Abstract: Hardware-enforced zoning is provided in Fibre Channel switches to protect against breaching of assigned zones in a switch network which can occur with software-based zoning techniques. The invention provides logic for performing a hardware-based validation of the Source ID S_ID of frames both at the point where the frame enters the Fibre Channel fabric, and at the point where the frame leaves the fabric. The S_ID is verified against an inclusion list or table of allowable S_IDs, which can be unique for each fabric port. The invention provides a way to increase the range of sources an inclusion table can express, by implementing wild cards, on an entry-by entry basis. If the S_ID is valid, it will enter the fabric and route normally. If invalid, the frame will not be routed but will be disposed of by the fabric according to FC rules.

Abstract: A method and apparatus for transport encoded asset data and content data, multiplexing the transport encoded content data with a plurality of NULL transport packets to provide “place holder” for the asset data transport packets, and replacing the NULL transport packets with asset data transport packets prior to transmitting the multiplexed transport stream to a set top box.

Abstract: A method and system for labeling data in a networked environment. The method and system comprise determining if a label should be added to a portion of data having an associated first header. If so, a second header is constructed containing a label. The second header is indicated in a reference in the first header. The label contains at least one attribute of the data. The second header is attached to the first header. The portion of data is then transmitted, along with the headers. In one embodiment, the second header may contain credential information related to the data portion.

Abstract: The invention relates to a packet switching device with a plurality of input and output ports and at least one switching unit (3 to 5) comprising a coupling matrix and an arbiter unit (9) for controlling the coupling matrix (8), wherein the arbiter unit is designed for generating a state matrix (11) whose lines each correspond to an input port and whose columns each correspond to an output port, said state matrix comprises elements which each represent a weighting for an interconnection between an input port and an output port of the packet switching device, and said arbiter unit (9) is designed for forming a first decision matrix consisting of several accepted interrelationships on the basis of an algorithm which is operative in parallel on several groups (12 and 14) of columns of the state matrix.

Abstract: The disclosure includes description of techniques for processing a network packet received at a network device. An example of the technique includes, in a first path, performing packet processing phases upon the network packet and storing state data for the phase phases. A second path can access the state data stored by the first path and determine a phase to perform next.

Abstract: In one embodiment, a method for efficiently classifying packets for a multi-processor/mutli-thread environment is provided. The method initiates with receiving a packet. Then, header information is extracted form the received packet. Next, a first hash value is calculated. Then, a field of interest in a lookup table is determined from the first hash value. Next, a second hash value is calculated. Then, the second hash value is compared to stored hash values in the field of interest of the lookup table to determine a match between the second hash value and one of the values in the field of interest of the lookup table. If there is a match, the received packet is transmitted to a processor corresponding to the one of the values in the row location of the lookup table. A network interface card and a system for efficiently classifying packets in a multicore/multithread environment are also provided.

Abstract: The present invention describes a system and method of improving packet forwarding throughput in a router by reducing head of line blocking. In one embodiment of the present invention, incoming packets are stored in a packet reorder buffer. The packets are reordered for forwarding while maintaining the order of packets in a distinct flow. Packets belonging to a distinct flow require to be forwarded in the order that the router receives them. Packets from different flows are reordered such that their forwarding order can be different than the order in which they were received. Packets from the same flow are sent out in the same order as the router receives them.

Abstract: Variable-length packets transmitted over a serial link do not have packet-start fields or unique symbols to mark the beginning of each packet. Instead, a length field indicates the packet's length, allowing the end of the packet to be located. Packets also do not have sequence numbers. When an error is detected, the receiver sends a control symbol over a reverse channel to signal the transmitter. The control symbol never occurs in a normal packet. Packet buffers in the transmitter and receiver have read and write pointers and also have de-allocation pointers that are synchronized between receiver and transmitter. As packets are error checked, the receiver advances its de-allocation pointer and updates the transmitter's de-allocation pointer, allowing the packets to be discarded from the transmitter's buffer only after the receiver finishes error checking. The transmitter re-transmits packets from its buffer starting from the de-allocation pointer when its receives the control symbol.

