92 results about "Burst switching" patented technology

A method and architecture for secure transmission of data within optical-switched networks. In one embodiment, the optical switched network comprises a photonic burst-switched (PBS) network. Under various schemes, security keys including encryption and decryption keys are generated by edge nodes and the decryption keys are distributed to other edge nodes in a PBS network. In one embodiment, the security keys are dynamically generated by a trusted platform module (TPM). A source edge node uses its encryption key to encrypt selected data bursts to be sent to a destination edge node via a virtual lightpath coupling the source and destination edge nodes. Security data are embedded in a control burst header indicates to the destination node whether corresponding data bursts sent via the virtual lightpath are encrypted. The security data also includes the decryption key and may also identify an encryption/decryption algorithm to be used. In some embodiments, public key infrastructure facilities are used in conjunction with employment of private and public keys and digital certificates.

The present invention relates to a switch mode power supply and a driving method for reducing switching loss and audible noise in the burst mode. The switch mode power supply includes a main switch, a power supply, an output unit, and a switch controller. The power supply includes a transformer having a primary coil connected to the main switch, and supplies power to a secondary coil of the transformer according to the operation of the main switch. The output unit is connected to the secondary coil of the transformer and outputs power supplied to the secondary coil of the transformer. The switch controller receives a feedback signal corresponding to the output voltage of the output unit, a sense signal corresponding to the current flowing to the main switch, and a sync signal corresponding to the voltage difference at the main switch, controls the on/off of the main switch, and determines whether to start the burst mode by using the feedback signal, and maintains the switching operation forcibly off period in the burst mode so that the reference frequency of burst switching may be less than a predetermined value.

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 extensions to the RSVP-TE signaling protocol, which uses various messages to reserve resources. A resource reservation request is passed between nodes during a downstream traversal of the lightpath route connecting a source node to a destination node via one or more switching nodes, wherein each node is queried to determine whether it has transmission resources (i.e., a lightpath segment) available during a future scheduled time period. 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, a reservation response message is sent back upstream along the route from the destination node to the source node. In response to receiving the response, the soft reservations are turned into hard reservations at each node.

A method and architecture for secure transmission of data within optical switched networks. In one embodiment, the optical switched network comprises a photonic burst-switched (PBS) network. Under various schemes, security keys are distributed to each edge node in a PBS network. A source edge node uses an encryption key to encrypt selected data bursts to be sent to a destination edge node via a virtual lightpath coupling the source and destination edge nodes. Security data are embedded in a control burst header indicates to the destination node whether corresponding data bursts sent via the virtual lightpath are encrypted. The security data may also identify an encryption/decryption algorithm and decryption keys to be used. Keys and/or certificates may be generated by or provided to the edge nodes. In some embodiments, public key infrastructure facilities are used in conjunction with employment of private and public keys and certificates.

A network (4) includes optical routers (19), which route information in fibers (10). Each fiber carries a plurality of data channels (16), carrying data in data bursts (28) and a control channel, carrying control information in burst header packets (32). A burst header packet includes routing information for an associated data burst (28) and precedes its associated data burst. Information on the data channels and control channel is organized in synchronized slots. Multiple burst header packets occupy portions of a slot, referred to as micro-slots. When the burst header packets are received, an egress processor (52) schedules the routing of their associated bursts. The egress processor (52) determines a time at which a data burst can be scheduled for passing through an optical matrix (40) to the desired output channel group (the burst can be delayed via fiber delay lines (46) if necessary).

At a master controller of a space switch in a node in a data network, a request is received from a source node that requests a connection to be established through the space switch. This request is compared to other such requests so that a schedule may be established for access to the space switch. The schedule is then sent to the source nodes as well as to a slave controller of the space switch. The source nodes send data bursts which are received at the space switch during a short guard time between successive reconfigurations of the space switch. Data bursts are received at the space switch at a precisely determined instant of time that ensures that the space switch has already reconfigured to provide requested paths for the individual bursts. The scheduling is pipelined and performed in a manner that attempts to reduce mismatch intervals of the occupancy states of input and output ports of the space switch. The method thus allows efficient utilization of the data network resources while ensuring virtually no data loss.

