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Thread: 1011 vs 511 BER Test Tone

  1. #1
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    Default 1011 vs 511 BER Test Tone

    Can someone comment on which test pattern is more rigorous or effective in testing a P25 system, the 1011 or 511 (V.52) pattern?
    Is there any difference or reason to use one versus the other?

    Thank you in advance for your comments,


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    The V.52 pattern is just a simple repeating bit pattern (less than 100 bits, if I remember). Most P25 subscriber radios won't decode or do anything with it. But it does seem to often be used for system coverage drive testing...

    The 1011 pattern is an actual P25 voice transmission with a 1011 Hz tone in the IMBE payload. Although it can be repeated by a repeater (it uses NAC 293, talkgroup 1, unit ID 1), you'll need to have the repeater generate the pattern itself for actual BER testing. If the repeater repeats the 1011 pattern, it will probably modify the busy status bits to reflect the status of it's input channel (as it's supposed to), which will introduce bit errors if your receiver is expecting the true standard 1011 pattern. There are a few P25 subscriber radios that will display the BER from a 1011 pattern when put into a special test mode, or display it via their programming/tuning software.

    I would think either would work well for coverage testing. I'd just go with whatever one your test receiver works with...