Adding SCC

For most of Carrier Aggregation, it usually mean Carrier Aggregation for Downlink only. However, recently (around the second half of 2016) I was getting a demand for Carrier Aggregation for Uplink as well. In this page, I will show you typical example of RRC message for 2CC CA DL only and 2CC CA DL and UL. The decodes below are Release 10 shaped, because that is the release the messages were captured under. The last section sets them against 36.331 v19.3.0, where the same configuration reaches thirty-one secondary cells and the acknowledgement no longer has to be carried on the PCell.

RRC Connection Reconfiguration for adding SCC - 2CC - DL Only

Following is an example for RRC Connection Reconfiguration for LTE advanced (with focus on Carrier Aggregation). I just enabled all IE on ASN to give you full details of parameters, but it reality the implementation would start with very limited set of parameters enabled and leaving large portions of parameter to some 3GPP default or hardcoded configuration based on aggrement between UE maker and Network Operator.

First part you have to pay attention to this sample RRC message is sCellToAddModList-r10 which is for adding the SCC and next important thing is pucch-ConfigDedicated-v1020 which is for defining uplink control channel for reporting Ack/Nack for aggregated Carrier. With this pucch setup, UE is supposed to use PUCCH format 1b with channel selection. The operation of PUCCH 1b for 2CC Carrier Aggregation is very complicated and confusing. Refer to LTE Advanced PUCCH page for the details.

The listing below is decoder output, not specification text. Every optional field in it was forced present to show the full structure, so a live message carries far fewer of them, and no value in it has been corrected against a later release.