In a first mode of burst communication in a telecommunication network comprising electronic edge nodes interconnected by bufferless core nodes, data bursts are formulated at the edge nodes, respective burst descriptors are communicated to a controller of a core node, and burst-transfer schedules are sent from the core node to respective edge nodes. In a second mode, each burst-stream is allocated a flow rate and a core node determines burst sizes and schedules burst-transfer permits.

In a bimodal burst-switching network, an edge node selects to send to a core node burst-transfer requests according to the first mode, or flow-rate-allocation requests according to the second mode, depending on proximity, storage capacity at the edge node, and delay-tolerance specifications.

A switching power supply apparatus operates with less power consumption as a whole as a result of reduced power loss suffered while the switching operation of the main switching device is being stopped in burst switching control. Burst switching control is achieved by a signal level checker circuit 15 repeatedly turning on and off a switch circuit 17 provided in the line by way of which a switching controller circuit 19 is supplied with operating power. In burst switching control, when the switching operation of a main switching device 5 is being stopped, the supply of operating power to the switching controller circuit 19 is also stopped. This helps reduce the power loss suffered while the switching operation is being stopped, and thus helps reduce the power consumption of the apparatus as a whole.

Expanding the coverage of a time-shared network comprising electronic edge nodes interconnected by bufferless fast-switching optical nodes is enabled by combining spatial switching with temporal switching. The output side of each edge node preferably connects to a large number of core switches through individual time-locked channels and the input side preferably connects to each of a small number of core switches through a channel band having a sufficiently large number of channels. Wavelength routers may be used to aggregate individually-routed channels into WDM links.

In a wide-coverage network comprising electronic edge nodes interconnected by bufferless core nodes, where each edge node comprises a source node and a sink node, both sharing an edge-node controller and having means for data storage and managing data buffers, the transfer of bursts from source nodes to sink nodes via the core nodes requires precise time coordination to prevent contention at the bufferless core nodes. A core node preferably comprises a plurality of optical switches each of which may switch entire channels or individual bursts.

Each source node has a time counter and each core node has at least one time counter. All time counters have the same period and time-coordination can be realized through an exchange of time-counter readings between each source node and its adjacent core nodes. The time-counter readings are carried in-band, alongside payload data bursts destined to sink nodes, and each must be timed to arrive at a corresponding core node during a designated time interval. The difficulty of securing time-coordination arises from two interdependent requirements:

• • communicating a time-counter reading from a controller of a source node to a controller of a core node requires that the source node be time-locked to the core node, and
  • time-locking a source node to a core node necessitates that a controller of the core node be able to receive a time-counter reading from the source-node controller during a designated interval of time.

To initiate or restore time locking, a secondary mechanism is required for directing upstream signals received from source nodes toward said master controller. The present disclosure provides such mechanisms.

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.

An optical network, which includes edge and switching nodes, optically communicate information formatted into bursts that are included in one or more optical channel transport unit (OTU) frames that are based on ITU-T recommendation G.709. The overhead portion of the OTU frame can include all of the fields defined in the G.709 standard, except that the two reserved bits are used to define an OTU frame type. When the FEC function is not used, the OTU frame can be arbitrarily partitioned to carry optical burst information. The information can be either control and/or data bursts or metadata related to the optical network and/or optical burst flow. When the FEC function is used, the OTU frame is used to include optical control or data bursts or optical metadata in the payload portion of the G.709 OTU frame.

A hybrid processor system for use on board a telecommunications multi-beam satellite is provided that is controllable by a network control centre via one or more control channels. The system links to ground terminals by: providing uplink and downlink traffic channels on several satellite beams; routing atomic switched information blocks from the uplink traffic channels to the downlink traffic channels; and exchanging signaling data with the ground terminals on one or more uplink signaling channels and one or more downlink signaling channels. The atomic switched information blocks have the same given time duration and the same given baseband bandwidth. The hybrid processor system includes a burst switching processor and an on-board processor controller which is configured to store service information items indicative of: the given time duration and the given baseband bandwidth of the atomic switched information blocks; the respective uplink bandwidth, the respective uplink frequencies, a respective time length of the respective uplink time slots, and respective structure features of the respective uplink time frames and superframes of each uplink channel; the respective downlink bandwidth, the respective downlink frequencies, a respective time length of the respective downlink time slots, and respective structure features of the respective downlink time frames and superframes of each downlink channel; and quality of service and priority rules for serving the ground terminals. The on-board processor controller is further configured to extract, from incoming signaling data capacity requests sent by the ground terminals by demodulating and decoding the incoming signaling data.

