LTE Call Flow Basics

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Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Released - For Current Employee/Consultant Use Only LTE Call Flows 80-N8310-1 A November 22, 2011 Submit technical questions at: https://support.cdmatech.com/ Qualcomm Confidential and Proprietary Restricted Distribution. Not to be distributed to anyone who is not an employee of either Qualcomm or a subsidiary of Qualcomm without the express approval of Qualcomm’s Configuration Management. Not to be used, copied, reproduced in whole or in part, nor its contents revealed in any manner to others without the express written permission of Qualcomm. Qualcomm reserves the right to make changes to the product(s) or information contained herein without notice. No liability is assumed for any damages arising directly or indirectly by their use or application. The information provided in this document is provided on an “as is” basis. 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Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Contents Released - For Current Employee/Consultant Use Only 1 Introduction...................................................................................................... 8 1.1 Purpose.......................................................................................................................... 8 1.2 Scope............................................................................................................................. 8 1.3 Conventions .................................................................................................................. 8 1.4 References..................................................................................................................... 8 1.5 Technical assistance ...................................................................................................... 8 1.6 Acronyms ...................................................................................................................... 8 2 Cell Selection ................................................................................................... 9 2.1 System scan call flow.................................................................................................. 10 2.2 Band scan call flow ..................................................................................................... 11 2.3 BCCH setup call flow ................................................................................................. 12 2.4 SIB collection and camping call flow ......................................................................... 13 3 Connection Establishment ........................................................................... 14 3.1 Connection establishment call flow ............................................................................ 15 4 Intra-LTE Handover ....................................................................................... 16 4.1 Intra-LTE handover call flow ..................................................................................... 17 5 Idle Mode Measurements .............................................................................. 21 5.1 Idle mode measurements call flow ............................................................................. 22 6 Connected Mode Measurements.................................................................. 23 6.1 Connected mode measurements call flow................................................................... 24 7 Paging ............................................................................................................ 25 7.1 Paging call flow .......................................................................................................... 26 8 BPLMN Search ............................................................................................... 27 8.1 Intra-LTE BPLMN search call flow ........................................................................... 28 8.2 From LTE BPLMN search.......................................................................................... 29 8.2.1 LTE and non-LTE searches call flow .............................................................. 29 8.2.2 Search exhausted call flow .............................................................................. 30 8.3 To LTE BPLMN search call flow............................................................................... 31 9 Radio Link Failure (RLF) ............................................................................... 32 9.1 Radio link failure call flow ......................................................................................... 33 80-N8310-1 A 2 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Contents 10 LTE→eHRPD Redirection ........................................................................... 39 10.1 LTE→eHRPD redirection call flow ......................................................................... 40 11 LTE→eHRPD Reselection ........................................................................... 41 11.1 LTE→eHRPD reselection call flow ......................................................................... 42 Released - For Current Employee/Consultant Use Only 12 eHRPD→LTE Reselection ........................................................................... 43 12.1 eHRPD→LTE reselection call flow ......................................................................... 44 13 LTE→WCDMA PS HO .................................................................................. 45 13.1 LTE→WCDMA PS HO call flow ............................................................................ 46 14 LTE SON/ANR .............................................................................................. 47 15 IRAT SON/ANR ............................................................................................. 48 16 Attach ........................................................................................................... 49 17 3GPP CSFB .................................................................................................. 50 17.1 3GPP CSFB call flow ............................................................................................... 51 18 CSFB (L→W Redirection with System Information Tunneling) ............... 52 18.1 CSFB (L→W redirection with system information tunneling) call flow ................. 53 19 GERAN→LTE Redirection........................................................................... 54 19.1 GERAN→LTE redirection call flow ........................................................................ 55 20 LTE→GERAN Redirection........................................................................... 56 20.1 LTE→GERAN redirection call flow ........................................................................ 57 21 GERAN→LTE Reselection .......................................................................... 58 21.1 GERAN→LTE reselection call flow ........................................................................ 59 22 LTE→GERAN Reselection .......................................................................... 60 22.1 LTE→GERAN reselection call flow ........................................................................ 61 23 LTE→WCDMA Redirection ......................................................................... 62 23.1 LTE→WCDMA redirection call flow ...................................................................... 63 24 WCDMA→LTE Redirection ......................................................................... 64 24.1 WCDMA→LTE redirection call flow ...................................................................... 65 25 Idle Mode Signaling Reduction (ISR) Flows .............................................. 66 25.1 ISR call flow ............................................................................................................. 67 80-N8310-1 A 3 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Contents 26 1X Preregistration and CSFB to 1X ............................................................ 69 26.1 1X preregistration and CSFB→1X call flow ............................................................ 70 27 LTE→1X Redirection and Reselection ....................................................... 72 27.1 LTE→1X redirection and reselection call flow ........................................................ 73 Released - For Current Employee/Consultant Use Only 80-N8310-1 A 4 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Contents Figures Figure 2-1 System scan call flow ................................................................................................. 10 Figure 2-2 Band scan call flow .................................................................................................... 11 Released - For Current Employee/Consultant Use Only Figure 2-3 BCCH setup call flow ................................................................................................ 12 Figure 2-4 SIB collection and camping call flow ........................................................................ 13 Figure 3-1 Connection establishment call flow ........................................................................... 15 Figure 4-1 Intra-LTE handover call flow 1.................................................................................. 17 Figure 4-2 Intra-LTE handover call flow 2.................................................................................. 18 Figure 4-3 Intra-LTE handover call flow 3.................................................................................. 19 Figure 4-4 Intra-LTE handover call flow 4.................................................................................. 20 Figure 5-1 Idle mode measurements call flow ............................................................................. 22 Figure 6-1 Connected mode measurements call flow .................................................................. 24 Figure 7-1 Paging call flow.......................................................................................................... 26 Figure 8-1 Intra-LTE BPLM search call flow ............................................................................. 28 Figure 8-2 LTE and non-LTE searches call flow ........................................................................ 29 Figure 8-3 Search exhausted call flow ......................................................................................... 30 Figure 8-4 LTE BPLMN search call flow ................................................................................... 31 Figure 9-1 Radio link call flow 1 ................................................................................................. 