1345results about "Correct operation testing" patented technology

A technique for training links in a computing system is disclosed. In one aspect, the technique includes configuring a first receiver in a first port using a first training sequence or a second training sequence; transmitting the second training sequence from the first port indicating the first receiver is configured; and receiving a second training sequence transmitted by a second port at the first port, the second training sequence transmitted by the second port indicating that a second receiver in the second port is configured. In a second aspect, the technique includes locking a communication link; handshaking across the locked link to indicate readiness for data transmission; transmitting information after handshaking across the locked link. And, in a third aspect, the technique includes transmitting a first training sequence from a first port and a second port; and synchronizing the receipt of the first training sequence at the first and second ports; transmitting a second training sequence from the first and second ports upon the synchronized receipt of the first training sequence at the first and second ports; and receiving the second training sequence transmitted by the first and second ports and the second and first ports, respectively, in synchrony.

A system may perform interconnect BIST (IBIST) testing on source synchronous links. The system may perform, at normal operating frequency, a source synchronous link test that tests a victim line on the source synchronous link using a transition weave pattern. The transition weave pattern causes interaction between a data transition on the victim line, previous transitions on the victim line, and transitions on the other lines of the link (the “aggressor” lines). The interaction caused may be: (i) a first crossing pulse on the victim line; (ii) a second crossing pulse of the opposite polarity on each aggressor line concurrent with the first crossing pulse on the victim line; and (iii) a reflection in the opposite direction of the first transition of the first crossing pulse, wherein the reflection results from a previous transition on the victim line.

A method of tracking network traffic anomalies in a computing system, comprises receiving an ingress network packet at a configurable logic device (CLD), associating a timestamp with the packet, identifying at least one anomaly based on the contents of the packet, and storing the anomalous packet and the timestamp in a persistent memory.

A transmitter comprises a local oscillator circuit operable to generate a reference signal, a modulator circuit operable to generate a data-carrying signal using the reference signal, and a test signal generator circuit operable to generate a test signal using the reference signal. The test signal has a first bandwidth, and a test signal insertion circuit is operable to combine the data-carrying signal and the test signal to generate a combined signal. An amount of bandwidth in the combined signal allocated to the test signal is greater than the first bandwidth such that a component of the combined signal corresponding to the test signal is bordered by whitespace. A receiver may then use the test signal to determine and correct for phase noise introduced in the transmitter.

A wireless communication system can comprise two or more antennas that interfere with one another via free space coupling, surface wave crosstalk, dielectric leakage, or other interference effect. The interference effect can produce an interference signal on one of the antennas. A cancellation device can suppress antenna interference by generating an estimate of the interference signal and subtracting the estimate from the interference signal. The cancellation device can generate the estimate based on sampling signals on an antenna that generates the interference or on an antenna that receives the interference. The cancellation device can comprise a model of the crosstalk effect. Transmitting test signals on the communication system can define or refine the model.

The present invention provides a method and system for estimating common amplitude and phase errors of a multiple channel wireless system. The multiple channel wireless system includes a plurality of transmission channels formed between a plurality of transmission antennas and a plurality of receiver antennas. The method includes estimating transmission channel elements between each transmission antenna and receiver antenna pair of the multiple channel wireless system. Calibration symbols are transmitted from each transmit antenna. Signals are received that correspond to the calibration symbols having traveled through the transmission channels. Received calibration symbols are estimated based upon spatial processing of the received signals and the estimated transmission channel elements. Common amplitude and phase errors are estimated for each transmit and receive antenna pair by comparing the transmitted calibration symbols with the received calibration symbols.

A switch router and one or more gateways incorporating a diagnostic and calibration system that performs RF characterization of an underlying cable plant. The switch router is connected at a point of insertion or point of distribution and each gateway is located downstream, such as at corresponding subscriber locations. The switch router and each gateway sends a test signal with known characteristics and power level, and the receiving device determines noise level and power loss for the corresponding downstream and upstream channel pair. The power loss information is used to calibrate the power level of the transmitters. The noise levels are used to determine if the selected modulation schemes employed for normal communications is realizable. A frequency analysis, such as FFT or the like, is performed on the upstream test signal spectrum to derive valuable frequency information for the upstream channel or the entire upstream bandwidth.