+-rrcConnectionReconfiguration-r8 ::= SEQUENCE [000101]
  +-measConfig ::= SEQUENCE OPTIONAL:Omit
  +-mobilityControlInfo ::= SEQUENCE OPTIONAL:Omit
  +-dedicatedInfoNASList ::= SEQUENCE OF OPTIONAL:Omit
  +-radioResourceConfigDedicated ::= SEQUENCE [000101] OPTIONAL:Exist
  | +-srb-ToAddModList ::= SEQUENCE OF OPTIONAL:Omit
  | +-drb-ToAddModList ::= SEQUENCE OF OPTIONAL:Omit
  | +-drb-ToReleaseList ::= SEQUENCE OF OPTIONAL:Omit
  | +-mac-MainConfig ::= CHOICE [explicitValue] OPTIONAL:Exist
  | | +-explicitValue ::= SEQUENCE [000]
  | |   +-ul-SCH-Config ::= SEQUENCE OPTIONAL:Omit
  | |   +-drx-Config ::= CHOICE OPTIONAL:Omit
  | |   +-timeAlignmentTimerDedicated ::= ENUMERATED [infinity]
  | |   +-phr-Config ::= CHOICE OPTIONAL:Omit
  | |   +-EXTENSION ::= SEQUENCE [01]
  | |     +-VERSION-BRACKETS1 ::= SEQUENCE OPTIONAL:Omit
  | |     +-VERSION-BRACKETS2 ::= SEQUENCE [1] OPTIONAL:Exist
  | |       +-mac-MainConfig-v1020 ::= SEQUENCE [111] OPTIONAL:Exist
  | |         +-sCellDeactivationTimer-r10 ::= ENUMERATED [rf16] OPTIONAL:Exist
  | |         +-extendedBSR-Sizes-r10 ::= ENUMERATED [setup] OPTIONAL:Exist
  | |         +-extendedPHR-r10 ::= ENUMERATED [setup] OPTIONAL:Exist
  | +-sps-Config ::= SEQUENCE OPTIONAL:Omit
  | +-physicalConfigDedicated ::= SEQUENCE [0000000000] OPTIONAL:Exist
  | | +-pdsch-ConfigDedicated ::= SEQUENCE OPTIONAL:Omit
  | | +-pucch-ConfigDedicated ::= SEQUENCE OPTIONAL:Omit
  | | +-pusch-ConfigDedicated ::= SEQUENCE OPTIONAL:Omit
  | | +-uplinkPowerControlDedicated ::= SEQUENCE OPTIONAL:Omit
  | | +-tpc-PDCCH-ConfigPUCCH ::= CHOICE OPTIONAL:Omit
  | | +-tpc-PDCCH-ConfigPUSCH ::= CHOICE OPTIONAL:Omit
  | | +-cqi-ReportConfig ::= SEQUENCE OPTIONAL:Omit
  | | +-soundingRS-UL-ConfigDedicated ::= CHOICE OPTIONAL:Omit
  | | +-antennaInfo ::= CHOICE OPTIONAL:Omit
  | | +-schedulingRequestConfig ::= CHOICE OPTIONAL:Omit
  | | +-EXTENSION ::= SEQUENCE [010]
  | |   +-VERSION-BRACKETS1 ::= SEQUENCE OPTIONAL:Omit
  | |   +-VERSION-BRACKETS2 ::= SEQUENCE [00000111111] OPTIONAL:Exist
  | |   | +-antennaInfo-r10 ::= CHOICE OPTIONAL:Omit
  | |   | +-antennaInfoUL-r10 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-cif-Presence-r10 ::= BOOLEAN OPTIONAL:Omit
  | |   | +-cqi-ReportConfig-r10 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-csi-RS-Config-r10 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-pucch-ConfigDedicated-v1020 ::= SEQUENCE [1111] OPTIONAL:Exist
  | |   | | +-pucch-Format-r10 ::= CHOICE [channelSelection-r10] OPTIONAL:Exist
  | |   | | | +-channelSelection-r10 ::= SEQUENCE [1]
  | |   | | |   +-n1PUCCH-AN-CS-r10 ::= CHOICE [setup] OPTIONAL:Exist
  | |   | | |     +-setup ::= SEQUENCE
  | |   | | |       +-n1PUCCH-AN-CS-List-r10 ::= SEQUENCE OF SIZE(1..2) [2]
  | |   | | |         +-N1PUCCH-AN-CS-r10 ::= SEQUENCE OF SIZE(1..4) [4]
  | |   | | |         | +- ::= INTEGER (0..2047) [10]
  | |   | | |         | +- ::= INTEGER (0..2047) [11]
  | |   | | |         | +- ::= INTEGER (0..2047) [12]
  | |   | | |         | +- ::= INTEGER (0..2047) [13]
  | |   | | |         +-N1PUCCH-AN-CS-r10 ::= SEQUENCE OF SIZE(1..4) [4]
  | |   | | |           +- ::= INTEGER (0..2047) [10]
  | |   | | |           +- ::= INTEGER (0..2047) [11]
  | |   | | |           +- ::= INTEGER (0..2047) [12]
  | |   | | |           +- ::= INTEGER (0..2047) [13]
  | |   | | +-twoAntennaPortActivatedPUCCH-Format1a1b-r10 ::= ENUMERATED [true] OPTIONAL:Exist
  | |   | | +-simultaneousPUCCH-PUSCH-r10 ::= ENUMERATED [true] OPTIONAL:Exist
  | |   | | +-n1PUCCH-AN-RepP1-r10 ::= INTEGER (0..2047) [0] OPTIONAL:Exist
  | |   | +-pusch-ConfigDedicated-v1020 ::= SEQUENCE [000] OPTIONAL:Exist
  | |   | | +-betaOffsetMC-r10 ::= SEQUENCE OPTIONAL:Omit
  | |   | | +-groupHoppingDisabled-r10 ::= ENUMERATED OPTIONAL:Omit
  | |   | | +-dmrs-WithOCC-Activated-r10 ::= ENUMERATED OPTIONAL:Omit
  | |   | +-schedulingRequestConfig-v1020 ::= SEQUENCE [0] OPTIONAL:Exist
  | |   | | +-sr-PUCCH-ResourceIndexP1-r10 ::= INTEGER OPTIONAL:Omit
  | |   | +-soundingRS-UL-ConfigDedicated-v1020 ::= SEQUENCE OPTIONAL:Exist
  | |   | | +-srs-AntennaPort-r10 ::= ENUMERATED [an1]
  | |   | +-soundingRS-UL-ConfigDedicatedAperiodic-r10 ::= CHOICE [setup] OPTIONAL:Exist
  | |   | | +-setup ::= SEQUENCE [11]
  | |   | |   +-srs-ConfigIndexAp-r10 ::= INTEGER (0..31) [0]
  | |   | |   +-srs-ConfigApDCI-Format4-r10 ::= SEQUENCE OF SIZE(1..3) [1] OPTIONAL:Exist
  | |   | |   | +-SRS-ConfigAp-r10 ::= SEQUENCE
  | |   | |   |   +-srs-AntennaPortAp-r10 ::= ENUMERATED [an1]
  | |   | |   |   +-srs-BandwidthAp-r10 ::= ENUMERATED [bw0]
  | |   | |   |   +-freqDomainPositionAp-r10 ::= INTEGER (0..23) [0]
  | |   | |   |   +-transmissionCombAp-r10 ::= INTEGER (0..1) [0]
  | |   | |   |   +-cyclicShiftAp-r10 ::= ENUMERATED [cs0]
  | |   | |   +-srs-ActivateAp-r10 ::= CHOICE [release] OPTIONAL:Exist
  | |   | |     +-release ::= NULL
  | |   | +-uplinkPowerControlDedicated-v1020 ::= SEQUENCE [11] OPTIONAL:Exist
  | |   |   +-deltaTxD-OffsetListPUCCH-r10 ::= SEQUENCE OPTIONAL:Exist
  | |   |   | +-deltaTxD-OffsetPUCCH-Format1-r10 ::= ENUMERATED [dB0]
  | |   |   | +-deltaTxD-OffsetPUCCH-Format1a1b-r10 ::= ENUMERATED [dB0]
  | |   |   | +-deltaTxD-OffsetPUCCH-Format22a2b-r10 ::= ENUMERATED [dB0]
  | |   |   | +-deltaTxD-OffsetPUCCH-Format3-r10 ::= ENUMERATED [dB0]
  | |   |   | +-EXTENSION ::= SEQUENCE
  | |   |   +-pSRS-OffsetAp-r10 ::= INTEGER (0..15) [0] OPTIONAL:Exist
  | |   +-VERSION-BRACKETS3 ::= SEQUENCE OPTIONAL:Omit
  | +-EXTENSION ::= SEQUENCE [00]
  |   +-VERSION-BRACKETS1 ::= SEQUENCE OPTIONAL:Omit
  |   +-VERSION-BRACKETS2 ::= SEQUENCE OPTIONAL:Omit
  +-securityConfigHO ::= SEQUENCE OPTIONAL:Omit
  +-nonCriticalExtension ::= SEQUENCE [01] OPTIONAL:Exist
    +-lateNonCriticalExtension ::= OCTET STRING OPTIONAL:Omit
    +-nonCriticalExtension ::= SEQUENCE [001] OPTIONAL:Exist
      +-otherConfig-r9 ::= SEQUENCE OPTIONAL:Omit
      +-fullConfig-r9 ::= ENUMERATED OPTIONAL:Omit
      +-nonCriticalExtension ::= SEQUENCE [010] OPTIONAL:Exist
        +-sCellToReleaseList-r10 ::= SEQUENCE OF OPTIONAL:Omit
        +-sCellToAddModList-r10 ::= SEQUENCE OF SIZE(1..maxSCell-r10[4]) [1] OPTIONAL:Exist
        | +-SCellToAddMod-r10 ::= SEQUENCE [111]
        |   +-sCellIndex-r10 ::= INTEGER (1..7) [1]
        |   +-cellIdentification-r10 ::= SEQUENCE OPTIONAL:Exist
        |   | +-physCellId-r10 ::= INTEGER (0..503) [2]
        |   | +-dl-CarrierFreq-r10 ::= INTEGER (0..maxEARFCN[65535]) [5790]
        |   +-radioResourceConfigCommonSCell-r10 ::= SEQUENCE [0] OPTIONAL:Exist
        |   | +-nonUL-Configuration-r10 ::= SEQUENCE [00]
