GSM (GLOBAL SYSTEM FOR MOBILE COMMUNICATION)

1. GSM (GLOBAL SYSTEM FOR MOBILE COMMUNICATION)

2. PRESENTATION PLAN • INTRODUCTION • CELLULAR MOBILE COMMUNICATIONS • GSM NETWORK ARCHITECTURE • MOBILITY AND TRAFFIC MANAGEMENT • GSM PROTOCOLS

3. HISTORY OF WIRELESS COMMUNICATION 1982 CEPT start to develop cell structure 1986 Basic GSM radio tarnsmission technics chosen 1988 The Telecommunication Standarts Instute define GSM 1989 Explanation is finished for GSM Generation 1 1991 First call in GSM

4. 1992 First GSM Network in the world • 1993 GSM Network is reached 32 • 1994 First GSM Network in Africa, • 1995 GSM Network is reached 117 • 1998 120 Million User on the World • 1999 First GPRS • 1998 480 Million User on the World

5. 2003 863 Million User on the World • 2004 3G World Congress • 2007 2.4 Billion user on the world

6. 1st Generation • Start to use in 1989 • Call forwarding • All calls • No answer • Engaged • Unreachable • Outgoing calls barring • Incoming calls barring • Global roaming

7. 2nd Generation • Finished process in 1995 • SMS(Short Message Services) • Multi Party Calling • Call holding • Call waiting • Mobile data service • Mobile fax service • Call line identity • Advice of charging • Cell broadcast

8. 2+ Generation • Start to use in 1998 • Services developed • DECT and GSM • VPN(Virtual Private Network) • Packet Radio • SIM development • Enjoyable services

9. Mobile RadioCellular Mobile Communications

10. Definition • A cellular mobile comms. system uses a large number of low-power wireless transmitters to create cells • Variable power levels allow cells to be sized according to subscriber density and demand within a particular region • As mobile users travel from cell to cell, their conversations are handed off between cells • Channels (frequencies) used in one cell can be reused in another cell some distance away

11. Mobile Comms. Principles • Mobile uses a separate, temporary radio channel to talk to the cell site • Cell site talks to many mobiles at once, using one channel per mobile • Channels use a pair of frequencies for communication • The forward link for transmitting from the cell site • The reverse link for the cell site to receive calls from the users

12. Mobile Comms. Principles • Radio energy dissipates over distance, so mobiles must stay near the base station to maintain communications • Basic structure of mobile networks includes telephone systems and radio services

13. Mobile Comms. Principles • Where mobile radio service operates in a closed network and has no access to the telephone system, mobile telephone service allows interconnection to the telephone network

14. Mobile Comms. Principles • Radio energy dissipates over distance, so mobiles must stay near the base station to maintain communications • basic structure of mobile networks includes telephone systems and radio services

15. Mobile Systems Using Cells • The cellular concept employs variable low-power levels • cells are sized according to the subscriber density and demand in a given area • Cells can be added to accommodate population growth

16. Mobile Systems Using Cells • As with early mobile radio systems, the base station communicates with mobiles via a channel • The channel is made of two frequencies, one for transmitting to the base station and one to receive information from the base station Mobile System using Cellular architecture

17. Cellular System Architecture • In modern cellular telephony, rural and urban regions are divided into areas according to specific provisioning guidelines • Deployment parameters, such as amount of cell-splitting and cell sizes, are determined by engineers experienced in cellular system architecture

18. Cells • A cell is the basic geographic unit of a cellular system • The term cellular comes from the honeycomb shape of the areas into which a coverage region is divided • Cells are base stations transmitting over small geographic areas that are represented as hexagons • Size varies depending on the landscape

19. Clusters • A cluster is a group of cells • No channels are reused within a cluster A seven Cell Cluster

20. Cell Splitting • Allows urban centres to be split into as many areas as necessary for acceptable service levels in heavy-traffic regions, while larger, less expensive cells can be used to cover remote rural regions

21. GSM NETWORK ARCHITECTURE

22. OPEN INTERFACES OF GSM • Network Switching Subsystem(NSS) • Base Station Subsystem(BSS) • Network Management Subsystem(NMS) or Operation and Support Subsystem(OSS) • They connect with Air,A,O&M interfaces