A system and method for providing a name service in a peer-to-peer environment is described. A peer group name server may be a standalone name server that may be used in peer-to-peer applications and environments. A network computing platform may be used as a basis for establishing and operating a peer-to-peer network. A peer group name server may cache information about peers, peer groups and other entities. Peers may discover other peers, peer groups and other entities through the peer group name server. A peer group name server may serve as a reverse lookup provider. A peer group name server may act as a registrar for named entities (e.g. peers) in the peer-to-peer networking environment. In one embodiment, peer group name servers may maintain information about other peer group name servers, thus making a network of decentralized peer group name servers.

An embodiment of the present invention offloads the generation and monitoring of test packets from a Central processing Unit (CPU) to a dedicated network integrated circuit, such as a router, bridge or switch chip associated with the CPU. The CPU may download test routines and test data to the network IC, which then generates the test packets, identifies and handles received test packets, collects test statistics, and performs other test functions all without loading the CPU. The CPU may be notified when certain events occur, such as when throughput or jitter thresholds for the network are exceeded.

A digital video recorder (DVR) is disclosed for storing a plaintext video program as an encrypted video program. The DVR comprises a random access storage (RAS) device for storing the encrypted video program in encrypted segments. The DVR further comprises a cryptography facility comprising an encoder for encrypting plaintext segments of the plaintext video program into the encrypted segments stored on the RAS device, and a decoder for randomly and independently decrypting the encrypted segments of the encrypted video program into plaintext segments during playback.

A data Interface for transferring digital data between a host and a client over a communication path using packet structures linked together to form a communication protocol for communicating a pre-selected set of digital control and presentation data. The signal protocol is used by link controllers configured to generate, transmit, and receive packets forming the communications protocol, and to form digital data into one or more types of data packets, with at least one residing in the host device and being coupled to the client through the communications path. The interface provides a cost-effective, low power, bi-directional, high-speed data transfer mechanism over a short-range “serial” type data link, which lends itself to implementation with miniature connectors and thin flexible cables which are especially useful in connecting display elements such as wearable micro-displays to portable computers and wireless communication devices.

A device to device (D2D) communication method based on a partial device control is disclosed. According to the present invention, the D2D communication method and, particularly, to a partial device control method for D2D communication a relates to, and provides a D2D resource allocation and release method, a D2D HARQ process operating method, a link adaptation method comprising D2D link power control and adaptive modulation and coding (AMC), a D2D control information signaling method, a CSI reporting method for D2D communication, and contents of a CSI report. The present invention can enhance the advantages of and compensate for the disadvantages of both methods through the combination of a base station control a base station control type D2D communication method and a device control type D2D communication method.

A disk drive including a method for determining an amplitude for signal transmission over an interconnect is disclosed. The drive includes a processor that is coupled to a signal measurement circuit and is under the control of a program in conjunction with the signal measurement circuit to transmit a first signal to the host over a transmission medium at a first transmission frequency according to a first speed negotiation process, receive a second signal from the host at the first transmission frequency, determine a first voltage amplitude of the second signal, transmit a third signal to the host at a second transmission frequency according to a second speed negotiation process, receive a fourth signal from the host at the second transmission frequency, determine a second voltage amplitude of the fourth signal, and determine an approximate voltage loss in response to the first and second voltage amplitudes.

An interface control system of network equipment, includes: a logical interface which is an interface of a logical group; physical ports which belong to the logical group; and an interface control section configured to incorporate the logical interface and the physical ports as management objects into a management interface when validation of a predetermined function has been performed to each of the logical interface and the physical ports.