        |   | | +-dl-Bandwidth-r10 ::= ENUMERATED [n50]
        |   | | +-antennaInfoCommon-r10 ::= SEQUENCE
        |   | | | +-antennaPortsCount ::= ENUMERATED [an2]
        |   | | +-mbsfn-SubframeConfigList-r10 ::= SEQUENCE OF OPTIONAL:Omit
        |   | | +-phich-Config-r10 ::= SEQUENCE
        |   | | | +-phich-Duration ::= ENUMERATED [normal]
        |   | | | +-phich-Resource ::= ENUMERATED [oneSixth]
        |   | | +-pdsch-ConfigCommon-r10 ::= SEQUENCE
        |   | | | +-referenceSignalPower ::= INTEGER (-60..50) [21]
        |   | | | +-p-b ::= INTEGER (0..3) [1]
        |   | | +-tdd-Config-r10 ::= SEQUENCE OPTIONAL:Omit
        |   | +-ul-Configuration-r10 ::= SEQUENCE OPTIONAL:Omit
        |   | +-EXTENSION ::= SEQUENCE
        |   +-radioResourceConfigDedicatedSCell-r10 ::= SEQUENCE [1] OPTIONAL:Exist
        |   | +-physicalConfigDedicatedSCell-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        |   | | +-nonUL-Configuration-r10 ::= SEQUENCE [1111] OPTIONAL:Exist
        |   | | | +-antennaInfo-r10 ::= SEQUENCE [1] OPTIONAL:Exist
        |   | | | | +-transmissionMode-r10 ::= ENUMERATED [tm3]
        |   | | | | +-codebookSubsetRestriction-r10 ::= BIT STRING SIZE(ALIGNED) [00] OPTIONAL:Exist
        |   | | | | +-ue-TransmitAntennaSelection ::= CHOICE [release]
        |   | | | |   +-release ::= NULL
        |   | | | +-crossCarrierSchedulingConfig-r10 ::= SEQUENCE OPTIONAL:Exist
        |   | | | | +-schedulingCellInfo-r10 ::= CHOICE [own-r10]
        |   | | | |   +-own-r10 ::= SEQUENCE
        |   | | | |     +-cif-Presence-r10 ::= BOOLEAN [FALSE]
        |   | | | +-csi-RS-Config-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        |   | | | | +-csi-RS-r10 ::= CHOICE [setup] OPTIONAL:Exist
        |   | | | | | +-setup ::= SEQUENCE
        |   | | | | |   +-antennaPortsCount-r10 ::= ENUMERATED [an1]
        |   | | | | |   +-resourceConfig-r10 ::= INTEGER (0..31) [0]
        |   | | | | |   +-subframeConfig-r10 ::= INTEGER (0..154) [0]
        |   | | | | |   +-p-C-r10 ::= INTEGER (-8..15) [-8]
        |   | | | | +-zeroTxPowerCSI-RS-r10 ::= CHOICE [setup] OPTIONAL:Exist
        |   | | | |   +-setup ::= SEQUENCE
        |   | | | |     +-zeroTxPowerResourceConfigList-r10 ::= BIT STRING SIZE(16) [0000000000000000]
        |   | | | |     +-zeroTxPowerSubframeConfig-r10 ::= INTEGER (0..154) [0]
        |   | | | +-pdsch-ConfigDedicated-r10 ::= SEQUENCE OPTIONAL:Exist
        |   | | |   +-p-a ::= ENUMERATED [dB-3]
        |   | | +-ul-Configuration-r10 ::= SEQUENCE [1111111] OPTIONAL:Exist
        |   | | | +-antennaInfoUL-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        |   | | | | +-transmissionModeUL-r10 ::= ENUMERATED [tm1] OPTIONAL:Exist
        |   | | | | +-fourAntennaPortActivated-r10 ::= ENUMERATED [setup] OPTIONAL:Exist
        |   | | | +-pusch-ConfigDedicatedSCell-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        |   | | | | +-groupHoppingDisabled-r10 ::= ENUMERATED [true] OPTIONAL:Exist
        |   | | | | +-dmrs-WithOCC-Activated-r10 ::= ENUMERATED [true] OPTIONAL:Exist
        |   | | | +-uplinkPowerControlDedicatedSCell-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        |   | | | | +-p0-UE-PUSCH-r10 ::= INTEGER (-8..7) [-8]
        |   | | | | +-deltaMCS-Enabled-r10 ::= ENUMERATED [en0]
        |   | | | | +-accumulationEnabled-r10 ::= BOOLEAN [FALSE]
        |   | | | | +-pSRS-Offset-r10 ::= INTEGER (0..15) [0]
        |   | | | | +-pSRS-OffsetAp-r10 ::= INTEGER (0..15) [0] OPTIONAL:Exist
        |   | | | | +-filterCoefficient-r10 ::= ENUMERATED [fc0] OPTIONAL:Exist
        |   | | | | +-pathlossReferenceLinking-r10 ::= ENUMERATED [pCell]
        |   | | | +-cqi-ReportConfigSCell-r10 ::= SEQUENCE [111] OPTIONAL:Exist
        |   | | | | +-cqi-ReportModeAperiodic-r10 ::= ENUMERATED [rm12] OPTIONAL:Exist
        |   | | | | +-nomPDSCH-RS-EPRE-Offset-r10 ::= INTEGER (-1..6) [-1]
        |   | | | | +-cqi-ReportPeriodicSCell-r10 ::= CHOICE [setup] OPTIONAL:Exist
        |   | | | | | +-setup ::= SEQUENCE [0000]
        |   | | | | |   +-cqi-PUCCH-ResourceIndex-r10 ::= INTEGER (0..1184) [0]
        |   | | | | |   +-cqi-PUCCH-ResourceIndexP1-r10 ::= INTEGER OPTIONAL:Omit
        |   | | | | |   +-cqi-pmi-ConfigIndex ::= INTEGER (0..1023) [0]
        |   | | | | |   +-cqi-FormatIndicatorPeriodic-r10 ::= CHOICE [widebandCQI-r10]
        |   | | | | |   | +-widebandCQI-r10 ::= SEQUENCE [0]
        |   | | | | |   |   +-csi-ReportMode-r10 ::= ENUMERATED OPTIONAL:Omit
        |   | | | | |   +-ri-ConfigIndex ::= INTEGER OPTIONAL:Omit
        |   | | | | |   +-simultaneousAckNackAndCQI ::= BOOLEAN [FALSE]
        |   | | | | |   +-cqi-Mask-r9 ::= ENUMERATED OPTIONAL:Omit
        |   | | | | |   +-csi-ConfigIndex-r10 ::= CHOICE OPTIONAL:Omit
        |   | | | | +-pmi-RI-Report-r10 ::= ENUMERATED [setup] OPTIONAL:Exist
        |   | | | +-soundingRS-UL-ConfigDedicated-r10 ::= CHOICE [setup] OPTIONAL:Exist
        |   | | | | +-setup ::= SEQUENCE
        |   | | | |   +-srs-Bandwidth ::= ENUMERATED [bw0]
        |   | | | |   +-srs-HoppingBandwidth ::= ENUMERATED [hbw0]
        |   | | | |   +-freqDomainPosition ::= INTEGER (0..23) [0]
        |   | | | |   +-duration ::= BOOLEAN [FALSE]
        |   | | | |   +-srs-ConfigIndex ::= INTEGER (0..1023) [0]
        |   | | | |   +-transmissionComb ::= INTEGER (0..1) [0]
        |   | | | |   +-cyclicShift ::= ENUMERATED [cs0]
        |   | | | +-soundingRS-UL-ConfigDedicated-v1020 ::= SEQUENCE OPTIONAL:Exist
        |   | | | | +-srs-AntennaPort-r10 ::= ENUMERATED [an1]
        |   | | | +-soundingRS-UL-ConfigDedicatedAperiodic-r10 ::= CHOICE [setup] OPTIONAL:Exist
        |   | | |   +-setup ::= SEQUENCE [11]
        |   | | |     +-srs-ConfigIndexAp-r10 ::= INTEGER (0..31) [0]
        |   | | |     +-srs-ConfigApDCI-Format4-r10 ::= SEQUENCE OF SIZE(1..3) [1] OPTIONAL:Exist
        |   | | |     | +-SRS-ConfigAp-r10 ::= SEQUENCE
        |   | | |     |   +-srs-AntennaPortAp-r10 ::= ENUMERATED [an1]
        |   | | |     |   +-srs-BandwidthAp-r10 ::= ENUMERATED [bw0]
        |   | | |     |   +-freqDomainPositionAp-r10 ::= INTEGER (0..23) [0]
        |   | | |     |   +-transmissionCombAp-r10 ::= INTEGER (0..1) [0]
        |   | | |     |   +-cyclicShiftAp-r10 ::= ENUMERATED [cs0]
        |   | | |     +-srs-ActivateAp-r10 ::= CHOICE [release] OPTIONAL:Exist
        |   | | |       +-release ::= NULL
        |   | | +-EXTENSION ::= SEQUENCE
        |   | +-EXTENSION ::= SEQUENCE
        |   +-EXTENSION ::= SEQUENCE