Abstract: A method is disclosed for transmitting data packets in wide area networks (WAN) by way of a synchronous digital data transmission network (SDH), wherein the data packets are packed into synchronous transport modules (STM-N) and are transmitted by way of virtual connections formed by subunits of synchronous transport modules of the same size. The virtual connections are entered into an address table and an evaluation of the target address of the data packets takes place in one of the network elements of the synchronous digital data transmission network. On the basis of the address table and the target address, at least for a part of the data packets, a decision is made by at least one of the network elements of the synchronous digital data transmission network as to which one of the virtual connections is used to transmit this data packet. Furthermore, a network element is disclosed, which operates in accordance with the transmission method.

Abstract: A method for enabling multi-tuple TCP sockets within a computer network is disclosed. All possible connection paths between a first computer and a second computer are initially determined. Then, tuple information of all the possible connection paths are stored in a respective socket of the first and second computers as multi-tuple information. Next, one of the possible connection paths is designated as a preferred path and the remaining possible connection paths are designated as alternate paths. Finally, data packets are transmitted via the preferred path after a TCP connection has been established between the first and second computers on the preferred path.

Abstract: Methods and apparatus are provided for converting video packets into IP packets. Video packets including null packets associated with timing information are received at a network entity coupling a video network to an IP network. Video packets are selectively combined into IP packets to allow transmission of video data onto the IP network in an efficient and effective manner. Null packets used to maintain timing information in the video network are removed. Mechanisms are provided for maintaining timing information even without transmitting extraneous packets.

Abstract: A translator for coupling a first network such as an internet protocol version 4 (IPv4) and a second network such as an internet protocol version 6 (IPv6) having different addressing architectures for IP addresses due to a difference in version or the like so as not to exhaust the IP addresses of one of the two networks, a network system using the translator, and a network coupling method therefor are provided. When a packet is transferred from the IPv6 network to the IPv4 network, the translator assigns any of a plurality of previously prepared IPv4 addresses to an IPv6 address stored in a source storing field of the IPv6 packet. The assigned address is stored in a source storing field of an IPv4 packet. A packet translation unit is provided for assigning the foregoing IPv6 address to an IPv4 address stored in a destination storing field of the IPv4 packet, when a packet is transferred from the IPv4 network to the IPv6 network, and for storing this address in a destination storing field of the IPv6 packet.

Abstract: A circuit arrangement and method for interfacing a node and a data fabric. In a computing arrangement that includes a plurality of nodes intercoupled by the data fabric, each node is assigned to one of a plurality of partitions. A node-interface circuit is configured to interface with the source node, and a translation circuit translates data between a first format compatible with the nodes and a second format compatible with the data fabric. An access control circuit either enables or disables transmission of data from the source node based on whether the source and destination nodes are in the same partition.

Abstract: A method, apparatus, and article of manufacture for retaining packet order in multiprocessor systems utilizing multiple transmit queues while minimizing spinlocks are disclosed herein. Embodiments of the present invention define multiple transmit queues for a given priority level of packets to allow parallel processing and queuing of packets having equal priority in different transmit queues. Queuing packets of equal priority in different transmit queues minimizes processor time spent attempting to acquire queue-specific resources associated with one particular transmit queue. In addition, embodiments of the present invention provide an assignment mechanism to maximize utilization of the multiple transmit queues by queuing packets corresponding to each transmit request in a next available transmit queue defined for a given priority level. Coordination between hardware and software allows the order of the queued packets to be maintained in the transmission process.

Abstract: A system and method of scheduling packets in a multi-threaded, multiprocessor network architecture provides enhanced speed and performance. The architecture involves a scheduler thread that transitions between queues in response to a depletion of queues by a weighted amount, a plurality of transmit threads that deplete the queues by the size of packets transmitted and a plurality of receive threads that initialize the weights for idle queues.

Abstract: A method, apparatus, and computer program product are provided for implementing packet ordering in a network processor. Packets are received and placed on a receive queue and a queue entry is provided for each received packet. The queue entry includes for each autoroute packet, an autoroute indication and a selected transmit queue. An associated ordering queue is provided with the receive queue. A software-handled packet is dequeued from the receive queue and the dequeued software-handled packet is placed on the ordering queue. Each autoroute packet reaching a head of the receive queue is automatically moved to the selected ordering queue.

