bursts and control bursts are carried by optical channels connecting the edge nodes and the core nodes. A method and a circuit are provided for generating burst descriptors wherein each burst is associated with a burst stream and each burst stream is allocated a service bitrate. The generated burst descriptors are used in each master controller in each core node to create the burst schedules. In a conventional burst-scheduling process, the burst queues at a master controller of an optical switch receives burst descriptors from the source nodes and schedules the burst switching times. In a distinct departure, according to the present invention, the burst descriptors are generated by a master controller of an optical switch in a core node, the switching times of the corresponding bursts are scheduled, and the schedules are distributed to the respective edge nodes. The burst-descriptor generation is based on burst-stream bitrate-allocation defined by the source nodes.

The invention discloses an all-optical time slice switching method based on time synchronization. According to the method, continuous service data streams in an optical network are assembled to periodically-repeated optical time slices in a segmented mode in a time domain and are transferred in an asynchronous transfer mode. Network nodes obtain high precision synchronization time through whole network time, an optical switch is controlled to switch optical time slices reaching at precise time points periodically to a target port, and therefore full optical switching is completed. When a connection request reaches, available routes, wavelengths and occupation time slots are calculated through source nodes according to network available time slot resource information, and are reserved through a connection management module. After resource reservation is finished, the source nodes send out optical time slices of bearer service periodically at reserved time slots. Destination nodes restore received optical time slices to original service steams. Compared with an existing switching technology, the all-optical time slice switching method has the remarkable advantages that reliable and flexible sub-wavelength granularity all-optical switching can be achieved without participation of all-optical caches and all-optical logic devices.

An optical communication system and method for use in communicating data between nodes using wavelength division multiplexing includes an optical backbone to provide an optical pathway between the nodes. Arbitration information on a dedicated arbitration wavelength transmitted during an arbitration cycle is used by the plurality of nodes to select one of a plurality of wavelengths at which to transmit data during a subsequent data cycle.

The invention discloses an optical flow switching network scheduling method and an optical flow switching system. Each node in the system is mainly composed of an IP switch and an optical cross connection module. Each IP switch is provided with an optical flow switching module. The optical flow switching module comprises a virtual output queue and a link-wavelength-time resource table, source routing table, a scheduling module, a control packet transceiver module, an electronic/optical conversion module, a switching control module and a clock module. At the same time of transmitting optical data stream, the source node requests to start optical path reservation in advance for optical data stream in virtual output queue, detects the availability of optical paths corresponding to multiple destination nodes, combines queue head request priority and optical data stream transmission time, finds out the earliest available optical paths and reserves a time period for the optical paths. The invention has the following beneficial effects: 1, centralized scheduling nodes are not needed in the network, each node executes distributed scheduling, and the computational complexity is low; 2, thatoptical path schedule calculation and the data transmission are carried out simultaneously, the head time of the data transmission is shorten, the network throughput is improved, the average waitingtime of the queue is reduced, and the bandwidth utilization ratio is optimized; 3, adding time dimension to the scheduling allocation of link wavelength resources, which can improve the performance ofthe algorithm; 4, that device can be deploy based on the exist network equipment, and the application conditions are ripe.

The invention provides an optical switch which is small in size, low in cost and large in number of light input/output ports. An optical switch (10) includes light input/output ports (1,2), each having a port group (110,120) of inputting/outputting a light, an optical path manipulation unit (5) having optical path switching units (5a,5b,5c) of switching an optical path of a light from an input port in the port group to an optical path toward an output port in the same port group according to each of the light input/output ports, and a condenser lens (6) condensing light from the light input/output ports on the optical path switching units corresponding to the port groups and optically-couples the light input/output ports with the optical path manipulation unit. The input/output optical paths of the light input/output ports with respect to the condenser lens are parallel to each other between the ports in the same port group and are unparallel to each other between the ports in the different port groups as seen from a direction perpendicular to a port arrangement direction.

The present invention relates to a stack type fully optical buffer, and belongs to the field of fully optical packet switching. The buffer is characterized by consisting of a plurality of cascading light guide units; the downlink output end of the light guide unit of each level is orderly connected with the downlink input end of lower level, so as to form a downlink channel; the uplink input end of each level is orderly connected with the uplink input end of higher level, so as to form an uplink channel. The data packet which is transmitted into the light guide unit of each level is controlled by a control end for uplink transmission or downlink transmission. The i-level downlink output end is connected with the control end of the level of i plus 2, so as to prevent the levels of i and i plus 2 from simultaneously transmitting the data to the level of i plus 1. When two data packets arrive to the buffer simultaneously, the data packet of higher priority is directly transmitted outwards, and the data packet of lower priority is stored in the buffer; and the storage depth of the original data packet in the buffer is deepened by one level. The fully optical buffer has the first-in but last-out, and last-in but first-out characteristics, the capability of simultaneously processing two data packets, and the advantages of easy expansion of the storage capacity, no requirement for additional control signals, and so on.

An optical packet switching system includes a plurality of network elements for transmitting and receiving optical packet signals. Each network element includes an optical signal-to-noise ratio (OSNR) acquiring unit for acquiring the OSNR of each optical packet signal, an average value calculating unit for calculating the average value of the OSNRs of optical packet signals received within a predetermined time duration for each of the plurality of source network elements, and a difference information transmitter for calculating the difference between the calculated average value of the OSNRs and a target value of the OSNRs and then transmitting the difference to a network element corresponding to the difference. A source network element that has received the difference information adjusts the characteristics of an optical packet signal to be transmitted in a manner such that the difference is reduced.