sCellToAddModList-r10 is the field that adds the cell : the listing prints it as SEQUENCE OF SIZE(1..maxSCell-r10[4]), and 36.331 v19.3.0 still sets maxSCell-r10 to 4. One reconfiguration in this form therefore adds at most four secondary cells.

Each entry is keyed by sCellIndex-r10 : the index is INTEGER (1..7), and every later activation, deactivation or release names the cell by it. The PCell takes no index of its own, which is why maxServCell-r10 is 5 rather than 4.

cellIdentification-r10 is what makes the entry a cell : it carries physCellId-r10 and dl-CarrierFreq-r10, so the UE learns which cell to receive on before any of the dedicated configuration under it is applied.

pucch-Format-r10 is a choice of two branches : 36.331 offers format3-r10 or channelSelection-r10, and this listing takes channelSelection-r10. That is the PUCCH format 1b with channel selection the paragraph above names.

RRC Connection Reconfiguration for adding SCC - 2CC - DL and UL

This example will show you how to add SCC1 for both Downlink and Uplink. It is allowed to establish the downlink only carrier aggregation, but it is not allowed to setup Uplink only carrier aggregation. So in most cases you would see Uplink SCC will be added at the same time when downlink SCC is added.

Example 1

The listing below is one complete reconfiguration as the decoder printed it. Two branches carry the whole of the carrier aggregation setup: sCellToAddModList-r10 near the bottom, and the ul-Configuration-r10 block inside the common configuration of the cell that list adds.

This block is a capture of one exchange. The values are the ones one network actually sent, and they are left as they were recorded.