Abstract: In one embodiment of the present invention, a system for memory interleaving in a high-speed switching environment includes multiple memory units that each include one or more memory devices. The system also includes multiple port modules. Each port module can receive a packet communicated from a component of a communications network, write the received packet to one or more of the memory units, and read a packet from one or more of the memory units for communication to the component of the communications network. The system also includes an interconnection network including a hierarchical structure that includes one or more switching stages.

Abstract: The present invention permits an I/O port to be used with a variety of different I/O devices, regardless of their device type implementation, such as tri-state I/O devices, pull-up I/O devices, or pull-down I/O devices. Thus, one set of pins may be used for various different I/O devices.

Abstract: The invention concerns the transmission of data packets in multicast mode, in which method the packets are sent from a sending end of a physical transmission medium and received by terminals at a receiving end of said medium. It finds a typical application in networks whose terminals cannot listen to each other, which is the case in satellite networks, for example, whereas management implies sending a query message to the terminals in order to determine the presence of an active group of terminals as a function of the reception of a response message from a terminal of said group. A signal is then sent to the terminals from the sending end, preferably the returned response, to indicate reception of a response message from a terminal of the group of terminals, so that terminals that have not sent a response message can act accordingly, in particular by interrupting their own process for sending a response.

Abstract: A signal processing apparatus receives a time divisional multiplexed signal including a plurality of kinds of data. The signal processing apparatus includes a processing unit for processing plural kinds of operations corresponding to the data of the time divisional multiplexed signal, and a changing unit for changing the operation of the processing unit to one of the operations, corresponding to the data at the timing of the transit of the data.

Abstract: A method and system reduce interference between overlapping first and second wireless LAN cells contending for the same medium. Each cell includes a respective plurality of member stations. An inter-cell contention-free period value is assigned to a first access point station in the first cell, associated with an accessing order in the medium for member stations in the first and second cells. The access point in the first cell transmits an initial shield packet to deter other stations from contending for the medium. The access point then transmits a beacon packet containing the inter-cell contention-free period value to member stations in the second cell. A second access point in the second cell can then delay transmissions by member stations in the second cell until after the inter-cell contention-free period expires.

Abstract: A method of bandwidth management enabling to insure a guaranteed bandwidth to each station of transmission network comprising a plurality of stations (10, 12, 14) forming a logical ring wherein a token frame is circulating from station to station, each station being allowed to transmit a credit (c) of data bytes upon reception of the token frame wherein the credit is increased in proportion to a variable TRTT standing for Token Round Trip Time which is the time taken for the token frame to circulate around the logical ring since the preceding reception of the token frame by the station. The credit is increased in proportion of a variable CIR standing for Committed Information Rate which is the guaranteed transmission rate that the station can use to transmit data wherein the value of CIR is determined by a class of bandwidth which has been previously selected by the station upon the preceding reception of the token frame by the station.

Abstract: A circuit and method for demultiplexing in a receiver a digital data stream including at least two types of data. In one particular application, such a receiver is used in a television system having a digital set-top-box receiver. A first control circuit extracts a packet identifier from an input data packet in the digital data stream, and generates a signal in dependence on whether the input data packet is of the first or second type. Sets of information associated with the first types of data packets and required by the receiver are stored in a memory under the control of a second control circuit. A third control circuit, responsive to receipt of the first type of input data packet, determines whether at least part of the input data packet matches the stored sets of information, and sets a match signal responsive thereto.

Abstract: A system and method for converting code associated with synchronous method calls to code that can be employed to perform asynchronous method calls and for supporting such asynchronous method calls is provided. The system includes a pattern generator that can break code for a synchronous method call into one or more constituent parts including a begin asynchronous operation method, an end asynchronous operation method, an asynchronous call state object and an asynchronous call result object. The system includes a pattern data store that holds data associated with converting a synchronous method call to an asynchronous method call, which facilitates employing the system consistently across environments like file input/output, stream input/output, socket input/output, networking, remoting channels, proxies, web forms, web services and messaging message queues.

Abstract: In a wireless communication network having a plurality of devices operating at different data rates that contend for access to the network, a method is provided that assigns network access parameters to one or more of the devices so as to control throughput on the network. Examples of network access control parameters are the maximum data packet size and the contention window size. Generally, the network access control parameter for slower data rate users is configured so that they do not occupy the network a disproportionate amount of time compared to faster data rate users.

