Trilithic
QAM Podcast

DIA Suite

Spectral Analysis Software

RPM Software Suite

The Trilithic DIA Suite is a powerful tool for analyzing the long-term performance of the Return Path, and for determining the suitability of selected bands for return services. The Suite is unmatched in its flexibility and ease of use, enabling the operator to identify low-level, chronic problems long before they can disrupt return services. Power Summing, a unique feature of the DIA Suite, can re-compute spectral data to evaluate ingress severity at several near-DOCSIS bandwidths, giving an accurate appraisal of the return path's ability to carry real-world traffic. DIA Components, CompressR and ProfilR CompressR is normally co-located on the system controller with IngressManagR Monitoring Software. Usually, it is set to operate in the background," continually summarizing and evaluating reverse spectral records generated by IngressManagR. CompressR can perform several computations on the arriving data, based on limits selectable by the operator. These include:

  • The calculated maximum, minimum and average ingress values for each connected node, in intervals of a few minutes to an hour;
  • The calculated percent of measurements, at each return frequency, that exceeded one or more user-set limits during a settable interval;
  • The availability of selectable bandwidths at a succession of return frequencies.

Computed results are stored as an Access-compatible data base in a hard drive data file. CompressR can also process stored spectral data from previously-archived files, and build summaries of historical trends spanning weeks or months. ProfilR is a report-generating application that interprets ingress summaries compiled by CompressR , reporting analyses in graphical format or as tabular reports. Because it works from summaries, rather than raw data, ProfilR operates swiftly, allowing an operator to analyze a large number of records with the minimum processing delay.

ProfilR reports cover the following parameters:

  • The Max/Min/Avg. levels of noise, ingress and traffic levels over specified intervals
  • The Average Discrete Ingress Probability
  • Ingress Threshold Probability
  • Specific Frequency Discrete Ingress Probability
  • Specific Channel Discrete Ingress Probability

To facilitate comparisons, data for several nodes may be displayed simultaneously. Each graph has a handy marker function which numerically reads out the value of any selected point. A "click and drag" Zoom function makes it easy to home in on a segment of the graph that is of special interest. All graphs can be stored for later recall.

Power Summing, a Unique DIA Feature

Much like a spectrum analyzer, the Guardian SST Return Analyzer analyzes return band ingress in a series of adjacent resolution bandwidths, "slices" of the spectrum each a few hundred kHz wide. However, most return services span several analyzer resolution bandwidths. In other ingress measurement systems this can cause errors, including underestimation of impulse ingress power and overestimation of coherent ingress (beats, common path distortions, etc).? CompressR solves this problem by summing the ingress power in a settable number of adjacent resolution bandwidths, allowing evaluation of ingress levels in bandwidths similar to those actually used by digital services.

DIA Displays MAX/MIN/AVG

Displays the Max, Min and Avg. levels - vs - frequency. Data for one or more nodes can be viewed sequentially by time increment. Time increments may be advanced either manually or automatically.

Waterfall & Power Summing Unavailability Reports

Displays successive traces of ingress levels or channel unavailability over time. With amplitude or channel unavailability displayed as variations in color, frequency on the y axis and the time on the x axis for the selected node.

Ingress Threshold Probability Report

Plots the unavailability as the percent of times the ingress level at each frequency crosses any of the four user-set thresholds for the specified period, by frequency.

Specific Frequency Discrete Ingress Probability Signal Report

Plots the unavailability as the percent of threshold violations for each of the four user thresholds for each time increment, for a selected frequency.

Specific Channel Discrete Ingress Probability Signal Report

Plots channel unavailability for a specified frequency band (channel or service) vs. time for each of the 4 thresholds.

The Average Discrete Ingress Probability Signal Report

Calculates the average probability that a node's ingress will exceed one to four thresholds over a user-specified time interval. The ADISP is a useful "Figure of Merit" for assessing a node's overall performance over time.

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