33 Figure 9-2 Radio link call flow 2 ................................................................................................. 34 Figure 9-3 Radio link call flow 3 ................................................................................................. 35 Figure 9-4 Radio link call flow 4 ................................................................................................. 36 Figure 9-5 Radio link call flow 5 ................................................................................................. 37 Figure 9-6 Radio link call flow 6 ................................................................................................. 38 Figure 10-1 LTE→eHRPD redirection call flow......................................................................... 40 Figure 11-1 LTE→eHRPD reselection call flow......................................................................... 42 Figure 12-1 eHRPD→LTE reselection call flow......................................................................... 44 Figure 13-1 LTE→WCDMA PS HO call flow ........................................................................... 46 Figure 14-1 LTE SON/ANR call flow ......................................................................................... 47 Figure 15-1 IRAT SON/ANR call flow ....................................................................................... 48 Figure 16-1 Attach call flow ........................................................................................................ 49 Figure 17-1 3GPP CSFB call flow .............................................................................................. 51 Figure 18-1 CSFB (L→W redirection with system information tunneling) call flow ................ 53 Figure 19-1 GERAN→LTE redirection call flow ....................................................................... 55 Figure 20-1 LTE→GERAN redirection call flow ....................................................................... 57 Figure 21-1 GERAN→LTE reselection call flow ....................................................................... 59 Figure 22-1 LTE→GERAN reselection call flow ....................................................................... 61 Figure 23-1 LTE→WCDMA redirection call flow ..................................................................... 63 Figure 24-1 WCDMA→LTE redirection call flow ..................................................................... 65 Figure 25-1 ISR flow call flow 1 ................................................................................................. 67 80-N8310-1 A 5 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Contents Figure 25-2 ISR flow 2 call flow 2 .............................................................................................. 68 Figure 26-1 1X preregistration and CSFB→1X call flow 1 ........................................................ 70 Figure 26-2 1X preregistration and CSFB→1X call flow 2 ........................................................ 71 Figure 27-1 LTE→1X redirection and reselection call flow ....................................................... 73 Released - For Current Employee/Consultant Use Only Tables Table 1-1 Reference documents and standards .............................................................................. 8 80-N8310-1 A 6 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 Revision history Revision Date Description A Nov 2011 Initial release Released - For Current Employee/Consultant Use Only 2 3 80-N8310-1 A 7 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 Introduction Released - For Current Employee/Consultant Use Only 1.1 Purpose This document explains the call flows in various LTE and IRAT scenarios. 1.2 Scope This document is for engineers who want to understand the details of the software architecture in place for LTE (Connected mode and the Idle state) and IRAT. 1.3 Conventions Function declarations, function names, type declarations, and code samples appear in a different font, e.g., #include. 1.4 References Reference documents, which may include Qualcomm documents, standards, and resources are listed in Table 1-1. Reference documents that are no longer applicable are deleted from this table; therefore, reference numbers may not be sequential. Table 1-1 Reference documents and standards Ref. Document Qualcomm Q1 Application Note: Software Glossary for Customers CL93-V3077-1 1.5 Technical assistance For assistance or clarification on information in this guide, submit a case to Qualcomm CDMA Technologies at https://support.cdmatech.com/. If you do not have access to the CDMATech Support Service website, register for access or send email to [email protected]. 1.6 Acronyms For definitions of terms and abbreviations, see [Q1]. 80-N8310-1 A 8 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 2 Cell Selection Released - For Current Employee/Consultant Use Only This procedure performs cell selection and reselection in Idle mode and cell selection during RLF in Connected mode. If entries are present in the acquisition database, i.e., a Most Recently Used (MRU) cache of recently camped cells, these frequencies are tried first through a system scan. If the system scan is not successful, band scan is initiated on the supported bands, one by one, to get candidate frequencies. In either case, acquisition is performed on candidate frequencies, followed by a mandatory SIB reading to determine cell barring and PLMN selection. Once a candidate cell is found, an S criteria quality check is performed on it and the lower layers are configured, at which point the UE goes to the Camped state. In reselection, the flow is restarted with the SIB reading phase on the target cell. Camping can be for full service (suitable cell) or limited service (acceptable cell). 80-N8310-1 A 9 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Cell Selection 2.1 System scan call flow Figure 2-1 shows the system scan call flow. MAC/ RRC RRC RRC RRC RRC NAS RLC/ ML1 CEP CSP Controller SIB LLC PDCP Released - For Current Employee/Consultant Use Only Initial Inactive Inactive LTE_RRC_SERVICE_REQ (PLMN info, Band Info, System Pref) Buffer Service Request till stack is started LTE_RRC_MODE CHANGE_REQI (Activate, UE not camped) LTE_CPHY_START_REQ Wait Change Mode Cnf Start LTE stack LTE_CPHY_START_CNF (Success) LTE_RRC_MODE CHANGE_CNFI (Success) Idle not camped LTE_RRC_IDLE_NOT_CAMPED_INDI Is req PLMN present in Acq DB ? Yes Make a prioritized list of bands that No needs to be scanned. Perform freq scan on bands in order of priority LTE_CPHY_SYSTEM_SCAN_REQ (1...N frequencies across bands) Wait System Scan Cnf ML1 does a list frequency scan on all center frequencies, returns the results sorted based on RSSI LTE_CPHY_SYSTEM_SCAN_CNF (1...N frequencies, sorted by RSSI) Store System Scan results. Try Acq on these results before doing a band scan Figure 2-1 System scan call flow 80-N8310-1 A 10 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Cell Selection 2.2 Band scan call flow Figure 2-2 shows the band scan call flow. MAC/ RRC RRC RRC RRC RRC NAS RLC/ ML1 CEP CSP Controller SIB LLC PDCP Released - For Current Employee/Consultant Use Only Is Band Scan required? Yes Make a prioritized list of bands that needs to be scanned. Perform freq scan on bands in order of priority Interface should support specifying No a list of bands to accommodate future optimizations. ML1 behaviour for multiple bands is TBD LTE_CPHY_BAND_SCAN_REQ (Band B) Wait Band Scan Cnf ML1 searches Band B for center frequencies - finds upto N (TBD) per band LTE_CPHY_BAND_SCAN_CNF (0...N frequencies in Band B) Store Band scan results Try Acq on candidate frequencies either from System Scan or Band scan results LTE_CPHY_ACQ_REQ (Band, Frequency, Blacklisted cells Wait Acq Cnf Acquisition Procedure. Run PSS and SSS correlatio , get Phy cell ID and timing of cell list Rank the candidate cells based on SSS correlation results If all frequencies are exhausted Setup and decode PBCH on top from the current list, System cell to get BW. First successful Scan/Band Scan would be PBCH decoded cell is reported performed as appropriate back in Acq_Cnf LTE_CPHY_ACQ_CNF (Success, Band, Freq, Phy Cell Id, BW) Figure 2-2 Band scan call flow 80-N8310-1 A 11 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Cell Selection 2.3 BCCH setup call flow Figure 2-3 shows the BCCH setup call flow. MAC/ RRC RRC RRC RRC RRC NAS RLC/ ML1 CEP CSP Controller SIB LLC PDCP Released - For Current Employee/Consultant Use Only Try SIB collection on the cell reported in Acq Cnf LTE_RRC_GET_SIBS_REQI (Freq, Phy cell id,cause = SELECTION) Wait SIB Cnf Create a new event to process this request. Based on supported RATs and SIB mask, prepare a list of SI that should be acquired Active Figure 2-3 BCCH setup call flow 80-N8310-1 A 12 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Cell Selection 2.4 SIB collection and camping call flow Figure 2-4 shows the SIB collection and camping call flow. MAC/ RRC RRC RRC RRC RRC NAS RLC/ ML1 Paging CSP Controller SIB LLC PDCP Released - For Current Employee/Consultant Use Only LTE_RRC_SIB_SCHEDULE_REQ (Freq, Phy cell id, SIB schedule) T0 – Start SIB colection LTE_RRC_GET_SIBS_CNFI T1 - Received mandatory SIBs (Freq, Phy cell id, Success ) (MIB,SIB1,SIB2) Get SIBs(SIB1, SIB2, sib_db_key) Restart guard timer with a larger value (4 * SIB2 Make an entry in Acq DB (PLMN, periodicity and 20s for Band, Freq, Phy cell Id, BW, etc) rest of SI) for other SIs Check access restrictions and Cell barring status LTE_CPHY_CELL_SELECT_REQ (Freq, Phy cell Id, S-Criteria, DRX) Perform S Criteria Wait Camp Cnf check and validate DRX params LTE_CPHY_CELL_SELECT_CNF (Freq, Phy cell id, Success/Failure, Failure reason) LTE_RRC_CFG_REQI Configure RACH LTE_MAC_CFG_REQ (RACH params) LTE_MAC_CFG_CNF (RACH params) LTE_CPHY_COMMON_CFG_REQ (Freq, Phy cell id, Setup PUSCH, PRACH,RACH paramaters, ) LTE_CPHY_COMMON_CFG_CNF (Success, Freq, Phy cell id) LTE_RRC_CFG_CNFI Camped LTE_RRC_CAMPED_INDI (Freq, Phy cell id, Cell Selection ) LTE_CPHY_DRX_REQ LTE_RRC_SERVICE_IND (Success, Service Info) Idle Camped This window indicates active T2 – Received all SIBs SIB collection by RRC. Figure 2-4 SIB collection and camping call flow 80-N8310-1 A 13 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 3 Connection Establishment Released - For Current Employee/Consultant Use Only 2 The connection establishment procedure is triggered for MO and MT calls. The RRC executes 3 access-barring logic based on SIM contents and SIBs and informs the upper layers if calls cannot 4 be started immediately. Otherwise, the RRC starts a RACH procedure in the MAC and the 5 sequence of messages 1 through 5 in the standard are executed (RACH, RACH response, 6 connection request, connection setup, and connection setup complete). The whole process is 7 guarded by spec timers, such as the T300. After successful completion, the UE enters the 8 Connected state. 