Call setup-procedure

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Call setup-procedure

  1. 1. Traffic&Redesign LCC Pakistan
  2. 2. Objective • Call setup,Mobility&Integrity is a Key of Optimization Traffic&Redesign 2 LCC Pakistan
  3. 3. Outline • GSM Protocol Architecture for Signaling • International Signaling relation via ISDN • GSM Interface & Layer’s Function • Call setup Overview • Key points in Call Setup. • Explanation of each point with layer 3&2 message & logical channels. • Question &Answers Traffic&Redesign 3 LCC Pakistan
  4. 4. GSM Protocol Architecture for Signaling Traffic&Redesign 4 LCC Pakistan
  5. 5. GSM Signaling Network Continue… Traffic&Redesign 5 LCC Pakistan
  6. 6. International Signaling relation via ISDN Traffic&Redesign 6 LCC Pakistan
  7. 7. SS7 Signaling Architecture Traffic&Redesign 7 LCC Pakistan
  8. 8. SS7 Layer in GSM Network Traffic&Redesign 8 LCC Pakistan
  9. 9. SS7 Layers in GSM Network Traffic&Redesign 9 LCC Pakistan
  10. 10. SS7 Layers in GSM Network… Traffic&Redesign 10 LCC Pakistan
  11. 11. SS7 Layers in GSM Network…  Mobile Application Part (MAP)   Mobile-specific extension of C7 standard. All messages exchanged between NSS Elements (MSC,HLR,VLR)  Transaction Capabilities Application Part (TCAP)    A connectionless transport service provided by the SCCP Provides core functionality to support roaming Allows its users to access other users via worldwide C7/SS7 network  Signalling Connection Control Part (SCCP)    Logical signalling connection between MSC and MS to support Layer 3 (MM/CM) message transfers Uses reduced set of C7 signalling instructions Routes messages via STPs  Message Transfer Part (MTP)  C7 protocols responsible for routing and transport of signalling messages Traffic&Redesign 11 LCC Pakistan
  12. 12. SS7 Layers in GSM Network… Traffic&Redesign 12 LCC Pakistan
  13. 13. GSM Protocol Summery Traffic&Redesign 13 LCC Pakistan
  14. 14. GSM Interfaces & Layers Traffic&Redesign 14 LCC Pakistan
  15. 15. A Interface Traffic&Redesign 15 LCC Pakistan
  16. 16. A Interface… BSSMAP - deals with procedures that take place logically between the BSS and MSC, examples : Trunk Maintenance, Ciphering, Handover, Voice/Data Trunk Assignment DTAP - deals with procedures that take place logically between the MS and MSC. The BSS does not interpret the DTAP information, it simply repackages it and sends it to the MS over the Um Interface. examples: Location Update, MS originated and terminated Calls, Short Message Service, User Supplementary Service registration, activation, deactivation and erasure Traffic&Redesign 16 LCC Pakistan
  17. 17. A Interface… Traffic&Redesign 17 LCC Pakistan
  18. 18. A Interface Traffic&Redesign 18 LCC Pakistan
  19. 19. Abis Interface Traffic&Redesign 19 LCC Pakistan
  20. 20. Abis Interface…  Messages exchanges between the BTS and BSC. Traffic exchanges  Signaling exchanges  Physical access between BTS and BSC is PCM digital links of E1(32) or T1(24) TS at 64kbit/s.  Speech:  Conveyed in timeslots at 4X16 kbit/s  Data:  Conveyed in timeslots of 4X16 kbit/s. The initial user rate, which may be 300, 1200, … is adjusted to 16 kbit/s  Traffic&Redesign 20 LCC Pakistan
  21. 21. Abis Interface… Level 1-PCM transmission (E1 or T1) Speech encoded at 16kbit/s and sub multiplexed in 64kbit/s time slots. Data which rate is adapted and synchronized. Level 2-LAPD protocol Radio Signaling Link (RSL) Operation and Maintenance Link (OML). Level 3-Application Protocol Radio Subsystem Management (RSM) Operation and Maintenance procedure (OAM) Traffic&Redesign 21 LCC Pakistan
  22. 22. Abis Interface… Traffic&Redesign 22 LCC Pakistan
  23. 23. LAPD Message Traffic&Redesign 23 LCC Pakistan