+-rrcConnectionReconfiguration-r8 ::= SEQUENCE [000101]
  +-measConfig ::= SEQUENCE OPTIONAL:Omit
  +-mobilityControlInfo ::= SEQUENCE OPTIONAL:Omit
  +-dedicatedInfoNASList ::= SEQUENCE OF OPTIONAL:Omit
  +-radioResourceConfigDedicated ::= SEQUENCE [000101] OPTIONAL:Exist
  | +-srb-ToAddModList ::= SEQUENCE OF OPTIONAL:Omit
  | +-drb-ToAddModList ::= SEQUENCE OF OPTIONAL:Omit
  | +-drb-ToReleaseList ::= SEQUENCE OF OPTIONAL:Omit
  | +-mac-MainConfig ::= CHOICE [explicitValue] OPTIONAL:Exist
  | +-sps-Config ::= SEQUENCE OPTIONAL:Omit
  | +-physicalConfigDedicated ::= SEQUENCE [0010000000] OPTIONAL:Exist
  | | +-pdsch-ConfigDedicated ::= SEQUENCE OPTIONAL:Omit
  | | +-pucch-ConfigDedicated ::= SEQUENCE OPTIONAL:Omit
  | | +-pusch-ConfigDedicated ::= SEQUENCE OPTIONAL:Exist
  | | | +-betaOffset-ACK-Index ::= INTEGER (0..15) [10]
  | | | +-betaOffset-RI-Index ::= INTEGER (0..15) [12]
  | | | +-betaOffset-CQI-Index ::= INTEGER (0..15) [15]
  | | +-uplinkPowerControlDedicated ::= SEQUENCE OPTIONAL:Omit
  | | +-tpc-PDCCH-ConfigPUCCH ::= CHOICE OPTIONAL:Omit
  | | +-tpc-PDCCH-ConfigPUSCH ::= CHOICE OPTIONAL:Omit
  | | +-cqi-ReportConfig ::= SEQUENCE OPTIONAL:Omit
  | | +-soundingRS-UL-ConfigDedicated ::= CHOICE OPTIONAL:Omit
  | | +-antennaInfo ::= CHOICE OPTIONAL:Omit
  | | +-schedulingRequestConfig ::= CHOICE OPTIONAL:Omit
  | | +-EXTENSION ::= SEQUENCE [01000000]
  | |   +-VERSION-BRACKETS1 ::= SEQUENCE OPTIONAL:Omit
  | |   +-VERSION-BRACKETS2 ::= SEQUENCE [00000100000] OPTIONAL:Exist
  | |   | +-antennaInfo-r10 ::= CHOICE OPTIONAL:Omit
  | |   | +-antennaInfoUL-r10 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-cif-Presence-r10 ::= BOOLEAN OPTIONAL:Omit
  | |   | +-cqi-ReportConfig-r10 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-csi-RS-Config-r10 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-pucch-ConfigDedicated-v1020 ::= SEQUENCE [1000] OPTIONAL:Exist
  | |   | | +-pucch-Format-r10 ::= CHOICE [channelSelection-r10] OPTIONAL:Exist
  | |   | | | +-channelSelection-r10 ::= SEQUENCE [1]
  | |   | | |   +-n1PUCCH-AN-CS-r10 ::= CHOICE [setup] OPTIONAL:Exist
  | |   | | |     +-setup ::= SEQUENCE
  | |   | | |       +-n1PUCCH-AN-CS-List-r10 ::= SEQUENCE OF SIZE(1..2) [2]
  | |   | | |         +-N1PUCCH-AN-CS-r10 ::= SEQUENCE OF SIZE(1..4) [4]
  | |   | | |         | +- ::= INTEGER (0..2047) [361]
  | |   | | |         | +- ::= INTEGER (0..2047) [362]
  | |   | | |         | +- ::= INTEGER (0..2047) [363]
  | |   | | |         | +- ::= INTEGER (0..2047) [364]
  | |   | | |         +-N1PUCCH-AN-CS-r10 ::= SEQUENCE OF SIZE(1..4) [4]
  | |   | | |           +- ::= INTEGER (0..2047) [365]
  | |   | | |           +- ::= INTEGER (0..2047) [366]
  | |   | | |           +- ::= INTEGER (0..2047) [367]
  | |   | | |           +- ::= INTEGER (0..2047) [368]
  | |   | | +-twoAntennaPortActivatedPUCCH-Format1a1b-r10 ::= ENUMERATED OPTIONAL:Omit
  | |   | | +-simultaneousPUCCH-PUSCH-r10 ::= ENUMERATED OPTIONAL:Omit
  | |   | | +-n1PUCCH-AN-RepP1-r10 ::= INTEGER OPTIONAL:Omit
  | |   | +-pusch-ConfigDedicated-v1020 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-schedulingRequestConfig-v1020 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-soundingRS-UL-ConfigDedicated-v1020 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-soundingRS-UL-ConfigDedicatedAperiodic-r10 ::= CHOICE OPTIONAL:Omit
  | |   | +-uplinkPowerControlDedicated-v1020 ::= SEQUENCE OPTIONAL:Omit
  | +-EXTENSION ::= SEQUENCE [00000]
  +-securityConfigHO ::= SEQUENCE OPTIONAL:Omit
  +-nonCriticalExtension ::= SEQUENCE [01] OPTIONAL:Exist
    +-lateNonCriticalExtension ::= OCTET STRING OPTIONAL:Omit
    +-nonCriticalExtension ::= SEQUENCE [001] OPTIONAL:Exist
      +-otherConfig-r9 ::= SEQUENCE OPTIONAL:Omit
      +-fullConfig-r9 ::= ENUMERATED OPTIONAL:Omit
      +-nonCriticalExtension ::= SEQUENCE [010] OPTIONAL:Exist
        +-sCellToReleaseList-r10 ::= SEQUENCE OF OPTIONAL:Omit
        +-sCellToAddModList-r10 ::= SEQUENCE OF SIZE(1..maxSCell-r10[4]) [1] OPTIONAL:Exist
        | +-SCellToAddMod-r10 ::= SEQUENCE [111]
        |   +-sCellIndex-r10 ::= INTEGER (1..7) [1]
        |   +-cellIdentification-r10 ::= SEQUENCE OPTIONAL:Exist
        |   | +-physCellId-r10 ::= INTEGER (0..503) [0]
        |   | +-dl-CarrierFreq-r10 ::= INTEGER (0..maxEARFCN[65535]) [3100]
        |   +-radioResourceConfigCommonSCell-r10 ::= SEQUENCE [1] OPTIONAL:Exist
        |   | +-nonUL-Configuration-r10 ::= SEQUENCE [00]
        |   | | +-dl-Bandwidth-r10 ::= ENUMERATED [n100]
        |   | | +-antennaInfoCommon-r10 ::= SEQUENCE
        |   | | | +-antennaPortsCount ::= ENUMERATED [an1]
        |   | | +-mbsfn-SubframeConfigList-r10 ::= SEQUENCE OF OPTIONAL:Omit
        |   | | +-phich-Config-r10 ::= SEQUENCE
        |   | | | +-phich-Duration ::= ENUMERATED [normal]
        |   | | | +-phich-Resource ::= ENUMERATED [one]
        |   | | +-pdsch-ConfigCommon-r10 ::= SEQUENCE
        |   | | | +-referenceSignalPower ::= INTEGER (-60..50) [18]
        |   | | | +-p-b ::= INTEGER (0..3) [0]
        |   | | +-tdd-Config-r10 ::= SEQUENCE OPTIONAL:Omit
        |   | +-ul-Configuration-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        |   | | +-ul-FreqInfo-r10 ::= SEQUENCE [11]
        |   | | | +-ul-CarrierFreq-r10 ::= INTEGER (0..maxEARFCN[65535]) [21100] OPTIONAL:Exist
        |   | | | +-ul-Bandwidth-r10 ::= ENUMERATED [n100] OPTIONAL:Exist
        |   | | | +-additionalSpectrumEmissionSCell-r10 ::= INTEGER (1..32) [1]
        |   | | +-p-Max-r10 ::= INTEGER (-30..33) [23] OPTIONAL:Exist
        |   | | +-uplinkPowerControlCommonSCell-r10 ::= SEQUENCE
        |   | | | +-p0-NominalPUSCH-r10 ::= INTEGER (-126..24) [-85]
        |   | | | +-alpha-r10 ::= ENUMERATED [al08]
        |   | | +-soundingRS-UL-ConfigCommon-r10 ::= CHOICE [release]
        |   | | | +-release ::= NULL
        |   | | +-ul-CyclicPrefixLength-r10 ::= ENUMERATED [len1]
        |   | | +-prach-ConfigSCell-r10 ::= SEQUENCE OPTIONAL:Exist
        |   | | | +-prach-ConfigIndex-r10 ::= INTEGER (0..63) [3]
        |   | | +-pusch-ConfigCommon-r10 ::= SEQUENCE
        |   | |   +-pusch-ConfigBasic ::= SEQUENCE
        |   | |   | +-n-SB ::= INTEGER (1..4) [1]
        |   | |   | +-hoppingMode ::= ENUMERATED [interSubFrame]
        |   | |   | +-pusch-HoppingOffset ::= INTEGER (0..98) [16]
        |   | |   | +-enable64QAM ::= BOOLEAN [FALSE]
        |   | |   +-ul-ReferenceSignalsPUSCH ::= SEQUENCE
        |   | |     +-groupHoppingEnabled ::= BOOLEAN [TRUE]
        |   | |     +-groupAssignmentPUSCH ::= INTEGER (0..29) [0]
        |   | |     +-sequenceHoppingEnabled ::= BOOLEAN [FALSE]
        |   | |     +-cyclicShift ::= INTEGER (0..7) [0]
        |   | +-EXTENSION ::= SEQUENCE [0000]
        |   +-radioResourceConfigDedicatedSCell-r10 ::= SEQUENCE [1] OPTIONAL:Exist
        |   | +-physicalConfigDedicatedSCell-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        |   | | +-nonUL-Configuration-r10 ::= SEQUENCE [1001] OPTIONAL:Exist
        |   | | | +-antennaInfo-r10 ::= SEQUENCE [0] OPTIONAL:Exist
        |   | | | | +-transmissionMode-r10 ::= ENUMERATED [tm1]
        |   | | | | +-codebookSubsetRestriction-r10 ::= BIT STRING OPTIONAL:Omit
        |   | | | | +-ue-TransmitAntennaSelection ::= CHOICE [release]
        |   | | | |   +-release ::= NULL
        |   | | | +-crossCarrierSchedulingConfig-r10 ::= SEQUENCE OPTIONAL:Omit
        |   | | | +-csi-RS-Config-r10 ::= SEQUENCE OPTIONAL:Omit
        |   | | | +-pdsch-ConfigDedicated-r10 ::= SEQUENCE OPTIONAL:Exist
        |   | | |   +-p-a ::= ENUMERATED [dB0]
        |   | | +-ul-Configuration-r10 ::= SEQUENCE [1011000] OPTIONAL:Exist
        |   | | | +-antennaInfoUL-r10 ::= SEQUENCE [10] OPTIONAL:Exist
        |   | | | | +-transmissionModeUL-r10 ::= ENUMERATED [tm1] OPTIONAL:Exist
        |   | | | | +-fourAntennaPortActivated-r10 ::= ENUMERATED OPTIONAL:Omit
        |   | | | +-pusch-ConfigDedicatedSCell-r10 ::= SEQUENCE OPTIONAL:Omit
        |   | | | +-uplinkPowerControlDedicatedSCell-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        |   | | | | +-p0-UE-PUSCH-r10 ::= INTEGER (-8..7) [0]
        |   | | | | +-deltaMCS-Enabled-r10 ::= ENUMERATED [en0]
        |   | | | | +-accumulationEnabled-r10 ::= BOOLEAN [TRUE]
        |   | | | | +-pSRS-Offset-r10 ::= INTEGER (0..15) [0]
        |   | | | | +-pSRS-OffsetAp-r10 ::= INTEGER (0..15) [0] OPTIONAL:Exist
        |   | | | | +-filterCoefficient-r10 ::= ENUMERATED [fc4] OPTIONAL:Exist
        |   | | | | +-pathlossReferenceLinking-r10 ::= ENUMERATED [pCell]
        |   | | | +-cqi-ReportConfigSCell-r10 ::= SEQUENCE [110] OPTIONAL:Exist
        |   | | | | +-cqi-ReportModeAperiodic-r10 ::= ENUMERATED [rm30] OPTIONAL:Exist
        |   | | | | +-nomPDSCH-RS-EPRE-Offset-r10 ::= INTEGER (-1..6) [0]
        |   | | | | +-cqi-ReportPeriodicSCell-r10 ::= CHOICE [release] OPTIONAL:Exist
        |   | | | | | +-release ::= NULL
        |   | | | | +-pmi-RI-Report-r10 ::= ENUMERATED OPTIONAL:Omit
        |   | | | +-soundingRS-UL-ConfigDedicated-r10 ::= CHOICE OPTIONAL:Omit
        |   | | | +-soundingRS-UL-ConfigDedicated-v1020 ::= SEQUENCE OPTIONAL:Omit
        |   | | | +-soundingRS-UL-ConfigDedicatedAperiodic-r10 ::= CHOICE OPTIONAL:Omit
        |   | | +-EXTENSION ::= SEQUENCE [00000]
        |   | +-EXTENSION ::= SEQUENCE [000]
        |   +-EXTENSION ::= SEQUENCE [00]
        +-nonCriticalExtension ::= SEQUENCE OPTIONAL:Omit