Abstract: Access to a variable rate multiple access system is controlled based upon a current loading. The current loading level is used to determine a transmission rate set point. The transmission rate set point may include a maximum transmission rate and a transmission probability. The transmission rate set point is passed to the remote unit which may access the system. A remote unit with data to send determines a desired transmission data rate. If the desire transmission data rate is equal to or greater than the maximum transmission data rate, the remote unit transmits at the maximum transmission data rate with a probability equal to the transmission probability.

Abstract: A radio apparatus and base station apparatus that flexibly respond to an increase or decrease in the number of users without being constrained by the number of users. An A-DPCH signal processing section (106) generates dedicated transmission signals corresponding in number to users multiplexed based on the number of users for each sector input from a control station apparatus and outputs the multiplexed signal to a multiplexing section (105). An HSDPA signal processing section (107) selects a transmission destination sector based on an instruction from a base station control section, generates multiplexed transmission data and outputs the multiplexed data to the multiplexing section (105). The multiplexing section (105) code-multiplexes dedicated transmission signals of A-DPCH and packet data in HSDPA communication for each sector and outputs the multiplexed data to a radio transmission section (104).

Abstract: In a data transmission method for information data containing additional information data therewith, comprising, at a transmitter side, following steps: adding error correction codes for correcting error to said additional information data; embedding said additional information data added with said error correction codes into the information data by plural times, repetitively; and transmitting the information data embedded with the repetitive additional information data therein, and comprising, at a receiver side, following steps: receiving the transmitted information data embedded with the repetitive additional information data therein; detecting the repetitive additional information data embedded from said transmitted information data received; determining said additional information data on a basis of a majority rule when receiving said information data; and correcting error with using the error correction codes received and determined when said additional information data contains error(s) therein.

Abstract: An improved monoblock laser cavity is made by elongating the Optical parametric oscillation (OPO) cavity. This can be accomplished by changing the coatings on the OPO material and Q-switch and by elongating the OPO cavity to approximately 2 to 3 times the OPO crystal length. The increase in the length of the OPO cavity will improve the beam divergence of the laser.

Abstract: Directing an input light beam into a laser diode operated at a power below that required for lasing stimulates emissions, resulting in an amplified output beam. A dynamic steering system can focus the input beam onto front face of the laser diode. The steering system optionally includes an optical element mounted solely on piezoelectric actuators. Control signals for the actuators in the steering system control a base position and cause alternating movements of the optical element. A detector measuring optical power leaking from a back face of the laser diode can determine the power of the amplified beam that exits from the front face, and derivatives of the measured power with respect to the alternating movements indicate required adjustments of the base position. A polarizing beam splitter and quarter-wave plate in the path of beams can separate the input and amplified beams.

Abstract: A laser driver. The laser driver comprises a diode driver, a power detector, a first extreme detector, a second extreme detector and a current controller. The diode driver receives bias and modulation currents to control a laser diode for generating light signals. The power detector detects optical power of the light signals. The first and second extreme detectors, both coupled to the power detector, detect the first and second extreme values among detected optical power. The first extreme value is either the maximum or the minimum optical power of the light signals, while the second extreme value is the other.

Abstract: The present invention provides methods and apparatus for flexible and reproducible control of quantum cascade laser frequency scans having short (nanosecond) pulse excitations. In accordance with a preferred embodiment of the invention, a method of digital frequency control for pulsed quantum cascade lasers includes digitally synthesizing a sub-threshold current, converting the sub-threshold current to analog form, and generating laser pulses. Preferably, the sub-threshold current is synchronized to the laser pulses.

Abstract: This semiconductor laser device has the same structure as the conventional broad-area type semiconductor laser device, except that both side regions of light emission areas of active and clad layers are two-dimensional-photonic-crystallized. The two-dimensional photonic crystal formed on both side regions of the light emission area is the crystal having the property that 780 nm laser light cannot be wave-guided in a resonator direction parallel to a striped ridge within the region. The light traveling in the direction can exist only in the light emission area sandwiched between two photonic crystal regions, which results in the light laterally confined by the photonic crystal region. The optical confinement of the region suppresses the loss in the light at both edges of the stripe serving as the boundary of the optical confinement, which reduces the curve of wave surface and uniforms the light intensity distributions of NFP and FFP.