80-N8310-1 A 14 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Connection Establishment 1 3.1 Connection establishment call flow 2 Figure 3-1 shows the connection establishment call flow. RRC- NAS Controller CEP SIB LLC CSP MAC eNB Released - For Current Employee/Consultant Use Only ConnEstablishRequest Inactive (LTE_RRC_CONN_ESTABLISH_REQ) GetState NO Verify that the UE is camped Reselection in progress ? NO GetSIB(SIB2) SIB2 info present ? YES YES AccessBa rred YES NO ConnectionEstablishmentStarted (LTE_RRC_CONNECTION_ESTABLISHMENT_STARTED_INDI) RACH Req(RRCConnRequest) (LTE_RRC_ACCESS_REQ) RRCConnectionRequest Access CellReselectionStarted (LTE_RRC_ACCESS_ABORT_REQ) Pending Retry (LTE_RRC_ACCESS_ABORT_CNF) ConnectionEstablishmentFailure(LTE_RRC_CONNECTION_ESTABLISHMENT_FAILURE_INDI) (LTE_RRC_PROCEED_WITH_RESEL_IND(TRUE)) Camped or Reselection Canceled RRCConnectionSetup (LTE_RRC_PROCEED_WITH_RESEL_IND(FALSE)) SRB1ConfigRequest (LTE_RRC_CFG_REQI) C-SRB1 SRB1ConfigConfirm (LTE_RRC_CFG_CNFI) RRCConnectionSetupComplete Connected Connected (LTE_RRC_CONNECTED_IND) ConnEstablishConfirm (LTE_RRC_CONN_ESTABLISH_CNF) 3 4 Figure 3-1 Connection establishment call flow 80-N8310-1 A 15 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 4 Intra-LTE Handover Released - For Current Employee/Consultant Use Only 2 In LTE, the handover procedure is used for Connected mode mobility and is driven by the 3 network. The network may hand over the UE to a target cell that is in the same band 4 (intrafrequency or interfrequency) or a different band (interband). When the UE receives the 5 handover message, it suspends the UL data temporarily, acquires the target cell frequency, and 6 applies the configuration given by the target cell in the handover message. If the target cell sends 7 an updated measurement configuration, the UE applies the new configuration. At the end of 8 applying the new configuration, the UE performs a RACH on the target cell. Once the RACH 9 succeeds, handover is considered complete and UL/DL data resumes. The RRC processes the 10 handover message and configures the lower layers with the new configuration. The following call 11 flows show the interaction of various RRC modules with the lower layers while the handover 12 message is processed. 80-N8310-1 A 16 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Intra-LTE Handover 1 4.1 Intra-LTE handover call flow 2 Figure 4-1, Figure 4-2, Figure 4-3, and Figure 4-4 show intra-LTE handover call flows. MEAS\ CPHY CONFIG LLC DL PDCP UL PDCP DL RLC UL RLC MAC SECURITY Released - For Current Employee/Consultant Use Only LTE_RRC_CONFIG_INITIAL 1. RRC Connection Reconfig With HO 1. Validate all the IE related to lower layers and security 2. Validation LTE_RRC_LLC_INITIAL 2. Start T304 (API) 3a. API to ready Security Configuration 3b.HO_STARTED_INDI To MH 1. Security Procedure builds PDCP security cmd 4. LTE_RRC_CFG_REQI (ASN.1 decoded msg ptr, cnf_needed) 1 - Update LLC database 2 – Get new security configuration for LTE_RRC_CONFIG_WAIT PDCP from RRC SECURITY module _FOR_CFG_CNF 3 – Configure Lower layers 5. LTE_PDCPUL_RECFG_ PREP_REQ A. Change state to HO in progress LTE_RRC_LLC_WAIT_FOR_ B. Stop enqueuing PDCP PDU to PDCP_CFG_PREP_CNF RLC C. Start flush timer on AM Rbs 6. LTE_PDCPUL_RECFG_ PREP_CNF 7. LTE_MAC_ACCESS_ABORT_REQ Abort Access procedure, if LTE_RRC_LLC_WAIT_FO it is on-going R_MAC_ACCESS_CNF 8. LTE_MAC_ACCESS_ABORT_CNF 9. LTE_CPHY_HANDOVER_REQ (Indicate HO - specify Freq and Phy Cell ID to ML1) 1. Perform Acquisition on Freq and Phy Cell ID LTE_RRC_LLC_WAIT_FO specified R_CPHY_CFG_CNF 2. Apply new CPHY configuration 10. LTE_CPHY_HANDOVER_CNF (Success) 3 4 Figure 4-1 Intra-LTE handover call flow 1 80-N8310-1 A 17 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Intra-LTE Handover MEAS \ CONFIG SECURITY LLC DL PDCP UL PDCP DL RLC UL RLC MAC CPHY 11. LTE_MAC_CFG_REQ (Indicate HO) 1. Fetch Buffered data from A2 LTE_RRC_LLC_WAIT_FOR_MAC_C 2. Demux data received from A2 FG_CNF 3. Put the demux data to RLC circular buffer 4 – Do Reset 5. Apply new MAC configuration Released - For Current Employee/Consultant Use Only 12. LTE_RLC_DL_DATA_IND 1. If received data has a status PDU, indicate it to RLC UL. RLC UL to process the status report and send ACK indication to PDCP UL 13. LTE_RLC_UL_STATUS_IND 14. LTE_PDCP_UL_ACK_IND 15. LTE_MAC_CFG_CNF 16. LTE_RLC_DL_CFG_REQ (Indicate HO – Wait for Sig) 1 - Re-assemble the RLC SDUs and LTE_RRC_LLC_WAIT_FO indicate that to PDCP DL R_RLC_CFG_CNF 2- Re-establish DL RLC 3 – Apply new DL RLC Configuration 17. LTE_PDCP_DL_DATA_IND 18. LTE_RLC_DL_CFG_CNF 19. LTE_RLC_UL_CFG_REQ (HO Indcation – Wait for sig) 1. Flush all the PDCP-RLC WMs 2. Release pkt_ptrs for UM/TM RBs only 3. Release all control message from PDCP 4 – Re-esablish UL RLC 5. Apply new UL RLC Configuration 20. LTE_RLC_UL_CFG_CNF 21. LTE_PDCP_DL_ CFG_REQ 1. Generate status report for all active RBs (LTE_PDCP_UL_STATUS_IND) and enqueue status message in corresponding UL PDCP-RLC WM 2. send status report to PDCP UL 3 Reset PDCP DL RoHC LTE_RRC_LLC_WAIT_ 4. Apply new Ciphering & Integrity FOR_PDCP_CFG_CNF configuration 5. Apply new DL PDCP Configuration 22. LTE_PDCP_UL_STATUS_IND 23. LTE_PDCP_DL_ CFG_CNF 1 2 Figure 4-2 Intra-LTE handover call flow 2 80-N8310-1 A 18 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Intra-LTE Handover RRC RRC RRC PDCP PDCP RLC RLC CRCFG Meas / LLC MAC CPHY DL UL DL UL Proc Sec proc Proc 24. LTE_PDCP_UL_CFG_REQ Released - For Current Employee/Consultant Use Only 1. Reset PDCP_UL RoHC 2. release all the PDCP packets for which discard timer has expired 3. Enqueue all PDCP packets which are not acked by RLC 4. Apply new Ciphering & Integrity configuration 5. Apply new UL PDCP Configuration 25. LTE_PDCP_UL_CFG_CNF 26. LTE_RRC_CFG_CNFI (SUCCESS) LTE_RRC_LLC_INITIAL Measurement IE present? 27. LTE_RRC_ No MEAS_CFG_REQI 28. LTE_CPHY_MEAS_REQ LTE_RRC_CONFI 1. CPHY to apply new measurement G_WAIT_FOR_ME configuration AS_CFG_CNF 29. LTE_CPHY_MEAS_CNF 30. LTE_RRC_ MEAS_CFG_CNFI A. Inform NAS of any bearer status change and NAS dedicated Info. B. Enqueue RRC Connection Reconfiguration Complete message. C. Initiate RACH Procedure to MAC 1 2 Figure 4-3 Intra-LTE handover call flow 3 80-N8310-1 A 19 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Intra-LTE Handover RRC RRC RRC RRC LLC PDCP RLC MAC CPHY SIB CSP CONFIG Proc 31. LTE_MAC_ACCESS_REQ (Reason = HO) LTE_RRC_CONFIG_WAIT 33. _FOR_MAC_ACCESS_ 1. MAC performs ACCESS HO_COMPLETED CNF procedure due to handover _IND to 32. LTE_MAC_ACCESS_CNF NAS and CSP (SUCCESS Released - For Current Employee/Consultant Use Only 34. .GET_SIBS_REQI to SIB module A. Stop T304 LTE_RRC_LLC_INITIAL B. Clear Procedure LTE_RRC_CONFIG_INITIAL LTE_RRC_CSP_INITIAL 36. SIB_UPDATED_INDI LTE_RRC_LLC_INITIAL 37. LTE_RRC_CFG_REQI 38. Get Updated SIB1 and SIB2 through API calls 39. LTE_CPHY_COMMON_CFG_REQ Apply CPHY configuration LTE_RRC_LLC_WAIT_ given by SIB1 and SIB2 FOR_CPHY_CFG_CNF LTE_RRC_CSP_WAIT_ FOR_CFG_CNF 40. LTE_CPHY_COMMON_CFG_CNF 41. LTE_MAC_CFG_REQ Apply RACH and PRACH LTE_RRC_LLC_WAIT_ configuration given by FOR_MAC_CFG_CNF SIB2 42. LTE_MAC_CFG_CNF 43. LTE_RRC_CFG_CNFI LTE_RRC_CSP_INITIAL LTE_RRC_LLC_INITIAL 1 2 Figure 4-4 Intra-LTE handover call flow 4 80-N8310-1 A 20 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 5 Idle Mode Measurements Released - For Current Employee/Consultant Use Only 2 The UE performs Idle mode measurements that form the basis for Idle mode 3 mobility/reselections. The network signals reselection parameters in the SIBs. SIB3 specifies 4 common reselection parameters, SIB4 specifies intrafrequency parameters, SIB5 signals 5 interfrequency parameters, and SIB6, SIB7, and SIB8 signal IRAT reselection parameters for 6 WCDMA, GSM, and CDMA respectively. The RRC reads each of these SIBs and configures the 7 L1 with the relevant reselection parameters. Based on these, the L1 reselects to the best available 8 cell. The following call flow shows Idle mode measurements functionality. 80-N8310-1 A 21 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Idle Mode Measurements 1 5.1 Idle mode measurements call flow 2 Figure 5-1 shows the Idle mode measurements call flow. SIB CSP Meas ML1 Released - For Current Employee/Consultant Use Only Cell Camped (MIB, SIB1, SIB2 received) 1. LTE_RRC_CAMPED_INDI Transition to IdleCamped state, wait for measurement SIBs 2. LTE_RRC_SIB_UPDATED_INDI (SIBs 3 and 4) 3. LTE_CPHY_IDLE_MEAS_CFG_REQ (Intra-freq measurements) Transition to ML1 starts idle mode WaitForIdleConfigcnf state measurements 4. LTE_CPHY_IDLE_MEAS_CFG_CNF Transition to IdleCamped state 5. LTE_RRC_SIB_UPDATED_INDI (SIBs 5, 6, 7, 8) 6. LTE_CPHY_IDLE_MEAS_CFG_REQ (inter-freq and inter-rat measuremnts) Transition to WaitForIdleConfigcnf state 7. LTE_CPHY_IDLE_MEAS_CFG_CNF Transition to IdleCamped state Neighbour cell (inter-freq or intra-freq) becomes better than serving cell ML1 stops idle mode measurements 8. LTE_CPHY_RESEL_IND Receives MIB, SIB1, SIB2 9. LTE_RRC_CAMPED_INDI Transition to IdleCamped state, wait for measurement SIBs 3 4 Figure 5-1 Idle mode measurements call flow 80-N8310-1 A 22 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 6 Connected Mode Measurements Released - For Current Employee/Consultant Use Only 2 The network configures the UE with Connected mode measurements. Based on these 3 measurements, the UE measures on the signaled frequencies and sends measurement reports to 4 the network. These reports form the basis for handover (nonblind) to be triggered. The UE needs 5 gaps to perform measurements on interfrequency and interRAT neighbor cells. The RRC is 6 responsible for configuring Connected mode measurements in the L1 and sending out the 7 measurement reports from the L1. The call flow describes the role the RRC plays in configuring 8 Connected mode measurements. 80-N8310-1 A 23 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Connected Mode Measurements 1 6.1 Connected mode measurements call flow 2 Figure 6-1 shows the Connected mode measurements call flow. RRC Released - For Current Employee/Consultant Use Only eNB RRC Config/LLC ML1 Measurements Connection is established 1. RRCConnectionReconfiguration OTA message (w/ measurements 2. lte_rrc_meas_validate config) _connected_config return 3. LTE_RRC_MEAS_CFG_REQI (no HO flag) 4. LTE_CPHY_CONN_MEAS_CFG_REQ ML1 applies the new measurement config. Starts measurements. 