Abstract: A test and measurement instrument and method for generating IQ-based time domain waveform information and presenting the IQ-based time domain waveform information together with other time domain waveform on a common axis through a user interface. The test and measurement instrument can include, for example, one or more input terminals to receive an electrical signal under test, an analog-to-digital converter (ADC) to digitize the signal under test, a digital downconverter to produce I (in-phase) and Q (quadrature) baseband component information from the digitized signal, a memory configured to store the IQ baseband component information, a user interface, and a controller. The controller can be configured to generate an IQ-based time domain waveform using the IQ baseband component information, and present the IQ-based time domain waveform and a second time domain waveform on a common axis through the user interface.

Abstract: A method of determining configuration parameters of a mobile network topology for testing and monitoring purposes at an interface (Iub) located between a first node and a second node of the mobile network where between the first and the second node there exist several channels includes finding the channel having signaling information, analyzing signaling information to determine the configuration parameters, updating the configuration parameters dynamically, and performing a monitoring activity or test scenario based on the configuration parameters.

Abstract: A balun structure is disclosed having positive and negative going signal paths coupled to a ninety degree hybrid. The positive signal path has a circuit trace and a phase shaper structure that provides three hundred and sixty degrees of phase shift at Port 1 of the hybrid. The negative going signal path has a circuit trace and a second order phase shaper that provides four hundred and fifty degrees of phase shift at Port 2 of the hybrid. Port 1 is coupled to Port 3 of the hybrid and functions as an output port. The first order phase shaper and the second order phase shaper compensate for the signal loss caused by a signal cable coupled to the output port and provide a frequency band from DC to at least 15 GHz and a transient response having less than ten percent pre-shoot.

Abstract: A serial data link measurement and simulation system for use on a test and measurement instrument presents on a display device a main menu having elements representing a measurement circuit, a simulation circuit and a transmitter. The main menu includes processing flow lines pointing from the measurement circuit to the transmitter and from the transmitter to the simulation circuit. The main menu includes a source input to the measurement circuit and one or more test points from which waveforms may be obtained. The simulation circuit includes a receiver. The measurement and simulation circuits are defined by a user, and the transmitter is common to both circuits so all aspects of the serial data link system are tied together.

Abstract: A shielded signal pass-through or via structure integral with an electronic circuit board is described. The structure includes a rigid inner generally cylindrical conductor; at least a semi-rigid intermediate annular dielectric surrounding the conductor; and a rigid outer annular conductor surrounding the dielectric material. Also described is an interconnect device that presents a contact array in a boss region of a unitary embossed printed circuit board (PCB) optionally equipped with one or more such shielded vias.

Abstract: A test and measurement instrument according to an embodiment of the present invention automatically detects excessive in-band but out-of-span energy and notifies the user of the condition.

Abstract: A test and measurement instrument according to an embodiment of the present invention converts digital data that represents an analog input signal into a time-domain bitmap, and then compares a region of that time-domain bitmap to a density threshold. When the density value violates the density threshold, a trigger signal is generated that causes digital data to be stored into a memory.

Abstract: A method for analyzing jitter using a test and measurement instrument includes obtaining a collection of time interval error (TIE) values corresponding to composite jitter of a waveform, optionally decomposing the composite jitter into jitter components that are correlated to the data pattern and components that are uncorrelated to the data pattern, and using a spectral approach to decompose the jitter components into jitter components that are recognizable as deterministic and jitter components that are unrecognizable as deterministic. Thereafter, the jitter components analyzed in the frequency domain are converted back to the time domain, and subtracted from the composite jitter, thereby isolating uncorrelated residual jitter. The uncorrelated residual jitter is decomposed into bounded uncorrelated jitter and random jitter, for example, by integrating a probability density (PDF) function of the residual jitter and analyzing the resulting cumulative distribution function (CDF) curve in Q-space.

Abstract: A test and measurement instrument according to an embodiment of the present invention provides a disparity cursor for making quick and easy disparity measurements. In operation, a user uses a sample cursor to specify a pixel of a first image and uses the disparity cursor to specify a pixel of a second image. The test and measurement instrument then automatically provides a measured disparity value based on the two pixels.

Abstract: An apparatus and method for splitting a wide band input signal and overlaying multiple frequency bands on each path associated with one or more digitizers. All frequencies from the split signal on each path can be fed to a mixer. The local oscillator of each mixer receives a sum of signals, which can each be set to any arbitrary frequency, as long as an associated matrix determinant of coefficients is non-zero. Each oscillator signal is multiplied by a coefficient, which can represent phase and magnitude, prior to summing the oscillator signals together. Each mixer mixes a combined signal with the input, thereby generating a set of multiple overlaid frequency bands. The digitized signals are processed to substantially reconstruct the original input signal. Thus, the wide band input signal is digitized using multiple individual digitizers. In particular, a system can support two wide band signals using four digitizers of narrower bandwidth.

Abstract: Test and measurement instrumentation collects time information independently in each clock domain using a device that monotonically changes state with the passage of time according to a local clock domain. The device under test therefore has a unique state for each synchronous time period. The instrumentation periodically samples the devices under test, collects the state of each device, and records the state of the devices in conjunction with any data collected in clock domains that are synchronous with the devices. The periodic samples are transformed into numeric values using an isomorphic or linear model. These values are then fitted to an assumed frequency model that relates the state of devices in otherwise unrelated clock domains.

