OCCUPIED BANDWIDTH

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 a specified percentage B /2 of the total mean power of a given emission . Unless otherwise specified by the CCIR for the appropriate class of emission , the value of B /2 should be taken as 0.5%. [ NTIA ] [ RR ] ( 188 ) Note 1: The percentage of the total power outside the occupied bandwidth is represented by B . Note 2: In some cases, e.g. , multichannel frequency-division multiplexing systems, use of the 0.5% limits may lead to certain difficulties in the practical application of the definition of occupied and necessary bandwidth ; in such cases, a different percentage may prove useful.