5. LTE_CPHY_CONN_MEAS_CFG_CNF 6. LTE_RRC_MEAS_CFG_CNFI 7. RRCConnectionReconfiguration Complete OTA message 8. LTE_CPHY_MEAS_REPORT_IND 9. MeasurementReport OTA message 3 4 Figure 6-1 Connected mode measurements call flow 80-N8310-1 A 24 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 7 Paging Released - For Current Employee/Consultant Use Only 2 The paging procedure is used by the network to notify the UE of a system information change or 3 to trigger RRC connection establishment to receive MT calls. In terms of paging, the RRC: 4  Updates the IMSI/S-TMSI given by the upper layers 5  Configures the L1 with idle DRX parameters from SIB2 6  Determines if there is a change in the system information 7  Passes information on MT calls to the upper layers to initiate RRC connection establishment 8 The following call flow shows the paging functions that the RRC performs. 80-N8310-1 A 25 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Paging 1 7.1 Paging call flow 2 Figure 7-1 shows the paging call flow. MessageHandler Paging NAS CSP SIB ML1 Released - For Current Employee/Consultant Use Only 1. LTE_RRC_SIM_UPDATE_IND Saves the UE IMSI NAS Attach procedure completes 2. LTE_RRC_SIM_UPDATE_IND Saves the UE s-TMSI Cell Selection and camping complete 4. LTE_RRC_CAMPED_INDI Paging retrieves default paging cycle and Nb from SIB procedure 5. LTE_CPHY_IDLE_DRX_REQ OTA Message 6. LTE_RRC_PAGING_DLM SystemInfoModification field present 7. LTE_RRC_GET_SIBS_REQI SIB procedure acquires new System Information 3 4 Figure 7-1 Paging call flow 80-N8310-1 A 26 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 8 BPLMN Search Released - For Current Employee/Consultant Use Only 2 Background PLMN (BPLMN) or PLMN search is an Idle mode procedure in which the UE 3 searches for PLMNs. Common scenarios are the UE searching for the home PLMN while it is 4 camped on a visitor PLMN (roaming) or the UE searching for full service when limited service is 5 currently available. This procedure is usually used when the UE is already in the Idle Camped 6 state, but it can also be done on powerup, when it is actually a foreground PLMN search. The 7 search can be conducted not only on LTE, but also on WCDMA and GSM. 8 For intra-LTE searches, the RRC requests the L1 to acquire SIBs on neighboring cells and pass 9 them on to the RRC. The L1 does this for a specific time in its sleep cycle before going to sleep. 10 The RRC extracts PLMN information from the SIB1 and stores the information. A found PLMN 11 is added to the list sent to the NAS after each PLMN passes a quality criterion check. 12 For searches conducted on other RATs, while the active RAT is LTE, the RRC suspends the L1 13 after getting the time remaining in its sleep cycle. It then activates another RAT to search in the 14 provided time and then deactivates it. The reverse happens when LTE is activated and deactivated 15 by another primary RAT for searches. 80-N8310-1 A 27 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST BPLMN Search 1 8.1 Intra-LTE BPLMN search call flow 2 Figure 8-1 shows the intra-LTE BPLMN search call flow. NAS PLMN_Search SIBS ML1 Released - For Current Employee/Consultant Use Only LTE_RRC_PLMN SEARCH_REQ type=hplmn_scan plmn_rat_list Start PLMN Search timer Search on other RATs If search termianting criteria is not met and if LTE is the next RAT to be searched LTE_CPHY_PLMN_START_REQ type=lte RRC will confirm receipt of SIB1, indicate if the cell/ LTE_RRC_SIB1_INDI SIB1 frequency is barred, and if it wants the S criterion evaluated at ML1. LTE_CPHY_PLMN_CELL_REQ LTE_CPHY_PLMN_CELL_CNF LTE_RRC_SIB1_INDI SIB1 LTE_CPHY_PLMN_CELL_REQ LTE_CPHY_PLMN_CELL_CNF Highest priority PLMN found on LTE Stop PLMN Search Timer LTE_CPHY_PLMN_STOP_REQ Any higher priority request will be put on PendQ LTE_CPHY_PLMN_STOP_CNF LTE_RRC_PLMN_SEARCH_CNF found_PLMN_RAT_Quality 3 4 Figure 8-1 Intra-LTE BPLM search call flow 80-N8310-1 A 28 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST BPLMN Search 1 8.2 From LTE BPLMN search 2 8.2.1 LTE and non-LTE searches call flow 3 Figure 8-2 shows the LTE and non-LTE searches call flow. Released - For Current Employee/Consultant Use Only NAS PLMN_Search SIBS IRAT ML1 LTE_RRC_PLMN_SEARCH_REQ search_type plmn_rat_list Start PLMN Search timer LTE_CPHY_PLMN_START_REQ type=lte LTE PLMN Search Completed LTE_CPHY_PLMN_STOP_REQ LTE_CPHY_PLMN_STOP_CNF LTE_CPHY_PLMN_START_REQ type=irat RAT-1 Search Completed RAT-n Search Completed Stop PLMN Search timer LTE_CPHY_PLMN_STOP_REQ LTE_CPHY_PLMN_STOP_CNF LTE_RRC_PLMN_SEARCH_CNF PLMN_RAT_Quality_list 4 5 Figure 8-2 LTE and non-LTE searches call flow 80-N8310-1 A 29 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST BPLMN Search 1 8.2.2 Search exhausted call flow 2 Figure 8-3 shows the search exhausted call flow. NAS PLMN_Search SIBS IRAT ML1 Released - For Current Employee/Consultant Use Only LTE_RRC_PLMN_SEARCH_REQ search_type plmn_rat_list Start PLMN Search timer Search on other RATs IRAT searh timer = min(PLMN search timer. 60s) LTE_CPHY_PLMN_START_REQ type=irat IRAT allotted time = LTE_CPHY_PLMN_TIME_AVAIL_IND min(IRAT search timer. sleep_time) sleep_time LTE_IRAT_PLMN_SEARCH_REQ rat_type, plmn_list, allotted_time LTE_CPHY_ML1_SUSPEND_REQ sleep RRC will schedule the LTE_CPHY_ML1_SUSPEND_CNF search only if the (allotted – IRAT Search ML1 propagation) time is inactive sufficient on that RAT LTE_CPHY_ML1_RESUME_REQ LTE_CPHY_ML1_RESUME_CNF LTE_IRAT_PLMN_SEARCH_CNF rat_type, found_plmn_list, status=incomplete LTE_CPHY_PLMN_TIME_AVAIL_IND IRAT allotted time = sleep_time min(IRAT search timer. sleep_time) LTE_IRAT_PLMN_SEARCH_REQ rat_type, plmn_list, allotted_time LTE_CPHY_ML1_SUSPEND_REQ sleep LTE_CPHY_ML1_SUSPEND_CNF ML1 IRAT Search inactive LTE_CPHY_ML1_RESUME_REQ LTE_CPHY_ML1_RESUME_CNF LTE_IRAT_PLMN_SEARCH_CNF rat_type, found_plmn_list, status=complete Search on other RATs Stop PLMN Search timer LTE_CPHY_PLMN_STOP_REQ LTE_CPHY_PLMN_STOP_CNF LTE_RRC_PLMN_SEARCH_CNF PLMN_RAT_Quality_list 3 4 Figure 8-3 Search exhausted call flow 80-N8310-1 A 30 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST BPLMN Search 1 8.3 To LTE BPLMN search call flow 2 Figure 8-4 shows the LTE BPLMN search call flow. NAS PLMN_Search SIBS IRAT Manager ML1 Released - For Current Employee/Consultant Use Only IRAT_PLMN_SEARCH_REQ LTE_CPHY_START_REQ LTE_CPHY_START_CNF IRAT_LTE_PLMN_SEARCH_REQ rat_type, plmn_list, allotted_time Start IRAT searh timer = allotted time LTE_CPHY_PLMN_START_REQ type=lte, irat_search_timer SIB1 LTE_RRC_SIB1_INDI LTE_RRC_PLMN_CELL_REQ LTE_RRC_PLMN_CELL_CNF LTE_CPHY_PLMN_COMPLETE_REQ status=incomplete Stop IRAT searh timer IRAT_LTE_PLMN_SEARCH_CNF LTE_CPHY_STOP_REQ rat_type, status=incomplete LTE_CPHY_STOP_CNF RRC will send LTE_CPHY_PLMN_STOP_ REQ if the IRAT_PLMN_SEARCH_CNF IRAT_search_timer expires, before ML1 completes the search IRAT_PLMN_SEARCH_REQ LTE_CPHY_START_REQ LTE_CPHY_START_CNF IRAT_LTE_PLMN_SEARCH_REQ rat_type, plmn_list, allotted_time Start IRAT searh timer = alooted time LTE_CPHY_PLMN_START_REQ type=lte, irat_search_timer SIB1 LTE_RRC_SIB1_INDI LTE_RRC_PLMN_CELL_REQ LTE_RRC_PLMN_CELL_CNF LTE_CPHY_PLMN_COMPLETE_IND Stop IRAT searh timer status=copmlete IRAT_LTE_PLMN_SEARCH_CNF LTE_CPHY_STOP_REQ rat_type, found_plmn_list, status=complete LTE_CPHY_STOP_CNF IRAT_PLMN_SEARCH_CNF 3 4 Figure 8-4 LTE BPLMN search call flow 80-N8310-1 A 31 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 9 Radio Link Failure (RLF) Released - For Current Employee/Consultant Use Only 2 RLFs are applicable only in Connected mode and could be caused by PHY layer problems, 3 RACH failures, RRC reconfiguration failures, and handover failures. When RLF is triggered, the 4 UE attempts the RRC connection reestablishment procedure. The RRC is responsible for this 5 procedure and does the following: 6  Suspends UL traffic 7  Reverts to the configuration prior to RLF 8  Performs cell selection to find the best possible cell 9  Sends an RRC connection reestablishment request message in the cell 10 If the selected cell has the UE context and can accept the UE, it sends an RRC connection 11 reestablishment message. On receiving this message, the UE resumes the Signaling Radio Bearer 12 (SRB1) and sends the RRC connection reestablishment complete message. When the UE receives 13 the subsequent RRC reconfiguration message in the cell, SRB2 and all the Data Radio 14 Bearers (DRBs) are resumed. The following call flows show the RRC connection reestablishment 15 procedure. 80-N8310-1 A 32 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Radio Link Failure (RLF) 1 9.1 Radio link failure call flow 2 Figure 9-1, Figure 9-2, Figure 9-3, Figure 9-4, Figure 9-5, and Figure 9-6 show the radio link 3 failure call flows. Released - For Current Employee/Consultant Use Only RRC ML1 LTE_CPHY_COMMON_CFG_REQ (Includes UE constants and Timers – T310, N310, and N311) LTE_CPHY_COMMON_CFG_CNF ML1 Detects Radio Link Problems when number of out of sync indications reach N310. Starts T310 T310 Expires LTE_PHY_RL_FAILURE_IND LTE_RRC_CRE_STARTED_INDI 4 5 Figure 9-1 Radio link call flow 1 80-N8310-1 A 33 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Radio Link Failure (RLF) RRC-CRE RRC-CSP RRC-LLC PDCP RLC MAC ML1 LTE_RRC_CRE_INITIAL LTE_RRC_CFG_REQI Cause: RLF Released - For Current Employee/Consultant Use Only - Cause RLF is used to Abort ML1 and suspend RBs. - If required (in case of Handover), use OC to configure lower layers back to old configuration. LTE_CPHY_ABORT_REQ CPHY cleans up LTE_RRC_LLC_ common, WAIT_FOR_CPHY_CNF dedicated and measurement configurations. Next commands to ML will be for cell selection (CSP). LTE_CPHY_ABORT_CNF LTE_PDCP_UL_ CFG_PREP_REQ Cause: RLF - Start PDCP HO-mode LTE_RRC_LLC_ - Stop enqueuing PDCP PDU WAIT_FOR_PDCP_CNF - Change the state of DRBs in ‘Prepare to Release’ to ‘Suspended’ like other DRBs LTE_PDCP_UL_ CFG_PREP_CNF LTE_MAC_CFG_REQ Cause: RLF - Put the demux from A2 to RLC LTE_RRC_LLC_ circular buffer WAIT_FOR_MAC_CNF - Apply old cfg as given by RRC - Do Reset LTE_MAC_CFG_CNF 1 2 Figure 9-2 Radio link call flow 2 80-N8310-1 A 34 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Radio Link Failure (RLF) RRC-CRE RRC-CSP RRC-LLC PDCP RLC MAC ML1 LTE_RLC[DL/UL]_CFG_REQ Cause: RLF LTE_RRC_LLC_WAIT_ - Apply old config FOR_RLC_CFG_CNF - Re-establish RLC for all RBs. LTE_RLC[DL/UL]_CFG_CNF LTE_PDCP[DL/UL]_ Released - For Current Employee/Consultant Use Only CFG_REQ Cause: RLF LTE_RRC_LLC_WAI T_FOR_RLC_CFG_ - Apply old RB config CNF - Keep RBs in suspended state LTE_PDCP[DL/UL]_ CFG_CNF LTE_RRC_CFG_CNFI LTE_RRC_INITIATE_ CELL_SEL_REQI Cause: RLF LTE_RRC_CRE_WAIT _FOR_UE_TO_CAMP CSP performs steps for cell selection and camps on cell. LTE_RRC_CFG_REQI Cause: common configuration (sib2) LTE_CPHY_COMMON_CFG_REQ (Default Configuration) LTE_RRC_LLC_ - Apply common WAIT_FOR_CPHY_CNF config as specified in SIB2 