The uplink arrives with the cell, not after it : ul-Configuration-r10 sits inside radioResourceConfigCommonSCell-r10 of the same sCellToAddModList-r10 entry, so the uplink carrier is configured in the very message that adds the cell.

The two halves are not equal : 36.331 makes nonUL-Configuration-r10 a mandatory member of RadioResourceConfigCommonSCell-r10 and ul-Configuration-r10 an optional one. That asymmetry is the structural reason a downlink only secondary cell is allowed and an uplink only one is not.

ul-CarrierFreq-r10 need not be sent : 36.331 marks it Need OP inside ul-FreqInfo-r10, so an uplink can be configured without it. This listing supplies it, and the decoder prints it as OPTIONAL:Exist.

Example 2

The second listing is the same configuration on a different carrier. Only two values move between the two decodes, so reading them side by side separates what belongs to the cell from what belongs to the configuration applied to it.

A second capture, again left exactly as it was recorded.

+-rrcConnectionReconfiguration-r8 ::= SEQUENCE [000101]
  +-measConfig ::= SEQUENCE OPTIONAL:Omit
  +-mobilityControlInfo ::= SEQUENCE OPTIONAL:Omit
  +-dedicatedInfoNASList ::= SEQUENCE OF OPTIONAL:Omit
  +-radioResourceConfigDedicated ::= SEQUENCE [000101] OPTIONAL:Exist
  | +-srb-ToAddModList ::= SEQUENCE OF OPTIONAL:Omit
  | +-drb-ToAddModList ::= SEQUENCE OF OPTIONAL:Omit
  | +-drb-ToReleaseList ::= SEQUENCE OF OPTIONAL:Omit
  | +-mac-MainConfig ::= CHOICE [explicitValue] OPTIONAL:Exist
  | +-sps-Config ::= SEQUENCE OPTIONAL:Omit
  | +-physicalConfigDedicated ::= SEQUENCE [0010000000] OPTIONAL:Exist
  | | +-pdsch-ConfigDedicated ::= SEQUENCE OPTIONAL:Omit
  | | +-pucch-ConfigDedicated ::= SEQUENCE OPTIONAL:Omit
  | | +-pusch-ConfigDedicated ::= SEQUENCE OPTIONAL:Exist
  | | | +-betaOffset-ACK-Index ::= INTEGER (0..15) [10]
  | | | +-betaOffset-RI-Index ::= INTEGER (0..15) [12]
  | | | +-betaOffset-CQI-Index ::= INTEGER (0..15) [15]
  | | +-uplinkPowerControlDedicated ::= SEQUENCE OPTIONAL:Omit
  | | +-tpc-PDCCH-ConfigPUCCH ::= CHOICE OPTIONAL:Omit
  | | +-tpc-PDCCH-ConfigPUSCH ::= CHOICE OPTIONAL:Omit
  | | +-cqi-ReportConfig ::= SEQUENCE OPTIONAL:Omit
  | | +-soundingRS-UL-ConfigDedicated ::= CHOICE OPTIONAL:Omit
  | | +-antennaInfo ::= CHOICE OPTIONAL:Omit
  | | +-schedulingRequestConfig ::= CHOICE OPTIONAL:Omit
  | | +-EXTENSION ::= SEQUENCE [01000000]
  | |   +-VERSION-BRACKETS1 ::= SEQUENCE OPTIONAL:Omit
  | |   +-VERSION-BRACKETS2 ::= SEQUENCE [00000100000] OPTIONAL:Exist
  | |   | +-antennaInfo-r10 ::= CHOICE OPTIONAL:Omit
  | |   | +-antennaInfoUL-r10 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-cif-Presence-r10 ::= BOOLEAN OPTIONAL:Omit
  | |   | +-cqi-ReportConfig-r10 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-csi-RS-Config-r10 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-pucch-ConfigDedicated-v1020 ::= SEQUENCE [1000] OPTIONAL:Exist
  | |   | | +-pucch-Format-r10 ::= CHOICE [channelSelection-r10] OPTIONAL:Exist
  | |   | | | +-channelSelection-r10 ::= SEQUENCE [1]
  | |   | | |   +-n1PUCCH-AN-CS-r10 ::= CHOICE [setup] OPTIONAL:Exist
  | |   | | |     +-setup ::= SEQUENCE
  | |   | | |       +-n1PUCCH-AN-CS-List-r10 ::= SEQUENCE OF SIZE(1..2) [2]
  | |   | | |         +-N1PUCCH-AN-CS-r10 ::= SEQUENCE OF SIZE(1..4) [4]
  | |   | | |         | +- ::= INTEGER (0..2047) [361]
  | |   | | |         | +- ::= INTEGER (0..2047) [362]
  | |   | | |         | +- ::= INTEGER (0..2047) [363]
  | |   | | |         | +- ::= INTEGER (0..2047) [364]
  | |   | | |         +-N1PUCCH-AN-CS-r10 ::= SEQUENCE OF SIZE(1..4) [4]
  | |   | | |           +- ::= INTEGER (0..2047) [365]
  | |   | | |           +- ::= INTEGER (0..2047) [366]
  | |   | | |           +- ::= INTEGER (0..2047) [367]
  | |   | | |           +- ::= INTEGER (0..2047) [368]
  | |   | | +-twoAntennaPortActivatedPUCCH-Format1a1b-r10 ::= ENUMERATED OPTIONAL:Omit
  | |   | | +-simultaneousPUCCH-PUSCH-r10 ::= ENUMERATED OPTIONAL:Omit
  | |   | | +-n1PUCCH-AN-RepP1-r10 ::= INTEGER OPTIONAL:Omit
  | |   | +-pusch-ConfigDedicated-v1020 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-schedulingRequestConfig-v1020 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-soundingRS-UL-ConfigDedicated-v1020 ::= SEQUENCE OPTIONAL:Omit
  | |   | +-soundingRS-UL-ConfigDedicatedAperiodic-r10 ::= CHOICE OPTIONAL:Omit
  | |   | +-uplinkPowerControlDedicated-v1020 ::= SEQUENCE OPTIONAL:Omit
  +-securityConfigHO ::= SEQUENCE OPTIONAL:Omit
  +-nonCriticalExtension ::= SEQUENCE [01] OPTIONAL:Exist
    +-lateNonCriticalExtension ::= OCTET STRING OPTIONAL:Omit
    +-nonCriticalExtension ::= SEQUENCE [001] OPTIONAL:Exist
      +-otherConfig-r9 ::= SEQUENCE OPTIONAL:Omit
      +-fullConfig-r9 ::= ENUMERATED OPTIONAL:Omit
      +-nonCriticalExtension ::= SEQUENCE [010] OPTIONAL:Exist
        +-sCellToReleaseList-r10 ::= SEQUENCE OF OPTIONAL:Omit
        +-sCellToAddModList-r10 ::= SEQUENCE OF SIZE(1..maxSCell-r10[4]) [1] OPTIONAL:Exist
        | +-SCellToAddMod-r10 ::= SEQUENCE [111]
        |   +-sCellIndex-r10 ::= INTEGER (1..7) [1]
