# Channel noise level

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In telecommunications, the term channel noise level has the following meanings:

## Contents

1. The ratio of the noise in the communication channel at any point in a transmission system to an arbitrary level chosen as a reference. [lower-alpha 1] [lower-alpha 2]
2. The noise power spectral density in the frequency range of interest.
3. The average noise power in the frequency range of interest.

## Notes

1. The channel noise level may be expressed in (a) dB above reference noise (dBrn), (b) dB above reference noise with C-message weighting (dBrnC), or (c) adjusted dB (dBa).
2. Each unit used to measure channel noise level reflects a circuit noise reading of a specialized instrument designed to account for different interference effects that occur under specified conditions.

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## References

•  This article incorporates  public domain material from the General Services Administration document: "Federal Standard 1037C".(in support of MIL-STD-188)