LTE_CPHY_COMMON_CFG_CNF LTE_CPHY_DEDICATED_CFG_REQ (Default Configuration) - Apply default config as specified in spec LTE_CPHY_DEDICATED_CFG_CNF 1 2 Figure 9-3 Radio link call flow 3 80-N8310-1 A 35 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Radio Link Failure (RLF) RRC-CRE RRC-Paging RRC-CSP RRC-LLC PDCP RLC MAC ML1 LTE_MAC_CFG_REQ (SIB2 and default configuration) - Apply Configuration from LTE_RRC_LLC_ SIB2 WAIT_FOR_MAC_CNF - Apply default config LTE_MAC_CFG_CNF Released - For Current Employee/Consultant Use Only LTE_RRC_CFG_CNFI LTE_RRC_LLC_INITIAL LTE_RRC_CAMPED_INDI - Stop T311 - Build RRC LTE_CPHY_IDLE_DRX_REQ Connection Re- establishment Request msg - Start T301 LTE_MAC_ACCESS_REQ (RRC Connection Re-establishment Request) LTE_CPHY_ START_RACH_ REQ LTE_RRC_CRE_ WAIT_FOR_CONN_RE - Perform RACH LTE_CPHY_ START_RACH_ LTE_MAC_ACCESS_CNF CNF LTE_RRC_RRC_CONNECTION_REESTABLISHMENT_DLM via PDCP-MH - Stop T301 - Send cfg reqi to resume SRB1 LTE_RRC_CFG_REQI Cause: LTE_RRC_CRE_CFG_REASON_SRB1 - Copy CC to OC LTE_RRC_CRE_ - Set Ordered Config and WAIT_FOR_SRB1 update OC with OTA _CFG_CNF message content - Configure Lower layers 1 2 Figure 9-4 Radio link call flow 4 80-N8310-1 A 36 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Radio Link Failure (RLF) RRC-CRE RRC-CSP RRC-LLC PDCP RLC MAC ML1 LTE_CPHY_DEDICATED_CFG_REQ (if dedicated cfg is present) LTE_RRC_LLC_ - Apply ML1 dedicated WAIT_FOR_PHY_CNF configuration LTE_CPHY_DEDICATED_CNF Released - For Current Employee/Consultant Use Only LTE_MAC_CFG_REQ (if dedicated mac cfg is present) LTE_RRC_LLC_ WAIT_FOR_MAC_CNF - Apply MAC configuration LTE_MAC_CFG_CNF LTE_RLC[DL\UL]_CFG_REQ Cause: reconfig - Apply RLC DL/UL LTE_RRC_LLC_ configuration for SRB1 WAIT_FOR_RLC_CNF LTE_RLC[DL\UL]_CFG_CNF LTE_PDCP[DL\UL]_ CFG_REQ Cause: reconfig Action: modify and resume SRB1 - Apply PDCP DL/UL configuration for SRB1 - Resume only SRB1 pipe, while keeping the LTE_RRC_LLC_ other UL RBs WAIT_FOR_PDCP_CNF suspended LTE_PDCP[DL\UL_ CFG_CNF - Swap OC and CC - clear OC status and set cfg ptr in use to CC LTE_RRC_LLC_INITIAL LTE_RRC_CFG_CNFI 1 2 Figure 9-5 Radio link call flow 5 80-N8310-1 A 37 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Radio Link Failure (RLF) RRC- RRC-CRE RRC-LLC PDCP RLC MAC ML1 MEAS - Send request to meas module with proper cause: if RLF is due to Rach failure, go back to old meas config, else re-apply old config Released - For Current Employee/Consultant Use Only LTE_RRC_MEAS_REQI Cause: revert config or Reapply config - Based on the cause, Measurement module reverts back to old config or re-applies LTE_CPHY_CONN_MEAS_REQ - ML1 to apply connected mode measurement info and start measuring LTE_RRC_SEND_UL_ LTE_CPHY_CONN_MEAS_CNF MSG_REQI (re-establishment Complete msg) LTE_RRC_CRE_ COMPLETED_INDI 1 2 Figure 9-6 Radio link call flow 6 80-N8310-1 A 38 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 10 LTE→eHRPD Redirection Released - For Current Employee/Consultant Use Only 2 When the UE is in an LTE network in RRC_CONNECTED_MODE, a redirection indication is 3 received through the connection release indication arriving from the network. Upon receiving the 4 indication, the UE should release the existent RRC connection in LTE as specified in [S1], and, 5 once it is in the RRC_IDLE state, it should move to the redirected frequency of the RAT. Both 6 will be specified with the connection release message. 80-N8310-1 A 39 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST LTE→eHRPD Redirection 1 10.1 LTE→eHRPD redirection call flow 2 Figure 10-1 shows the LTE→eHRPD redirection call flow. LTE NW NAS CM DS DO CP / DO L1 RRC Released - For Current Employee/Consultant Use Only CONNECTED Connection Rel DLM Redirection IE 1 Validate target redirected frequency/band LTE_RRC_CONN_REL_IND Loadbalancing TAU: FALSE LTE_CM_ACT_DRB_RELEASED_IND IDLE CM_CALL_EVENT_RAB_REL_IND 2 LTE stack suspended EPS bearers are not released eHRPD_Redirection_Request Redirection RAT: CDMA2000-HRPD HDR stack (union)Redirection info: band,freq (list activated 3 includes SIB8 eHRPD neighbor list info) Attempt HDR Acq with 4 redirected band,freq followed by SIB8 eHRPD neighbor list eHRPD Activation Ind ::Success Stop Mode Req Deactivate Req Cause:Redirection Cause:Redirection LTE stack deactivated EPS bearers are 5 not released 6 Deactivate Cnf Stop Mode Cnf eHRPD Activation Rsp CM_SS_EVT_SRV_CHANGED 7 (SYS MODE = 1X/DO) Registration session Sd_ss_ind_hdr_opr_ses_opened (eHRPD/HRPD) CM_SS_EVT_SRV_CHANGED (eHRPD/HRPD) Start BSR timer VSNCP Config Procedure performed since there are active PS applications using default EPS bearers 8 PDN_Disconnect_Req (Context transfer to DO) PDN_Disconnect_Req (Context transfer to DO) EPS bearers are released LTE_CM_DEACT_BEARER_CONTEXT_REQUEST_IND LTE_CM_DEACT_BEARER_CONTEXT_REQUEST_IND 3 4 Figure 10-1 LTE→eHRPD redirection call flow 80-N8310-1 A 40 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 11 LTE→eHRPD Reselection Released - For Current Employee/Consultant Use Only 2 When it is camped on LTE, the UE shall regularly measure the serving cell and other LTE and 3 IRAT (including eHRPD) cells based on E-UTRAN SI information and UE preferred modes in an 4 attempt to find a better cell. If the measurement evaluation of a certain cell indicates that it fulfills 5 the cell reselection criteria as specified in [S1], the UE selects that cell. 6 In LTE, cell reselections are performed when the UE is in the RRC_IDLE state. 80-N8310-1 A 41 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST LTE→eHRPD Reselection 1 11.1 LTE→eHRPD reselection call flow 2 Figure 11-1 shows the LTE→eHRPD reselection call flow. ML1 LTE RRC NAS CM DS DO CP/DO L1 Released - For Current Employee/Consultant Use Only IDLE Idle Measurement Config (SIB8 resel params + CDMA timing info Perform measurement of eHRPD cells. Evaluate cell reselection criteria LTE_CPHY_CELL_RESEL_IND (1X/DO) LTE_CPHY_SUSPEND_REQ (Reselection to eHRPD) LTE stack suspended LTE_CPHY_SUSPEND_CNF (LTE OSTMR, CDMA Sys Time) LTE_IRAT_DO_RESEL_REQ (Reselection Params, LTE OSTMR, CDMA Sys Time) DO stack activated DO CAMPING Activation Indication Stop Mode Req Deactivate Req Cause: Resel Disable reselections to LTE_CPHY_STOP_REQ Cause: Resel other RATs EPS bearers are LTE_CPHY_STOP_CNF) not released Deactivate Cnf Stop Mode Cnf Activation Rsp Enable reselections to other RATs LTE stack deactivated CM_SS_EVT_SRV_CHANGED System = 1X/DO Registration session Sd_ss_ind_hdr_opr_ses_opened (eHRPD/HRPD) CM_SS_EVT_SRV_CHANGED (System = eHRPD/HRPD) Start BSR timer VSNCP Config Proc performed PDN_Disconnect_Req (Context transfer to DO) PDN_Disconnect_Req (Context transfer to DO) EPS bearers are released LTE_CM_DEACT_BEARER_CONTEXT_REQUEST_IND LTE_CM_DEACT_BEARER_CONTEXT_REQUEST_IND 3 4 Figure 11-1 LTE→eHRPD reselection call flow 80-N8310-1 A 42 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 12 eHRPD→LTE Reselection Released - For Current Employee/Consultant Use Only 2 When it is camped on eHRPD, the UE shall regularly measure the serving cell and other eHRPD 3 and IRAT (including LTE) cells based on OtherRATNeighborList information and UE preferred 4 modes in an attempt to find a better cell. If the measurement evaluation of a certain cell indicates 5 that it fulfills the cell reselection criteria as specified, the UE selects that cell. 6 In eHRPD, cell reselections are performed when the UE is in the Idle state. 7 The UE performs cell reselection→HRPD/eHRPD as follows: 8 1. The UE camps on eHRPD. 9 2. DO CP (L3) periodically reads OtherRATNeighborList and updates DO L1 with the LTE 10 neighbors (including priority), PLMIDs to aid in measurements, and reselection to LTE. 11 3. DO L1 schedules and triggers measurements on LTE cells based on the cell reselection 12 priority provided. 13 4. DO L1 triggers LTE L1 to perform measurements while the DO stack is entering the Sleep 14 state; the measurements of the LTE cells are performed by LTE L1. 15 5. LTE L1 uses the cell reselection algorithm mentioned in Chapter 2 to evaluate cells for 16 reselection. 17 6. The LTE cell chosen for reselection is then sent in an indication to the DO CP. 18 7. The DO CP initiates the LTE cell reselection process with LTE RRC. 19 8. LTE RRC notifies the CM with an activation indication if reselection is successful. 20 9. LET RRC notifies the DO CP with Reselection Reject if reselection fails. 80-N8310-1 A 43 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST eHRPD→LTE Reselection 1 12.1 eHRPD→LTE reselection call flow 2 Figure 12-1 shows the eHRPD→LTE reselection call flow. DATA DO CM / MMOC NAS/EMM REG RRC ML1 Released - For Current Employee/Consultant Use Only Active RAT INACTIVE / DEREG LTE STACK DEACTIVATED LTE Cells that are barred are not specifically excluded from LTE MEASUREMENTS measurements INACTIVE Cell reselection evaluation Information in this request LTE_RRC_SYSTEM_UPDATE_REQ is used during eHRPD RPLMN,,HPLMN,eHPLMN,ePLMN reselection. Forbidden TA list Get RAT Pri List Req If UE had done a prev Attach Get RAT Pri List Rsp on LTE, changes to ePLMN list and the forbidden TA list will be provided to RRC through SYSTEM UPDATE REQ LTE Resel Request Params: Requested PLMN (m) HPLMN (o) eHPMN (o) RAT pri list (m) LTE STACK ACTIVATED Nw select_mode is always set to Automatic mode Acquisition attempt After successful acq, RRC should send LTE_RRC_ACT_IND Activation Indication to CM_SS_EVT_SERV_CHANGED CM System = LTE PS Suspend = TRUE HDRMC_PROT_ REG does not have to do any PLMN Data DEACT_CMD_F selection here since the procedure Suspended involves moving from eHRPD to LTE INACTIVE and all the PLMN, freq and cell info comes from eHRPD side. mmoc_rpt_prot_ deactd_cnf() CM_SERVICE_REQ (type:irat) Once REG has come to the right This will let CM know when NAS state, it should not trigger EMM or has finished processing the RRC for new service. Instead it CM_SERVICE_REQ so it can CM_SERVICE_CNF (No Svc) should send “No Svc” in Service Cnf send the Activation rsp back to back to CM. RRC ACT_RSP IS EMM was previosuly in REGISTERED-No cell LTE_RRC_SERVICE_IND available state, it should trigger a TAU If EMM was previously in Deregistered – no cell Enable reselections to available state, then it would need to do a Fresh other RATs Attach procedure Transfer of bearer context from eHRPD to LTE NAS determines if TAU is required CM_SERVICE_IND PS Suspend = FALSE Transfer of call objects from eHRPD to LTE CM_SS_EVT_SERV_CHANGED System = LTE PS Suspend = FALSE Data Resumed 3 4 Figure 12-1 eHRPD→LTE reselection call flow 80-N8310-1 A 44 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 13 LTE→WCDMA PS HO Released - For Current Employee/Consultant Use Only 2 The purpose of this procedure is to move the UE from LTE to WCDMA in Connected mode. It is 3 triggered using the LTE RRC MobilityFromEUTRACommand message. The command carries 4 information that is necessary for generating WCDMA keys, along with a container that is 5 essentially the WCDMA RRC HandoverToUTRANCommand. 