  24. 24. LAPD Message…..  The length is limited to 260 octets of information.  LAPD has the address of the destination terminal, to identify the TRX, since this is a point to multipoint interface.  Each TRX in a BTS corresponds to one or several signaling links. These links are distinguished by TEI (Terminal Equipment Identities).  SAPI=0, SAPI=3, SAPI=62 for OAM. Traffic&Redesign 24 LCC Pakistan
  25. 25. Um Interface  Level 1-Physical TDMA frame  Logical channels multiplexing  Level 2-LAPDm(modified from LAPD)  No flag  No error retransmission mechanism due to real time constraints  Level 3-Radio Interface Layer (RIL3) involves three sub layers  RR: paging, power control, ciphering execution, handover  MM: security, location IMSI attach/detach  CM: Call Control(CC), Supplementary Services(SS), Short Message Services(SMS),  Traffic&Redesign 25 LCC Pakistan
  26. 26. Layer1 Signaling Traffic&Redesign 26 LCC Pakistan
  27. 27. Layer 2 Signaling Traffic&Redesign 27 LCC Pakistan
  28. 28. LAPDm Message • • In LAPDm the use of flags is avoided. LAPDm maximum length is 21 octets of information. It makes use of “more” bit to distinguish last frame of a message. • No frame check sequence for LAPDm, it uses the error detecting performance of the transmission coding scheme offered by the physical layer Traffic&Redesign 28 LCC Pakistan
  29. 29. LAPDm Message….  The acknowledgement for the next expected frame in the indicator N(R ).  On radio interface two independent flows(one for signaling, and one for     SMS) can exist simultaneously. These two flows are distinguished by a link identifier called the SAPI(service access point identifier). LAPDm SAPI=0 for signaling and SAPI=3 for SMS. SAP1=0 for radio signaling, SAPI=62 for OAM and SAPI=63 for layer 2 management on the Abis interface. There is no need of a TEI, because there is no need to distinguish the different mobile stations, which is done by distinguishing the different radio channels. Traffic&Redesign 29 LCC Pakistan
  30. 30. Layer 3 Signaling Traffic&Redesign 30 LCC Pakistan
  31. 31. Layer3 Signaling Message Format at air Interface Traffic&Redesign 31 LCC Pakistan
  32. 32. Protocol Discriminator Traffic&Redesign 32 LCC Pakistan
  33. 33. Transaction Identifier Traffic&Redesign 33 LCC Pakistan
  34. 34. Message Type Traffic&Redesign 34 LCC Pakistan
  35. 35. Traffic&Redesign 35 LCC Pakistan
  36. 36. Traffic&Redesign 36 LCC Pakistan
  37. 37. Information Element Traffic&Redesign 37 LCC Pakistan
  38. 38. Measurement Report Traffic&Redesign 38 LCC Pakistan
  39. 39. Layer 3 Function Traffic&Redesign 39 LCC Pakistan
  40. 40. RR Management Traffic&Redesign 40 LCC Pakistan
  41. 41. Mobility Management Traffic&Redesign 41 LCC Pakistan
  42. 42. Connection Management Traffic&Redesign 42 LCC Pakistan
  43. 43. RR Massage, Channel & MT Code Traffic&Redesign 43 LCC Pakistan
  44. 44. MM Massage Traffic&Redesign 44 LCC Pakistan
  45. 45. CM Message Traffic&Redesign 45 LCC Pakistan
  46. 46. Call Setup Overview • • • • MS Idle Mode Behavior Call setup signaling flow with Layer2&Layer3 explanation Handover signaling flow Location updated signaling Flow Traffic&Redesign 46 LCC Pakistan
  47. 47. MS Idle Mode Behavior Traffic&Redesign 47 LCC Pakistan
  48. 48. Idle Mode Measurements..explain in call Setup Traffic&Redesign 48 LCC Pakistan
  49. 49. Call Setup Signaling Flow Traffic&Redesign 49 LCC Pakistan
  50. 50. Call Setup Signaling Flow … Traffic&Redesign 50 LCC Pakistan
  51. 51. Call Setup With Counters Traffic&Redesign 51 LCC Pakistan
