The document outlines basic call flows for location updates, mobile originating calls (MOC), mobile terminating calls (MTC), and IP calls. It describes the key steps as: 1) Location update involves identity response, authentication between the SIM and MSC, update location requests, and ciphering. 2) For MOC, the mobile station sends a setup message with the dialed number, the MSC sends a send routing information message to the HLR, and the HLR responds with routing instructions allowing the call to be connected. 3) For MTC, the MSC requests a roaming number from the HLR, the HLR provides a number and the MSC pages the mobile station to alert

1. With traces from Huawei MSOFT

2. BASIC Call Flow
 Basic Call Flow
1. Location Update
2. MOC TDM
3. MOC IP
4. MTC TDM
5. MTC IP

3. Basic Call Flow
Location Update (LOC UP)

4. Location Update

5. LOC Up: Identity Response

6. LOC UP: Authentication

7. LOC UP: AUC Internal Structure
AUC
RANDOM
number
generator
RAND
 IMSI

A3
A8
IMSI ↔Ki
Ki
Kc

MSC
HLR
SRES

 IMSI
 triplet
 triplet

8. LOC UP: Authentication

9. LOC UP: Authentication


SIM
MSC
SRES
?
SRES = SRES
RAND
A3
SRES
Ki
A8
Kc

RAND

RAND
SRES
Kc

10. LOC UP: Authentication Request

11. LOC UP: Authentication Response

12. LOC UP: Update Location Req

13. LOC UP: Insert Subscriber Data

14. LOC: IMEI receive

15. LOC UP: Ciphering

16. LOC UP: TMSI Reallocation

17. Basic Call Flow
Mobile Originating Call
(MOC)

18. MOC: Complete call Trace

19. CM Service Request

20. Setup message contains the dialed number from the Mobile station (MS)
MOC : “Setup” Message

21. MOC: (SRI) Send Routing Information

22. MOC: Reply from HLR

23. Assignment Request

24. MOC: IAM – Initial Address Message

25. MOC: ACM – Address Complete Message

26. MOC: Connect & Release

27. Basic Call Flow
Mobile Terminating Call (MTC)

28. MTC: Complete Trace

29. MTC: Provide Roaming Number (PRN)

30. MTC: PRN Response

31. MTC: IAM

32. Paging Request

33. Paging Response

34. Set UP

35. IP CALL

36. Call Flow through IP( MOC)

37. BICC TYPE IAM

38. TO BICC TYPE APM

39. FROM BICC TYPE APM

40. Call Flow through IP( MTC)

41. PRN

42. PRN Response

43. BICC TYPE IAM

44. Set UP

45. TO BICC TYPE APM

46. FROM BICC TYPE APM

47. Assignment Request

48. ALERT AND BICC TYPE ACM

49. CONNECT AND BICC TYPE ANM

50. DISCONNECT AND RELEASE

51. THANK YOU