Sec. 87.135  Bandwidth of emission.

    (a) Occupied bandwidth is the width of a frequency band such that, 
below the lower and above the upper frequency limits, the mean powers 
emitted are each equal to 0.5 percent of the total mean power of a given 
emission.
    (b) The authorized bandwidth is the maximum occupied bandwidth 
authorized to be used by a station.
    (c) The necessary bandwidth for a given class of emission is the 
width of the frequency band which is just sufficient to ensure the 
transmission of information at the rate and with the quality required 
under specified conditions.