A.6 Guidelines regarding use of need codes

38.3313GPPNRProtocol specificationRadio Resource Control (RRC)Release 17TS

The following rule provides guidance for determining need codes for optional downlink fields:

– if the field needs to be stored by the UE (i.e. maintained) when absent:

– use Need M (=Maintain);

– else, if the field needs to be released by the UE when absent:

– use Need R (=Release);

– else, if UE shall take no action when the field is absent (i.e. UE does not even need to maintain any existing value of the field):

– use Need N (=None);

– else (UE behaviour upon absence does not fit any of the above conditions):

– use Need S (=Specified);

– specify the UE behaviour upon absence of the field in the procedural text or in the field description table.