Abstract: System and method for forwarding a ciphering key to a decipher application comprising capturing a first message carrying the ciphering key from a first network interface, identifying a network node associated with the first network interface, identifying a monitor responsible for processing messages captured from interfaces coupled to the network node, and forwarding the ciphering key to the monitor. In an alternative embodiment, the method may further comprise capturing second messages carrying encrypted messages from a second network interface, and deciphering the second messages using the ciphering key. The method may also comprise identifying user equipment associated with the first messages, and selecting a deciphering application running on the monitor using a user equipment identity.

Abstract: System and method for correlating multiple frames of data associated with a single call into a call record. One embodiment comprises correlating data in a radio access network by capturing data passing to and from a radio network controller, identifying ATM Adaptation Layer type 5 (AAL5) frames within the data, assigning a first call identifier to the AAL5 frames, identifying ATM Adaptation Layer type 2 (AAL2) frames within the data, assigning a second call identifier to the AAL2 frames, and combining AAL2 frames and AAL5 frames having a same first call identifier and a same second call identifier into a call record. The data passing to and from the first radio network controller may be data passing over an Iub interface between a Node B and the radio network controller or data passing over an Iur interface between two radio network controllers.

Abstract: System and method for automatically detecting nodes, components and interfaces in a network. A preferred embodiment comprises detecting nodes in a network, wherein the nodes are coupled to a network controller, comprises identifying ports for the network controller, capturing messages received by the network controller at the ports, parsing the messages to identify a node address parameter, wherein the node address parameter uniquely identifies the node to the network controller, and if the node address parameter has not been previously identified, adding a new entry to a node database.

Abstract: Carrier frequency detection for an N-ary modulated signal is achieved by digitizing the N-ary modulated signal, frequency shifting the digitized N-ary modulated signal to prevent aliasing, raising the frequency-shifted signal to the Nth power, transforming the raised signal to frequency domain data and determining an initial maximum frequency peak, iteratively fine shifting the frequency of the N-ary modulated signal around the initial maximum frequency peak and repeating the raising, transforming and determining steps to obtain a plurality of maximum frequency peaks, and calculating the carrier frequency from the maximum frequency peaks and the total related frequency shift.

Abstract: An acquisition apparatus for a test and measurement instrument including a splitter configured to split an input signal into a plurality of split signals, a plurality of oscillators, each oscillator configured to generate a periodic signal, a plurality of combiners, each combiner configured to combine an associated plurality of the periodic signals into an associated signal combination where at least one of the signal combinations is substantially non-periodic. The apparatus also includes a plurality of mixers, each mixer configured to mix an associated split signal and an associated signal combination into an associated mixed signal, a first digitizer configured to digitize an associated split signal, and a plurality of second digitizers, each second digitizer configured to digitize an associated mixed signal.

Abstract: A wideband signal analyzer has a plurality of frequency conversion paths for simultaneously processing different contiguous frequency bands of an input signal. Each frequency conversion path provides time domain data for input to a digital signal processor. The digital signal processor interpolates each group of time domain data to produce interpolated time domain data having a number of data points that satisfies a Nyquist condition for a combined bandwidth of the frequency conversion paths. A calibration signal set to a border frequency between a pair of frequency conversion channels is used to calibrate the gains and phase differences between the frequency conversion paths so that the digital signal processor identifies corresponding time domain data between the interpolated time domain data groups. A suite of frequency domain data is calculated by the digital signal processor from the interpolated time domain data groups and stored for subsequent display.

Abstract: An Arbitrary Waveform Generator has a controller programmed to generate a sequence of test waveforms using previously-defined waveform data files. The controller generates this series of test waveforms by direct synthesis to cause said each waveform to contain a respective different predetermined amount of Rj, Sj and ISI jitter components. In this way, the Arbitrary Waveform Generator produces a sequence of waveforms incorporating varying amounts of ISI to sweep said ISI jitter components from a an initial amount of ISI, for example, zero ISI, and continually increment said amount of ISI to a full unit interval of ISI in predetermined increments, for example, 0.1 UI steps.

Abstract: A variable attenuation signal acquisition probing system and voltage measurement system uses an optical cavity to acquire a signal under test. The probing system has an optical transmitter and receiver that are coupled to the optical cavity via an optical transmission system. The optical cavity has an electrode structure having apertures formed in the optical cavity that are parallel to propagation path of the optical signal within the cavity. A modulated optical signal is generated by the optical cavity in response to the signal under test creating an electro-magnetic field distribution in electro-optic material in the optical cavity that overlaps the optical path of the optical signal propagating in the optical cavity which varies the index of refraction of electro-optic material in the optical path. Changes in the polarization state of the optical signal attenuates the magnitude of the output electrical signal of the optical receiver.

Abstract: A system is provided for performing external correction to reduce, or eliminate, the frequency dependent response related to an external device for receiving analog signals. The system includes an ADC and a spectrum processor for converting time-domain digital data into a spectrum. An external correction is provided between the ADC and the spectrum processor to reduce, or eliminate, the frequency dependent response associated with the external device. A corresponding method is provided that determines the frequency response of the external device, determines the gain at the center frequency, determines the normalized frequency response, constructs and inverse filter and applies the inverse filter to the digitized time-domain data and scales the results prior to any conversion, or transformation, into the frequency domain.

