Section: 11.2.3 Mandatory information in inter-node RRC messages
Content: For the AS-Config transferred within the HandoverPreparationInformation: - The source node shall include all fields necessary to reflect the current AS configuration of the UE, except for the fields sourceSCG-NR-Config, sourceSCG-EUTRA-Config and sourceRB-SN-Config, which can be omitted in case the source MN did not receive the latest configuration from the source SN. For RRCReconfiguration included in the field rrcReconfiguration, ReconfigurationWithSync is included with only the mandatory subfields (e.g. newUE-Identity and t304) and ServingCellConfigCommon; - Need codes or conditions specified for subfields according to IEs defined in clause 6 do not apply. I.e. some fields shall be included regardless of the "Need" or "Cond" e.g. discardTimer; - Based on the received AS configuration, the target node can indicate the delta (difference) to the current AS configuration (as included in HandoverCommand)to the UE. The fields newUE-Identity and t304 included in ReconfigurationWithSync are not used for delta configuration purpose. The candidateCellInfoListSN(-EUTRA) in CG-Config and the candidateCellInfoListMN(-EUTRA)/candidateCellInfoListSN(-EUTRA) in CG-ConfigInfo need not be included in procedures that do not involve a change of node. For fields scg-CellGroupConfig, scg-CellGroupConfigEUTRA and scg-RB-Config in CG-Config (sent upon SN initiated SN change or other conditions as specified in field descriptions) and fields mcg-RB-Config, scg-RB-Config and sourceConfigSCG in CG-ConfigInfo (sent upon change of SN): - The source node shall include all fields necessary to reflect the current AS configuration of the UE, unless stated otherwise in the field description. For RRCReconfiguration included in the field scg-CellGroupConfig in CG-Config, ReconfigurationWithSync is included with only the mandatory subfields (e.g. newUE-Identity and t304) and ServingCellConfigCommon; - Need codes or conditions specified for subfields according to IEs defined in clause 6 do not apply; - Based on the received AS configuration, the target node can indicate the delta (difference) as compared to the current AS configuration to the UE. The fields newUE-Identity and t304 in ReconfigurationWithSync are always included by the target node, i.e. they are not used for delta configuration purpose to UE. For fields in CG-Config and CG-ConfigInfo listed below, absence of the field means that the receiver maintains the values informed via the previous message. Note that every time there is a change in the configuration covered by a listed field, the MN or SN shall include the field and it shall provide the full configuration provided by that field unless stated otherwise. Otherwise, if there is no change, the field can be omitted: - configRestrictInfo; - gapPurpose; - measGapConfig (for which delta signaling applies); - measGapConfigFR2 (for which delta signaling applies); - measResultCellListSFTD; - measResultSFTD-EUTRA; - sftdFrequencyList-EUTRA; - sftdFrequencyList-NR; - ue-CapabilityInfo; - servFrequenciesMN-NR. For other fields in CG-Config and CG-ConfigInfo, the sender shall always signal the appropriate value even if same as indicated in the previous inter-node message, unless explicitly stated otherwise.