Abstract: A laser beam generating unit has a semiconductor laser unit having a plurality of beam emitting portions located in the shape of a matrix, and a plurality of optical fibers for individually transmitting laser beam emitted from the beam emitting portions. An optical fiber bundle is formed by binding a plurality of the optical fibers on a side where laser beam emits, and laser beam is emitted through a taper adaptor provided on the side where laser beam emits. Then, laser beam can be transmitted by the optical fibers at a good condition, and can be collected by a beam transmitting path of the adaptor having the thinner diameter with high efficiency and the power density can be raised.

Abstract: A microcavity structure includes a first waveguide that includes a first photonic crystal microcavity. A second waveguide includes a second photonic crystal microcavity. A microcavity active region is created by overlapping the first and second microcavities.

Abstract: There are provided a bi-directional transceiver module and a method for driving the same. The bi-directional transceiver module includes a 1.3 ?m Distributed Bragg Reflection Laser Diode (DBR LD) including an active layer which performs light-emission in response to a light at 1.3 ?m and a DBR mirror formed near the active layer. The DBR mirror is formed to prevent an upstream signal emerging from the 1.3 ?m DBR LD from being deleted by a PD. A monitoring PD and a PD for detecting an optical signal are integrated and mounted behind the DBR mirror using a butt-joint method. The 1.3 ?m DBR LD, the monitoring PD, and the PD for detecting the optical signal are electrically isolated by insulated areas. To drive the bi-directional transceiver module, a forward bias (+) is applied to a p-electrode formed on the 1.3 ?m DBR LD, a backward bias (?) is applied to p-electrodes formed on the monitoring PD and the PD for detecting the optical signal, and a n-electrode as a common electrode is grounded.

Abstract: Apparatus and methods for altering one or more spectral, spatial, or temporal characteristics of a light-emitting device are disclosed. Generally, such apparatus may include a volume Bragg grating (VBG) element that receives input light generated by a light-emitting device, conditions one or more characteristics of the input light, and causes the light-emitting device to generate light having the one or more characteristics of the conditioned light.

Abstract: Apparatus and methods for altering one or more spectral, spatial, or temporal characteristics of a light-emitting device are disclosed. Generally, such apparatus may include a volume Bragg grating (VBG) element that receives input light generated by a light-emitting device, conditions one or more characteristics of the input light, and causes the light-emitting device to generate light having the one or more characteristics of the conditioned light.

Abstract: In a rake receiver, a correlation-value calculation section calculates correlation values between spreading codes and reception signals from an input terminal and outputs the calculated correlation values to a delayed-profile creation section and a difference-history creation section. The delayed-profile creation section determines average correlation values and issues the values as a delayed profile to a path selection section. For each reception timing, the difference-history creation section compares the latest correlation value with a previous correlation value held by the difference-history creation section, to determine a difference history, and issues the difference history to the path selection section. The path selection section rearranges the delayed profile in decreasing order of the average correlation values.

Abstract: The invention relates to a system for transmitting data according to the frequency hopping method. The digital data, which is transmitted in suddenly changing transmission frequency hops, is encoded according to a woven code consisting of an interlinked external and internal convolution code. The data to be transmitted by hop is preferably distributed over several parallel hops sent with different frequencies.

Abstract: According to the invention, the method comprises the steps of calculating and evaluating the auto-correlation functions and/or cross-correlation functions of N possible secondary synchronization codes (SSC) and the primary synchronization code (PSC) and choosing the M secondary synchronization codes (SSC) amongst said N possible secondary synchronization codes (SSC) so that said the M chosen secondary synchronization codes (SSC) have at least one of the statistical properties of their auto-correlation function and cross-correlation function that is best in term of detection, and allocating a sub-set of said M secondary synchronization codes (SSC) comprising K secondary synchronization codes (SSC) to said base station.

Abstract: A low-power receiver architecture of use in direct sequence spread spectrum communications system receivers, such as in a code division multiple access system, is provided. The receiver employs analog correlation, wherein its analog-digital, converters are able to operate at the system symbol rate, and the requirement for finite impulse response filters is obviated. The low-power receiver architecture is also applicable as a front-end structure for multiple-mode receivers.

