The lower frequency configured in spectrum group. This is a
mandatory object and can be modified when the row is active.
To configure a band frequency in the spectrum group, the value
of this object must be lower than the value of the corresponding
instance of ccsSpecGroupFreqUpper. To configure a fixed center
frequency in the spectrum group, the value of this object must
be equal to the value of the corresponding instance of
ccsSpecGroupFreqUpper.