The document discusses the Base Station Subsystem (BSS) and Network and Switching Subsystem (NSS) in mobile communications. The BSS connects the mobile station to the NSS and consists of the Base Transceiver Station (BTS) and Base Station Controller (BSC). The NSS includes the Mobile services Switching Center (MSC), Home Location Register (HLR), and Visitor Location Register (VLR). Together, the BSS and NSS provide critical functions such as mobility management, call control, and short message services that enable mobile communication.

1. IMPLEMENTATION OF BSS AND NSS IN MOBILE COMMUNICATION WHAT IS BSS ? WHAT IS NSS ?

2. GSM Architecture SMSC VMSC GSM Air interface B S AUC A C HLR interface Abis interface MSC PSTN TRAU VLR B BTS S BTS C EIR BTS OMCS BTS BTS BTS Network and switching subsystem Mobile A interface SS7 / speech X.25 Station OMCR SS7 Base Station System

4. Radio Resources management (RR).

5. Mobility Management (MM).

6. Communication Management (CM).

7. Operation, Administration and Maintenance (OAM).FUNCTIONS OF GSM

9. The Mobile Station (MS).

10. The Network and Switching Subsystem (NSS).

11. The Operation and Support Subsystem (OSS)THE GSM NETWORK

13. It connects the Mobile Station and the NSS. It is in charge of the transmission and reception. The BSS can be divided into two parts:

14. The Base Transceiver Station (BTS) or Base Station.

15. The Base Station Controller (BSC).INTRODUCTION TO BSS

17. The Subscriber Identity Module (SIM).

18. The SIM card is protected by a four-digit Personal Identification Number (PIN). In order to identify the subscriber to the system, the SIM card contains some parameters of the user such as its International Mobile Subscriber Identity (IMSI).Mobile Station (MS)

20. The Gateway Mobile services Switching Center (GMSC)

21. Home Location Register (HLR)

22. Visitor Location Register (VLR)

23. The Authentication Center (AuC)

24. The Equipment Identity Register (EIR)

25. The GSM Interworking Unit (GIWU)The Network and Switching Subsystem (NSS)

27. However, the increasing number of base stations, due to the development of cellular radio networks, has provoked that some of the maintenance tasks are transferred to the BTS. This transfer decreases considerably the costs of the maintenance of the system.The Operation and Support Subsystem (OSS)

29. The self test tasks, usually incorporated in the components of the BSS and NSS, also contribute to the OAM functions.

30. The BSC, in charge of controlling several BTS, is another example of an OAM function performed outside the OSS.Operation, Administration and Maintenance (OAM)

32. Short Message Services management Communication Management (CM)

33. The user movements can produce the need to change the channel or cell, especially when the quality of the communication is decreasing. This procedure of changing the resources is called handover. Three different types of handovers can be distinguished: * Handover of channels in the same cell. * Handover of cells controlled by the same BSC. * Handover of cells controlled by different MSCs. What is handover and its importance ?

34. 12 Handover Types GMSC MSC BSC BSC C-3 BSC MSC C-4 C-2 C-1 BSC

35. 13 Intra BSC handover HO performed HO required Activate TCH(facch) with HoRef# if 1. Check for HO passed 2. Channel avail in new BTS Acknowledges and alloctes TCH (facch) Periodic Measurement Reports MS tunes into new frequency and TS and sends HO message to new BTS (facch) HO cmd with HoRef# Receives new BTS data(FACCH) Release TCH Periodic Measurement Reports (SACCH) BSC BTS 2 Periodic Measurement Reports (SACCH) Cell 2 BTS 1 Cell 1

37. Emergency calls

38. Teletex.

39. Short Message Services

40. Fax mail.

41. Voice mail.GSM Services

42. The aim of this Powerpoint presentation was to deliver the importance and the role of BSS and NSS in GSM network. For the time being there is no other such efficient setup that can take place of BSS and NSS Conclusion

44. http://www.itu.int/sites/wwwfiles/tel_wireless.htm

45. A STUDY MODULE FROM NOKIA SIEMENS NETWORKS .REFERENCES

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