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1.oeo000030 lte access fault diagnsis issue1

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Huawei

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1.oeo000030 lte access fault diagnsis issue1

  1. 1. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  2. 2. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  3. 3. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  4. 4. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  5. 5. After UE select a suitable cell, it initials attach flow, including the following procedures: LTE Access Fault Diagnosis Random access RRC connection setup (RRC cause: MO signaling) NAS authentication procedure E-RAB setup (Activate default EPS bearer) Setup dedicated bearer (Optional, only for some Smart UE that support VoIP) Above figure shows the detailed procedure Confidential Information of Huawei. No Spreading Without Permission
  6. 6. If UE request service again while in idle status, it initials “Service Request” procedure LTE Access Fault Diagnosis The whole procedure are very similar as initial attach procedure except: The cause of RRC connection is “MO Data” No authentication and UE capability query procedure as UE context already exists in MME Confidential Information of Huawei. No Spreading Without Permission
  7. 7. TAU procedure is a UE idle behavior, ensure that UE location is known by MME. The LTE Access Fault Diagnosis scenarios of TAU can be: UE initial attach UE move to a new TA area Periodic TA update Confidential Information of Huawei. No Spreading Without Permission
  8. 8. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  9. 9. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  10. 10. There are five RA preamble formats, which are used for cells of different radii. LTE FDD LTE Access Fault Diagnosis supports preamble formats 0-3, and LTE TDD supports preamble formats 0-4. The preamble format can be set through the PreambleFmt parameter, and the cell radius can be set through the CellRadius parameter. Format 4 is a special RACH preamble for LTE-TDD only. Confidential Information of Huawei. No Spreading Without Permission Preamble Format Length TCP TSEQ FDD Cell Radius (R) TDD Cell Radius (R) 0 1ms 103.1 µs 800 µs R ≤ 14.5km 1.4 km < R ≤ 14.5 km 1 2ms 684.4 µs 800 µs 29.5 km < R ≤ 77.3 km 29 .5km < R ≤ 77.3 km 2 2ms 203.1 µs 1,600 µs 14 .5km < R ≤ 29.5 km 14.5 km < R ≤ 29.5 km 3 3ms 684.4 µs 1,600 µs 77 .3km < R ≤ 100 km 77 .3km < R ≤ 100 km 4 167.9 µs 14.58 µs 133.33 µs Not involved. R ≤ 1.4 km
  11. 11. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  12. 12. Upon receiving the UE preamble, the eNodeB transmits an RA response over DL-SCH. LTE Access Fault Diagnosis The UE monitors the Physical Dedicated Control Channel (PDCCH) in the Transmission Time Interval (TTI) until it obtains the required RA response. The response contains RA-Preamble Identifier, Timing Alignment Information, Initial UL Grant, and Temporary C-RNTI. If multiple-UE send the preamble with the same RA-RNTI, then eNodeB detects that the conflict occurs. This conflict will be handled in contention resolution procedure. A message on the DL-SCH can carry multiple RA responses to be transmitted to multiple use. For the UE ; If the received RA-Preamble Identifier is consistent with the identifier that the UE previously sent, the UE infers that the response is successful. Then, the UE transmits uplink scheduled data. Otherwise, the response fails. In this case, if the number of random access attempts is smaller than the maximum, the UE attempts random access again. Otherwise, random access fails. Confidential Information of Huawei. No Spreading Without Permission
  13. 13. With the grant ,the UE transmits uplink scheduled data over the UL-SCH. This message is LTE Access Fault Diagnosis scrambled by temporary C-RNTI. In this message, UE will carry its unique ID for contention resolution if random access conflict. Based on different random access scenarios, the message could be RRC connection request RRC reestablishment request RRC reconfiguration complete (Handover confirmation) Other user data In case of “RRC connection request” message, UE sends its UE ID to identify the different UE. This UE ID could be: If UE already get S-TMIS from MME, then use S-TMIS as UE ID If UE initial attach, UE generate a random number according to its IMSI as UE ID In the other case, UE at least send its C-RNTI to identify the different UE Confidential Information of Huawei. No Spreading Without Permission
  14. 14. After the UE sends message 3,the contention resolution timer starts. The UE monitors the LTE Access Fault Diagnosis PDCCH before the timer expires. In the following situations, the UE infers that the contention resolution is successful and it notifies the upper layer and stops the : The UE obtains the C-RNTI when monitoring the PDCCH. Temporary C-RNTI is obtained when the UE monitors the PDCCH. In addition, the MAC Packet Data Unit (MAC PDU) is successfully decoded. If the contention resolution timer expires, the UE infers that the contention resolution fails. Then, the UE performs RA again if the number of RA attempts is smaller than the maximum number of attempts. Confidential Information of Huawei. No Spreading Without Permission
  15. 15. Purpose of RRC connection LTE Access Fault Diagnosis Setup SRB1 Send NAS message to EPC Relevant counters: A: RRC connection attempts (L.RRC.ConnReq.Att) B: RRC connection setup successful (L.RRC.ConnReq.Succ) Confidential Information of Huawei. No Spreading Without Permission
  16. 16. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  17. 17. After UE succeed attach to MME, MME initial the ERAB setup procedure, to setup LTE Access Fault Diagnosis dedicated S1 control plane for UE. At the same time, the default PDN connectivity and EPS bearer will also be setup. After ERAB setup, there is already IP connectivity between UE and gateway which is called “Always on line” function. Relevant counters: A: ERAB setup attempts (L.E-RAB.InitAttEst) B: ERAB setup successful (L.E-RAB.InitSuccEst) Confidential Information of Huawei. No Spreading Without Permission