A time-shared network comprising edge nodes and optical core nodes may be dynamically divided into several embedded networks, each of which covering selected edge nodes. At least one of the edge nodes may host an embedded-network controller operable to form multiple-source flow-rate allocation requests each of the requests specifying flow-rate allocations to a plurality of paths from several source nodes to several sink nodes. A core node may also host an embedded-network controller or several embedded-network controllers. The time-shared network may use both time-division multiplexing and burst switching.

Transmitting data in a ring network that transmits bursts and data packets. A path setup message is sent to request a data transmission between a source node and a destination node j through intermediate nodes connecting the source node and the destination node j. Each intermediate node determines that a connection to a next node along the path is available when the connection to the next node, that normally transmits bursts and data packets, transmits data packets. A current data transmission of data packets on the path is stopped when the entire path is determined to be available.

Control information associated with data bursts to be switched on a burst-switched router is transmitted using payload envelopes (100) on one or more control channels (16). A control channel scheduling module (86) defines sets of contiguous payload envelopes, referred to as “frontiers” (110). A frontier contains a predetermined number of payload envelopes that could be transmitted over a maximum time difference from the time of arrival of a control packet to a latest time of departure for the control packet. After selecting a control packet, a current frontier is determined from a current time and a frontier index. Scheduling information for the current and next frontiers is stored in memory (116). The memory is searched for an available gap to accommodate the control packet (144) in one of either the current set or a next frontier based on the scheduling information.

The invention relates to a packing and unpacking method of an ultra high-speed optical burst-switched network and a system thereof. The packing method comprises the following steps: 1) gathering an electric field IP data packet; 2) generating offset time after the gathered IP data packet is subject to route analysis, and forming an optical control packet; 3) modulating the IP data packet into an optical signal, and performing rate multiplication to the modulated optical signal to form an optical data packet; 4) forming a packet optical bursting packet by the optical control packet and the optical data packet, and transmitting the packet optical bursting packet. The invention provides the packing and unpacking method of ultra high-speed optical burst-switched network and the system thereof, which ensures that OBS network has high transmission rate, simple structure and low cost.

This invention discloses a method supporting the real-time operation in the luminous burst exchange, in the control scheme of the core node; allow two kinds of resource bespoke manners, as to the non real-time operation, still adopt the order manner of the present JET mechanism, that is to estimating establishment and estimating releasing manners. As to the real-time operation, adopt the extending manner of the JET mechanism, similar to the establishment and the releasing of displaying, adopt the estimating establishment to improve the efficiency of the luminous circuit, but send the information of display when releasing.

The invention provides a novel method to reduce the minimum offset time and pre-transmission delay for each data burst in Optical Burst Switching or Labeled Optical Burst Switching or other packet or burst switched systems. Under this method, the control packet is relayed as soon as it is determined if bandwidth for the data burst at the data burst output port(s) can be reserved successfully, greatly speeding up the setup and configuration of the Switching Element.

A laser power grid for operation with data networks employs WDM and incorporates wavelength addressing. The laser power grid (100) includes a laser power supply station (110) comprising a plurality of continuous-work laser sources (112, 114, 115, 116, 118), a laser distribution grid (130) for distributing light propagations of different wavelengths throughout a data network and an optical switching network (142, 144, 145, 146, 148) coupled to the laser distribution grid for locally turning the laser power on when it is needed. The laser power grid replaces systems of tunable lasers. It is considerably faster and cheaper than systems of tunable lasers and produces less waste heat within the data network surroundings. The laser power grid incorporates parallel fast optical communication in complex multi-node communication and computer networks and enables the implementation of burst switching and packet switching by wavelength addressing.