        |   +-cellIdentification-r10 ::= SEQUENCE OPTIONAL:Exist
        |   | +-physCellId-r10 ::= INTEGER (0..503) [0]
        |   | +-dl-CarrierFreq-r10 ::= INTEGER (0..maxEARFCN[65535]) [3048]
        |   +-radioResourceConfigCommonSCell-r10 ::= SEQUENCE [1] OPTIONAL:Exist
        |   | +-nonUL-Configuration-r10 ::= SEQUENCE [00]
        |   | | +-dl-Bandwidth-r10 ::= ENUMERATED [n100]
        |   | | +-antennaInfoCommon-r10 ::= SEQUENCE
        |   | | | +-antennaPortsCount ::= ENUMERATED [an1]
        |   | | +-mbsfn-SubframeConfigList-r10 ::= SEQUENCE OF OPTIONAL:Omit
        |   | | +-phich-Config-r10 ::= SEQUENCE
        |   | | | +-phich-Duration ::= ENUMERATED [normal]
        |   | | | +-phich-Resource ::= ENUMERATED [one]
        |   | | +-pdsch-ConfigCommon-r10 ::= SEQUENCE
        |   | | | +-referenceSignalPower ::= INTEGER (-60..50) [18]
        |   | | | +-p-b ::= INTEGER (0..3) [0]
        |   | | +-tdd-Config-r10 ::= SEQUENCE OPTIONAL:Omit
        |   | +-ul-Configuration-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        |   | | +-ul-FreqInfo-r10 ::= SEQUENCE [11]
        |   | | | +-ul-CarrierFreq-r10 ::= INTEGER (0..maxEARFCN[65535]) [21048] OPTIONAL:Exist
        |   | | | +-ul-Bandwidth-r10 ::= ENUMERATED [n100] OPTIONAL:Exist
        |   | | | +-additionalSpectrumEmissionSCell-r10 ::= INTEGER (1..32) [1]
        |   | | +-p-Max-r10 ::= INTEGER (-30..33) [23] OPTIONAL:Exist
        |   | | +-uplinkPowerControlCommonSCell-r10 ::= SEQUENCE
        |   | | | +-p0-NominalPUSCH-r10 ::= INTEGER (-126..24) [-85]
        |   | | | +-alpha-r10 ::= ENUMERATED [al08]
        |   | | +-soundingRS-UL-ConfigCommon-r10 ::= CHOICE [release]
        |   | | | +-release ::= NULL
        |   | | +-ul-CyclicPrefixLength-r10 ::= ENUMERATED [len1]
        |   | | +-prach-ConfigSCell-r10 ::= SEQUENCE OPTIONAL:Exist
        |   | | | +-prach-ConfigIndex-r10 ::= INTEGER (0..63) [3]
        |   | | +-pusch-ConfigCommon-r10 ::= SEQUENCE
        |   | |   +-pusch-ConfigBasic ::= SEQUENCE
        |   | |   | +-n-SB ::= INTEGER (1..4) [1]
        |   | |   | +-hoppingMode ::= ENUMERATED [interSubFrame]
        |   | |   | +-pusch-HoppingOffset ::= INTEGER (0..98) [16]
        |   | |   | +-enable64QAM ::= BOOLEAN [FALSE]
        |   | |   +-ul-ReferenceSignalsPUSCH ::= SEQUENCE
        |   | |     +-groupHoppingEnabled ::= BOOLEAN [TRUE]
        |   | |     +-groupAssignmentPUSCH ::= INTEGER (0..29) [0]
        |   | |     +-sequenceHoppingEnabled ::= BOOLEAN [FALSE]
        |   | |     +-cyclicShift ::= INTEGER (0..7) [0]
        |   +-radioResourceConfigDedicatedSCell-r10 ::= SEQUENCE [1] OPTIONAL:Exist
        |   | +-physicalConfigDedicatedSCell-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        |   | | +-nonUL-Configuration-r10 ::= SEQUENCE [1001] OPTIONAL:Exist
        |   | | | +-antennaInfo-r10 ::= SEQUENCE [0] OPTIONAL:Exist
        |   | | | | +-transmissionMode-r10 ::= ENUMERATED [tm1]
        |   | | | | +-codebookSubsetRestriction-r10 ::= BIT STRING OPTIONAL:Omit
        |   | | | | +-ue-TransmitAntennaSelection ::= CHOICE [release]
        |   | | | |   +-release ::= NULL
        |   | | | +-crossCarrierSchedulingConfig-r10 ::= SEQUENCE OPTIONAL:Omit
        |   | | | +-csi-RS-Config-r10 ::= SEQUENCE OPTIONAL:Omit
        |   | | | +-pdsch-ConfigDedicated-r10 ::= SEQUENCE OPTIONAL:Exist
        |   | | |   +-p-a ::= ENUMERATED [dB0]
        |   | | +-ul-Configuration-r10 ::= SEQUENCE [1011000] OPTIONAL:Exist
        |   | | | +-antennaInfoUL-r10 ::= SEQUENCE [10] OPTIONAL:Exist
        |   | | | | +-transmissionModeUL-r10 ::= ENUMERATED [tm1] OPTIONAL:Exist
        |   | | | | +-fourAntennaPortActivated-r10 ::= ENUMERATED OPTIONAL:Omit
        |   | | | +-pusch-ConfigDedicatedSCell-r10 ::= SEQUENCE OPTIONAL:Omit
        |   | | | +-uplinkPowerControlDedicatedSCell-r10 ::= SEQUENCE [11] OPTIONAL:Exist
        |   | | | | +-p0-UE-PUSCH-r10 ::= INTEGER (-8..7) [0]
        |   | | | | +-deltaMCS-Enabled-r10 ::= ENUMERATED [en0]
        |   | | | | +-accumulationEnabled-r10 ::= BOOLEAN [TRUE]
        |   | | | | +-pSRS-Offset-r10 ::= INTEGER (0..15) [0]
        |   | | | | +-pSRS-OffsetAp-r10 ::= INTEGER (0..15) [0] OPTIONAL:Exist
        |   | | | | +-filterCoefficient-r10 ::= ENUMERATED [fc4] OPTIONAL:Exist
        |   | | | | +-pathlossReferenceLinking-r10 ::= ENUMERATED [pCell]
        |   | | | +-cqi-ReportConfigSCell-r10 ::= SEQUENCE [110] OPTIONAL:Exist
        |   | | | | +-cqi-ReportModeAperiodic-r10 ::= ENUMERATED [rm30] OPTIONAL:Exist
        |   | | | | +-nomPDSCH-RS-EPRE-Offset-r10 ::= INTEGER (-1..6) [0]
        |   | | | | +-cqi-ReportPeriodicSCell-r10 ::= CHOICE [release] OPTIONAL:Exist
        |   | | | | | +-release ::= NULL
        |   | | | | +-pmi-RI-Report-r10 ::= ENUMERATED OPTIONAL:Omit
        |   | | | +-soundingRS-UL-ConfigDedicated-r10 ::= CHOICE OPTIONAL:Omit
        |   | | | +-soundingRS-UL-ConfigDedicated-v1020 ::= SEQUENCE OPTIONAL:Omit
        |   | | | +-soundingRS-UL-ConfigDedicatedAperiodic-r10 ::= CHOICE OPTIONAL:Omit

