VoLTE quality triggered SRVCC to GSM feature parameter description

VoLTE quality triggered SRVCC to GSM architecture explanation details

1. LTE2354 : SIB, paging and RA messages via RAT2 with localized VRB LTE3443 : VoLTE quality triggered SRVCC to GSM

2. MBB CS TS Deep Feature Analysis L18 LTE2354 SIB, paging and RA messages via RAT2 with localized VRB 11/23/2018 Document ID / v. 0.1 / Life cycle status / Dept. / Author <TS , Hangzhou , China> <>

3. Introduction Before & after Before DCI Format 1C with distributed VRBs is used for SIBs, Paging, RA message 2 transmissions DCI Format 1A with distributed VRBs is used for RA message 4 transmission Distributed VRBs are mapped to PRBs according to 3GPP rules – scheduling of Paging, SIBs, RA message 2 and message 4 is not aware of CAT-M (LTE3128) PRBs and PRBs blanked in Slim Carrier (LTE3145) After DCI Format 1A with localized VRBs is used for SIBs, Paging, RA message 2 and message 4 transmission Localized VRBs are mapped to PRBs 1-to-1 which avoids CAT-M (LTE3128) PRBs and PRBs blanked in Slim Carrier (LTE3145) deployment when scheduling Paging, SIBs and RA message 2 and message 4 Nokia Internal Use

4. Downlink resources Introduction Nokia Internal Use R esource E lement ( RE ) - the minimum time-frequency resource unit used for downlink transmission, which is defined as one subcarrier over one OFDM symbol R esource B lock ( RB ) - generic term used for Virtual Resource Block (VRB) and Physical Resource Block (PRB) P hysical R esource B lock ( PRB ) - a group of 12 subcarriers contiguous in frequency over one slot in time V irtual R esource B lock ( VRB ) - abstract resource which is used by the scheduler, scheduler always uses Virtual Resource Blocks for defining allocations. VRBs are of two types: Localized VRBs - equal to Physical RBs, Localized VRBs address PRBs directly Distributed VRBs - usage of frequency diversity without direct mapping to PRBs R esource B lock G roup ( RBG ) - a group of resource blocks. Allocating resources in RBG reduces signaling overhead by reducing the number of bits. The size and number of RBGs depend on the bandwidth.

5. Resource Allocation Types and DCI formats in LTE Introduction Nokia Internal Use Resource Allocation Type specifies the way in which the scheduler allocate s R esource B locks for each transmission There are three different R esource A llocation T ypes in LTE : type 0, 1 and 2 Downlink Control Information is carried over PDCCH eNB uses DCI to send downlink /uplink scheduling commands to a UE The DCI can be constructed using several different formats E ach format contains a specific set of information and has specific purpose Before LTE2354 DCI Format 1C with distributed VRBs is used for SIBs, Paging, RA msg2 transmissions, and DCI Format 1A with distributed VRBs for RA msg4 DCI Format Possible Resource Allocation Type 1 Type 0 or Type 1 1A Type 2 1B Type 2 1C Type 2 1D Type 2 2 Type 0 or Type 1 2A Type 0 or Type 1 LTE2354 introduces RAT2 with Localized VRB for SIBs, RA msg2, msg4 and paging using DCI format 1A DL resource allocation

6. Feature overview Introduction Nokia Internal Use LTE2354 S introduces R esource A llocation T ype (RAT) 2 with localized V irtual R esource B lock (VRB) assignment for S ystem I nformation B roadcast (SIB), R andom A ccess R esponse (RAR ) message 2 and m essage 4 and paging using D ownlink C hannel I nformation (DCI) format 1A (specified in 3GPP 36.212 & 36.213 ) The larger transport block size of up to 2216 bits ( 3GPP 36.213 / Sec. 7.1.7.2.1 ) is used for DCI format 1A Localized VRBs are mapped to PRBs 1-to-1 which avoids CAT-M PRBs and PRBs blanked in Slim Carrier deployment when scheduling Paging, SIBs and RA msg 2 and msg 4 LTE2354 is activated on cell level using dedicated feature activation flag 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 Direct VRB-to-PRB mapping 1 st slot 2 nd slot 1 st slot 2 nd slot VRB PRB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 VRBs are distributed over wider frequency Localized Distributed Localized VRBs avoid scheduling of SIB, paging, RA msg2 and msg4 in CAT-M PRBs and PRBs blanked by Slim Carrier

7. Introduction Resource Allocation Types in LTE – RAT0 Nokia Internal Use RBG Size (P) System Bandwidth 1 ≤ 10 2 11 - 26 3 27 - 64 4 64 - 110 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 RBG0 RBG1 RBG2 RBG3 RBG4 RBG5 RBG6 RBG7 RBG8 RBG9 RBG10 RBG11 RBG12 RBG13 RBG14 RBG15 16 0 0 0 1 1 0 1 0 0 0 0 0 0 0 0 0 0 V RB RBG   In R esource A llocation T ype ( RAT0 ) , the resource block assignment information includes a bitmap indicating RBGs that are allocated where an RBG is a set of consecutive VRBs In this case , the granularity of resource assignment is an RBG The RBG size is a function of the system bandwidth The bitmap size is of # of RBG bits and each bit corresponds to a unique RBG in the set The RBG is allocated to a UE if the corresponding bit of the bitmap is set to 1 bitmap

8. Introduction Resource Allocation Types in LTE – RAT1 Nokia Internal Use In Resource Allocation Type 1, all resource blocks are divided into several subgroups The number of signaling bits can be reduced because the scheduler uses one subgroup which consists of smaller number of RBs In comparison to RAT0 allocation resolution is greater The RBG size is a function of the system bandwidth 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 RBG0 RBG1 RBG2 RBG3 RBG4 RBG5 RBG6 RBG7 RBG8 RBG9 RBG10 RBG11 RBG12 RBG13 RBG14 RBG15 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Subset 0 Subset 1 Subset 2 Subset: 01 Bitmap: 00110100000000 These numbers indicate the bit position of the resource blocks allocated for each subset PRB RBG RBG Size (P) System Bandwidth 1 ≤ 10 2 11 - 26 3 27 - 64 4 64 - 110   Not supported in Nokia product

9. Introduction Resource Allocation Types in LTE – RAT2 Nokia Internal Use In this type, resource allocation information indicates a set of contiguously allocated VRBs PRB allocations vary from a single PRB up to a maximum number of PRBs spanning the system bandwidth For VRB allocations, the information about allocation consists of a starting VRB number and a number of consecutive VRBs that is signaled using Resource Indication Value (RIV) VRBs are mapped to PRBs using one of two rules: Localized – VRBs mapped 1-to-1 to PRBs Distributed – VRBs are contiguous but are distributed to PRBs over wider frequency range start point # contiguous RBs 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 Direct VRB-to-PRB mapping 1 st slot 2 nd slot 1 st slot 2 nd slot VRB PRB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 VRBs are distributed over wider frequency Localized Distributed Resource Allocation Type 2 VRB Localized VRBs avoid scheduling of SIB, paging, RA msg2 and msg4 in CAT-M PRBs and PRBs blanked by Slim Carrier

10. Technical Details Differentiation between RAT0/RAT1 and RAT2 PDCCH with RAT0 and RAT1 resource allocation have the same format and are distinguished from each other via the Type field PDCCH with RAT2 have a different format from PDCCH with a type 0 or type 1 resource allocation Lack of Type field indicates RAT2 Field Name Length (Bits) Comment Resource Allocation Type 1 Differentiation between RAT0 and RAT1. RAT0 is indicated by value ‘0‘ and RAT1 by value ‘1’

11. Technical Details DCI Format 1A for RAT2 with Localized VRB – Format Flag Format flag Localized or Distributed VRBs Resource Block assignment MCS HARQ Redundancy version N_1A_PRB Format Flag is used for Format0 and Format 1A differentiation Value ‘1’ indicates DCI format 1A Value ‘0’ indicates DCI format 0 Field # of bits Format0/format1A flag 1 Localized/Distributed flag 1 Resource block assignment 5 (1.4 MHz), 7 (3 MHz), 9 (5 MHz), 11 (10 MHz), 12 (15 MHz), 13 (20 MHz) MCS 5 HARQ process number 3 Redundancy version 2 Reserved bit 1 N_1A_PRB 1

12. Technical Details DCI Format 1A for RAT2 with Localized VRB In case of Resource Allocation Type 2 , Localized or Distributed VRBs can be used: Value ‘0’ indicates Localized VRBs Value ‘1’ to indicates Distributed VRBs Format flag Localized or Distributed VRBs Resource Block assignment MCS HARQ Redundancy version N_1A_PRB Field # of bits Format0/format1A flag 1 Localized/Distributed flag 1 Resource block assignment 5 (1.4 MHz), 7 (3 MHz), 9 (5 MHz), 11 (10 MHz), 12 (15 MHz), 13 (20 MHz) MCS 5 HARQ process number 3 Redundancy version 2 Reserved bit 1 N_1A_PRB 1

