Abstract: Network monitoring devices and network monitoring techniques are disclosed and use inferential statistical approaches to determine one or more Key Performance Indicators, particularly for Circuit Switched FallBack (CSFB) scenarios. For example, the network monitoring node monitors a plurality of ciphered or clear text messages for a network interface in a communication network, determines a Mobile Terminating (MT) count for MT calls and a Mobile Originating (MO) count for User Equipment (UE) from at least one message of the plurality of messages and defines an inferred MT ratio based on the MT count and the MO count for a total number of messages. The network monitoring device further applies the inferred MT ratio to a CSFB idle mode count for UE and/or a CSFB active mode count for UE to yield an estimated total number of CSFB idle mode successes and an estimated total number of CSFB active mode successes, respectively.

Abstract: An active shunt ammeter for measuring current flowing through a device under test (DUT) and method are disclosed. The active shunt ammeter includes an input configured to receive an input signal having a frequency within a frequency band and representing the current flowing through the DUT. An output is configured to generate an output voltage representing the current flowing through the DUT. The active shunt ammeter also includes a gain circuit having an amplifier with a gain characteristic that varies respect to frequency within the frequency band and a feedback element having an impedance coupled from an output of the gain circuit to a negative input of the gain circuit, the feedback element impedance being configured to change with frequency to correlate with the amplifier gain characteristic such that the feedback element impedance divided by the amplifier gain over the frequency band has minimal frequency dependency.

Abstract: Embodiments of the invention include systems and methods for measuring or otherwise calculating polarization mode dispersion (PMD) of an optical fiber, or other device, by comparing the optical signal through the PMD element with the optical signal obtained directly from the transmitter, and calculating the PMD from the discrepancy between the two. Any distortions on the transmitter signal are effectively calibrated out, increasing measurement accuracy over conventional approaches.

Abstract: A digital down-conversion acquisition function, includes a key spectral analysis function, in time-interleaved acquisition systems to enable acquisitions at very high sample rates and bandwidths. Digital down-conversion allows data compression into acquisition memory for down-converted complex baseband I/Q data within a given frequency range of interest. With a fixed-size acquisition memory, this enables acquisitions over a longer time span, thus enabling a lower spectral resolution bandwidth. These approaches allow down-converted complex baseband I/Q data from a narrow frequency band of interest to be acquired efficiently. Reconstruction of the acquired down-converted waveform from the time-interleaved components stored in each acquisition memory of each distributed acquisition components to result in a coherent waveform is also disclosed.

Abstract: A relay fault detection and correction system includes a signal detector structured to measure primary and secondary signals, and generates a fault output signal if the signals appear to be unterminated due to a relay not connecting the signals to the loads. A cycle circuit is structured to cause a relay controller to cycle a potentially under-performing relay between its states a number of times after the signal detector generates the fault output.

Abstract: A method for optimizing data access in a data warehouse having a model driven architecture is provided. A data model for storing time series measurement data representing a plurality of dimensions and measurements is received. The data model includes one or more aggregation tables. A query having one or more predicates is received from a user. The one or more predicates are analyzed to determine whether the received query can be optimized using the existing aggregation tables. The received query is optimized using the aggregation tables, in response to determining that such query optimization is possible.

Abstract: A method of controlling the gain or sensitivity of a test and measurement system. The test and measurement system includes a host, a controller with an optical transmitter and an optical receiver, optical-to-electrical converter, an accessory head, and a device under test. The method includes determining whether a gain or sensitivity adjustment of the test and measurement system is required, determining the amount of gain or sensitivity adjustment, and adjusting the output power of a laser of the optical transmitter in response to the determination of the gain or sensitivity adjustment of the test and measurement system.

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 includes an input terminal to receive a signal, acquisition circuitry to capture a plurality of triggered acquisitions, trigger circuitry to cause a trigger event responsive to trigger criteria, and a controller to dynamically reconfigure the trigger criteria between triggered acquisitions. The controller is configured to dynamically reconfigure the trigger criteria from the first set of trigger criteria to subsequent sets of trigger criteria between each of the triggered acquisitions. A method is disclosed for scanning information associated with an initial triggered acquisition and, depending on the nature of the scanned information, dynamically adjusting the next or any subsequent set of trigger criteria.

