LTE Advanced - Handover                            Home : www.sharetechnote.com

 

 

 

There can be many different scenario (combination) of Handover with Carrier Aggregation. I will start with the simplest case, but recently I am seeing various requirement to reduce the number of steps for Handover (e.g, PCC handover and adding SCC in a single RRC Connection Reconfiguration etc).

 

Case 1 : Remove SCC before Handover -> HO for PCC -> Add SCC

 

Probably one of the simplest case of scenario we can think of would be  as follows (By 'the simplest case', I mean it is the simplest in logic (the easiest to understand/implement), it didn't mean that it is the simplest in terms of the number of protocol sequence. Actually, it requires the longest steps in terms of protocol sequence). As you see here, just PCC has been changed as final result of Handover. In this scenario, Network remove SCC first before Handover and perform PCC handover and then add SCC again.

 

 

 

Case 2 : Remove SCC and Handover for PCC in single step -> Add SCC

 

 

 

(2) RRC Connection Reconfiguration (for Handover to PCC2 and Release SCC1)

 

        c1: rrcConnectionReconfiguration (4)

            rrcConnectionReconfiguration

                rrc-TransactionIdentifier: 0

                criticalExtensions: c1 (0)

                    c1: rrcConnectionReconfiguration-r8 (0)

                        rrcConnectionReconfiguration-r8

                            mobilityControlInfo

                                targetPhysCellId: 10 // Physical Cell ID of PCC2

                                carrierFreq

                                    dl-CarrierFreq: 2300 // DL Channel Number of PCC2

                                carrierBandwidth

                                    dl-Bandwidth: n50 // Bandwidth of PCC2

                                t304: ms1000 (5)

                                newUE-Identity: 1032 [bit length 16, 0001 0000  0011 0010 decimal value 4146]

                                radioResourceConfigCommon

                                    prach-Config

                                        rootSequenceIndex: 64

                                        prach-ConfigInfo

                                            prach-ConfigIndex: 3

                                            ...0 .... highSpeedFlag: False

                                            zeroCorrelationZoneConfig: 2

                                            prach-FreqOffset: 19

                                    pusch-ConfigCommon

                                        pusch-ConfigBasic

                                            n-SB: 1

                                            hoppingMode: interSubFrame (0)

                                            pusch-HoppingOffset: 0

                                            .0.. .... enable64QAM: False

                                        ul-ReferenceSignalsPUSCH

                                            ..0. .... groupHoppingEnabled: False

                                            groupAssignmentPUSCH: 0

                                            0... .... sequenceHoppingEnabled: False

                                            cyclicShift: 0

                                    pucch-ConfigCommon

                                        deltaPUCCH-Shift: ds2 (1)

                                        nRB-CQI: 4

                                        nCS-AN: 6

                                        n1PUCCH-AN: 0

                                    ul-CyclicPrefixLength: len1 (0)

                                rach-ConfigDedicated

                                    ra-PreambleIndex: 63

                                    ra-PRACH-MaskIndex: 0

                            radioResourceConfigDedicated

                                physicalConfigDedicated

                                    pusch-ConfigDedicated

                                        betaOffset-ACK-Index: 9

                                        betaOffset-RI-Index: 6

                                        betaOffset-CQI-Index: 6

                                    antennaInfo: explicitValue (0)

                                        explicitValue

                                            transmissionMode: tm1 (0)

                                            ue-TransmitAntennaSelection: release (0)

                                                release: NULL

                                    schedulingRequestConfig: setup (1)

                                        setup

                                            sr-PUCCH-ResourceIndex: 41

                                            sr-ConfigIndex: 27

                                            dsr-TransMax: n32 (3)

                            securityConfigHO

                                handoverType: intraLTE (0)

                                    intraLTE

                                        .... 0... keyChangeIndicator: False

                                        nextHopChainingCount: 0

                            nonCriticalExtension

                                nonCriticalExtension

                                    nonCriticalExtension

                                        sCellToReleaseList-r10: 1 item

                                            Item 0

                                                SCellIndex-r10: 1 // Serving Cell Index of SCC1

 

 

(7) RRC Connection Reconfiguration (for adding SCC1)

 

       c1: rrcConnectionReconfiguration (4)

            rrcConnectionReconfiguration

                rrc-TransactionIdentifier: 0

                criticalExtensions: c1 (0)

                    c1: rrcConnectionReconfiguration-r8 (0)

                        rrcConnectionReconfiguration-r8

                            radioResourceConfigDedicated

                                mac-MainConfig: explicitValue (0)

                                    explicitValue

                                        timeAlignmentTimerDedicated: infinity (7)

                                        mac-MainConfig-v1020

                                physicalConfigDedicated

                                    cqi-ReportConfig-r10

                                        cqi-ReportAperiodic-r10: release

                                        nomPDSCH-RS-EPRE-Offset: 0dB (0)

                                    pucch-ConfigDedicated-v1020

                                        pucch-Format-r10: channelSelection-r10 (1)

                                            channelSelection-r10

                                                n1PUCCH-AN-CS-r10: setup (1)

                                                    setup

                                                        n1PUCCH-AN-CS-List-r10: 2 items

                                                            Item 0

                                                                N1PUCCH-AN-CS-r10: 4 items

                                                                    Item 0

                                                                        N1PUCCH-AN-CS-r10 item: 101

                                                                    Item 1

                                                                        N1PUCCH-AN-CS-r10 item: 102

                                                                    Item 2

                                                                        N1PUCCH-AN-CS-r10 item: 103

                                                                    Item 3

                                                                        N1PUCCH-AN-CS-r10 item: 104

                                                            Item 1

                                                                N1PUCCH-AN-CS-r10: 4 items

                                                                    Item 0

                                                                        N1PUCCH-AN-CS-r10 item: 105

                                                                    Item 1

                                                                        N1PUCCH-AN-CS-r10 item: 106

                                                                    Item 2

                                                                        N1PUCCH-AN-CS-r10 item: 107

                                                                    Item 3

                                                                        N1PUCCH-AN-CS-r10 item: 108

                            nonCriticalExtension

                                nonCriticalExtension

                                    nonCriticalExtension

                                        sCellToAddModList-r10: 1 item

                                            Item 0

                                                SCellToAddMod-r10

                                                    sCellIndex-r10: 1

                                                    cellIdentification-r10

                                                        physCellId-r10: 400

                                                        dl-CarrierFreq-r10: 5790

                                                    radioResourceConfigCommonSCell-r10

                                                        nonUL-Configuration-r10

                                                            dl-Bandwidth-r10: n50 (3)

                                                            antennaInfoCommon-r10

                                                                antennaPortsCount: an1 (0)

                                                            phich-Config-r10

                                                                phich-Duration: normal (0)

                                                                phich-Resource: oneSixth (0)

                                                            pdsch-ConfigCommon-r10

                                                                referenceSignalPower: 18dBm

                                                                p-b: 1

                                                    radioResourceConfigDedicatedSCell-r10

                                                        physicalConfigDedicatedSCell-r10

                                                            nonUL-Configuration-r10

                                                                antennaInfo-r10

                                                                    transmissionMode-r10: tm1 (0)

                                                                    ue-TransmitAntennaSelection: release (0)

                                                                        release: NULL

                                                                pdsch-ConfigDedicated-r10

                                                                    p-a: dB0

 

 

Case 3 : Remove SCC before Handover -> Handover for PCC and Add SCC in a single step

 

 

 

Case 4 : Remove SCC , HO for PCC, Add SCC all in  single step

 

Personally I haven't seen any real implementation for this case and haven't confirmed in 3GPP specification in detail, but just by logical point of view we can think of following scenario as well.