6 LTE RRC uses the NAS to derive the mapped UMTS keys that are passed to the WCDMA RRC. 7 After successfully suspending the LTE stack, WCDMA is brought up. The handover is successful 8 after WCDMA acquires the target cell and applies the configuration to jump to Connected mode. 9 Timing information is passed to speed up the WCDMA acquisition procedure. 80-N8310-1 A 45 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST LTE→WCDMA PS HO 1 13.1 LTE→WCDMA PS HO call flow 2 Figure 13-1 shows the LTE→WCDMA PS HO call flow. DS CM NAS L RRC W RRC Released - For Current Employee/Consultant Use Only Contains Inter RAT Handover Info, WCDMA_RRC_LTE_UTRA_CAPABILITIES_REQ specifically START-PS WCDMA_RRC_LTE_UTRA_CAPABILITIES_RSP LTE Network sends MobilityFromEUTRACommand to trigger the PS HO. MobilityFromEUTRACommand If cs-FallbackIndicator is set, LTE RRC stores the information to inform NAS later if the HO procedure fails. LTE_RRC_NAS_UMTS_KEY_IND LTE RRC forwards the nas- Key derivation SecurityParamsFromEUTRA IE to Suspends L stack for WCDMA NAS for NAS to derive UMTS mapped security context and suspends the LTE stack. LTE_RRC_NAS_UMTS_KEY_RSP WCDMA_RRC_LTE_PSHO_REQ 1. UMTS Keys Once LTE stack is suspended and the 2. Target RAT Container (Handover To UTRAN mapped UMTS security context is Command) available to LTE RRC, it sends the Handover request to W RRC W acquires target cell Applies HO configuration In success scenario, WCDMA RRC succeeds in acquisition and applies the config.and sends out the activation indication to NAS RRC_ACTIVATION_IND (L2W PS HO) In success scenario, WCDMA RRC LTE_RRC_CONN_ABORT_REQ succeeds in acquisition and applies the (LTE_RRC_CONN_ABORT_CAUSE_IRAT_SUCCESS) config.and sends out the activation indication to NAS L Connection Releaed LTE_RRC_CONN_REL_IND (LTE_RRC_CONN_REL_ABORTED_IRAT_SUCCESS) LTE_RRC_DEACTIVATE_REQ IRAT L stack deactivated LTE_RRC_DEACTIVATE_CNF RRC_ACTIVATION_RSP Handover to UTRAN Complete RAB Info?? TBD – acts as a trigger for DS to resume UTRAN Mobility Information RRC_SERVICE_IND RAU with RAB info WCDMA sends out service indication CM service indication after it gets the Core Network Info in (WCDMA) UTRAN Mobility Information message CM event service changed (WCDMA) 3 4 Figure 13-1 LTE→WCDMA PS HO call flow 80-N8310-1 A 46 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 14 LTE SON/ANR Released - For Current Employee/Consultant Use Only 2 Figure 14-1 shows the LTE SON/ANR call flow. Successful acquisition of CGI Info RRC RRC ML1 Meas SIB CONNECTED LTE_RRC_MEAS_ CFG_REQI Meas id with reportConfig set to purpose ‘reportCGI’ added 1. Validate at most one meas id with report config for ‘reportCGI’ 2. Start T321 1s (for EUTRA) 8s (for IRAT) LTE_CPHY_CONN_MEAS_CFG_REQ Meas id tied to reportCGI cell added WAIT_FOR_CONNECTE D_CONFIG_CNF 1. Apply new meas config 2. Perform measurements on the concerned freq LTE_CPHY_CONN_MEAS_CFG_CNF Acquire SIB1 on reportCGI cell CONNECTED (Best effort attempt to get CGI info when gaps are configured) LTE_RRC_MEAS_CFG_CNFI LTE_MAC_RRC_BCCH_ DL_DATA_IND (Containing SIB1 for the LTE_RRC_UNSOLICITED_ reportCGI cell) SIB_INDI - Since 1. Decode SIB1 trigger_report_ind_ 2. Validate if the PCI matches cause is set to CGI, the one given by the meas obj ML1 should send 3. Stop T321 LTE_CPHY_CONN_MEAS_CFG_REQ Meas report Meas id tied to reportCGI cell deleted, with serving cell ReportConfig for CGI report modified, measurements trigger_report_ind_cause set to CGI 1. Delete Meas id corresponding to the reportCGI cell WAIT_FOR_CONNECTE 2. Stop SIB reading in CGI cell D_CONFIG_CNF since Meas id tied to CGI is deleted LTE_CPHY_CONN_MEAS_CFG_CNF CONNECTED LTE_CPHY_MEAS_REPORT_IND With serving cell measurements Populate CGI Info in the report Send Meas report for CGI 3 4 Figure 14-1 LTE SON/ANR call flow 80-N8310-1 A 47 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 15 IRAT SON/ANR Released - For Current Employee/Consultant Use Only 2 Figure 15-1 shows the IRAT SON/ANR call flow. Successful acquisition of CGI Info for an IRAT cell Control L RRC Meas L RRC IRAT LTE ML1 Layer of CONNECTED other RAT LTE_RRC_MEAS_ CFG_REQI Meas id with IRAT reportConfig set to purpose ‘reportCGI’ added 1. Validate at most one meas id with report config for ‘reportCGI’ 2. Start T321 8s (for IRAT) LTE_CPHY_CONN_MEAS_CFG_REQ Meas id tied to reportCGI cell added WAIT_FOR_CONNECTE 1. Apply new meas config D_CONFIG_CNF 2. Prepare to notify RRC when ready to read IRAT CGI LTE_CPHY_CONN_MEAS_CFG_CNF CONNECTED CDRX starts LTE_RRC_MEAS_CFG_CNFI LTE_CPHY_IRAT_CGI_START_IND With L1_TimeAvailForIRATCGI 1. Check if RLF or Conn Release is not in progress 2. Determine TimeAvailforIRATCGI = Min(L1_TimeAvailForIRATCGI, RemainingT321) 3. If TimeAvailforIRATCGI >= Min time needed for CGI acq in other RAT, start TimeAvailforIRATCGI LTE_RRC_IRAT_CGI_REQI Including TimeAvailforIRATCGI LTE_CPHY_ML1_SUSPEND_REQ Suspend LTE L1 LTE_CPHY_ML1_SUSPEND_CNF SUSPENDED IRAT_CGI_REQ Including TimeAvailforIRATCGI 1. Schedule IRAT CGI reading 2. Acquire CGI IRAT_CGI_RSP Success, containing CGI info from the other RAT LTE_RRC_IRAT_CGI_CNFI Success, including IRAT CGI info 3 4 Figure 15-1 IRAT SON/ANR call flow 80-N8310-1 A 48 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 16 Attach Released - For Current Employee/Consultant Use Only 2 Figure 15-1 shows the attach call flow. 3 4 Figure 16-1 Attach call flow 80-N8310-1 A 49 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 17 3GPP CSFB Released - For Current Employee/Consultant Use Only 2 LTE does not support voice services. One of the solutions to enable LTE smartphones is using 3 Circuit-Switched Fallback (CSFB). The call on LTE triggers the NAS layer to send an extended 4 service request to the LTE MME. The LTE network responds by moving the UE to 3G (in this 5 scenario, WCDMA redirection; other scenarios could move the UE to GERAN or trigger a 6 handover). Normal redirection rules apply and the call is set up per legacy behavior. To speed up 7 camping, the network can send WCDMA system information that is passed by LTE RRC to 8 WCDMA (or GERAN, as the case may be). 80-N8310-1 A 50 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 3GPP CSFB 1 17.1 3GPP CSFB call flow 2 Figure 17-1 shows the 3GPP CSFB call flow. UI CM GW-NAS EMM L-RRC WRRC Released - For Current Employee/Consultant Use Only Legacy “SEND” MM Initiates the CSFB procedure with EMM and buffer MO Call Request the CM Call request. If CS+PS (Call Info) attached for CSFB Start 3GPP (LTE RAT) CSFB Request Extended Service Request Start T3417ext RRC Connection Establishment (if required) - ESR msg is sent to N/W - N/W redirect the UE to GW RRC Conn Rel (Redir) MM concludes here RRC_Redir_Req CSFB is successful. GW will be activated, call will IRAT In-Progress WCDMA Camped be initiated after Re- Succ direction completed. Stop T3417ext IRAT In-Progress Data will be suspended by NAS WRRC Activation Ind as it happened in L- GW redirection. Will Stop LRRC be resumed again after RAU and gets CSFB Ends Succ the FULL service INACTIVE back on GW. Activation Rsp ACTIVE RRC service indication Case1: NMO2 UMTS LAI same as LAI given by LTE NW in attach accept. UE is already updated in this LA, Initiate the CS Call first and RAU in-parallel. Cause in EST_REQ shall be CS call. LAU will be done after call ends. Case2: No LA change, RA change NMO1. initiate pending CS call first and normal RAU in-parallel. Cause in EST_REQ shall be CS call. Perform Combined RAU after the call. Case3: LA and RA not changed. No LU/RAU to be performed. So initiate pending MO Call. CM_SERVICE_IND (GW service) Legacy GW MO CALL will be Followed 3 4 Figure 17-1 3GPP CSFB call flow 80-N8310-1 A 51 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 18 CSFB (L→W Redirection with System 2 Information Tunneling) Released - For Current Employee/Consultant Use Only 3 Redirection from E-UTRAN to UTRAN (or GERAN) can be enhanced so that system 4 information can be provided in the E-UTRAN RRCConnectionRelease message, together with 5 redirection information. 80-N8310-1 A 52 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST CSFB (L→W Redirection with System Information Tunneling) 1 18.1 CSFB (L→W redirection with system information 2 tunneling) call flow 3 WCDMA/GERAN uses the contents of the SIB container for faster camping and call setup. 4 Figure 18-1 shows the CSFB (L→W redirection with system information tunneling) call flow. Released - For Current Employee/Consultant Use Only WCDMA RRC LTE RRC E-UTRA NAS RRC Connection Release (Target RAT UTRA, BCCH container) WCDMA_RRC_LTE_REDIR_REQ UARFCN list, (PSC+BCCH container) list UARFCN + PSC available BCCH container for the redirected cell present and NO all mandatory SIBs are present Setup PCCPCH, READ SIBS YES UE camped successfully on WCDMA RRC_ACTIVATION_IND LTE_RRC_DEACTIVATE LTE_RRC_DEACTIVATE_CNF RRC_ACTIVATION_RSP 5 LTOW Successful Redirection with BCCH container 6 Figure 18-1 CSFB (L→W redirection with system information tunneling) call flow 80-N8310-1 A 53 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 19 GERAN→LTE Redirection Released - For Current Employee/Consultant Use Only 2 When the UE is in a dedicated GSM connection, a redirection indication may be received through 3 the channel release message. Upon receiving the channel release message, the UE should initiate 4 deactivation of the dedicated channel. Once the dedicated channel is released, the UE should 5 process the redirection indication and move to the specified RAT/frequency (LTE in this 6 scenario). 80-N8310-1 A 54 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST GERAN→LTE Redirection 1 19.1 GERAN→LTE redirection call flow 2 Figure 19-1 shows the GERAN→LTE redirection call flow. Released - For Current Employee/Consultant Use Only 3 4 Figure 19-1 GERAN→LTE redirection call flow 80-N8310-1 A 55 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 20 LTE→GERAN Redirection Released - For Current Employee/Consultant Use Only 2 When the UE is in an LTE network in RRC_CONNECTED_MODE, a redirection indication can 3 be received through the connection release indication arriving from the network. Upon receiving 4 the indication, the UE should release the existent RRC connection in LTE. Once it is in the 5 RRC_IDLE state, it should move to the redirected frequency of the RAT, both of which will be 6 specified with the connection release message. 