Layer 3 Messaging and Call Procedures

1. Layer 3 Messaging and Call Procedures Naren Mohan Naren.mohan@ericsson.com

2. Agenda • Protocol Layers & Signaling • Radio Network Procedures • Example Call Flows • KPI Calculation Triggers

3. Channels • Logical Channels – Defines what information to be transferred • Transport Channels – Defines how data should be transferred. • Physical Channels – Carry the data

4. CTRL UE USER DATA USER DATA UTRAN CTRL RRC RRC Signaling Radio Bearer L3/RRC Radio Bearer RLC RLC RLC RLC Logical Channel L2/RLC MAC MAC Transport Channel L2/MAC PHY PHY Physical Channel L1 Protocol Layers

5. Layer 3 Signaling • The Control Signaling is used for troubleshooting the problems. These messages are carried in the Logical Control Channels such as DCCH, CCCH, BCCH. • Radio Resource Control (RRC) Protocol messages contain the necessary control information and the commands – Obtained from TEMS. • In the Iub we may be interested in the NBAP and RANAP protocol messages – Obtained from UETR. CC SM CC SM MM GMM MM GMM RRC RANAP RRC RANAP RLC/MAC SCCP RLC/MAC SCCP PHY Sig. Bearer PHY Sig. Bearer UE WRAN MSC/VLR or SGSN

6. RRC Protocol Functions • Carries most of the Control Signaling between the UE and the UTRAN. • Carries all the information required to setup, modify and release lower layer entities. • RRC Controls • Radio Bearer parameters such as RLC Timers, QoS • Transport channel parameters such as the Transport format Combination (TFC) • Physical Channel parameters such as Code usage, carrier frequency • Radio Resource Supervision

7. CELL_PCH CELL_FACH CELL_DCH Radio Bearer Reconfiguration RRC Connection Establishment RRC Connection Establishment RRC Connection Release RRC Connection Release IDLE MODE RRC States RRC Connected Mode

8. Layer 3 Procedures • RRC Setup and RRC release • Measurement Reports • Active Set Update • Radio Bearer Setup and Reconfiguration • Transport Channel Reconfiguration • Physical Channel Reconfiguration • All Call setup and tear down messages (such as PDP Activation/Deactivation, Alerting/Release etc) - These are Call Control and Session Management messages.

9. MIB SIB n SIB 1 SIB 3 SIB 5 SIB 7 SIB 11 LA/ RA Updating, Paging, idle mode timers CRS Parameters Cell / Common Ch. Configuration Power Control on Common Channels Measurement Management SIB n.1 SIB n.2 System Information Blocks (BCH) • RRC Protocol Schedules the SIBs. • The system information blocks are arranged as a tree structure. The Master Info. Block (MIB) contains the reference and scheduling info for the SIBs. • UE receives SIBs in Idle or CELL_FACH modes

10. UE RNC RRC: Measurement Report (DCCH) RRC: Measurement Control (BCCH/DCCH) RRC: Active Set Update (DCCH) Measurement Procedures Remember !!! – Unlike GSM, the measurement reports event triggered. You can see long times of silence from the UE. These are not to be confused as missing messages. UE Measures the SCs and performs Evaluation for Event Trigger Criteria. RNC Evaluates based on the measurements and Network Configuration.

11. UE RNC RRC: RRC Connection Request (CCCH) RRC: RRC Connection Setup Complete (DCCH) RRC: RRC Connection Setup (CCCH) RRC Connection Establishment • Cause codes will indicate the problem if RRC Connection is rejected Cause Code for connection Request Sent: •Originating Streaming Call • Originating Interactive Call • Originating Background Call • Terminating Conversational Call • Terminating Streaming Call • Terminating Interactive Call • Terminating Background Call • Emergency Call • Registration • Originating High Priority Signalling • Call re-establishment • Terminating High Priority Signalling • Terminating cause unknown RRC Connection can be rejected to Admission & Congestion Control Features Contains the UE Capability (HS or R99)