Abstract: An electromechanical microswitch, comprising first and second electromagnets mounted in spaced-apart orientation to one another where each electromagnetic has a field center located a first distance above the mounting surface. A permanent magnet is positioned between the electromagnets and includes a magnetic field center that is higher above the mounting surface than that of the electromagnets so that the permanent magnet is magnetically biased toward the mounting surface. A stripline switch element is mountable between the permanent magnet and mounting surface, and biased against circuit structures on the mounting surface, whereby the stripline switch element moves between first and second activated positions under influence of the electromagnets.

Abstract: Conductive strips are stacked, insulated, folded, and formed into geometric shapes to provide a low resistance, low inductance, shunt, wherein the geometric shape readily enables cooling to reduce changes in resistance due to self-heating effects. One such geometric shape is attained by winding the conductive strips into a spiral. Another geometric shape is a shape resembling a wave. Both geometric shapes allow cooling by directing airflow from a fan across their surface portions. A variable-speed cooling-fan is controlled in response to measured temperature of the shunt, or in response to a measurement of the current through the shunt. Differential cooling may be employed by means of changing the amount of airflow across various portions of the shunt in response to measured temperature of the shunt.

Abstract: A device is capable of receiving a waveform and capturing acquisitions of the waveform. Different boundary masks can be applied to the waveform acquisitions, depending on the timing of the acquisition. When a timing interval finishes, a different dynamic boundary mask can be loaded from memory. Boundary masks can include any number of segments, and can be used whenever desired.

Abstract: A method for producing sampled data, which as the requested sampling period is increased, each sample is the average of an increasing number of ADC samples such that a maximum number of ADC samples are evenly space across the sample period. The method can include choosing one of multiple ADC with varying speed versus resolution capabilities to further increase the quality of the sampled data as the sampling period increases.

Abstract: A test system can include a probe suitable to be coupled between a test measurement device and a device under test (DUT). The probe can include a signal input to receive an active signal from the DUT and a signal output to provide the active signal to the test measurement device. The probe can also include an input ground to connect to the DUT ground and an output ground to connect to the test measurement device ground. A probe ground connection checking device can automatically determine whether the probe ground connections to the DUT ground and test measurement device ground are solid.

Abstract: A two stage adaptive filter for use in a batch receiver includes an equalizer filter having as inputs an acquired signal representing a batch of data points and an equalizer filter value. The filtered signal is batch processed to produce reference and data symbols, which symbols are input to a residual filter to generate iteratively over the batch an error value. The error value is convolved with the equalizer filter value to produce a new equalizer filter value for use by the equalizer filter when a next batch of data points is processed.

Abstract: Computationally efficient methods and related systems, for use in a test and measurement instrument, such as an oscilloscope, optimize the performance of DFEs used in a high-speed serial data link by identifying optimal DFE tap values for peak-to-peak based criteria. The optimized DFEs comply with the behavior of a model DFE set forth in the PCIE 3.0 specification.

Abstract: There is provided a passive network monitoring device that monitors one or more network interfaces between network nodes including a SGW node, a PGW node, an ePDG node, and a PCRF node and a PCEF node. The device receives a handover indication for UE from untrusted non-3GPP network access to 3GPP network access and receives a response to an attach request from one or more of the network interfaces, the response including a MSIP address and a charging ID for the UE. The device determines the UE is from a single subscriber based on each of the handover, the MSIP address of the response and the charging ID of the response, and correlates information for the UE at each of the one or more network interfaces with the single subscriber.

Abstract: A distributed network monitoring device monitors via a lightweight session tracking module of a network monitoring device, control plane data for connectivity sessions of User Equipment (UE) in a communication network. The lightweight session tracking module selectively identifies at least one bearer for a corresponding connectivity session according to one or more control plane attributes and associates each selectively identified bearer for the corresponding connectivity session with a bearer routing rule for user plane data. A packet routing module receives user plane data for connectivity sessions of UE and transmits the user plane data of the connectivity sessions according to the bearer routing rule of the lightweight session tracking module to a flow processing module for subsequent data flow analysis.

Abstract: An electromechanical microswitch, comprising first and second electromagnets mounted in spaced-apart orientation to one another where each electromagnetic has a field center located a first distance above the mounting surface. A permanent magnet is positioned between the electromagnets and includes a magnetic field center that is higher above the mounting surface than that of the electromagnets so that the permanent magnet is magnetically biased toward the mounting surface. A stripline switch element is mountable between the permanent magnet and mounting surface, and biased against circuit structures on the mounting surface, whereby the stripline switch element moves between first and second activated positions under influence of the electromagnets.