Two values separate the two listings : dl-CarrierFreq-r10 reads 3048 here against 3100 above, and ul-CarrierFreq-r10 reads 21048 against 21100. Every other line in the two decodes is identical.

This decode stops early : it ends at soundingRS-UL-ConfigDedicatedAperiodic-r10, and the closing EXTENSION lines and the nonCriticalExtension that the listing above carries are missing from it. The capture is left truncated rather than completed.

How far the SCell configuration has moved since Release 10

The decodes above belong to Release 10, and 36.331 has changed a great deal since. A second list configures a UE that supports more than five component carriers. A secondary cell can be added in a state that is neither active nor released. The acknowledgement need no longer be carried on the PCell. This section names the fields that carry those changes.

The four cell limit belongs to one list, not to the feature : 36.331 v19.3.0 still sets maxSCell-r10 to 4, and it adds sCellToAddModListExt-r13 for every cell past the first four. The second list is bounded by maxSCell-r13, which is 31.

The index range grew with it : SCellIndex-r10 is INTEGER (1..7) and SCellIndex-r13 is INTEGER (1..31), while maxServCell went from 5 in Release 10 to 32 in Release 13.

A secondary cell can now be added dormant : SCellToAddMod-r10 carries an extension group holding sCellState-r15, an ENUMERATED of activated and dormant. The cell can therefore be configured in a state the listings above cannot express.

Release 14 added a sounding reference signal field : the extension group before that one holds srs-SwitchFromServCellIndex-r14, INTEGER (0..31), which names a serving cell by its index.

The extension lists are matched by position : 36.331 requires sCellToAddModListExt-v1370, sCellToAddModList-v10l0 and sCellToAddModListExt-v13c0 to hold the same number of entries as the list they extend, and in the same order. A reader matches them by position, because none of them repeats the index.

Dual connectivity doubles the lists again : sCellToAddModListSCG-r12 carries the secondary cells of the secondary cell group, and it is paired with sCellToAddModListSCG-Ext-r13 exactly as the master group's pair works.

Release 15 groups the cells : sCellGroupToAddModList-r15 arrived beside the flat list, with maxSCellGroups-r15 set to 4, so secondary cells can be handled as groups rather than one at a time.

PUCCH is no longer tied to the PCell : pucch-SCell appeared in Release 13, and PUCCH-ConfigDedicated-r13 replaced the v1020 extension chain with one structure carrying format4-r13 and format5-r13 beside the channel selection branch the listings above use.

The Release 10 list is still the one a five carrier UE uses : 36.331 says sCellToAddModList-r10 is used to add or modify SCells for a UE that does not support carrier aggregation with more than five component carriers. The decodes above are therefore not superseded. They are the branch that still applies.

Reference

One specification carries every field named on this page. It was resolved at v19.3.0, which is the latest published version at the time of writing.

3GPP TS 36.331 v19.3.0, E-UTRA Radio Resource Control protocol specification. RRCConnectionReconfiguration, SCellToAddMod-r10, RadioResourceConfigCommonSCell-r10 and the PUCCH-ConfigDedicated family.
LTE Advanced PUCCH, the page this one sends the reader to for PUCCH format 1b with channel selection.