24. MOBILITY FUNCTIONS • Registration and Database • SIM (The Subscriber Identity Module) • Location Update

25. Registration and Database • HLR (Home Location Register) It includes all permanent user’s information • VLR(Visitor Location Register) It includes temporary user’s information according to user’s position • MSC (Mobile Switching Center) It is an integrated structure with phone exchange(Santral)

26. Databases of GSM Network

27. SIM • It includes numbers which provide definition of user for network • It also includes reachable networks list

28. Location Update

29. Procedure of Location Update

30. SET UP CALLS IN GSM NETWORK • +90 400 398 0102 • MSISDN = CC + NDC + SN • CC : Country Code • NDC : National Destination Code • SN : Subscriber Number • GMSC : Gateway Mobile Services Switching Center

31. REACH CALLS FROM PSTN TO GSM NETWORK

32. GUİDE CALL TO GSM NETWORK

33. CONTENT OF HLR • MSISDN • IMSI • They provide the right call, right service IMSI = MCC+MNC+MSIN MCC = Mobile Country Code MNC = Mobile Network Code MSIN = Mobile Sucscriber Identification Number

34. MSRN (Mobile Station Roaming Number) MSRN = CC + NDC + SN CC : Country Code NDC : National Destination Code SN : Subscriber Number 2.MSC wants to MSRN FROM HLR(Left Photo) HLR gives MSRN to MSC for startin call(Right Photo)

35. PROCEDURE OF CALL SET UP

36. Procedure • The number is MSISDN • PSTN central analyse the MSISDN and connect to GMSC • GMSC analyse the MSISDN and send message HLR • HLR control databases and thrust into the user’s location • HLR query MSC/VLR

37. MSC/VLR produce MSRN • MSC/VLR send MSRN to HLR, HLR send it to GMSC • GMSC realise MSC/VLR for forwarding call • MSC/VLR gets MSRN and starts to call • MSC/VLR starts to paging process in location area.The user is found with paging signal and call set up

38. PROCEDURE OF CALL SET UP FROM MOBİLE USER

39. HANDOVER • TWO REASON • When The Radio Signal’s quality and power decreases to necessary scores, the connection deliver to more powerful cell • When The Trraffic Capacity approaches to maximum , the connection deliver to less density of traffic cell

40. SIGNALS AND PROTOCOLS • STANDART MESSAGES • SENDER WANTS TO SERVICE • OPERATOR ASK THAT YOU WANTS TO TALK ,BUT WHICH USER • OPERATOR CONNECT TO RECEIVER • WHEN THE RECEIVER REPLIES TO CALL ,THE CALL STARTS • WHEN THE RECEIVER OR SENDER CLOSE THE PHONE , THE OPERATOR FINISH CONNECTION TO EACH OTHER

41. PROCEDURE OF SIGNALS

42. COMMON CHANNEL SIGNALLING SYSTEM • MTP(MASSAGE TRANSFER PART) • TUP(TELEPHONE USER PART) • SSCP(SIGNALLING CONNECTION AND CONTROL PART)

43. MTP(MASSAGE TRANSFER PART)

44. PHYSICAL CONNECTION It includes data links and their propertie DATA LINK CONTROL It helps to transfer messages between component of network perfectly NETWORK LAYER It provides to transfer messages between component of network

45. TUP(TELEPHONE USER PART)

46. User’s identification • Who get this messages or signals • Who make a process this signal • TUP,NUD,ISUP help to set up calls and they make same task

47. SIGNALLING CONNECTION AND CONTROL PART

48. It provides virtual connections • It guarentee to transfer messages from every signals point to every signals point secure • It provides multi-point communication

49. Briefly • MTP transmit messages • TUP use this messages.It sets up calls,manages calls and finishes calls • SCCP create virtual connections and multi-point communication

50. OTHER SS7 APPLICATION IN GSM NETWORK • BSSAP(Base Station Subsystem Application Part) • MAP (Mobile Application Part) • TCAP (Transaction Capabilities Application Part)