12. RRC Connection Establishment UE starts timer T=0, counter N=1 UE sends RRC Connection Request UE increments Timer T N T >T300 Y Y N = N + 1 T=0 N > N300 N Y UE sends RRC Connection Setup Complete Fail. UE goes into idle mode UE gets RRC Connection Setup N RRC Procedure Successful N UE gets RRC Connection Reject Y N Cause = “Wait’ Y N = N + 1 T=0 UE sends RRC Connection Request Wait for ‘wait’ seconds

13. UE RNC CN RRC: Radio Bearer Setup Complete (DCCH) RANAP: Radio Access Bearer Response (DCCH) RRC: Radio Bearer Setup (DCCH) RANAP: Radio Access Bearer Request Radio Bearer Setup • RAB (Radio Access Bearer) is setup between Core and UE. • Radio Bearer is setup between UE and UTRAN to support the RAB.

14. UE RNC RRC: Measurement Report (e1a, e1b, e1c) (DCCH) RRC: Active Set Update Complete (DCCH) Timeout of 5 s RRC: Active Set Update (DCCH) Active Set Update • UTRAN sends Active Set Update to the UE in CELL_DCH mode. • The result could be one of the following • Radio Link Addition • Radio Link Removal • Radio Link Replacement (Combined Addition/Removal)

15. UE RNC RRC: Radio Bearer Reconfiguration Complete (DCCH) RRC: Radio Bearer Reconfiguration (DCCH) Radio Bearer Reconfiguration • RB Reconfiguration occurs for the following scenarios • Channel Type Switch i.e., DCH to FACH, FACH to DCH • Reconfiguration of the Radio Bearer after RB Setup (such as RLC timer reconfiguration) FACH/DCH DCH/FACH

16. UE RNC RRC: Transport Channel Reconfiguration Complete (DCCH) RRC: Transport Channel Reconfiguration (DCCH) Transport Channel Reconfiguration • Transport Channel Reconfiguration procedure triggers the Channel Rate Switching. 64K <-> 128K <-> 384K

17. UE RNC RRC: Physical Channel Reconfiguration Complete (DCCH) RRC: Physical Channel Reconfiguration (DCCH) Physical Channel Reconfiguration • Physical channel reconfiguration procedure is used to establish, reconfigure and release physical channels. • Used to enter Compressed mode before IRAT, HSDPA Cell Change

18. UE RNC RRC: RRC Connection Release Complete (CCCH) RRC: RRC Connection Release (DCCH / CCCH) RRC: RRC Connection Abnormal Release (DCCH / CCCH) RRC Connection Release • When the RRC Connection is released, the UE will be in IDLE mode. Radio Bearers will be released. • RRC Connection can be released abnormally if

19. UE RRC: Downlink Direct Transfer – CALL PROCEEDING (DCCH) RRC: Measurement Control (DCCH) RRC: Downlink Direct Transfer - CONNECT (DCCH) RRC: Downlink Direct Transfer – ALERTING (DCCH) RRC: Radio Bearer Setup (DCCH) RRC: Security Mode Command (DCCH) RRC: Direct Transfer - Release (DCCH) RRC: RRC Connection Setup (CCCH) RRC: Downlink Direct Transfer – Auth & Ciph Request (DCCH) • Call Setup Phase • KPIs: • Call Setup Success Rate • Call Setup Time RRC: Uplink Direct Transfer - SETUP (DCCH) RRC: Measurement Report (DCCH) RRC: Uplink Direct Transfer – Release Complete (DCCH) RRC: Downlink Direct Transfer – CONNECT ACK (DCCH) RRC: RRC Connection Request (CCCH) RRC: Initial Direct Transfer - CM Service Request (DCCH) RRC: RRC Connection Setup Complete (DCCH) RRC: Uplink Direct Transfer - DISCONNECT (DCCH) RRC: Security Mode Complete (DCCH) RRC: Uplink Direct Transfer - Auth & Ciph Response (DCCH) RRC: Radio Bearer Setup Complete (DCCH) • Total Call Time • KPIs: • Dropped Call Example Voice Call Flow (MOC) RNC RRC Connection is released after the Call Release.