  52. 52. Paging Types  Paging locates MS to cell Level for call routing  Three paging message types:  Type 1 - 2 MSs using IMSI/TMSI  Type 2 - 3 MSs (1xIMSI, 2xTMSI)  Type 3 - 4 MSs using TMSI only  Paging message requires 4 bursts (1 CCCH block)  Paging messages may be stored at BSS  Transmitted on PCH  If DRX is implemented MS listens only to allocated paging group Traffic&Redesign 52 LCC Pakistan
  53. 53. Timers involved in Call Process Traffic&Redesign 53 LCC Pakistan
  54. 54. Traffic&Redesign 54 LCC Pakistan
  55. 55. Traffic&Redesign 55 LCC Pakistan
  56. 56. Layer2&3 involved in Call setup Traffic&Redesign 56 LCC Pakistan
  57. 57. Call Setup Measurements Layer3 • RR Management Message • MM Management Message • CM Management Message Layer2 • • • • • • • • RR-RSP I-CMD SABM-CMD UA-RSP DISC-CMD Call Setup Call Establishment Call End Traffic&Redesign 57 LCC Pakistan
  58. 58. Layer3 Message…. RR Management Message Traffic&Redesign 58 LCC Pakistan
  59. 59. RR …Paging Message Structure Protocol Discriminator The Channel Field (bits 1-2 of octet 2) indicates the further combination of channel which will be needed. It is coded as follows Traffic&Redesign 59 LCC Pakistan
  60. 60. Channel Needed To indicate what type of channel is required for the transaction linked to the paging procedure. First Channel 00 Any channel 01 SDCCH 10 TCH/F 11 TCH/H or TCH/F Second Channel Same as first channel RR-Paging Message • Paging Request Type1 Page mode • To control the action of MS belonging to the paging subgroup corresponding to the paging subchannel. Page Mode 00 Normal Paging 01 Extended Paging 10 Paging Re organisation 11 Same as before Mobile Identity • To provide either the IMSI, the (P) TMSI but not the IMEI bases paging. IMSI <= 15 digts (P) TMSI= 4 Octets • Odd/even indication Value 0 : Even number of identity digits ( • Traffic&Redesign 60 Type of Identity LCC Pakistan
  61. 61. Paging Request Type2 Traffic&Redesign 61 LCC Pakistan
  62. 62. Paging Request Type3 Traffic&Redesign 62 LCC Pakistan
  63. 63. RR… System Information 1. 2. 3. PD for System Information is always 6. Skip Indicator is 0000 Message Type as below Protocol Traffic&Redesign 63 Discriminator LCC Pakistan
  64. 64. System Information in Idle Mode Traffic&Redesign 64 LCC Pakistan
  65. 65. System Information Type1 Traffic&Redesign 65 LCC Pakistan
  66. 66. System Information Type1 Traffic&Redesign 66 LCC Pakistan
  67. 67. System Information Type2 Traffic&Redesign 67 LCC Pakistan
  68. 68. System Information Type2 Traffic&Redesign 68 LCC Pakistan
  69. 69. System Information Type 2ter Traffic&Redesign 69 LCC Pakistan
  70. 70. System Information Type 2ter Traffic&Redesign 70 LCC Pakistan
  71. 71. System Information Type3 Traffic&Redesign 71 LCC Pakistan
  72. 72. System Information Type3 Traffic&Redesign 72 LCC Pakistan
  73. 73. System Information Type3 Traffic&Redesign 73 LCC Pakistan
  74. 74. System Information Type4 Traffic&Redesign 74 LCC Pakistan
  75. 75. System Information Type4 Traffic&Redesign 75 LCC Pakistan
  76. 76. System Information Type4 Traffic&Redesign 76 LCC Pakistan
  77. 77. System Information in Dedicated Mode Traffic&Redesign 77 LCC Pakistan
  78. 78. System Information Type5 Traffic&Redesign 78 LCC Pakistan
  79. 79. System Information Type5 Traffic&Redesign 79 LCC Pakistan
  80. 80. System Information Type6 Traffic&Redesign 80 LCC Pakistan
  81. 81. System Information Type 6 Traffic&Redesign 81 LCC Pakistan
  82. 82. RR…Channel Request Establishment cause (3 bit). • Answer to page • MOC/MTC • Location update • SMS NECI Parameters setting is explain in next slide Channel Request Message Format Random Reference • MS Generate Random Number (3...5bit) by Using Random algorithm. • Number slot spread Tran • No of Max Retransmission Traffic&Redesign 82 LCC Pakistan
  83. 83. Channel Request Message…. Enable NECI Disable NECI Traffic&Redesign 83 LCC Pakistan