13. Technical Details DCI Format 1A for RAT2 with Localized VRB – Resource Block assignment 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 DCI-FORMAT-1A-10MHz Format0-1A-Flag DciFormat1A ResourceAllocation LocalizedVRB LocalizedVRB RIV 259 MCS 0 HARQ-Process 0 NDI 0 RV 0 TPC 00 DAI 00 Floor(259/50)+1 = 6 = Number of RBs 259 mod 50 = 9 = Starting RB Number RBG 0 RBG 1 RBG 2 RBG 3 RBG 4 RBG 5 RBG 6 RBG 7 RBG 8 RBG 9 RBG 10 RBG 11 RBG 12 RBG 13 RBG 14 RBG 15 16 Starting from RB 9 6 RBs 10 MHz = 50 RBs VRB RBG Max number of RBs for specified bandwidth Example : 10 MHz, RAT2 localized, RIV=259 Format flag Local or Distributed VRBs Resource Block assignment MCS HARQ Redundancy version N_1A_PRB In this step data is mapped to VRBs , there will be next step for mapping of VRBs to PRBs RAT2 can be expressed by two values:  Number of RBs and Start RB Resource Indication Value (RIV) is a number to specify PDSCH resource allocation RIV represents Number of RBs and Start RB in a single value The conversion from the number of RB and Start RB to RIV is defined as:     Source: 3GPP 36.213 7.1.6.3 Resource allocation type 2

14. Technical Details DCI Format 1A for RAT2 – related parameter DCI Format Possible Resource Allocation Type 1 Type 0 or Type 1 1A Type 2 1B Type 2 1C Type 2 1D Type 2 2 Type 0 or Type 1 2A Type 0 or Type 1 If LNCEL: dlsDciCch == 0 (DCI format 1C) D istributed VRBs are used for SIBs, paging and RA msg2 and msg4 If LNCEL: dlsDciCch == 1 (DCI format 1A) L ocalized VRBs are used for SIBs, paging and RA msg2 and msg4 Format flag Local or Distributed VRBs Resource Block assignment MCS HARQ Redundancy version N_1A_PRB RAT2 DCI format 1A Localized VRBs RAT2 DCI format 1C Distributed VRBs Parameter LNCEL: dlsDciCch specifies which DCI format and type of VRBs is used for common channel transmission:

15. Technical Details DCI Format 1A for RAT2 with Localized VRB – MCS When DCI format 1A is used to schedule resources for paging, SIB or RAR, then QPSK modulation is always used ignoring the scheme specified with the assigned MCS Format flag Local or Distributed VRBs Resource Block assignment MCS HARQ Redundancy version N_1A_PRB Field # of bits Format0/format1A flag 1 Localized/Distributed flag 1 Resource block assignment 5 (1.4 MHz), 7 (3 MHz), 9 (5 MHz), 11 (10 MHz), 12 (15 MHz), 13 (20 MHz) MCS 5 HARQ process number 3 Redundancy version 2 Reserved bit 1 N_1A_PRB 1

16. Technical Details DCI Format 1A for RAT2 with Localized VRB – HARQ When DCI format 1A is used to schedule resources for paging, SIB or RAR*, HARQ process number is reserved since no ACK/NACK is required in this case Format flag Local or Distributed VRBs Resource Block assignment MCS HARQ Redundancy version N_1A_PRB Field # of bits Format0/format1A flag 1 Localized/Distributed flag 1 Resource block assignment 5 (1.4 MHz), 7 (3 MHz), 9 (5 MHz), 11 (10 MHz), 12 (15 MHz), 13 (20 MHz) MCS 5 HARQ process number 3 Redundancy version 2 Reserved bit 1 N_1A_PRB 1 *Not applicable for C-RNTI

17. Technical Details DCI Format 1A for RAT2 with Localized VRB – Redundancy version UE assumes Redundancy Versions (RV) 0, 2, 3, 1 for the 4 SIB1 transmissions within its repetition period of 80ms RV can be calculated from current SFN as RV = MOD(roundup(3/2*MOD(SFN/2,4)),4) Format flag Local or Distributed VRBs Resource Block assignment MCS HARQ Redundancy version N_1A_PRB For other SIBs than SIB1, UE assumes RV cycles a cycle 0,2,3,1,0,2,3,1,... during the subframes in SI window starting from the beginning of the window RV = MOD(roundup(3/2*mod(subFrameNumber,4)),4) where subFrameNumber is the subframe index within the SI window ( i.e 0...si-WindowLength-1) For paging, and random access response messages, RV version 0 is always used SIB1 Other SIBs Paging and Random Access Field # of bits Format0/format1A flag 1 Localized/Distributed flag 1 Resource block assignment 5 (1.4 MHz), 7 (3 MHz), 9 (5 MHz), 11 (10 MHz), 12 (15 MHz), 13 (20 MHz) MCS 5 HARQ process number 3 Redundancy version 2 Reserved bit 1 N_1A_PRB 1

18. Technical Details TBS index N_1A_PRB Modulation TBS 2 2 32 1 2 2 56 2 2 2 72 1 3 2 88 3 2 2 104 4 2 2 120 5 2 2 144 6 2 2 176 4 3 2 208 7 2 2 224 8 2 2 256 9 2 2 296 10 2 2 328 11 2 2 376 8 3 2 392 12 2 2 440 9 3 2 456 13 2 2 488 10 3 2 504 14 2 2 552 11 3 2 584 15 2 2 600 16 2 2 632 12 3 2 680 17 2 2 969 13 3 2 744 18 2 2 776 19 2 2 840 20 2 2 904 16 3 2 968 21 2 2 1000 22 2 2 1064 23 2 2 1128 18 3 2 1160 24 2 2 1192 25 2 2 1256 19 3 2 1288 20 3 2 1384 26 2 2 1480 22 3 2 1608 23 3 2 1736 24 3 2 1800 25 3 2 1864 26 3 2 2216 Supported transport block sizes in downlink for PDSCH format 1A used for SIB, paging, RAR message are defined in the 3GPP 36.213 Table 7.1.7.2.1-1 Value ‘0’ of N_1A_PRB indicates N_1A_PRB = 2 Value ‘1’ of N_1A_PRB indicates N_1A_PRB = 3 DCI Format 1A for RAT2 with Localized VRB – N_1A_PRB Format flag Localized or Distributed VRBs Resource Block assignment MCS HARQ Redundancy version N_1A_PRB Field # of bits Format0/format1A flag 1 Localized/Distributed flag 1 Resource block assignment 5 (1.4 MHz), 7 (3 MHz), 9 (5 MHz), 11 (10 MHz), 12 (15 MHz), 13 (20 MHz) MCS 5 HARQ process number 3 Redundancy version 2 Reserved bit 1 N_1A_PRB 1 Note: For C-RNTI Reserved bit and N_1A_PRB indicate the TPC command

19. Deployment Aspects Feature activation /de - activation Feature Disabled LNCEL: dlsDciCch ==0 RAT2 with Distributed VRBs using DCI Format 1C is used for scheduling SIBs, paging and RA msg2 . RAT2 with Distributed VRBs using DCI Format 1A is used for RA message 4 transmission . Feature Enabled LNCEL: dlsDciCch ==1 RAT2 with Localized VRBs using DCI Format 1A is used for scheduling SIBs, paging and RA msg2 and msg4 . LTE2354 is activated on cell level via parameter LNCEL: dlsDciCch REQUIRES CELL LOCKING

20. Deployment Aspects Test case #1. Activation of LTE2354 For SI-RNTI, P-RNTI, RA-RNTI, C-RNTI included DCI should be Format 1A - Format0-1A-Flag should be set to 1 Field Type should be not present – lack of this field indicates that RAT2 is used Resource Allocation field should include value 0 that indicates Localized VRBs Verify DCI content within PDCCH Verification of DCI content for SI-RNTI, P-RNTI, RA-RNTI, C-RNTI after activation of LTE2354 ( LNCEL: dlsDciCch ==1 ) DCI-FORMAT-1A-10MHz Format0-1A-Flag 1 ResourceAllocation 0 LocalizedVRB RIV 150 MCS 2 HARQ-Process 0 RV 0 TPC 00 QCAT – example of decoded PDCCH with DCI format 1A

21. LTE3443 VoLTE quality triggered SRVCC to GSM [email protected] Version 1.0 based on Marek Brylka’s material

22. Please note that the NEI materials are for internal use only. If they shall be used as a source for the customer presentation, it is mandatory to align the contents with the Product Management and/or local sales teams at first! The results of simulations shown in this presentation are examples only. They demonstrate trends (not absolute values) expected after feature activation. The presented simulations should be analyzed with respect to the assumptions taken. They may differ from results achievable in real networks. This NEI slide deck reflects the state of the feature/solution as it is at the moment of the NEI slide deck release and is being updated up to C5 (release available) milestone. Disclaimer Nokia Internal Use

23. Open I ssues Item Description Comments Nokia Internal Use

24. LTE3443 VoLTE quality triggered SRVCC to GSM Table of contents Performance Aspects Counters and KPIs, Feature Impact Analysis and Verification Introduction Motivation and Feature Overview Technical Details Detailed Functionality Description 1 Inter – dependencies Interdependencies with other features and functions Benefits and Gains Simulation, Lab and Field Findings Configuration Management Parameters and Parameterization Scenarios Nokia Internal Use Deployment Aspects Activation, Configuration Examples, Fault Mgmt, Trial Area

25. Introduction LTE3443 VoLTE quality triggered SRVCC to GSM Table of contents

26. Introduction LTE3443 VoLTE quality triggered SRVCC to GSM Before From LTE network perspective, SRVCC to GSM is possible if RSRP or RSRQ of serving cell is poor In this case the decision for triggering of SRVCC is based on event B2 measurements reported by the UE After Degradation of voice quality , detected by serving eNB , due to: gaps in DL PDCP packets gaps in UL PDCP packets poor UL residual BLER is a new trigger for SRVCC to GSM In this case the decision for triggering of SRVCC is based on event B1 measurements reported by the UE Nokia Internal Use

