sorry, your question was RxQual vs RxQual %, not Full vs Sub…
The RxQual defined on the GSM standard 05.08 is not in %. It is a value from 0 to 7, corresponding to BER ranges.
I suppose the RxQual %, since it is not a standard-defined parameter, may or not have different definitions on different measurement systems, but for Ericsson TEMS Investigation, it means the bit error rate corresponding to the RxQual (number) reported. For this system, the % values range from 0 to 26%, and the (number) values from 0 to 7, and their relationship is as defined on GS 05.08.
BR,
Joao S Veiga