CHANNEL NOISE LEVEL

1. The ratio of the channel noise at any point in a transmission system to an arbitrary level chosen as a reference. ( 188 ) Note 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 ). Note 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. 2. The noise power density spectrum in the frequency range of interest. ( 188 ) 3. The average noise power in the frequency range of interest. ( 188 )