27. Technical Details Table of contents

28. Technical Details Dependency Table Release/version RL release eNodeB NetAct FDD LTE FDD-LTE 18 FL18 NetAct 1 8 .2 TDD LTE TDD-LTE 18 TL18 NetAct 1 8 .2 Flexi Zone Micro (FZM /FZP ) FDD-LTE 1 8 FLF18 NetAct 1 8 .2 Flexi Zone Controller (FZ C ) N/A N/A NetAct 1 8 .2 Single RAN SRAN1 8A SBTS1 8A TBD HW & IOT HW requirements MME SAE GW UE Specified by 3GPP - FSMF/FZM/ AirScale SM - - 3GPP R8 UE capabilities - BSW/ASW ASW Sales information Release information Release information – general Nokia Internal Use

29. SRVCC is a procedure which assures voice service continuity in CS domain of 2G/3G RATs in case VoLTE call can not be maintained in LTE PS domain any more SRVCC is only possible if supported both by the network and by the UE terminal capabilities (Feature Group Indications) If FGI9 and FGI23 are set to 1, the UE supports SRVCC to GERAN based on event B2 measurements; If additionally FGI15 is to 1 , SRVCC to GERAN is also possible based on event B1 measurements Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use Index of indicator Definition   Notes 9 - EUTRA RRC_CONNECTED to GERAN GSM Dedicated handover - related to SR-VCC - can only be set to 1 if the UE has set bit number 23 to 1 15 - Measurement reporting event: Event B1 – Neighbour > threshold for GERAN, 1xRTT or HRPD, if the UE has set bit number 23, 24 or 26 to 1, respectively - can only be set to 1 if the UE has set at least one of the bit number 22, 23, 24, 26 or 39 to 1. 23 - GERAN measurements, reporting and measurement reporting event B2 in E-UTRA connected mode

30. Till FL18/TL18 , in Nokia portfolio SRVCC to GSM is supported/enhanced by set of features: LTE873 SRVCC to GSM LTE2572 RSRQ based B2 LTE64 VoLTE dedicated thresholds LTE3127 SRVCC to GSM measurement optimization activation of GERAN measurements for SRVCC, disables all other LTE inter- freq /inter-RAT measurements, active so far LTE3290 SRVCC trigger enhancements SRVCC is avoided in alerting phase of VoLTE call setup Poor RSRP or RSRQ on LTE side and sufficient RSSI on GERAN side , defined by 3GPP as event B2 conditions and reported by the UE, is a trigger for SRVCC to GSM procedure Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use RSSI RSRP/RSRQ b2TimeToTriggerGERANMeas b​2​Time​To​Trigger​Rsrq​G​E​R​A​N​Meas Trigger point for SRVCC to GSM hysB2ThresholdGERAN hysB2ThresholdRsrqGERAN b​2​Threshold​1​G​E​R​A​N b​2​Threshold​1​G​E​R​A​N​Qci​1 b​2​Threshold​1​Rsrq​G​E​R​A​N b​2​Threshold​1​Rsrq​G​E​R​A​N​Qci​1 b​2​Threshold​2​Rssi​G​E​R​A​N b​2​Threshold​2​Rssi​G​E​R​A​NQci1 Event B2 conditions for SRVCC to GSM met

31. With LTE3443, activated by LNBTS:actVoLteQualSRVCCtoGsm = true , the trigger for SRVCC, from serving eNB point of view, may be lack of correctly transmitted/received packets for voice (QCI1) in DL/UL, detected by PDCP layer (PDCP PDU gaps) in UL , detected by MAC layer (high UL residual BLER) If the serving eNB detects above mentioned voice service quality degradation, event B1 measurements are activated for VoLTE user such mechanism is possible even if RSRP/RSRQ of serving LTE cell is satisfying; event B1 measurement are activated because it is enough to check whether the target GERAN cell has sufficient RSSI level to maintain the voice call in CS domain Only if event B1 conditions are reported by the UE, the eNB triggers SRVCC to GSM procedure Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use Call flow degradation for voice packets in DL or UL detected by eNB PDCP or for voice packets in UL packets detected by eNB MAC Activation of event B1 conditions for mobility to GERAN UE sends Measurement Report with event B1 and eNB triggers SRVCC towards GSM procedure

32. Event B1 conditions which comes with LTE3443 , reuse parameters (threshold for RSSI, hysteresis, TimeToTrigger , report interval) applicable for event B2 and introduced by LTE873, LTE64 reportConfig for event B1 introduced by LTE3443 Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use ReportConfigInterRAT VoLTE quality triggered SRVCC Parameter name set value length basic type > triggerType = event Sequence > > eventId =eventB1 Sequence > > > b1-Threshold   single ThresholdGERAN > > > > ThresholdGERAN MMI parameter LNHOG: b2Threshold2RssiGERAN / LNHOG: b2Threshold2RssiGERANQci1 single INTEGER(0..63) > > hysteresis MMI parameter LNHOG: hysB2ThresholdGERAN single INTEGER(0..30) > > timeToTrigger MMI parameter (restricted up to ms256) LNHOG:b2TimeToTriggerGERANMeas single ENUMERATED{ms0,ms40,ms64,ms80,ms100,ms128,ms160,ms256,ms320,ms480,ms512,ms640,ms1024,ms1280,ms2560,ms5120} > maxReportCells = maxCellReport single INTEGER(1..maxCellReport) > reportInterval MMI parameter LNHOG: reportIntervalGERAN single ENUMERATED{ms120,ms240,ms480,ms640,ms1024,ms2048,ms5120,ms10240,min1,min6,min12,min30,min60,spare3,spare2,spare1} > reportAmount infinity single ENUMERATED {r1, r2, r4, r8, r16, r32, r64, infinity}

33. Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Decision to activate event B1 measurements for SRVCC to GSM Nokia Internal Use C-plane conditions QCI1 Bearer established UE capabilities supporting SRVCC to GSM EPC supporting SRVCC no sidelink * session active for the UE etc. PDCP PDU UL/DL gap detection MAC UL residual BLER conditions (based on LTE2493) Flow Control Trigger Combination Function If for a given VoLTE UE , supporting SRVCC to GSM , there is at least one Voice Quality Problem (VQP) type detected, then event B1 measurements may be activated VQP_DL_ON or VQP_UL_ON or VQP_BLER_ON VQP ON VQP ON VQP_BLER ON VQ- TrON (Voice Quality Trigger ON) reported by Trigger Combination Function results in event B1 measurements (SRVCC to GSM) activation for the UE * sidelink refers to functionality introduced by LTE2612 ProSe Direct Communications for Public Safety VQ- TrON – Voice Quality Trigger ON VQP_DL_ON – Voice Quality Problem ON for DL VQP_UL_ON – Voice Quality Problem ON for UL

34. Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Decision to activate event B1 measurements for SRVCC to GSM -> PDCP trigger Nokia Internal Use C-plane conditions QCI1 Bearer established UE capabilities supporting SRVCC to GSM EPC supporting SRVCC no sidelink * session active for the UE etc . PDCP PDU UL/DL gap detection MAC UL residual BLER conditions (based on LTE2493) Flow Control Trigger Combination Function If for a given VoLTE UE , supporting SRVCC to GSM , there is at least one Voice Quality Problem (VQP) type detected, then event B1 measurements may be activated VQP_DL_ON or VQP_UL_ON or VQP_BLER_ON VQP ON VQP ON VQP_BLER ON * sidelink refers to functionality introduced by LTE2612 ProSe Direct Communications for Public Safety VQ- TrON (Voice Quality Trigger ON) reported by Trigger Combination Function results in event B1 measurements (SRVCC to GSM) activation for the UE

35. PDCP PDU gap detection for DL packets in eNB - VQP ON Every PDCP PDU in DL forwarded towards RLC layer has its timestamp assigned by PDCP layer Timestamp is added to PDCP PDU when header with SN is added to the PDCP SDU Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use Timestamp added PDCP SDU PDCP PDU PDCP DL eNB UE

36. PDCP PDU gap detection for DL packets in eNB - VQP ON IP packets for voice, which come to PDCP layer as PDCP SDUs, are generated with periodicity of 20ms As result it is expected that in general the timestamp for each consecutive PDCP PDU will differ by about 20ms (as indicated on previous slide timestamp is added to PDCP PDU) Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use PDCP SDU PDCP SDU PDCP SDU PDCP SDU PDCP SDU PDCP SDU PDCP SDU PDCP SDU PDCP SDU PDCP SDU PDCP SDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU 20ms 20ms … … … T [ ms ] … … T [ ms ] PDCP DL Timestamp X Timestamp X - 40ms Timestamp X - 20ms Timestamp X - 60ms

37. PDCP PDU gap detection for DL packets in eNB - VQP ON PDCP PDUs before sending to RLC layer are stored in the buffer, however it is required that the eNB discards packets which get stuck in the buffer for too long eNB removes the voice packets from the DL PDCP buffer after time which is impacted by parameter LNBTS:pdcpProf101:tDiscard eNB removes the packets from the buffer also if maximum number of HARQ retransmissions in DL is reached but no HARQ ACK is received by the eNB All this leads to voice packet gap in DL, so in transmission from eNB towards the UE Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU Timestamp X Timestamp X - 40ms Timestamp X - 20ms Timestamp X - 60ms … … PDCP PDU discarded from the PDCP buffer before sending to the RLC layer or lost due to no HARQ ACK Not poor RSRP or RSRQ of serving cell but lack of correctly transmitted packets which degrade voice call quality perceived by end user is a trigger to leave LTE side via SRVCC T [ ms ] PDCP DL Every DRB/EPS has pdcp profile. See rrc conn reconfig message.