A method for determining an amplitude for signal transmission over an interconnect is disclosed. The method includes transmitting a first signal to a host over a transmission medium at a first transmission frequency according to a first speed negotiation process and receiving a second signal from the host at the first transmission frequency. The method also includes measuring a first voltage amplitude of the second signal and transmitting a third signal to the host at a second transmission frequency according to a second speed negotiation process. The method further includes receiving a fourth signal from the host at the second transmission frequency, measuring a second voltage amplitude of the fourth signal, and determining an approximate voltage loss in response to the first and second voltage amplitudes.

Processing of loop-back information returned by one or more mobile stations that are served by a wireless communication network permits the network to compensate its transmit signals for increased transmission efficiency and reduced signal interference at the mobile stations. Generally, the network forms one or more transmit signals as a combination of different signals intended for the different mobile stations, and remembers transmit information associated with these transmit signals. The mobile stations return loop-back signals to the network, which determines transmit signal compensation information by comparing loop-back information to memorized information. The mobile stations may loop-back samples from composite received signals, from processed received signal samples, or loop-back estimates. In the first case, processing at the network involves compensating the combined transmit signals at the transmit modulation rate, while the second case involves symbol rate processing of the individual information streams intended for the different mobile stations.

A method for analyzing Gigabit Ethernet (GBE) and fiber channel protocol communications is provided which provides a more detailed understanding of the errors, than that provided under the IEEE 802.3z standard. The method creates an additional parity error signal which is not specified under the IEEE 802.3z standard. The parity error signals and IEEE 802.3z invalid code word signals are used to provide an analysis of whether the underlying communication errors are a result of 8B / 10B coding word errors or running disparity errors. A system and apparatus to monitor performance in accordance with the above-mentioned method is also provided.

A test signal generator at a transmitter station and a facsimile generator at a receiver station go through an acquisition and tracking process which aligns the two signals so that a logical processor can compute the frequency transfer function of the entire propagation path for use in an adaptive, concurrently sent communication signal. The frequency transfer function is conveyed back to the transmit end via a control channel permitting an adaptivity function at the transmit end to influence subsequent selection of communication parameters, among which are typically transmitted data rate, selection of modulation, selection of forward error correcting coding, and selection of frequency band for transmission. The same measurement is conveyed to an adaptivity function at the receive end for use in the communications receiver to select demodulator variables such as gain control, and equalization of amplitude and phase, versus frequency. The adaptivity function also permits interspersing of reverse-direction communications over the same frequency bands in a time-share mode between forward-direction and reverse-direction communication with the measurement signals having to be transmitted in only one direction. An alternate embodiment invention of this type is described which is additionally useful for mobile communications channels. Another variation embodiment is described for pure propagation measurements only, absent conveyance of end-user information.

A jitter measurement technique utilizing a high-bandwidth undersampling voltage measurement instrument is presented. A trigger is derived from the a signal having a repetitive signal pattern. The signal is compared with a threshold at a plurality of times relative to the trigger during multiple repetitions of the signal pattern to produce measurement samples indicative of signal level relative to the threshold. The measurement samples are used to determine the probability of signal edge states as a function of time for the multiple repetitions. The probability of signal edge states are used to determine an edge probability density as a function of time. A histogram of signal state transition times can be prepared from the edge probability density. Mean deviation of edge transitions of the signal can be estimates, and standard deviation of edge transitions of the signal can be estimated to give the root-mean-square (rms) jitter of the signal.

The invention is test apparatus and methods for performing loopback tests. The tests involve generating a packet-based test message having a source address and a destination address. When the test message arrives at the destination, the addresses are exchanged and the message is returned to the source. The addresses can be level 2 addresses, such as MAC addresses, and / or level 3 addresses, such as IP addresses. The returned message and the propagation properties observed for the test message can be used to determine information about the network being tested.

A method and a system for compensating for a permutation of L pairs of cable such that the compensation is localized in a trellis decoder of a receiver. The L pairs of cable correspond to L dimensions of a trellis code associated with the trellis decoder. The trellis code includes a plurality of code-subsets. The permutation of the L pairs of cable is determined. A plurality of sets of swap indicators based on the permutation of the L pairs of cable is generated. Each of the sets of swap indicators corresponds to one of the code-subsets. The code-subsets are remapped based on the corresponding sets of swap indicators.