Abstract: A capacitance-type liquid measuring probe 10 includes two concentric metallic tubes 12 and 14 extending downwardly into a tank of oil. The concentric metallic tubes 12 and 14 form the plates of a capacitor. The probe 10 measures the oil level in the tank during jet engine testing by detecting a change in electrical capacitance between the two concentric metallic tubes 12 and 14, the capacitance change being caused by a change in the level of the oil. The measuring circuitry 30 includes thermal compensating resistors and a temperature-stabilized detector. The measurement electronic circuit package is separately-housed and connected to the probe 10 via a cable 44 so that the circuitry 30 can be located remotely from the hot environment in which the probe 10 operates.

Abstract: A waveform generator has a waveform generation circuit storing waveform data for an analog waveform signals having dead time periods without the need for storing data on the dead time. A sequencer having a sequence memory stores sequence data that controls the sequencing of one or more signal components and associated dead times of the analog waveform signal. The timing of the dead time is controlled by a sampling clock and a wait time counter. The generation of the signal components is controlled by the sampling clock controlling the generation of addresses for a waveform memory storing digital data of the sampling components. The waveform memory digital data is converted to an analog waveform signal.

Abstract: A signal conditioning apparatus can include a coaxial cable having at least one slot formed therein. A conductive film can be applied to the coaxial cable so as to cover each slot. A device mounting surface can be formed within the slot and a protection device can be mounted on the device mounting surface. A housing consisting of one or more interlockable portions can be coupled to the coaxial cable.

Abstract: Tiling or blockiness detection based on spectral power signature uses one-dimensional vectors at block edges to find a spectral signature created by the tiling or blockiness in an image. A baseband component of the image, such as luminance, is edge enhanced, and then the pixel values along each horizontal line are summed to form a one-dimensional column vector of summed edge values for the image. The power of the column vector and the power of selected frequency components within the column vector are determined. The powers are then combined and converted to dimensionless tiling or blockiness values relative to each of the selected frequencies.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable. The resistive center conductor signal cable of the signal acquisition probe is coupled to a compensation system in a signal processing instrument via an input node and input circuitry in the signal processing instrument. The signal acquisition probe and the signal processing instrument have mismatched time constants at the input node with the compensation system having an input amplifier with feedback loop circuitry and a shunt pole-zero pair coupled to the input circuitry providing pole-zero pairs for maintaining flatness over the signal acquisition system frequency bandwidth.

Abstract: Systems and methods for the adaptive monitoring of telecommunications networks are described. In some embodiments, a method may include monitoring traffic transmitted through a mobile telecommunications network (e.g., 3G, 4G, LTE, etc.) and identifying a monitoring rule. The monitoring rule may associate a selected portion of the traffic (e.g., based on content type, source, destination, transport protocol, session, etc.) with a monitoring sampling ratio, and the monitoring sampling ratio may determine a fraction of the selected portion of the traffic usable to provide one or more performance indicators (e.g., service indicators, network congestion, connection maintenance, service quality, and/or network availability). The method may further include modifying the monitoring sampling ratio in response to a change in network monitoring conditions (e.g., one or more probes operating at or near capacity, scheduled maintenance events, peak traffic times, etc.

Abstract: Systems and methods for session-aware GTPv1 load balancing are described. In some embodiments, a method may include receiving a first message transmitted from an SGSN to a GGSN using a GTP-C protocol and storing a downlink UP TEId and IP address and a downlink CP TEId and IP address. The method may also include receiving a second message transmitted from the GGSN to the SGSN using the GTP-C in response to the first message and storing an uplink UP TEId and IP address and an uplink CP TEId and IP address. The method may further include identifying one or more messages exchanged between the SGSN and the GGSN using a GTP-U protocol as belonging to a given session in response to the one or more messages including at least one of: (i) the downlink UP TEId and IP address, or (ii) the uplink UP TEId and IP address.

Abstract: Systems and methods for session-aware GTPv2 load balancing are described. In some embodiments, a method may include receiving a first and a second transaction between an MME and an S-GW over an Sll interface of an LTE/SAE network using a control portion of a second version of a GTPv2-C protocol and storing an uplink UP TEId and IP address, a downlink CP TEId and IP address, and an uplink CP TEId and IP address obtained from the first transaction, and a downlink UP TEId and IP address obtained from the second transaction. The method may further include identifying messages between an eNodeB and the S-GW over a direct tunnel using a user portion of a GTPv1-U protocol as belonging to a session in response to the messages including at least one of: the first uplink UP TEId and IP address, or the first downlink UP TEId and IP address.

Abstract: A system and method for enforcing network policies is disclosed. Data is captured from network interfaces. A cell congestion level is determined from the captured data. Cells having a congestion level above a first threshold are identified. A first alert is transmitted to a network policy management entity when the cell is above the first threshold. Cells having a congestion level above a second threshold are identified. A second alert is transmitted to the network policy management entity when the cell is above the second threshold. The first threshold set at a point below a maximum capacity of the cell, and the second threshold set at a point near or at the maximum capacity of the cell.