38. PDCP PDU gap detection for DL packets in eNB - VQP ON With LTE3443 the eNB controls the timestamp delta between each two consecutively successfully transmitted PDCP PDUs for a given VoLTE call If timestamp delta is higher than VOLTEQUALPR : badQuality D LGapThres then the VQP ON ( Voice Quality Problem ON ) message is sent to the Flow Control functional block Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU Timestamp Y … PDCP PDUs sent successfully Timestamp Z PDCP PDUs sent successfully Timestamp X Timestamp Y - Timestamp X < VOLTEQUALPR : badQuality D LGapThres -> no Voice Quality Problem detected Timestamp Z - Timestamp Y > VOLTEQUALPR : badQuality D LGapThres -> Voice Quality Problem detected Flow control VQP ON message T [ ms ] PDCP DL

39. PDCP PDU gap detection for DL packets in eNB - VQP ON It could be that some of the PDCP PDUs are discarded by the eNB or lost from the transmitting buffer but the timestamp delta between consecutively correctly transmitted PDCP PDUs is still lower than period defined by VOLTEQUALPR : badQuality D LGapThres In this case no VQP problem is detected and no VQP ON message is sent to the Flow Control box Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU Timestamp X … PDCP PDUs sent to the RLC layer Timestamp Y PDCP PDUs sent to the RLC layer Timestamp Y - Timestamp X < VOLTEQUALPR : badQuality D LGapThres -> no Voice Quality Problem detected even if some packets in between are discarded T [ ms ] PDCP DL

40. Recovery from VQP ON to VQP OFF for DL voice packets VQP OFF message is sent to the Flow Control functional block, if serving eNB detects that all PDCP PDUs transmitted to the RLC layer within time window defined by VOLTEQUALPR : goodQualityGapThres   have consecutive SNs (Sequence Numbers) Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU Timestamp X … PDCP PDUs sent to the RLC layer Timestamp Y VQP OFF Timestamp Y - Timestamp X > VOLTEQUALPR : goodQualityGapThres -> if all PDCP PDUs with timestamps between Timestamp X and Timestamp Y have consecutive SNs in their PDCP PDU headers eNB takes the decision no Voice Quality Problem occurs any more so the VQP OFF is sent towards Flow Control block Flow control VQP OFF message VQP ON PDCP SDU SN HEADER T [ ms ] PDCP DL

41. PDCP PDU gap detection for UL packets in eNB - VQP ON For UL direction , for each PDCP PDU coming from RLC layer, eNB assigns timestamp Similarly to DL case, for good transmission conditions it is expected that the UL PDCP PDUs will arrive at the eNB with periodicity of about 20ms Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use Timestamp added PDCP SDU PDCP PDU PDCP UL UE eNB

42. PDCP PDU gap detection for UL packets in eNB - VQP ON It could be that packets on UE side are discarded from PDCP buffer according to 3GPP standardized mechanism ( 3GPP 36.323, 5.4 ) In Nokia product, PDCP discard on UE side for voice packets is controlled by already mentioned LNBTS:pdcpProf101:tDiscard parameter The value of LNBTS:pdcpProf101:tDiscard is provided to the UE with the help of RRC:RRCConnectioneReconfiguration message at establishment of QCI1 DRB Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use PDCP UL

43. PDCP PDU gap detection for UL packets in eNB - VQP ON If packets will be discarded on UE side due to discardTimer expiry, then at serving eNB this will be reflected by some gap in incoming UL voice PDCP PDUs stream The packets are also removed from UE PDCP buffer if maximum number of HARQ retransmission is reached but no HARQ ACK is received by the UE When eNB PDCP detects the gap in received SNs (Sequence Numbers) of PDPC PDUs and the delta between timestamps for successfully received PDCP PDUs is higher than VOLTEQUALPR : badQualityULGapThres the VQP ON (Voice Quality Problem ON) message is sent to the Flow Control functional box Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU Timestamp X - 20ms Timestamp X - 40ms … Timestamp Y Timestamp X UL PDCP PDUs missing on eNB due to discarding on UE side or no HARQ ACK Timestamp Y - Timestamp X > VOLTEQUALPR : badQuality U LGapThres -> Voice Quality Problem detected Flow control VQP ON message T [ ms ] PDCP UL

44. Recovery from VQP ON to VQP OFF for UL voice packets VQP OFF message is sent to Flow Control functional block if serving eNB detects that all PDCP PDUs received from RLC layer within time window defined by VOLTEQUALPR : goodQualityGapThres   have consecutive SNs (Sequence Numbers) Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU PDCP PDU Timestamp X … PDCP PDUs received from the RLC layer Timestamp Y VQP OFF Timestamp Y - Timestamp X > VOLTEQUALPR : goodQualityGapThres -> if all PDCP PDUs with timestamps between Timestamp X and Timestamp Y have consecutive SNs in their PDCP PDU headers eNB takes the decision no Voice Quality Problem occurs any more so the VQP OFF is sent towards Flow Control Flow control VQP OFF message VQP ON PDCP SDU SN HEADER T [ ms ] PDCP UL

45. Monitoring split for DL and UL packets The operator may decide whether the packet gaps detected by PDCP layer of serving eNB shall be monitored for UL or for DL or for both directions This concept is realized just by configuring or not of mentioned parameters badQuality D LGapThres , badQualityULGapThres from the MOC VOLTEQUALPR which are of type optional Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use

46. Avoiding of C-Plane overload due to VQP status change The change of VQP (Voice Quality Problem) from OFF to ON, and vice versa, for both DL and UL shall lead to activation/deactivation of event B1 measurements for the UE Frequent changes of VQP status per UE , for many VoLTE users served by the same LTE cell may significantly impact C-Plane processing To minimize C-Plane overload, the trigger condition indications coming from many users are queued in Flow Control functional block and sent to the Trigger Combination Function in a predefined rate Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use Flow control Collects the list of VQP ON/OFF per each VoLTE UE Trigger Combination Function is an eNB block which commands to activate/deactivate event B1 for SRVCC to GERAN for e given UE, based on received VQP status The change of VQP status is sent for max 5 VoLTE UEs with periodicity of 100ms

47. Avoiding of C-Plane overload due to VQP status change Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use PDCP VQP ON Flow Control Trigger Combination Function VQP ON VQP OFF VQP OFF VQP ON 100ms 100ms 100ms Added to the list Removed from the list Added to the list Notification sent to the TCF 100ms Added to the list VQP OFF Notification sent to the TCF Reporting occasions between FC and TCF Removed from the list Event B1 activation Event B1 deactivation Added to the list Flow Control sends towards Trigger Combination Function VQP reports with periodicity of 100ms one report covers status for max 5 UEs Initial conditions: EPS Bearer with QCI1 established VQP OFF no event B1 for SRVCC to GSM activated Example for VQP states detected for only one UE

48. Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Decision to activate event B1 measurements for SRVCC to GSM Nokia Internal Use C-plane conditions QCI1 Bearer established UE capabilities supporting SRVCC to GSM EPC supporting SRVCC no sidelink * session active for the UE etc. PDCP PDU UL/DL gap detection MAC UL residual BLER conditions (based on LTE2493) Flow Control Trigger Combination Function If for a given VoLTE UE , supporting SRVCC to GSM , there is at least one Voice Quality Problem (VQP) type detected, then event B1 measurements may be activated VQP_DL_ON or VQP_UL_ON or VQP_BLER_ON VQP ON VQP ON VQP_BLER ON VQ- TrON (Voice Quality Trigger ON) reported by Trigger Combination Function results in event B1 measurements (SRVCC to GSM) activation for the UE * sidelink refers to functionality introduced by LTE2612 ProSe Direct Communications for Public Safety

49. Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Decision to activate event B1 measurements for SRVCC to GSM -> MAC trigger Nokia Internal Use C-plane conditions QCI1 Bearer established UE capabilities supporting SRVCC to GSM EPC supporting SRVCC no sidelink * session active for the UE etc. PDCP PDU UL/DL gap detection MAC UL residual BLER conditions (based on LTE2493) Flow Control Trigger Combination Function If for a given VoLTE UE , supporting SRVCC to GSM , there is at least one Voice Quality Problem (VQP) type detected, then event B1 measurements may be activated VQP_DL_ON or VQP_UL_ON or VQP_BLER_ON VQP ON VQP ON VQP_BLER ON VQ- TrON (Voice Quality Trigger ON) reported by Trigger Combination Function results in event B1 measurements (SRVCC to GSM) activation for the UE * sidelink refers to functionality introduced by LTE2612 ProSe Direct Communications for Public Safety

50. UL residual BLER LTE2493 Enhanced VoLTE Performance Monitoring introduced among others measurements of VoLTE uplink final residual BLER as a metric of voice quality. ulQci1ResBler = 100 * M8026C269 / M8026C270 where: M8026C270 provides the total number of initial HARQ transmissions for the QCI1 ( VoLTE ) bearer in the uplink M8026C269 provides the number of failed TB transmissions after the maximum number of HARQ retransmission count for the QCI1 ( VoLTE ) bearer in the uplink LTE3443 re-uses the LTE2493 input data, in order to determine the final residual UL BLER (ulQci1ResBler ) and take the decision whether this BLER indicates good or bad Voice Quality Residual UL BLER as defined by LTE2493 is evaluated with periodicity of 10240ms For LTE3443 Residual UL BLER value is evaluated with a periodicity of 500ms . Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use MAC UL