Abstract: The invention provides methods and apparatus for multiple user detection (MUD) processing that have application, for example, in improving the capacity CDMA and other wireless base stations. One aspect of the invention provides a multiprocessor, multiuser detection system for detecting user transmitted symbols in CDMA short-code spectrum waveforms. A first processing element generates a matrix (hereinafter, “gamma matrix”) that represents a correlation between a short-code associated with one user and those associated with one or more other users. A set of second processing elements generates, e.g., from the gamma matrix, a matrix (hereinafter, “R-matrix”) that represents cross-correlations among user waveforms based on their amplitudes and time lags. A third processing element produces estimates of the user transmitted symbols as a function of the R-matrix.

Abstract: Systems and techniques are disclosed relating to communications. The systems and techniques involve the synchronizing to a signal having a plurality of bits by computing energy for a plurality of different phase offset signal portions, generating a ratio from the signal portion with the highest computed energy and the signal portion with the second highest computed energy, and comparing the ratio to a threshold to determine whether the signal portion with the highest computed energy can be used to determine bit timing.

Abstract: A transceiver includes a switching unit configurable for isolating an input of a receiver from an output of a transmitter during a local calibration mode. A known signal present at the output at a first power level during the calibration mode will also be present at the input at a second power level lower than the first power level and will be converted by the quadrature demodulator. A compensation factor is estimated for compensating the receiver section for imbalances in the in-phase and quadrature phase signals resulting from conversion of the known signal. Remote calibration is implemented using a method for remotely compensating for I-Q imbalance wherein a data packet having a known signal is transmitted to a receiver for conversion by a quadrature demodulator and compensation factors are estimated for compensating for imbalances in the in-phase and quadrature phase signals resulting from conversion of the known signal.

Abstract: A single subscriber line multi-point communication system is disclosed. In general, the multi-point communication system can include a first transceiver coupled to a subscriber line capable of transmitting and receiving at least two modulation methods, either of said modulation methods being operable to transmit a test signal, and a second transceiver coupled to said subscriber line capable of transmitting and receiving said at least two modulation methods, the second transceiver being operable to receive the test signal and determine at least one channel parameter from the test signal. A master transceiver that can be used in various embodiments of a single subscriber line multi-point communication system, and a tributary transceiver are further disclosed.

Abstract: A link quality estimating method and apparatus adopts a fading value to modify an estimated link quality of a channel thereby obtaining a measure being very close to the real link quality. The method is implemented by utilizing two sequentially received long training symbols to derive two sets of subcarrier gain values Hk,1 and Hk,2. Based on the subcarrier gain values Hk,1 and Hk,2, parameters representing the estimated channel gain value (A), the fading value (F) and the noise quantity (B) of the channel are all calculable. With these parameters, the link quality (LQ) of said communication channel is derived.

Abstract: A system includes a sampling circuit, an analog filter, an analog input, a modulator, and a modulating source. The modulating source includes an output that generates an impulse response encoded as a sigma-delta sequence. The output of the modulating source is coupled to the modulator, which is coupled to the analog input. The analog filter is coupled to the modulator and the sampling circuit. When the system is configured as a filter, an analog signal is modulated with the sigma-delta sequence. The modulated signal is filtered and then sampled.

Abstract: A method for reducing a propagation delay of a digital filter. The digital filter has an input path and an output path and includes a set of delay elements and a number of taps. The taps couples the input path to the output path. Each of the taps includes a coefficient, a multiplier and an adder. Each of the delay elements is disposed between two adjacent taps. The delay elements are placed in both the input path and the output path of the digital filter, such that the digital filter has fewer delay elements in the input path than a direct-form digital filter having the same number of taps in a direct-form structure and has fewer delay elements in the output path than a transposed-form digital filter having the same number of taps in a transposed-form structure, and such that the digital filter has same transfer function as the direct-form digital filter and the transposed-form digital filter.

Abstract: The invention relates to an LMS-based asynchronous receiver for digital transmission and recording systems. The receiver comprises a digital adaptive equalizer (EQ) for receiving a received sequence rn and for delivering an equalized sequence yn. The equalizer (EQ) operates at the sampling rate 1/Ts, asynchronous to the data rate 1/T. An equalizer adaptation method using LMS techniques is described for adapting equalizer taps asynchronously to the data rate via a control loop. A first sampling rate converter (SRC1) performs timing recovery at the data rate 1/T after equalization on the equalized sequence yn. A second sampling rate converter (SRC2) is provided for converting a delayed version of the received sequence rn into an intermediate control sequence ik at the data rate 1/T.