A method and apparatus are disclosed. The method includes one or more of the following: compiling statistical models of physical layers of a communications system; creating a priori distributions of cross-talk transfer functions; storing the models and the a priori distribution in a storage medium; and using the models and the a priori distributions to diagnose probable causes of events detected in said communications system.

A radio interference detection and screening system for performs on-locomotive testing of Locomotive Control Unit (LCU) radios. To eliminate bit errors during LCU sensitivity testing (also known as Bit Error Rate (BER) testing), the system detects interfering transmission signals which may cause bit errors in the transmission of test data, and suspends the LCU sensitivity performance testing during periods of detected external transmissions. Once the interfering transmissions are no longer detected by the system, the LCU then resumes the LCU sensitivity performance testing.

A test signal generator at a transmitter station and a facsimile generator at a receiver station go through an acquisition and tracking process which aligns the two signals so that a logical processor can compute the frequency transfer function of the entire propagation path for use in an adaptive, concurrently sent communication signal. The frequency transfer function is conveyed back to the transmit end via a control channel permitting an adaptivity function at the transmit end to influence subsequent selection of communication parameters, among which are typically transmitted data rate, selection of modulation, selection of forward error correcting coding, and selection of frequency band for transmission. The same measurement is conveyed to an adaptivity function at the receive end for use in the communications receiver to select demodulator variables such as gain control, and equalization of amplitude and phase, versus frequency. The adaptivity function also permits interspersing of reverse-direction communications over the same frequency bands in a time-share mode between forward-direction and reverse-direction communication with the measurement signals having to be transmitted in only one direction. An alternate embodiment invention of this type is described which is additionally useful for mobile communications channels. Another variation embodiment is described for pure propagation measurements only, absent conveyance of end-user information.

A fault detection device capable of detecting network faults by itself with high accuracy in multi-vendor environments, without the need to interoperate with an associated device according to an identical protocol. A monitoring control packet transmitter generates a fault monitoring control packet and transmits the generated packet to the associated device with which the fault detection device need not interoperate to detect faults according to the same protocol. A transmit packet counter keeps count of the transmitted fault monitoring control packet. A receive packet counter receives a control packet transmitted from the associated device, and keeps count of the received control packet. A fault detector monitors the count of transmitted packets and the count of received packets and, if at least one of the counts remains unchanged for a fixed period of time, judges that a fault has occurred and sends a fault notification to outside.

A method an apparatus for interface failure survivability using error correction provides operation of an interface when a number of bits of the interface less than or equal to available error correction depth are present. Initialization tests are used to determine whether the interface errors due to failed interconnects or circuits can be corrected, or whether the interface must be disabled. Subsequent alignment at initialization or during operation idle periods may be disabled for any failed bit paths. The failed bit path indications are determined and maintained in hardware, and used to bypass subsequent calibrations that could otherwise corrupt the interface. A fault indication specifying total failure may be generated and used to shut down the interface and / or connected subsystem in response to an uncorrectable condition and request immediate repair. A second fault indication specifying correctable failure may be generated and used to indicate a need for eventual repair.

An integrated circuit (12) contains a serializing transmitter, including a phase locked loop (31) that supplies seven clocks (41) with different phases to a serializer circuit (32). The serializer circuit accepts 7-bit words at a parallel input (42), and outputs these words serially in an end-to-end manner on a twisted pair (17), as a clock signal. The serializer circuit also accepts 7-bit words on a further parallel input (43), and transmits them serially in an end-to-end manner on a twisted pair (18), as serialized data. The integrated circuit also includes a built-in self-test circuit (33), which can supply test information to the two parallel inputs of the serializer circuit, and which can monitor the two twisted pairs while the serializer circuit operates at high data rates typical of normal operation, in order to detect any errors introduced by the serializer circuit. The self-test circuit produces a single digital output (48) to indicate whether an error has been detected.