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      How Does VeCheck Handle OFDM Exclusion Bands?

      A Review and Update for CX380C's VeCheck Channel Allocation Auto Discovery

      Let’s highlight how powerful of a tool CX380C’s VeCheck has become:

      A Review of Known Great Attributes

      VeCheck’s main function is a full Auto Discovery of active channels in the plant, using multiple test engines.
      • Identifies primary and secondary DOCSIS channels
        • This is especially helpful when the end user has no idea what the primary DOCSIS channels are, which are used to get the Cable Modem online.
        • Identifying secondary DOCSIS prevents wasted time, as these channels cannot get online.
        • Detects OFDM Channels and the PLC. In this era of DOCSIS 3.1 broadband, it is critical to measure the quality of OFDM.
      • Convenient shortcut buttons to connect as a Cable Modem, initiate OFDM Analysis, or access Single Channel

      • Another key benefit is to be able to generate a channel table for the system under test, replacing the painful processes of the past (e.g. using ReVeal SW and manually editing channels).
      • Once a channel table is saved for the system, additional and future testing can be very fast. For example, in ‘Use Channel Table’ mode, a Level-only scan for the full plant is done in less than 10 seconds.

      New CX380C VeCheck Enhancement: Improved Handling of OFDM Exclusions

      • Cable Operators may modify OFDM channel lineups for optimum performance. This includes utilizing exclusion bands.  
      • What is an exclusion band? A band of frequencies that are not used by the overall OFDM channel (zero bit load subcarrier groups). Purposes:
        • May still have legacy QAM channels or Pilot tones used within this band.
        • Notch out known, strong interferers such as LTE signals.
      • VeCheck now has improved capabilities to adapt to ever changing OFDM Configurations, including user configured exclusion bands
        • Before: VeCheck could not detect and show the carriers within the exclusion bandwidths.
        • Now: We have developed a method to properly detect and show these carriers.  

      The ever-improving VeCheck feature is another example for why CX380C is the best-in-class, workhorse test tool for maintenance techs.

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