80-N8310-1 A 56 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST LTE→GERAN Redirection 1 20.1 LTE→GERAN redirection call flow 2 Figure 20-1 shows the LTE→GERAN redirection call flow. NW LTE RRC NAS CM DS GSM RR CONNECTED Released - For Current Employee/Consultant Use Only Connection Rel DLM Redirection IE Validate target redirected frequency/band list LTE_RRC_CONN_REL_IND Loadbalancing TAU: FALSE LTE_CM_ACT_DRB_RELEASED_IND IDLE EPS bearers are not CM_CALL_EVENT_RAB_REL_IND released LTE SUSPENDED LTE_IRAT_GSM_REDIR_REQ (Redirection band/freq list + Dedicated Priorities(o) + T3230(o)) ACTIVATED Attempt GSM Acq with redirected band,freq list RR_ACTIVATION_IND (Redirection) CM_MM_PS_DATA_SUSPEND_IND Disable reselections to other RATs LTE_RRC_DEACTIVATE_REQ CM_SS_EVENT_SRV_CHANGED Cause:Redirection (CM_SS_PS_DATA_SUSPEND_MASK) LTE DEACTIVATED EPS bearers are not released Data Suspended LTE_RRC_DEACTIVATE_CNF RR_ACTIVATION_RSP RR_SERVICE_IND Transfer of EPS bearer context Enable reselections from LTE to GSM to other RATs RAU performed if required CM_SERVICE_IND PS Suspend = FALSE Transfer of call objects from LTE to GSM CM_SS_EVT_SRV_CHANGED (System = GSM PS Suspend = FALSE) Data Resumed 3 4 Figure 20-1 LTE→GERAN redirection call flow 80-N8310-1 A 57 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 21 GERAN→LTE Reselection Released - For Current Employee/Consultant Use Only 2 When it is camped on GSM, the UE shall regularly measure the serving cell and other G and 3 IRAT (including LTE) cells based on the E-UTRAN neighbor cell list obtained in the 4 measurement information message or the SI2quater message. The purpose of these measurements 5 is an attempt to find a better cell. If the measurement evaluation of a specific cell indicates that it 6 fulfills the cell reselection, the UE selects that cell. 7 Cell reselections can be performed by the UE when it is in GSM or GPRS Idle or Packet Transfer 8 modes. 80-N8310-1 A 58 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST GERAN→LTE Reselection 1 21.1 GERAN→LTE reselection call flow 2 Figure 21-1 shows the GERAN→LTE reselection call flow. GL1 MAC RR / GRR NAS CM DS LTE RRC Released - For Current Employee/Consultant Use Only Perform measurement of IDLE LTE cells. Measurement results Evaluate cell reselection criteria GRR_MAC_CELL_RESEL_IND MAC_GRR_MAC_STATUS Idle MPH_STOP_GSM_MODE_REQ MPH_STOP_GSM_MODE_CNF GSM STACK STOPPED GSM_TO_LTE_RESEL_REQ Reselection Params + Dedicated priorities (o) + T3230 value + Equiv PLMN list + UE supported RATs/bands ACTIVATED CAMPING LTE_RRC_ACTIVATION_IND (Reselection) Disable reselections CM_MM_PS_DATA_SUSPEND_IND to other RATs RR_GSM_STOP_MODE_REQ CM_SS_EVENT_SRV_CHANGED (CM_SS_PS_DATA_SUSPEND_MASK) GRR_MAC_NO_SERVICE Bearers are not released Data Suspended RR_GSM_STOP_MODE_CNF LTE_RRC_ACTIVATION_RSP LTE_RRC_SERVICE_IND Transfer of bearer context Enable from GSM to LTE reselections to other RATs TAU performed if required CM_SERVICE_IND PS Suspend = FALSE Transfer of call objects from GSM to LTE CM_SS_EVT_SRV_CHANGE D (System = LTE PS Suspend = FALSE) Data Resumed 3 4 Figure 21-1 GERAN→LTE reselection call flow 80-N8310-1 A 59 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 22 LTE→GERAN Reselection Released - For Current Employee/Consultant Use Only 2 When it is camped on LTE, the UE shall regularly measure the serving cell and other LTE and 3 IRAT (including GSM) cells based on e-UTRAN SI information and UE preferred modes in an 4 attempt to find a better cell. If the measurement evaluation of a specific cell indicates that it 5 fulfills the cell reselection criteria, the UE selects that cell. 6 In LTE, cell reselections are performed when the UE is in the RRC_IDLE state. 7 Information Elements (IEs) needed by the UE for cell reselection to GERAN are contained in the 8 following e-UTRAN system information messages: 9  SystemInformationBlockType3 (SIB3) 10  SystemInformationBlockType7 (SIB7) 80-N8310-1 A 60 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST LTE→GERAN Reselection 1 22.1 LTE→GERAN reselection call flow 2 Figure 22-1 shows the LTE→GERAN reselection call flow. ML1 LTE RRC NAS CM DS GSM RR Released - For Current Employee/Consultant Use Only IDLE Idle Measurement Config (SIB7 resel params) Perform measurement of GERAN cells. Evaluate cell reselection criteria LTE_CPHY_CELL_RESEL_IND (GERAN) LTE_CPHY_SUSPEND_REQ (Reselection to GERAN) SUSPENDED LTE_CPHY_SUSPEND_CNF LTE_IRAT_GSM_RESEL_REQ (Reselection Params + Dedicated Priorities(o) + T3230(o)) ACTIVATED CAMPING RR_ACTIVATION_IND (Reselection) Disable reselections to CM_MM_PS_DATA_SUSPEND_IND other RATs LTE_RRC_DEACTIVATE_REQ CM_SS_EVENT_SRV_CHANGED Cause:Reselection (CM_SS_PS_DATA_SUSPEND_MASK) LTE_CPHY_STOP_REQ DEACTIVATED EPS bearers are not released LTE_CPHY_STOP_CNF Data Suspended LTE_RRC_DEACTIVATE_CNF RR_ACTIVATION_RSP RR_SERVICE_IND Transfer of EPS bearer context Enable reselections from LTE to GSM to other RATs RAU performed if required CM_SERVICE_IND PS Suspend = FALSE Transfer of call objects from LTE to GSM CM_SS_EVT_SRV_CHANGED (System = GSM PS Suspend = FALSE) Data Resumed 3 4 Figure 22-1 LTE→GERAN reselection call flow 80-N8310-1 A 61 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 23 LTE→WCDMA Redirection Released - For Current Employee/Consultant Use Only 2 Redirections are an alternate way to perform handovers, which provide the ability for the network 3 to move the UE from LTE (to another network in the case of IRAT redirections). Redirections 4 happen during RRC connection release. 5 The following steps give the high-level approach used for IRAT redirection from LTE to 6 WCDMA. 7 IRAT redirection from LTE→WCDMA is triggered when the UE receives an RRC connection 8 release message with the redirection information IE to UTRA. 9 1. The LTE RRC module first releases RF resources and then initiates the IRAT redirection 10 procedure with its peer WCDMA RRC module. 11 2. If WCDMA successfully camps, it informs the common NAS layer about being activated 12 because of the IRAT redirection. 13 3. NAS is the common glue between LTE RRC and WCDMA RRC, so it shuts down LTE and 14 gives a go ahead to the WCDMA stack. 15 4. After successful registration, the NAS informs the upper layers of the RAT change. 16 5. If WCDMA camping fails, it gets back to LTE RRC and LTE RRC returns a no service 17 indication to the NAS, which does its OoS handling. The MMSS eventually kicks in to 18 perform cell selection. 19 The redirection process is aborted for any higher-priority user requests. 80-N8310-1 A 62 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST LTE→WCDMA Redirection 1 23.1 LTE→WCDMA redirection call flow 2 Figure 23-1 shows the LTE→WCDMA redirection call flow. CM/ WCDMA WCDMA DS NAS LTE RRC LTE ML1 eUTRAN MMoC RRC L1 Released - For Current Employee/Consultant Use Only LTE Service LTE Service LTE Service RRC Connected Deactivated Deactivated eMM Connected Step 1: RRC Connection Release RRC Connection Release (RedirectedCarrier Info = UTRA) with Redirection to WCDMA RRC Idle Redirection triggered by LTE_RRC_CONN_REL_IND NAS still maintains the a RRC Connection EPS bearer context. Release message LTE Service eMM Idle LTE_CM_ACT_DRB_RELEASED_IND LTE RRC Suspended state indicates a IRAT procedure CM_CALL_EVENT_RAB_REL_IND from LTE is in progress LTE stack is suspended Step 2: LTE Stack suspended Suspended - RRC Suspended - ML1 stopped CM_CALL_RAB_REESTAB_IND_CMD LTE_CPHY_STOP_REQ If LTE RRC has sent a connection release to ESM_DRB_REESTABLISH_REQ Stopped NAS, NAS will not send any conn est. requests till it NAS buffers the request receives a service LTE_CPHY_STOP_CNF indication from LTE RRC LTE RRC activates Step 3: WCDMA stack activated by WCDMA stack by LTE stack WCDMA_RRC_IRAT_REDIRECTION_REQ sending request to WCDMA RRC Inter-RAT in progress NAS is informed that LTE to WCDMA inter- Step 4: Successful WCDMA camping RAT procedure is successful so it WCDMA Camped Successfully deactivates LTE Step 5: LTE NAS notified of successful WCDMA activation WCDMA_RRC_ACTIVATION_IND (Success) Inter-RAT in progress DS starts LTE LTE WCDMA in Inter-RAT in progress state “EMM Registered/No Cell” internal timer to retry CM_MM_PS_DATA_SUSPEND_IND request. Different from eHRPD When timerCM_SS_EVENT_SRV_CHANGED For 3GPP, RAU can take (LTE) a long time so DS is where CM gets this and expires, DS shuts down LTE. retries request (CM_SS_PS_DATA_SUSPEND_MASK ) ESM_DRB_REESTABLISH_REJ suspended for the Inter- on new RAT RAT procedure CM RAB RE EST Rejected Data Available Ind (through CM) Step 6: LTE stack LTE_RRC_DEACTIVATE_REQ deactivated Deactivated LTE_RRC_DEACTIVATE_CNF Step 7: WCDMA successful WCDMA_RRC_ACTIVATION_RSP NAS confirms the mode Active transition to active to the activation confirmed RRC_SERVICE_IND (WCDMA) WCDMA stack NAS transfers bearer context information from WCDMA Routing Area Update LTE to WCDMA Is necessary before NAS sends out new service indication to upper layers Step 8: CM and DS layers informedCM_SERVICE_IND (WCDMA) of successful RAT change Suspend = False WCDMA CM transitions its call objects to WCDMA now CM_SS_EVENT_SRV_CHANGED and informs upper layers (WCDMA) DS retries the bearer re- Suspend = FALSE establishment on the new active RAT i.e. WCDMA WCDMA RAB Reestablish Req (Retried on WCDMA) 3 4 Figure 23-1 LTE→WCDMA redirection call flow 80-N8310-1 A 63 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 24 WCDMA→LTE Redirection Released - For Current Employee/Consultant Use Only 2 WCDMA→LTE redirections can happen via either connection release or connection reject. 3 The major difference between redirection to LTE due to RRC connection release and RRC 4 connection reject is the wait timer that comes as part of the RRC connection reject message in 5 WCDMA. The network typically redirects to LTE at WCDMA connection establishment if it 6 wants data sessions on 4G LTE but voice on 3G WCDMA. 7 For redirection due to connection release, the network sends a list of LTE frequencies. LTE RRC 8 starts cell selection and informs the common NAS layer if it is successful. The WCDMA stack is 9 deactivated. 