Abstract: A realtime power mask trigger generator for an instrument that acquires data in response to a trigger signal integrates power amplitudes over a defined bandwidth within a frequency spectrum for an input signal to produce an average signal power, and compares the average signal power with a specified reference power level for the defined bandwidth. Violation of the reference power level by the average signal power generates the trigger signal for acquiring data from the input signal about the trigger event by the instrument. The frequency spectrum may be divided into more than one defined frequency bandwidth, and each defined frequency bandwidth may have its own specified reference power level. The defined frequency bandwidths and associated reference power levels define a realtime power mask trigger.

Abstract: A method and apparatus adapted to calibrate signal path of a signal analysis system such that loading effects of additional probes are substantially removed from the measurement. A signal under test from a device under test is coupled to a test probe and used with selectable impedance loads in the test probe to acquires sets of samples for characterizing transfer parameters of the device under test and compute open circuit voltages at the test probe. Other probes are coupled to the device under test and a set of measurement samples are acquired via the test probe. An equalization filter in either the frequency or time domain is computed from the open circuit voltage and measurement samples for reducing signal errors attributable to the measurement loading of the device under test by the test probe and other probes.

Abstract: A method of automatically grouping channels for display uses a pair of multipurpose knobs, one assigned for selection and the other assigned for movement. A channel or a grouping of channels that forms a “virtual group” may be selected from a menu or from a display by the selection knob. The selected channel or virtual group may then be moved to another position on the display by the movement knob. If the movement of the selected channel or virtual group is stopped in proximity to another channel or virtual group, a new virtual group automatically is formed. If movement of the selected channel or virtual group is stopped between proximate channels or within another virtual group, the selected channel or virtual group is inserted automatically between the proximate channels or within the other virtual group to form a new virtual group.

Abstract: An indicia for channels that are collected into a group has a head situated adjacent channel numbers representing the channels included within the group, and has a tail that encompasses the channel numbers. When the last channel in the group is selected, further turning of a Select knob in the same direction results in selection of the group, which selection is indicated by highlighting at least a portion of the indicia.

Abstract: A mode selection amplifier circuit has multiple differential amplifier circuits coupled to receive input signals A, B and C. Each differential amplifier circuit is selectively operable for generating a signal output representative of an output mode with the output mode of each differential amplifier circuit selected from one of algebraic combinations of the signal inputs A?C, B?C, A?B and (A+B)/2?C. The mode selection amplifier circuit is usable in a signal acquisition probe for providing various signal output modes to a measurement test instrument.

Abstract: A method and apparatus adapted to calibrate a signal path of a signal analysis system such that digital samples acquired by the system are processed for representing an arbitrary impedance loading of the device under test. The method and apparatus calibrates the signal path to characterize transfer parameters of the device under test within a spectral domain. A reflection coefficient (?L) is defined representative of an arbitrary impedance load coupled to the device under test and an equalization filter is computed to represent the loading of the device under test by the arbitrary impedance. Additional digital samples are acquired using the equalization filter to effect thereby a representation of the arbitrary impedance loading of the device under test.

Abstract: An up-sampled half band reconstruction filter has a seagull architecture in the form of a pair of parallel infinite impulse response (IIR) filters, one receiving as an input an input signal delayed by one sample time and the other receiving as an input a reverse version of the input signal delayed by one sample time. The outputs from the pair of parallel IIR filters are combined with the input signal to produce a reconstruction filter output in response to the input signal.

Abstract: A method and apparatus adapted to calibrate a signal path of a signal analysis system such that digital samples of a signal under test acquired by the system are processed for representing the impedance of a device under test. The method and apparatus calibrates the signal path to characterize transfer parameters of the device under test within a spectral domain. A reference impedance (Zref) is retrieved that is associated with the signal analysis system. The transfer parameters of the device under test and the reference impedance (Zref) are processed to effect thereby a representation of the device under test impedance (Zeq) as a function of frequency.

Abstract: A terminal element for fiber optic communication has an elongated body defining a body axis and having a first end from which an optical fiber extends along the body axis. The body has a second end with an angled surface offset at an angle from the body axis. The fiber extends partly through the length of the body, and terminates at a fiber end surface. The second portion has an optical entry surface registered with the fiber end surface such that light emitted from the fiber end surface enters the optical entry surface. At least one of the fiber end surface, angled surface and optical entry surface has a figured optical form with a non-planar shape.

Abstract: K2T measurement of video signals, regardless of video format, is determined by generating a graticule using an algorithm having a single variable that is a function of the video format for the particular video signal. The graticule is set to a normalized value of one for a range of +/?T, where T is a function of the video format. The graticule is set to a normalized value over a range of +/?(1.5T to flatBreak) according to a human vision masking model algorithm expressed as K+C/t, where K is a constant K factor, t is a function of T, and C is the single variable that is a function of the video format. The normalized value of the graticule beyond a point designated by flatBreak is a constant=K. Finally a linear curve fit between one and K+C/t over the range of +/?(T to 1.5T) sets the remaining values for the graticule.

Abstract: A noise rejection filter for a trigger circuit uses an algorithm that updates the filter output monotonically so long as the signal slope remains unchanged, maintains the filter output at a constant level when the signal slope changes but the difference between the sample value and the filter output is less than or equal to a hysteresis value, and changes the signal slope while updating the filter output when the difference is greater than the hysteresis value. This maintains the peaks of the input signal at the filter output. The noise rejection filter may be used in a trigger circuit prior to a comparator so that the trigger signal from the comparator accurately reflects the signal pulse width at a desired trigger level and trigger events are detected when the desired trigger level is near the peaks of the input signal.