5.1 General

38.3313GPPNRProtocol specificationRadio Resource Control (RRC)Release 17TS

5.1.1 Introduction

This clause covers the general requirements.

5.1.2 General requirements

The UE shall:

1> process the received messages in order of reception by RRC, i.e. the processing of a message shall be completed before starting the processing of a subsequent message;

NOTE: Network may initiate a subsequent procedure prior to receiving the UE’s response of a previously initiated procedure.

1> within a clause execute the steps according to the order specified in the procedural description;

1> consider the term ‘radio bearer’ (RB) to cover SRBs, DRBs and MRBs unless explicitly stated otherwise;

1> set the rrc-TransactionIdentifier in the response message, if included, to the same value as included in the message received from the network that triggered the response message;

1> upon receiving a choice value set to setup:

2> apply the corresponding received configuration and start using the associated resources, unless explicitly specified otherwise;

1> upon receiving a choice value set to release:

2> clear the corresponding configuration and stop using the associated resources;

1> in case the size of a list is extended, upon receiving an extension field comprising the entries in addition to the ones carried by the original field (regardless of whether the network signals more entries in total); apply the following generic behaviour unless explicitly stated otherwise:

2> create a combined list by concatenating the additional entries included in the extension field to the original field while maintaining the order among both the original and the additional entries;

2> for the combined list, created according to the previous, apply the same behaviour as defined for the original field.

5.1.3 Requirements for UE in MR-DC

In this specification, the UE considers itself to be in:

– EN-DC, if and only if it is configured with nr-SecondaryCellGroupConfig according to TS 36.331[10], and it is connected to EPC,

– NGEN-DC, if and only if it is configured with nr-SecondaryCellGroupConfig according to TS 36.331[10], and it is connected to 5GC,

– NE-DC, if and only if it is configured with mrdc-SecondaryCellGroup set to eutra-SCG,

– NR-DC, if and only if it is configured with mrdc-SecondaryCellGroup set to nr-SCG,

– MR-DC, if and only if it is in (NG)EN-DC, NE-DC or NR-DC.

NOTE: This use of these terms deviates from the definition in TS 37.340 [41] and other specifications. In TS 37.340, these terms include also the case where the UE is configured with E-UTRA or NR MCG only (i.e. no NR or E-UTRA SCG) but with one or more bearers terminated in a secondary node (i.e. using NR PDCP).

The UE in (NG)EN-DC only executes a subclause of clause 5 in this specification when the subclause:

– is referred to from a subclause under execution, either in this specification or in TS 36.331 [10]; or

– applies to a message received on SRB3 (if SRB3 is established); or

– applies to field(s), IE(s), UE variable(s) or timer(s) in this specification that the UE is configured with.

When executing a subclause of clause 5 in this specification, the UE follows the requirements in clause 5.1.2 and in all subclauses of this specification applicable to the messages (including processing time requirements), fields, IEs, timers and UE variables indicated in the subclause under execution.