51. High UL residual BLER detection If ulQci1ResBler , measured for VoLTE user is higher than VOLTEQUALPR:badQualityRBlerThres and these conditions are valid for VOLTEQUALPR:rBlerCondTimeToTrigger then such UE is added to the list of VoLTE users for which MAC layer sends VQP_BLER ON to the Trigger Combination Function Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM VOLTEQUALPR:badQualityRBlerThres VOLTEQUALPR:goodQualityRBlerThres ulQci1ResBler [%] VOLTEQUALPR: rBlerCondTimeToTrigger = 1s (as an example) UE is a candidate for reporting VQP_BLER ON to Trigger Combination Function Nokia Internal Use MAC UL T [ ms ] 500 1000 1500 2000 2500 3000 Note: parameter range for VOLTEQUALPR:rBlerCondTimeToTrigger is 0…3s, step 0.5s

52. Low UL residual BLER detection If ulQci1ResBler , measured for VoLTE user is lower than VOLTEQUALPR:goodQualityRBlerThres and these conditions are valid for VOLTEQUALPR:rBlerCondTimeToTrigger then such UE is added to the list of VoLTE users for which MAC layer sends VQP_BLER OFF to the Trigger Combination Function Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use MAC UL UE is a candidate for reporting VQP_BLER OFF to Trigger Combination Function VOLTEQUALPR:badQualityRBlerThres VOLTEQUALPR:goodQualityRBlerThres ulQci1ResBler [%] VOLTEQUALPR: rBlerCondTimeToTrigger = 1s (as an example) T [ ms ] 500 1000 1500 2000 2500 3000 Note: parameter range for VOLTEQUALPR:rBlerCondTimeToTrigger is 0…3s, step 0.5s

53. Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use UL residual BLER reporting to the Trigger Combination Function Every MAC VQP status change for VoLTE user, places such UE on the list which is inspected by the eNB MAC layer reports the detected changes to Trigger Combination Function with the periodicity of 100ms Per one report the status of only one VoLTE user may be sent Trigger Combination Function 100ms 100ms 100ms MAC VQP_BLER ON UE1 UE2 UE3 Event B1 activation possible Event B1 deactivation possible Event B1 deactivation possible VQP_BLER OFF VQP_BLER OFF MAC UL MAC sends towards Trigger Combination Function VQP reports with periodicity of 100ms one report covers status for 1 UE T [ ms ]

54. Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Decision to activate event B1 measurements for SRVCC to GSM Nokia Internal Use C-plane conditions QCI1 Bearer established UE capabilities supporting SRVCC to GSM EPC supporting SRVCC no sidelink * active for the UE etc. PDCP PDU UL/DL gap detection MAC UL residual BLER conditions (based on LTE2493) Flow Control Trigger Combination Function If for a given VoLTE UE , supporting SRVCC to GSM , there is at least one Voice Quality Problem (VQP) type detected, then event B1 measurements may be activated VQP_DL_ON or VQP_UL_ON or VQP_BLER_ON VQP ON VQP ON VQP_BLER ON VQ- TrON (Voice Quality Trigger ON) reported by Trigger Combination Function results in event B1 measurements (SRVCC to GSM) activation for the UE * sidelink refers to functionality introduced by LTE2612 ProSe Direct Communications for Public Safety

55. Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Decision to deactivate event B1 measurements for SRVCC to GSM Nokia Internal Use C-plane conditions QCI1 Bearer released Sidelink * activated for VoLTE user etc. PDCP PDU UL/DL gap detection MAC UL residual BLER conditions (based on 2493) Flow Control Trigger Combination Function If Voice Quality Problem (VQP) disappears or VoLTE call is disconnected existing event B1 measurements are deactivated; VQP_DL_OFF and VQP_UL_OFF and VQP_BLER_OFF or QCI1 released or sidelink activated VQP OFF VQP OFF VQP_BLER OFF VQ- TrOFF (Voice Quality Trigger OFF) reported by Trigger Combination Function results in event B1 measurements (SRVCC to GSM) deactivation for the UE * sidelink refers to functionality introduced by LTE2612 ProSe Direct Communications for Public Safety

56. Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Remarks for event B1 based measurement activation If no GSM cell is allowed for SRVCC (LNRELG: srvccAllowed = forbidden ) , no measurement reconfiguration will be done when the trigger happens If EPC does not support SRVCC , no measurement reconfiguration will be done when the trigger happens If UE does not support B1 measurement or SRVCC to GSM (to support SRVCC with B1 , FGI9, 15, 23 have to be set to true) , no measurement reconfiguration will be done when the trigger happens Nokia Internal Use

57. Technical Details LTE3443 VoLTE quality triggered SRVCC to GSM Actions after event B1 activation Activation of event B1 based on VQP triggers coming from PDCP or MAC does not assure that SRVCC to GSM will be triggered The UE has to find GSM cell with sufficient RSSI as indicated by event B1 conditions eNB triggers SRVCC to GSM only after receiving RRC:MeasurementReport with event B1 Further steps in SRVCC procedure are the same as defined for LTE873 SRVCC to GSM Nokia Internal Use

58. Interdependencies LTE3443 VoLTE quality triggered SRVCC to GSM Table of contents

59. LTE873 SRVCC to GSM LTE873 is a precondition for LTE3443; the same GERAN targets and radio conditions applicable for target GERAN cells are used by LTE873 and LTE3443; the only difference is that for LTE3443 no radio conditions for serving cell (RSRP/RSRQ) are checked; LTE873 relies on event B2 based measurements, while for LTE3443 event B1 is used; however from target GERAN cell point of view, exactly the same radio conditions are used for both mentioned events B2 and B1 LTE2493 Enhanced VoLTE Performance Monitoring UL VoLTE residual BLER measurements as such are introduced by LTE2493; in this context LTE2493 is prerequisite for UL residual BLER SRVCC trigger introduced by LTE3443 Interdependencies prerequisites Nokia Internal Use  More details available on WebNEI : LTE873  More details available on WebNEI : LTE2493

60. LTE64 Service based handover thresholds If VoLTE dedicated thresholds for event B2 based SRVCC towards GSM are configured, the LTE3443 uses this VoLTE dedicated threshold applicable for event B1 based SRVCC to GSM LTE3290 SRVCC trigger enhancement Event B1 Measurement Report for SRVCC to GSM trigger due to LTE3443 is ignored if delay timer introduced by LTE3290 is running LTE907 TTI bundling If LTE907 is enabled, final residual BLER triggers SRVCC according to LTE3443 functionality if UE is in TTIB mode; PDCP voice gaps, trigger SRVCC according to LTE3443 independently of the TTIB mode Interdependencies extensions Nokia Internal Use  More details available on WebNEI : LTE64  More details available on WebNEI : LTE3290  More details available on WebNEI : LTE907

61. LTE3127 SRVCC to GSM measurement optimization In case of GERAN measurement activation for VoLTE users, LTE3127 eliminates all other already active inter-frequency LTE and Inter-RAT measurements; the same rule apply also for case, GERAN measurements are activated by LTE3443 LTE1127 Service based mobility trigger LTE3443 SRVCC trigger does not stop LTE1127 triggered A4 measurements LTE570 Periodic UE measurements LTE3443 SRVCC trigger does not stop the (LTE570) periodical intra frequency measurements Interdependencies extensions Nokia Internal Use  More details available on WebNEI : LTE3127  More details available on WebNEI : LTE1127  More details available on WebNEI : LTE570

62. LTE3120 VoLTE quality triggered SRVCC to WCDMA If LTE3120 and LTE3443 are enabled in the same cell, B1 measurements for GSM and WCDMA are configured in parallel; the report that is received first from eNodeB determines which RAT is used for SRVCC (this feature is FL19/TL19 candidate) Interdependencies extensions Nokia Internal Use

63. LTE2612 ProSe Direct Communications for Public Safety If the UE is configured for sidelink communication, VQ triggered SRVCC to GSM is not used LTE1170 Inter eNode B IF Load Balancing LTE1841 Inter-Frequency Load Equalization LTE3443 SRVCC trigger stop running LB A4 measurements LTE1357 LTE-UTRAN load balancing LTE3443 SRVCC trigger stop running LB B1 measurements LTE2051 Measurement based Idle Mode Load Balancing LTE3443 SRVCC trigger stop running IMLB A4 measurements Interdependencies limitations Nokia Internal Use  More details available on WebNEI : LTE2612  More details available on WebNEI : LTE1170  More details available on WebNEI : LTE1357  More details available on WebNEI : LTE2051  More details available on WebNEI : LTE1841

64. Benefits and Gains LTE3443 VoLTE quality triggered SRVCC to GSM Table of contents

65. LTE 3443 seem to bring benefits especially in areas highly loaded by VoLTE traffic and overlapped by GSM layer Feature reduces the number of calls for which low voice quality is perceived by end users this is possible by moving VoLTE users towards CS domain of GSM via SRVCC procedure LTE3443 may be treated also as supporting feature for GBR congestion resolution so far existing mechanism introduced by feature bundle LTE496/LTE497/LTE534 would finally lead to disconnections of GBR bearers now VoLTE calls, which are of GBR traffic, may be moved toward GSM before they are disconnected by congestion handling mechanism Benefits and Gains LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use GSM LTE VoLTE users with low voice quality due missing packets may be steered towards GSM via SRVCC procedure SRVCC to GSM