  84. 84. Immediate Assignment Channel Control Parameters • Separated/Combined/Hybrid Channel configuration. • Training Sequence Code(0..7) After a suitable channel has been found, the BSC determines the most suitable training sequence code by examining all the interfering connections(C/I based). • RF Hopping Channel(Hopping List) Establishment cause is a 3 bit. • Answer to page • MOC/MTC • Location update • SMS NECI(New establishment cause Indication) is disabled. • Timing Advance is a access delay. (1 TA=550M) • MA List Traffic&Redesign 84 LCC Pakistan
  85. 85. CM Service Request CM Service Type To specify which service is requested from network Mobile Station Class mark • Define certain attributes of the MS equipment in use on a certain transaction. Mobile Identity • Traffic&Redesign 85 LCC Pakistan
  86. 86. Mobile Station Class mark • Define certain attributes of the MS equipment in use on a certain transaction. • Revision Level • Establish Indication • Encryption Algorithm • RF Power Capability • SOLSA (Support of localized service area) • VBS/VGCS • CM Service Prompt • SM Capability • Traffic&Redesign 86 LCC Pakistan
  87. 87. Cipher Response Traffic&Redesign 87 LCC Pakistan
  88. 88. Traffic&Redesign 88 LCC Pakistan
  89. 89. call setup Traffic&Redesign 89 LCC Pakistan
  90. 90. Call Processing or Call Progress Traffic&Redesign 90 LCC Pakistan
  91. 91. Assignment Command Traffic&Redesign 91 LCC Pakistan
  92. 92. Assignment Command Traffic&Redesign 92 LCC Pakistan
  93. 93. Assignment Command Traffic&Redesign 93 LCC Pakistan
  94. 94. Assignment Command… Traffic&Redesign 94 LCC Pakistan
  95. 95. Traffic&Redesign 95 LCC Pakistan
  96. 96. Traffic&Redesign 96 LCC Pakistan
  97. 97. Traffic&Redesign 97 LCC Pakistan
  98. 98. Traffic&Redesign 98 LCC Pakistan
  99. 99. Measurement Report Message format Traffic&Redesign 99 LCC Pakistan
  100. 100. Measurements Report (MS Report after each 480ms) If the list of the Neighboring cells is changed by the operator ,this parameters (set=0,1) toggles. it tells the locating algorithm in the BSC which neighboring cells description the MS has used , that is updated or old one. The MS must send continuous measurement reports but for some reason if MS does not have measurement , it can indicate to the network with this bit. These Element contains the averaged received signal Quality of the serving cells on all time slots and on subset of time slots. The signal quality mapped to a corresponding BER% value before decoding as follows. RX Qual 0= BER<0.2% RX Qual1=BER 0.2% to 0.4% . . . RX Qual 7=BER>12.8%. Traffic&Redesign This bit indicate if the MS used Discontinuous Transmission on the uplink. If 1 Dtx used, 0 is not used These elements contains the averaged received signal strength, BCCH, & Basic of the nth(n=1 to 6) Neighbor cells. • BCCH Allocation List….set to 1 in neighbor cells parameters description. • with 5 bits (0..31) • BSIC consist of 6 bits 100 These Element contains the averaged received signal level of the serving cells on all time slots and on subset of time slots. The signal strength mapped on RX Level value between 0..63. RX Level 0= less than -110dbm RX Level 1=-110dbm to -109dbm. . . . RX Level 63=greater than -48dbm. LCC Pakistan
  101. 101. Traffic&Redesign 101 LCC Pakistan
  102. 102. Traffic&Redesign 102 LCC Pakistan
  103. 103. Traffic&Redesign 103 LCC Pakistan
  104. 104. Traffic&Redesign 104 LCC Pakistan
  105. 105. HO Procedure Traffic&Redesign 105 LCC Pakistan
  106. 106. Location Updated Traffic&Redesign 106 LCC Pakistan
  107. 107. Question&Answer Open Discussion… Traffic&Redesign 107 LCC Pakistan

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