20. UE RRC: Radio Bearer Setup (DCCH) RRC: Transport Channel Reconfiguration (DCCH) RRC: RRC Connection Setup (CCCH) RRC: Direct Transfer – SM Deactivate PDP Context Accept (DCCH) RRC: Downlink Direct Transfer – Auth & Ciph Request (DCCH) RRC: Security Mode Command (DCCH) RRC: Measurement Control (DCCH) RRC: Downlink Direct Transfer – SMACTIVATE PDP CONTEXT ACCEPT (DCCH) • Call Setup Phase • KPIs: • Call Setup Success Rate • Call Setup Time RRC: Transport Channel Reconfiguration Complete (DCCH) RRC: RRC Connection Request (CCCH) RRC: RRC Connection Setup Complete (DCCH) RRC: Initial Direct Transfer - CM Service Request (DCCH) RRC: Uplink Direct Transfer - Auth & Ciph Response (DCCH) RRC: Measurement Report (DCCH) RRC: Radio Bearer Setup Complete (DCCH) RRC: Uplink Direct Transfer – SM Deactivate PDP Context Request (DCCH) RRC: RRC Connection Release (DCCH) RRC: Security Mode Complete (DCCH) RRC: Uplink Direct Transfer – SMACTIVATE PDP CONTEXT REQUEST (DCCH) • Total Call Time • KPIs: • Dropped Call Example PS R99 Call Flow RNC Channel Switching

21. UE RNC • KPI • Call Setup Success Rate • Call Setup Time RRC: Physical Channel Reconfiguration (DCCH) RRC: Active Set Update (DCCH) RRC: Active Set Update (DCCH) RRC: Physical Channel Reconfiguration (DCCH) RRC: RRC Connection Setup (CCCH) RRC: Uplink Direct Transfer – SMACTIVATE PDP CONTEXT REQUEST (DCCH) RRC: Active Set Update Complete (DCCH) RRC: RRC Connection Request (CCCH) RRC: Physical Channel Reconfiguration Complete (DCCH) RRC: Physical Channel Reconfiguration Complete (DCCH) RRC: RRC Connection Setup Complete (DCCH) RRC: Measurement Report (e1a) (DCCH) RRC: Measurement Report (e1d) (DCCH) RRC: Active Set Update Complete (DCCH) RRC: Downlink Direct Transfer – SMACTIVATE PDP CONTEXT ACCEPT (DCCH) • KPI • HS Cell Change Success Rate • HS Cell Change time Example HSDPA Call Flow E1A: Radio Link Addition Not a HS Cell Change. Here the procedure is to realign the parameters. E1D: Change of Best Server HS Cell Change

22. UE RRC: Transport Channel Reconfiguration (DCCH) RRC: Downlink Direct Transfer – Connect (DCCH) RRC: Physical Channel Reconfiguration (DCCH) RRC: Active Set Update (DCCH) RRC: Transport Channel Reconfiguration (DCCH) RRC: Measurement Control (DCCH) RRC: Measurement Control (DCCH) RRC: Downlink Direct Transfer – SM ACTIVATE PDP CONTEXT ACCEPT (DCCH) RRC: Radio Bearer Setup (DCCH) RRC: Cell Change Order From UTRAN (DCCH) RRC: Physical Channel Reconfiguration Complete (DCCH) RRC: Radio Bearer Setup Complete (DCCH) RRC: Measurement Report (e2d) (DCCH) RRC: Measurement Report (e3a) (DCCH) RRC: Handover From UTRAN (DCCH) RRC: Active Set Update Complete (DCCH) RRC: Transport Channel Reconfiguration Complete (DCCH) RRC: Measurement Report (e1b) (DCCH) RRC: Transport Channel Reconfiguration Complete (DCCH) RRC: Uplink Direct Transfer – SM ACTIVATE PDP CONTEXT REQUEST (DCCH) RRC: Uplink Direct Transfer – SM Alerting (DCCH) Example IRAT Handover (PS) RNC UE Enters Compressed Mode, Starts measuring in GSM Handover to GSM. UE performs RA update in GSM Handover to GSM. Handover Complete message in GSM indicates successful Handover