66. Configuration Management LTE3443 VoLTE quality triggered SRVCC to GSM Table of contents

67. Definition of terms and rules for parameter classification* Configuration Management Nokia Internal Use The ‘Basic Parameters’ category contains primary parameters which should be considered during cell deployment and must be adjusted to a particular scenario : Network Element (NE) identifiers Planning parameters, e.g. neighbour definitions, frequency, scrambling codes, PCI, RA preambles Parameters that are the outcome from dimensioning, i.e. basic parameters defining amount of resources Basic parameters activating basic functionalities, e.g. power control, admission control, handovers Parameters defining operators’ strategy, e.g. traffic steering, thresholds for power control, handovers, cell reselections, basic parameters defining feature behaviour The ‘Advanced Parameters’ category contains the parameters for network optimisation and fine tuning: Decent network performance should be achieved without tuning these parameters Universal defaults ensuring decent network performance need to be defined for all parameters of this category. If this is not possible for a given parameter it must be put to the ‘Basic Parameters’ category Parameters requiring detailed system knowledge and broad experience unless rules for the ‘Basic Parameters’ category are violated All parameters (even without defaults, e.g. optional structures) related to advanced and very complex features The ‘ Obsolete parameters ’ category is intended for parameters that are candidates to be removed from the product in a future release : P arameters always used with default value P arameters that are not used by operators P arameters that are not relevant anymore * - purpose: Categories of parameters have been defined to simplify network parametrization. Parameterization effort shall be focused mainly on Basic ones. Categorization is reflected in a ‘view’ definition in NetAct CM Editor.

68. Configuration Management LTE3443 VoLTE quality triggered SRVCC to GSM LNBTS actSrvccToGsm = true actVoLteQualSRVCCtoGsm = true … LNCEL-2 assignedVoLteQualProfId = Y … LNCEL-1 assignedVoLteQualProfId = X … VOLTEQUALPR-1 voLteQualPrId = Y badQualityRBlerThres goodQualityRBlerThres rBlerCondTimeToTrigger badQualityDLGapThres badQualityULGapThres goodQualityGapThres VOLTEQUALPR-2 voLteQualPrId = … badQualityRBlerThres goodQualityRBlerThres rBlerCondTimeToTrigger badQualityDLGapThres badQualityULGapThres goodQualityGapThres LNCEL-96 assignedVoLteQualProfId = … … VOLTEQUALPR-96 voLteQualPrId = X badQualityRBlerThres goodQualityRBlerThres rBlerCondTimeToTrigger badQualityDLGapThres badQualityULGapThres goodQualityGapThres … … Under LNBTS up to 96 independent VoLTE Quality Profiles VOLTEQUALPR may be defined A given cell is using VoLTE Quality Profile indicated by parameter LNCEL:assignedVoLteQualProfId which is a pointer to VOLTEQUALPR:voLteQualPrId

69. Nokia Internal Use Abbreviated name Full name PKDB link LNBTS:actVoLteQualSRVCCtoGsm Activate VoLTE quality triggered SRVCC to GSM LNCEL:assignedVoLteQualProfile Assigned VoLTE quality profile VOLTEQUALPR:voLteQualPrId VoLTE quality profile identifier Mandatory MO : /LNBTS/LNADJG /LNCEL/LNHOG /LNCEL/LNRELG

70. Nokia Internal Use Abbreviated name Full name PKDB link VOLTEQUALPR: badQualityRBlerThres Bad quality residual BLER threshold VOLTEQUALPR: goodQualityRBlerThres Good quality residual BLER threshold VOLTEQUALPR: rBlerCondTimeToTrigger Residual BLER condition time to trigger VOLTEQUALPR: badQualityDLGapThres Bad quality DL voice gap threshold VOLTEQUALPR: badQualityULGapThres Bad quality UL voice gap threshold VOLTEQUALPR: goodQualityGapThres Good quality UL DL voice gap threshold PMCCP:maxVBreakDistThresh Max voice break distribution threshold

71. Deployment Aspects LTE3443 VoLTE quality triggered SRVCC to GSM Network graphic boxes Network element boxes Table of contents Nokia Internal Use

72. Deployment Aspects LTE3443 VoLTE quality triggered SRVCC to GSM Nokia Internal Use High number of VoLTE users is established in the cell The users are moving towards cell edge , however no low RSRP or RSRQ is reached to activate event B2 based measurement for SRVCC to GSM (acc. to to LTE873) The more UEs moving towards cell edge , the more physical radio resources are needed to keep requested GBR requirements for VoLTE traffic If GBR congestion is detected some of the VoLTE bearers may be deprioritized – this means some of them will be scheduled less frequent as required what can degrade the voice call quality directly perceived by the end user If congestion is not resolved within 300ms, the eNB may decide to release some of existing voice connections With LTE3443, event B1 for SRVCC to GSM may be activated at congestion detection state and lead to congestion resolution by moving the VoLTE UEs to GSM, reducing at the same time number of possible VoLTE call disconnections

73. Performance Aspects LTE3443 VoLTE quality triggered SRVCC to GSM Table of contents

74. Performance Aspects LTE3443 VoLTE quality triggered SRVCC to GSM Monitoring of PDCP packet loss for DL/UL (1/3) Despite of detection of Voice Quality Problem (VQP) based on the missing packets in DL ( VOLTEQUALPR : badQuality D LGapThres ) and UL ( VOLTEQUALPR : badQuality U LGapThres ), the eNB is able to collect the distribution of the PDCP packets gaps in DL and UL as such For this purposes 11 bins for DL and 11 bins for UL reflected by new counters were created 11 bins for DL reflected by new counters DL_VB_PERIOD_BIN 1 (M8067C0)... DL_VB_PERIOD_BIN 11 (M8067C10) 11 bins for UL reflected by new counters UL_VB_PERIOD_BIN 1 (M8067C11)... UL_VB_PERIOD_BIN 11 (M8067C21) Nokia Internal Use

75. Performance Aspects LTE3443 VoLTE quality triggered SRVCC to GSM Monitoring of PDCP packet loss for DL/UL (2/3) Gap span for each bin in DL/UL is evaluated based on new parameter PMCCP:maxVBreakDistThresh with possible values 1...10 s, step 1 s according to following formula Gap span for BIN X, where X = 1…10 ( X -1 )*( PMCCP:maxVBreakDistThresh /10) < Gap Span <= X *( PMCCP:maxVBreakDistThresh /10) Gap span for BIN X, where X = 11 ( X -1)*( PMCCP:maxVBreakDistThresh /10) < Gap Span As an example for PMCCP:maxVBreakDistThresh = 2s (default value) the detected Voice Breaks will fall into bins and increment appropriated counters according to the ranges as below Nokia Internal Use BIN1 (0,0.2] BIN2 (0.2,0.4] BIN3 (0.4,0.6] BIN4 (0.6,0.8] BIN5 (0.8,1.0] BIN6 (1.0,1.2] BIN7 (1.2,1.4] BIN8 (1.4,1.6] BIN9 (1.6,1.8] BIN10 (1.8,2.0] BIN11 >2.0 maxVBreakDistThresh =This parameter sets the threshold for the Voice Break of the related counters. So, it’s just for counter calculation purpose. For example, default value=2s. Bin1 means the loss time is between 0~0.2s. In my case, the Bin2 and Bin4 has counter value. But, due to Bin2 and Bin4 happened not in correct Successful SRVCC duration (17:00 counter), SRVCC trigger is BLER, not PDCP loss timer.

76. Performance Aspects LTE3443 VoLTE quality triggered SRVCC to GSM Monitoring of PDCP packet loss for DL/UL (3/3) Having information collected by bins, an Operator is able to create PDCP Voice Breaks histograms for DL/UL, giving the view whether PDCP Voice Break problem is significant or not It is expected that the Voice Breaks will be dominant in the first bins and the trend shall be decreasing for next bins, but the most valuable information is numerousness collected in bins for a given collection period Nokia Internal Use BIN1 BIN2 BIN3 BIN4 BIN5 BIN6 BIN7 BIN8 BIN9 BIN10 BIN11 numerousness bins This way the Operator is able to compare its service requirements against the network conditions and take a decision whether activation of PDCP gap triggered SRVCC to GSM is reasonable or not Histograms may also be helpful for tuning parameters which control VQP_ON triggered by PDCP packet gaps

77. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description ISYS_HO_GERAN_SRVCC_PREP_VQ (M8016C61) #LTE Inter System Handover This measurement provides the number of Inter-System Handover preparations to the GERAN with VoLTE -Quality-triggered SRVCC. Trigger event: Transmission of an S1AP:HANDOVER REQUIRED message to the source MME for an Inter-System
Handover to the GERAN with VoLTE Quality Triggered SRVCC. Use case: Preparation Phase Success Ratio for VoLTE -Quality-triggered SRVCC to GERAN Proposed KPI#1 (new) = ISYS_HO_GERAN_SRVCC_PREP_VQ ISYS_HO_GERAN_SRVCC_ATT_VQ In my case, it has counter value

78. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description ISYS_HO_GERAN_SRVCC_ATT_VQ (M8016C62) #LTE Inter System Handover This measurement provides the number of Inter-System Handover attempts to GERAN with VoLTE -Quality-triggered SRVCC (Single Radio Voice Call Continuity, 3GPP TS 23.216). Trigger event: Reception of an S1AP:HANDOVER COMMAND message (source eNB <- MME; 3GPP TS 36.413) in case this message is received in response to the preparation for an Inter-System Handover to GERAN with VoLTE -Quality-triggered SRVCC (Single Radio Voice Call Continuity,
3GPP TS 23.216). Use case: Preparation Phase Success Ratio for VoLTE -Quality-triggered SRVCC to GERAN Proposed KPI#1 (new) = ISYS_HO_GERAN_SRVCC_PREP_VQ ISYS_HO_GERAN_SRVCC_ATT_VQ In my case, it has counter value

79. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description ISYS_HO_GERAN_SRVCC_SUCC_VQ (M8016C63) #LTE Inter System Handover This measurement provides the number of successful Inter-System Handover completions to GERAN with VoLTE -Quality-triggered SRVCC (Single Radio Voice Call Continuity, 3GPP TS 23.216). Trigger event: Reception of an S1AP:UE CONTEXT RELEASE COMMAND message (source eNB <- MME; 3GPP TS 36.413) with Cause value "Radio Network Layer (Successful Handover)" in case this message is received for an Inter-System Handover to GERAN with VoLTE -Quality-triggered SRVCC (Single Radio Voice Call Continuity, 3GPP TS 23.216). Use case: Execution Phase Success Ratio for VoLTE -Quality-triggered SRVCC to GERAN Proposed KPI#2 (new) = ISYS_HO_GERAN_SRVCC_ATT_VQ ISYS_HO_GERAN_SRVCC_SUCC_VQ In my case, it has counter value

80. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description ISYS_HO_GER_SRVCC_P_FAIL_TI_VQ (M8016C64) #LTE Inter System Handover This measurement provides the number of failed Inter-System Handover preparations to the GERAN with VoLTE -Quality-triggered SRVCC due to the expiration of the guarding timer. Trigger event: This counter is updated when Inter-System Handover preparation to GERAN with VoLTE -Quality-triggered SRVCC fails due to expiration of the guarding timer TS1RELOCprep_InterRAT. This
counter is updated for the source cell of the handover. Use case: Preparation Phase Failure Ratio for VoLTE -Quality-triggered SRVCC to GERAN due to guarding time expiry Proposed KPI#3 (new) = ISYS_HO_GERAN_SRVCC_PREP_VQ ISYS_HO_GER_SRVCC_P_FAIL_TI_VQ

81. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description ISYS_HO_GER_SRVCC_P_FAIL_AC_VQ (M8016C65) #LTE Inter System Handover This measurement provides the number of failed Inter-System Handover preparations to the GERAN with VoLTE -Quality-triggered SRVCC due to admission control of the target cell. Trigger event: This counter is updated when an S1AP:HANDOVER PREPARATION FAILURE message is received from the MME with cause "No radio resources available in target cell" for an Inter-System Handover to the GERAN with VoLTE -Quality-triggered SRVCC. This counter
is updated for the source cell of the handover. Use case: Preparation Phase Failure Ratio for VoLTE -Quality-triggered SRVCC to GERAN due to admission control rejection Proposed KPI#4 (new) = ISYS_HO_GERAN_SRVCC_PREP_VQ ISYS_HO_GER_SRVCC_P_FAIL_AC_VQ

82. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description ISYS_HO_GER_SRVCC_P_FAIL_OT_VQ (M8016C66) #LTE Inter System Handover The number of failed Inter-System Handover preparations to the GERAN with VoLTE -Quality-triggered SRVCC due to other reasons (target cell). Trigger event: This counter is updated when an S1AP:HANDOVER PREPARATION FAILURE message is received from the MME with a cause other than "No radio resources available in target cell" for an Inter-System Handover to the GERAN with VoLTE -Quality-triggered SRVCC. Use case: Preparation Phase Failure Ratio for VoLTE -Quality-triggered SRVCC to GERAN due other reasons Proposed KPI#5 (new) = ISYS_HO_GERAN_SRVCC_PREP_VQ ISYS_HO_GER_SRVCC_P_FAIL_OT_VQ In my case, it has counter value

83. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description ISYS_HO_GER_SRVCC_FAIL_TIM_VQ (M8016C67) #LTE Inter System Handover The number of VoLTE -Quality-triggered SRVCC HO execution failures due to expiry of the guarding timer. Trigger event: This counter is updated following the expiry of the guarding timer TS1RELOCoverall in case that this timer was started because of an Inter-System Handover to GERAN with VoLTE -Quality-triggered SRVCC. Use case: Execution Phase Failure Ratio for VoLTE -Quality-triggered SRVCC to GERAN due to TS1RELOCoverall guarding time expiry Proposed KPI#6 (new) = ISYS_HO_GERAN_SRVCC_ATT_VQ ISYS_HO_GER_SRVCC_FAIL_TIM_VQ

84. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description DL_VB_PERIOD_BIN1 (M8067C0) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 1. The range is dependent on the value of the PMCCP: maxVBreakDistThresh parameter. The range of bin 1 is as follows: < UE in Voice Break Period for DL <= 0,1 * PMCCP: maxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin1. Packet loss period is detected as difference in the time between the last successful PDCP SDU sent and the first new successful PDCP SDU sent after the period of discarded SDUs (or the lower layer indicated as not possible to proceed).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

85. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description DL_VB_PERIOD_BIN2 (M8067C1) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 2. The range is dependent on the value of the PMCCP: maxVBreakDistThresh parameter. The range of bin 2 is as follows: 0,1 * PMCCP: maxVBreakDistThresh < UE in Voice Break Period for DL <= 0,2 * PMCCP: maxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin2. Packet loss period is detected as difference in the time between the last successful PDCP SDU sent and the first new successful PDCP SDU sent after the period of discarded SDUs (or the lower layer indicated as not possible to proceed).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

86. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description DL_VB_PERIOD_BIN3 (M8067C2) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 3. The range is dependent on the value of the PMCCP: maxVBreakDistThresh parameter. The range of bin 3 is as follows: 0,2 * PMCCP: maxVBreakDistThresh < UE in Voice Break Period for DL <= 0,3 * PMCCP: maxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin3. Packet loss period is detected as difference in the time between the last successful PDCP SDU sent and the first new successful PDCP SDU sent after the period of discarded SDUs (or the lower layer indicated as not possible to proceed).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

87. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description DL_VB_PERIOD_BIN4 (M8067C3) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 4. The range is dependent on the value of the PMCCP: maxVBreakDistThresh parameter. The range of bin 4 is as follows: 0,3 * PMCCP: maxVBreakDistThresh < UE in Voice Break Period for DL <= 0,4 * PMCCP: maxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin4. Packet loss period is detected as difference in the time between the last successful PDCP SDU sent and the first new successful PDCP SDU sent after the period of discarded SDUs (or the lower layer indicated as not possible to proceed).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

88. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description DL_VB_PERIOD_BIN5 (M8067C4) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 5. The range is dependent on the value of the PMCCP: maxVBreakDistThresh parameter. The range of bin 5 is as follows: 0,4 * PMCCP: maxVBreakDistThresh < UE in Voice Break Period for DL <= 0,5 * PMCCP: maxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin5. Packet loss period is detected as difference in the time between the last successful PDCP SDU sent and the first new successful PDCP SDU sent after the period of discarded SDUs (or the lower layer indicated as not possible to proceed).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

89. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description DL_VB_PERIOD_BIN6 (M8067C5) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 6. The range is dependent on the value of the PMCCP: maxVBreakDistThresh parameter. The range of bin 6 is as follows: 0,5 * PMCCP: maxVBreakDistThresh < UE in Voice Break Period for DL <= 0,6 * PMCCP: maxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin6. Packet loss period is detected as difference in the time between the last successful PDCP SDU sent and the first new successful PDCP SDU sent after the period of discarded SDUs (or the lower layer indicated as not possible to proceed).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

90. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description DL_VB_PERIOD_BIN7 (M8067C6) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 7. The range is dependent on the value of the PMCCP: maxVBreakDistThresh parameter. The range of bin 7 is as follows: 0,6 * PMCCP: maxVBreakDistThresh < UE in Voice Break Period for DL <= 0,7 * PMCCP: maxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin7. Packet loss period is detected as difference in the time between the last successful PDCP SDU sent and the first new successful PDCP SDU sent after the period of discarded SDUs (or the lower layer indicated as not possible to proceed).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

91. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description DL_VB_PERIOD_BIN8 (M8067C7) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 8. The range is dependent on the value of the PMCCP: maxVBreakDistThresh parameter. The range of bin 8 is as follows: 0,7 * PMCCP: maxVBreakDistThresh < UE in Voice Break Period for DL <= 0,8 * PMCCP: maxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin8. Packet loss period is detected as difference in the time between the last successful PDCP SDU sent and the first new successful PDCP SDU sent after the period of discarded SDUs (or the lower layer indicated as not possible to proceed).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

92. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description DL_VB_PERIOD_BIN9 (M8067C8) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 9. The range is dependent on the value of the PMCCP: maxVBreakDistThresh parameter. The range of bin 9 is as follows: 0,8 * PMCCP: maxVBreakDistThresh < UE in Voice Break Period for DL <= 0,9 * PMCCP: maxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin9. Packet loss period is detected as difference in the time between the last successful PDCP SDU sent and the first new successful PDCP SDU sent after the period of discarded SDUs (or the lower layer indicated as not possible to proceed).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

93. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description DL_VB_PERIOD_BIN10 (M8067C9) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 10. The range is dependent on the value of the PMCCP: maxVBreakDistThresh parameter. The range of bin 10 is as follows: 0,9 * PMCCP: maxVBreakDistThresh < UE in Voice Break Period for DL <= 1 * PMCCP: maxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin10. Packet loss period is detected as difference in the time between the last successful PDCP SDU sent and the first new successful PDCP SDU sent after the period of discarded SDUs (or the lower layer indicated as not possible to proceed).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

94. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description DL_VB_PERIOD_BIN11 (M8067C10) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period which exceeds the range of the parameter PMCCP: MaxVBreakDistThr esh commissioned by the customer. The range of bin 11 is as follows: PMCCP:maxVBreakDistThresh < UE in Voice Break Period for DL Trigger event: This counter is updated if packet loss period exceed the maximum value defined by Customer. Maximum value is defined by PMCCP:MaxVBreakDistThresh parameter. Packet loss period is detected as difference in the time between the last successful PDCP SDU sent and the first new successful PDCP SDU sent after the period of discarded SDUs (or the lower layer indicated as not possible to proceed).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

95. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description UL_VB_PERIOD_BIN1 (M8067C11) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 1. The range is dependent on the value of the PMCCP:MaxVBreakDistThresh parameter. The range of bin 1 is as follows: <= UE in Voice Break Period for UL <= 0,1 * PMCCP:MaxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin1. Packet loss period is detected as difference in the time between the last successfully decoded PDCP SDU and the first new successfully decoded PDCP SDU after period of lost SDUs (SN are missing).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

96. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description UL_VB_PERIOD_BIN2 (M8067C12) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 2. The range is dependent on the value of the PMCCP:MaxVBreakDistThresh parameter. The range of bin 2 is as follows: 0,1 * PMCCP:MaxVBreakDistThresh < UE in Voice Break Period for UL <= 0,2 * PMCCP:MaxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin2. Packet loss period is detected as difference in the time between the last successfully decoded PDCP SDU and the first new successfully decoded PDCP SDU after period of lost SDUs (SN are missing).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

97. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description UL_VB_PERIOD_BIN3 (M8067C13) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 3. The range is dependent on the value of the PMCCP:MaxVBreakDistThresh parameter. The range of bin 3 is as follows: 0,2 * PMCCP:MaxVBreakDistThresh < UE in Voice Break Period for UL <= 0,3 * PMCCP:MaxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin3. Packet loss period is detected as difference in the time between the last successfully decoded PDCP SDU and the first new successfully decoded PDCP SDU after period of lost SDUs (SN are missing).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

98. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description UL_VB_PERIOD_BIN4 (M8067C14) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 4. The range is dependent on the value of the PMCCP:MaxVBreakDistThresh parameter. The range of bin 4 is as follows: 0,3 * PMCCP:MaxVBreakDistThresh < UE in Voice Break Period for UL <= 0,4 * PMCCP:MaxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin4. Packet loss period is detected as difference in the time between the last successfully decoded PDCP SDU and the first new successfully decoded PDCP SDU after period of lost SDUs (SN are missing).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

99. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description UL_VB_PERIOD_BIN5 (M8067C15) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 5. The range is dependent on the value of the PMCCP:MaxVBreakDistThresh parameter. The range of bin 5 is as follows: 0,4 * PMCCP:MaxVBreakDistThresh < UE in Voice Break Period for UL <= 0,5 * PMCCP:MaxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin5. Packet loss period is detected as difference in the time between the last successfully decoded PDCP SDU and the first new successfully decoded PDCP SDU after period of lost SDUs (SN are missing).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

100. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description UL_VB_PERIOD_BIN6 (M8067C16) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 6. The range is dependent on the value of the PMCCP:MaxVBreakDistThresh parameter. The range of bin 6 is as follows: 0,5 * PMCCP:MaxVBreakDistThresh < UE in Voice Break Period for UL <= 0,6 * PMCCP:MaxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin6. Packet loss period is detected as difference in the time between the last successfully decoded PDCP SDU and the first new successfully decoded PDCP SDU after period of lost SDUs (SN are missing).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

101. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description UL_VB_PERIOD_BIN7 (M8067C17) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 7. The range is dependent on the value of the PMCCP:MaxVBreakDistThresh parameter. The range of bin 7 is as follows: 0,6 * PMCCP:MaxVBreakDistThresh < UE in Voice Break Period for UL <= 0,7 * PMCCP:MaxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin7. Packet loss period is detected as difference in the time between the last successfully decoded PDCP SDU and the first new successfully decoded PDCP SDU after period of lost SDUs (SN are missing).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

102. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description UL_VB_PERIOD_BIN8 (M8067C18) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 8. The range is dependent on the value of the PMCCP:MaxVBreakDistThresh parameter. The range of bin 8 is as follows: 0,7 * PMCCP:MaxVBreakDistThresh < UE in Voice Break Period for UL <= 0,8 * PMCCP:MaxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin8. Packet loss period is detected as difference in the time between the last successfully decoded PDCP SDU and the first new successfully decoded PDCP SDU after period of lost SDUs (SN are missing).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

103. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description UL_VB_PERIOD_BIN9 (M8067C19) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 9. The range is dependent on the value of the PMCCP:MaxVBreakDistThresh parameter. The range of bin 9 is as follows: 0,8 * PMCCP:MaxVBreakDistThresh < UE in Voice Break Period for UL <= 0,9 * PMCCP:MaxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin9. Packet loss period is detected as difference in the time between the last successfully decoded PDCP SDU and the first new successfully decoded PDCP SDU after period of lost SDUs (SN are missing).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

104. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description UL_VB_PERIOD_BIN10 (M8067C20) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period matching the range of bin 10. The range is dependent on the value of the PMCCP:MaxVBreakDistThresh parameter. The range of bin 10 is as follows: 0,9 * PMCCP:MaxVBreakDistThresh < UE in Voice Break Period for UL <= 1 * PMCCP:MaxVBreakDistThresh Trigger event: This counter is updated if packet loss period is within the range of bin10. Packet loss period is detected as difference in the time between the last successfully decoded PDCP SDU and the first new successfully decoded PDCP SDU after period of lost SDUs (SN are missing).
Note: This counter is related to monitoring VoLTE -quality-triggered SRVCC to GSM/WCDMA.

105. Performance Aspects New counters Feature LTE3443 introduced 29 new counters Counter name Description UL_VB_PERIOD_BIN11 (M8067C21) #LTE VoLTE Voice Break Period Histogram This counter provides sum of events when UEs are having packet loss for period which exceeds the range of the parameter PMCCP:MaxVBreakDistThresh commissioned by the customer. The range of bin 11 is as follows: PMCCP:maxVBreakDistThresh < UE in Voice Break Period for UL Trigger event: This counter is updated if packet loss period exceed the maximum value defined by Customer. Maximum value is defined in PMCCP:MaxVBreakDistThresh parameter. Packet loss period is detected as difference in the time between the last successfully decoded PDCP SDU and the first new successfully decoded PDCP SDU after the period of lost SDUs (SN are missing).
Note: The counter is related to monitoring VoLTE quality triggered SRVCC to GSM/WCDMA.

106. Feature impact How to measure? It is expected that existing KPIs which control PDCP SDU Loss Ratio for DL and UL and PDCP SDU Discard Ratio for DL will improve. This is because with LTE3443 UEs, which contribute to high Loss Ratio or Discard Ratio may be now moved from LTE to GSM via SRVCC procedure. As result such unwanted UEs state is shortened on LTE side KPIs: E-UTRAN PDCP SDU Loss Ratio in the UL, QCI1 ( LTE_5311b ) E-UTRAN PDCP SDU Loss Ratio in the DL, QCI1 ( LTE_5305c ) E-UTRAN PDCP SDU Discard Ratio in DL, QCI1 ( LTE_5256 c ) It is recommended to verify histograms of UL residual BLER introduced by LTE2493. It is expected that the bins defined for high BLER (above VOLTEQUALPR:badQualityRBlerThres ) will be updated less frequently, due to fact SRVCC to GSM may be triggered by high UL residual BLER Counters: UL_QCI1_RES_BLER_BIN1 ( M8054C11 ) … UL_CI1_RES_BLER_BIN1 1 ( M8054C 2 1 ) Nokia Internal Use

107. Feature impact How to measure? It is recommended to verify histograms of DL/UL PDCP Voice Break It is expected that the Voice Breaks will be dominant in the first bins and the trend shall be decreasing for next bins, but the most valuable information is numerousness collected in bins for a given collection period Based on this the Operator is able to compare its service requirements against the network conditions and take a decision whether activation of PDCP gap triggered SRVCC to GSM is reasonable or not Counters: DL_VB_PERIOD_BIN1 ( M8067C0 ) … DL_VB_PERIOD_BIN11 ( M8067C10 ) UL_VB_PERIOD_BIN1 ( M8067C11 ) … UL_VB_PERIOD_BIN11 ( M8067C21 ) As LTE3443 introduces additional trigger for SRVCC to GSM it is expected that the number of SRVCC to GSM preparations and SRVCC attempts will increase KPIs: Inter RAT HO Preparation Attempts to GERAN with SRVCC ( LTE_6107a ) E-UTRAN Inter RAT HO Attempts to GERAN SRVCC ( LTE_5565a ) Nokia Internal Use

108. Learning Index link : https://nokialearn.csod.com/DeepLink/ProcessRedirect.aspx?module=lodetails&lo=dcac74da-3f00-40a2-bcd7-e3a05103cb98