80-N8310-1 A 64 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST WCDMA→LTE Redirection 1 24.1 WCDMA→LTE redirection call flow 2 Figure 24-1 shows the WCDMA→LTE redirection call flow. Released - For Current Employee/Consultant Use Only Network RRC GSM-RR Connection Release Message (With Interrat-Redirection Info) Releases all channels LTE_RRC_WCDMA_REDIR_REQ (Cause: LTE_RRC_IRAT_W_REDIR_CAUSE_C NAS ONN_RELEASE) RRC_REL_IND Timer started Start cell Selection on the list of EARFCN’s provided by UTRAN RRC_EST_REQ 10s timer No suitable cell found from the list within 10s. Start power scan on all freq for Buffer EST_REQ suitable cell. Timer Expired UE camped suitably on a EUTRA cell LTE_RRC_ACTIVATION_IND RRC_STOP_WCDMA_MODE_REQ Stop lower layers and go to inactive mode. RRC_STOP_WCDMA_MODE_CNF LTE_RRC_ACTIVATION_RSP 3 4 Figure 24-1 WCDMA→LTE redirection call flow 80-N8310-1 A 65 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 25 Idle Mode Signaling Reduction (ISR) 2 Flows Released - For Current Employee/Consultant Use Only 3 The ISR feature enables the UE and the network to share the UE’s context between an MME and 4 an SGSN. Doing so extends the paging area for the UE to simultaneously cover all the TAs 5 served by the MME and the RA served by the SGSN, thereby allowing the UE to roam across 6 these TAs and the RA without having to inform the network of a change in its location. As a 7 result, when the UE transitions between an E-UTRAN eNB serving one of the UE’s registered 8 TAs and the UTRAN/GERAN RNC that serves the UE’s registered RA, it need not perform the 9 TAU or RAU (or combined RAU) procedures. This effectively reduces signaling in Idle mode. 10 To benefit from the ISR feature, the UE must have visited an E-UTRAN TA and a 11 UTRAN/GERAN RA at a minimum, and must hold valid identities in both the domains. Further, 12 the network, realizing that the UE has context in both the domains, must explicitly activate ISR 13 for the UE. 14 The network may choose to explicitly deactivate ISR at any time. 15 When certain changes to the UE configuration occur, the UE must locally deactivate ISR so that 16 it ensures that both domains are informed of the latest configuration. 17 The UE must also locally deactivate the ISR to ensure that it enables the network to route CS 18 pages to the UE’s most recently registered domain at all times. 80-N8310-1 A 66 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Idle Mode Signaling Reduction (ISR) Flows 1 25.1 ISR call flow 2 Figure 25-1 and Figure 25-2 show the ISR call flow. DS/CM ESM SM EMM MM NW Released - For Current Employee/Consultant Use Only UE is powered up in E-UTRAN and is registered. EMM_REGISTERED.NORMAL_SERVICE and GMM_REGISTERED.NO_CELL_AVAILABLE UE moves to idle state while in LTE UE moves to GW GMM_REGISTERED.ATTEMPTING-TO-UPDATE and EMM_REGISTERED.NO_CELL_AVAILABLE Routing Area Update Routing Area Accept GMM_REGISTERED.NORMAL_SERVICE (ISR on) Bearer Context Transfer upon RAT change Both RAU and TAU periodic timers are valid and continue to run Service_Ind UE moves to idle state while in GW UL Data NAS OTA Service Request Service Request UE moves to idle state while in GW UE moves to LTE Bearer Context Transfer upon RAT change EMM_REGISTERED.NORMAL_SERVICE and GMM_REGISTERED.NO_CELL_AVAILABLE Service_Ind Both RAU and TAU periodic timers are valid and continue to run UL Data Service Request Service Request Bearer Context Transfer upon RAT change UE moves to GW GMM_REGISTERED.NORMAL_SERVICE and EMM_REGISTERED.NO_CELL_AVAILABLE Service_Ind 3 4 Figure 25-1 ISR flow call flow 1 80-N8310-1 A 67 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST Idle Mode Signaling Reduction (ISR) Flows DS/CM ESM SM EMM MM NW UE is powered up in E-UTRAN and is registered. EMM_REGISTERED.NORMAL_SERVICE and GMM_REGISTERED.NO_CELL_AVAILABLE Released - For Current Employee/Consultant Use Only UE moves to idle state while in LTE since the EMM is in UE moves to GW EMM_REGISTERED.NO_ GMM_REGISTERED.ATTEMPTING_TO_UPDATE and CELL_AVAILABLE it will EMM_REGISTERED.NO_CELL_AVAILABLE send a failure immediately UL Data LTE_EMM_SERVICE_REQ Routing Area Update LTE_ESM_FAILURE_IND DRB Reestablish Rej Routing Area Accept GMM_REGISTERED.NORMAL_SERVICE (ISR on) Bearer Context Transfer upon RAT change Both RAU and TAU periodic timers are valid and continue to run Service_Ind UE moves to idle state while in GW UL Data NAS OTA Service Request Service Request UE moves to idle state while in GW UE moves to LTE Bearer Context Transfer upon RAT change EMM_REGISTERED.NORMAL_SERVICE and GMM_REGISTERED.NO_CELL_AVAILABLE Service_Ind Both RAU and TAU periodic timers are valid and continue to run UL Data LTE_EMM_SERVICE_REQ Service Request Bearer Context Transfer upon RAT change UE moves to GW GMM_REGISTERED.NORMAL_SERVICE and EMM_REGISTERED.NO_CELL_AVAILABLE Service_Ind 1 2 Figure 25-2 ISR flow 2 call flow 2 80-N8310-1 A 68 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 26 1X Preregistration and CSFB to 1X Released - For Current Employee/Consultant Use Only 2 1xCircuit-Switched Fallback (1xCSFB) services include support for 1X voice calls and SMS 3 support while monitoring the LTE network. The core 1xCSFB services are: 4  1X preregistration support of an LTE tunnel 5  MO and MT SMS 6  MO and MT calls 7 There are two methods of setting up a call through 1xCSFB, the redirection approach, which 8 requires a transfer from LTE to 1X through a redirection and then a call to be set up on the 1X 9 side, and the hard handoff approach, where the call is set up through the 1X tunnel on the LTE 10 network and then a transfer (hard handoff) is done directly into 1X traffic. Both solutions are 11 standardized and required for Rel 9 spec compliance; however, for performance reasons, the 12 handoff approach is preferred. 80-N8310-1 A 69 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1X Preregistration and CSFB to 1X 1 26.1 1X preregistration and CSFB→1X call flow 2 Figure 26-1 and Figure 26-2 show the 1X preregistration and CSFB→1X call flows. CM/ LTE LTE EUTR 1x UI SD 1xCP 1xL1 LTE L1 MMoC NAS RRC AN NWK Released - For Current Employee/Consultant Use Only No Service Step 1: 1x Pre-registration over LTE tunnel Inactive Inactive CM tries to acquire service on startup CM_SERVICE_REQ (LTE is preferred system) PROTOCOL_ACTIVATE 1x stack is ready to (LTE_CSFB) receive MSGR messages from LTE now 1xCP is activated in a special mode MSGR Registered for CSFB builds so it starts up and LTE_RRC_SERVICE_REQ registers with LTE acquires EUTRAN message router. LTE_RRC_SERVICE_CNF (Success) CM_CAMPED_IND Camped LTE_RRC_CONN_EST_REQ NAS Attach LTE_RRC_CONN_EST_CNF (Success) CM_SERVICE_CNF SIB 8 contains CSFB related info LTE Service and is passed on to 1x SIB 8 If SIB 8 has 1xRTT info, UE LTE_IRAT_SIB8_IND assumes network supports 1xCSFB and tries to proceed with pre- 1x constructs 1x registration registration over LTE tunnel message If RRC is not connected, LTE_IRAT_UL_DATA_REQ NAS will get it to connected (1x Reg. Msg.) state RRC Connected LTE_RRC_UL_DATA_REQ The req goes out as a UL Direct Transfer message over LTE air interface UL Info. Transfer RRC Msg LTE_RRC_UL_DATA_CNF (Success) Optional LTE_IRAT_UL_DATA_CNF 1x Reg Success Order (Success) DL Info. Trans RRC Msg (1x CS Reg Rsp) LTE_IRAT_DL_DATA_IND (Registration Success Order) Idle Tunnel State 3 4 Figure 26-1 1X preregistration and CSFB→1X call flow 1 80-N8310-1 A 70 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1X Preregistration and CSFB to 1X UI/DS CM/MMOC 1xCP NAS L-RRC(NW) Legacy “SEND” Perform PSIST check and If not CS+PS confirm to proceed or abort. MO Call Request attached for 3GPP Store the call info if the call is to (Call Info) be proceeded. MO Call Confirm Released - For Current Employee/Consultant Use Only Create 1xCSFB Call Object 1xCSFB Origination CM will start a 30 Request Extended Service second silent timer Start T3417 Request RRC Connection Establishment (if required) LTE_RRC_IRAT_TUNNEL_DL_MSG_IND (HO from EUTRA Prep Req HO_EUTRA indicates that the 1x 3g1xParam,Rand) parms are for a call HO_EUTRA (1X Param) GCSNA ORM Formulate ORM from MO Call LTE_RRC_IRAT_TUNNEL_UL_MSG_REQ Request’s call object and the 1X (UL Handover Preparation Transfer Param. GCSNA ORM) Mobility EUTRA Stop T3417 LTE_RRC_1xCSFB_HO_STARTED_IND Suspend Data Req LTE Suspend ONEX_CP_LTE_1xCSFB_HO_REQ(UHDM) * SRCH/MUX Time transferred to Traffic Channel * 1X TCH acquired, HOCM is ACKed. Handover complete ind (SID, NID, Band, Chan, MCC) Stop Mode Req (reason = IRAT) Abort Req Modify CSFB Call LTE Connection Object to be 1x Release Call Object Connection Release Ind DS will not transfer Deactivate Req data on HDR as 1x is acquired for LTE CSFB call Deactivated Deactivate Cnf SS event Stop Mode Cnf (1x service, CSFB call Handover Complete Cnf mode) 1x Call Connect Call Connect event to all clients 1xCSFB procedure successful. CM will clear silent redial timer. 1 2 Figure 26-2 1X preregistration and CSFB→1X call flow 2 80-N8310-1 A 71 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST 1 27 LTE→1X Redirection and Reselection Released - For Current Employee/Consultant Use Only 2 This flow covers LTE→1X redirection and reselections. The main differences in the framework 3 of the two flows are the trigger points: 4  Reselections to 1X are triggered by the L1 layer based on earlier measurements. 5  Redirections to 1X are triggered by the network during RRC connection release. 6 The rest of the steps are similar. The LTE stack is suspended/stopped and the request is sent to 7 the 1X. 8 On successful 1X camping, the CM deactivates LTE and 1X proceeds. 80-N8310-1 A 72 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only Cheruvu, Bharadwaj (bcheruvu) - 12/03/2012 12:21:20 PM PST LTE→1X Redirection and Reselection 1 27.1 LTE→1X redirection and reselection call flow 2 Figure 27-1 shows the LTE→1X redirection and reselection call flow. LTE EUTRA ML1 NAS CM SD 1x CP RRC Released - For Current Employee/Consultant Use Only IDLE Trigger for Reselection Reselection Case LTE_RRC_CELL_RESEL_IND (1X) ML1 sends this out to LTE RRC LTE_RRC_SUSPEND_REQ based on measurements (UE Initiated) LTE stack suspended LTE_RRC_SUSPEND_CNF IRAT_RESEL_REQ (1X Cell info included, Band, Chan, PN) CONNECTED Redirection Case Trigger for redirection is the Connection Rel DLM with Redirection IE RRC Connection Release message from the network Validate target redirected frequency/band LTE_RRC_CONN_REL_IND Loadbalancing TAU: FALSE LTE stack suspened DRB release EPS bearers are not released IRAT_REDIR_REQ (1X Cell info included, List of Band/Chans) 1x stack activated Puts SD in the correct context sd_ss_set_lte_1x_info( ) • SD gets the list of band/chan’s to base operation on rather than PRL. LTE_1X_MODE, • Can be thought of as interRAT procedure. Upper layers not involved. Chan List • Suspends all interaction with CM in this context LTE_1X_ENTER • 1xCP will keep the PNs. sd_ss_act_get() Channel info • CP will pair up PN information with band/chan info return from SD 1X CAMPING Activation Indication (Success) Stop Mode Req Deactivate Req Cause: Resel Cause: Resel During this window, the entire EPS bearers are process can be aborted due to higher LTE stack deactivated not released priority user request Deactivate Cnf Stop Mode Cnf Activation Rsp (Success) sd_ss_ind_cdma_opr_oh_info2 3 4 Figure 27-1 LTE→1X redirection and reselection call flow 80-N8310-1 A 73 Qualcomm Confidential and Proprietary MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Released - For Current Employee/Consultant Use Only