23. UE RNC MSC/ MGW BSC Timer: T_RELOC_Prep RANAP: Relocation Required RRC: Measurement Report (e3a) (DCCH) BSSMAP: Handover Request BSSMAP: Handover Request Ack RANAP: Relocation Command RRC: Handover from UTRAN RR: Handover Access RR: Handover Complete RANAP: Iu Release Command RANAP: Iu Release Complete CS IRAT Handover (Core Perspective)

24. UE RNC RRC: RRC Connection Release (DCCH) RRC: Radio Bearer Setup (DCCH) RRC: RRC Connection Setup (CCCH) RRC: Active Set Update (DCCH) RRC: Physical Channel Reconfiguration (DCCH) RRC: Radio Bearer Reconfiguration (DCCH) RRC: Uplink Direct Transfer – SMACTIVATE PDP CONTEXT REQUEST (DCCH) RRC: Measurement Report (e1a) (DCCH) RRC: Radio Bearer Setup Complete (DCCH) RRC: RRC Connection Setup Complete (DCCH) RRC: RRC Connection Request (CCCH) RRC: Radio Bearer Reconfiguration Complete (DCCH) RRC: Physical Channel Reconfiguration Complete (DCCH) RRC: Active Set Update Complete (DCCH) RRC: Cell Update (CCCH) RRC: Downlink Direct Transfer – SMACTIVATE PDP CONTEXT ACCEPT (DCCH) Example HSDPA/FACH Iur Handover UE does Channel Type Switch to CELL_FACH RRC Establishment Cause Code: “Call Re-Establishment” Or “Directed Signalling Re-establishment”

25. Some Abnormal Cases

26. Abnormal Drop Case UETR TEMS LOGS from UE

27. KPI Definitions

28. Total Call Duration KPI Definition – CS Drop AMR RRC Connection Request RRC Connection Setup Complete Alerting Disconnect Connect Event = Dropped Call Dedicated Mode To Idle Mode RRC Connection Abnormal Release CS Dropped Call Rate (Long Call) = Effective Calls = Total Call Duration / 90 sec (MHT)

29. Total Call Duration KPI Definition – PS Drop Packet Call RRC Connection Request RRC Connection Setup Complete Activate PDP Context Accept Session Start (TEMS Internal) Session End/Error (TEMS Internal) Deactivate PDP Context Req/Accept RRC Connection Request /RRC Connection Setup Complete RRC Connection Request /RRC Connection Setup Complete PS Drop Rate (Long Calls) = Effective Calls = Total Call Duration / 60 sec (MHT)

30. AMR RRC Connection Request RRC Connection Setup Complete Alerting RRC Connection Reject No Alerting Or Connect RRC Connection Request Exceeds N300 If total time between RRC Connection Request And Connect Exceeds 50 Seconds (setup timeout) = Access Failure Packet Call RRC Connection Request RRC Connection Setup Complete Activate PDP Context Accept No Activate PDP Context Accept /Session Start RRC Connection Reject RRC Connection Request Exceeds N300 If total time between RRC Connection Request And Session Start Exceeds 50 Seconds (setup timeout) = Access Failure KPI Definition – Call Setup Success

31. Session Duration KPI Definition - Throughput Session Duration Activate PDP Context Accept Session Start (TEMS Internal) Session Start (TEMS Internal) Session End/Error (TEMS Internal) Session End/Error (TEMS Internal) Deactivate PDP Context Req/Accept RRC Connection Request /RRC Connection Setup Complete

32. UMTS GSM Handover Command Inter System To Utran Handover Access Handover Complete Measurement Report UMTS GSM/GPRS Cell Change Order from UTRAN Command Routing Area Update Request Routing Area Update Accept Measurement Report KPI Definition - IRAT UMTS To GSM CS Handover UMTS To GSM PS Handover