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• #9656 vOrOn tag M@Db0Y #9654

  2010-03-10 11:14:20 #9656

  Összes hozzászólása itt Válaszok az összes hozzászólására itt Válaszok erre a hozzászólásra

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  vOrOn

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  válasz M@Db0Y #9654 üzenetére

  Lusta vagyok lefordítani, elnézést.

  Downstream (Rx) Receive Power Level:

  For all modems:

  -15 dBmV to +15 dBmV maximum.
  -12 dBmV to +12 dBmV recommended.
  0 dBmV is the "optimal" level.

  Upstream (Tx) Transmit Power (a.k.a. Return Signal) level:

  +8 dBmV to +58 dBmV maximum for QPSK. (DOCSIS 1.x)
  +8 dBmV to +55 dBmV maximum for 8 QAM and 16 QAM. (DOCSIS 1.x)
  +8 dBmV to +54 dBmV maximum for 32 QAM and 64 QAM. (A-TDMA DOCSIS 2.0)
  +8 dBmV to +53 dBmV maximum for S-CDMA DOCSIS 2.0 modulation rates.
  Recommended upstream signal levels are +35 dBmV to +52 dBmV.

  SNR (signal to noise ratio) levels:

  QPSK: 12 dB minimum. 15 dB or higher recommended. (often used in upstream channels)
  16 QAM: 18 dB minimum. 21 dB or higher recommended. (often used in upstream channels)
  64 QAM: 24 dB minimum. 27 dB or higher recommended. (often used in downstream channels)
  256 QAM: 30 dB minimum. 33 dB or higher recommended. (often used in downstream channels)
  There is no upper SNR limit, although in practice 40 dB is about the highest seen.

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