  18. 18. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  19. 19. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  20. 20. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  21. 21. Trace of UE capability LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  22. 22. After SRB2 setup, all the NAS message on UU interface in carried by SRB2 with the LTE Access Fault Diagnosis message RRC_DL_INFO_TRANSF or RRC_UL_INFO_TRANSF Confidential Information of Huawei. No Spreading Without Permission
  23. 23. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  24. 24. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  25. 25. NAS procedure is coming after RRC complete, including LTE Access Fault Diagnosis Attach request (default) Default EPS bearer activity (default) Dedicate EPS bearer setup (optional) Authentication (optional) Identification (optional) NAS procedure is associated with ERAB setup procedure, for NAS delivery, on UU interface NAS can be combined in common RRC message as NAS PDU or directly transferred as “RRC_DL/UL_INFO_TRANSF” message; on S1 interface, NAS can be combined in common S1AP message as NAS PDU or directly transferred as “S1AP_DL/UL_NAS_TRANS” message Confidential Information of Huawei. No Spreading Without Permission
  26. 26. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  27. 27. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  28. 28. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  29. 29. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  30. 30. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  31. 31. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  32. 32. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  33. 33. The barred cell only impacts on initial UE access, handover in is not affected. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  34. 34. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  35. 35. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  36. 36. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  37. 37. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  38. 38. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  39. 39. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  40. 40. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  41. 41. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  42. 42. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  43. 43. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  44. 44. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  45. 45. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  46. 46. This failure is caused by eNodeB admission failure. If PUCCH or SRS resource is limited, LTE Access Fault Diagnosis eNodeB should stop admit all services including RRC. Confidential Information of Huawei. No Spreading Without Permission
  47. 47. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  48. 48. Relevant RRC failure counter: LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission Counter name Description L.RRC.SetupFail.ResFail Number of RRC connection setup failures due to resource allocation failures L.RRC.SetupFail.NoReply Number of RRC connection setup failures due to no responses from the UE L.RRC.SetupFail.Rej Number of RRC Connection Reject messages sent to the UE in a cell
  49. 49. This NAS procedure refers to the procedure between UE initial message and Initial UE LTE Access Fault Diagnosis context setup response message, including attach, authentication, identification, default bearer activity. If NAS procedure is failure, then MME will send a UE context release command, and the release cause is NAS, so eNodeB will consider this release is normal release and doesn’t count it in performance static. Possible scenarios: Authentication failure: Incorrect subscriptions user data in HSS Solution: Check subscription data in HSS Attach failure: Parameters between UE and EPC is not identical Solution: Check the if the following parameters are identical with EPC 1. PLMN 2. TAC PDN activity failure: Wrong configuration of APN in UE or EPC Confidential Information of Huawei. No Spreading Without Permission
  50. 50. This failure refers the fault between “Initial context setup request” message and “Initial LTE Access Fault Diagnosis context setup response” message. If any step occur fault, then ERAB setup procedure fails. Confidential Information of Huawei. No Spreading Without Permission
  51. 51. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  52. 52. Scneario: the L.E-RAB.FailEst.NoReply counter is incremented each time the eNodeB LTE Access Fault Diagnosis receives no responses from the UE before the corresponding timer expires after sending an RRC signaling message to the UE during the initial UE context setup procedure or the E- RAB setup procedure Possible cause: Poor DL/UL coverage which cause message missing. UE internal process error Confidential Information of Huawei. No Spreading Without Permission
  53. 53. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  54. 54. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  55. 55. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  56. 56. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  57. 57. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  58. 58. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  59. 59. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  60. 60. Tracing message LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  61. 61. Message tracing LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  62. 62. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  63. 63. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  64. 64. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  65. 65. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  66. 66. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  67. 67. Cautioned WordsCautioned WordsCautioned WordsCautioned Words 1 Tracing ( Signaling/ Message/Interface etc) The privacy-related information may be anonymity for user's privacy protection. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission
  68. 68. LTE Access Fault Diagnosis Confidential Information of Huawei. No Spreading Without Permission

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