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GSM Fundamentals Asiacell Telecom Platform Course 1 GSM Fundamentals.

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1 GSM Fundamentals Asiacell Telecom Platform Course 1 GSM Fundamentals

2 Asiacell Telecom Platform Course 2 Contents Basic Concepts of Cellular Mobile System GSM Network Components Terrestrial Interface Service Area and Number Planning Channels on The Air Interface Radio Techniques The Future Development

3 GSM Fundamentals Asiacell Telecom Platform Course GSM Development Standard Protocol for GSM take effect System was named as Global System for Mobile Communication GSM system began to provide service in Europe(2G) Provide services for the whole world Micro Cell Technique is used in GSM system

4 GSM Fundamentals Asiacell Telecom Platform Course 4 Channel Bandwidth: 200KHz Duplex Separation: 45 MHz The Frequency Spectrum MHz GSMEGSMGSMEGSM Uplink Downlink

5 GSM Fundamentals Asiacell Telecom Platform Course 5 Frequency Spectrum in GSM System ARFCN: Absolute Radio Frequency Channel Number

6 GSM Fundamentals Asiacell Telecom Platform Course 6 Frequency Allocation in Iraq ARFCN: Absolute Radio Frequency Channel Number GSM900 Operator Frequency Bandwidth Channel Number ARFCN UpLinkDownLink Zain MHz and Korek MHz Asiacell MHz GSM1800 Operator Frequency Bandwidth Channel Number ARFCN UpLinkDownLink Zain MHz Korek MHz Asiacell MHz

7 GSM Fundamentals Asiacell Telecom Platform Course 7 Cell Structure degree Omni Cell Sector Cell 120 degree 120 degree

8 GSM Fundamentals Asiacell Telecom Platform Course 8 Cell Structural in Sulymaniyah

9 GSM Fundamentals Asiacell Telecom Platform Course 9 Frequency Re-Use Because frequency resource of mobile system is very limited, The different Subscribers must use the same frequency in different place. Of course, the quality of communication must be ensured. What is Frequency Re-Use?

10 GSM Fundamentals Asiacell Telecom Platform Course 10 Frequency Re-Use How can we reuse frequency? 7(Site)X 1(Cell) Re-use

11 GSM Fundamentals Asiacell Telecom Platform Course 11 Frequency Re-Use 4(Site)X 3(Cell) Re-use

12 GSM Fundamentals Asiacell Telecom Platform Course 12 Contents Basic Concepts of Cellular Mobile System GSM Network Components Terrestrial Interface Service Area and Number Planning Channels on The Air Interface Radio Techniques The Future Development

13 GSM Fundamentals Asiacell Telecom Platform Course 13 GSM Network Components BTS BSC BTS BSC SS7 SMS system PSTN ISDN MSC/VLR GMSC HLR/AUC Other PLMN MS BTS MS M2000 Server

14 GSM Fundamentals Asiacell Telecom Platform Course 14 Mobile StationMS International Mobile Equipment Identity (IMEI) – Mobile Equipment MS=ME+SIM International Mobile Subscriber Identity (IMSI) – Subscriber Identity Module

15 GSM Fundamentals Asiacell Telecom Platform Course 15 Subscriber Identity Module – SIM International Mobile Subscriber Identity (IMSI) Temporary Mobile Subscriber Identity (TMSI) Location Area Identity (LAI) Subscriber Authentication Key (Ki) International Mobile Subscriber Identity (IMSI) Temporary Mobile Subscriber Identity (TMSI) Location Area Identity (LAI) Subscriber Authentication Key (Ki) * PIN and PUK are used to SIM security

16 GSM Fundamentals Asiacell Telecom Platform Course 16 Base Station Subsystem (BSS) - Base Station Controller (BSC) - Base Transceiver Station (BTS) - Transcoder and Sub multiplexer (TCSM) or Transcoder and Rate Adaptation Unit (TRAU) BTS BSC BTS TCSMMSC/VLR BSS MS

17 GSM Fundamentals Asiacell Telecom Platform Course 17 Base Transceiver Station (BTS) BTS (Base Transceiver Station): Transmit & Receive signal with MS then transfer to Base Station Controller (BSC) Signal Process: Speech Coding, Channel Coding, Interleaving, Ciphering, Modulation However, one BTS has coverage area limited. Size of coverage area depend on population of subscriber. A unit of coverage area is called Cell BTS BSC BTS MS

18 GSM Fundamentals Asiacell Telecom Platform Course 18 Base Station Controller (BSC) BSC: Store cell information and parameter: eg. Cell ID, BSIC, Cell frequency (ARFCN), Output power Control BTS to process: eg. Call set up, Handover Process, Frequency Hopping, Power Control. Receive BTS alarm and send BTS & BSC alarm to OMC Measurement traffic statistic Remote BTS O&M via BSC BTS BSC BTS BSC MS

19 GSM Fundamentals Asiacell Telecom Platform Course 19 Transcoder and Sub-Multiplexer

20 GSM Fundamentals Asiacell Telecom Platform Course 20 Network Switching System (NSS) SS7 PSTN ISDN Other PLMN MSC/VLRGMSC HLR/AUC EIR NSS MSC = Mobile Switching Center GMSC = Gateway MSC HLR = Home Location Register IWF = Inter-Working Function VLR = Visitor Location Register AuC = Authentication Center EIR = Equipment Identity Register EC = Echo Canceller BSS EC IWF

21 GSM Fundamentals Asiacell Telecom Platform Course 21 Mobile Service Switching Center – MSC Call Processing Operations and Maintenance Support Inter-network & Inter-working Billing Call Processing Operations and Maintenance Support Inter-network & Inter-working Billing

22 GSM Fundamentals Asiacell Telecom Platform Course 22 Home Location Register (HLR) Subscriber ID (IMSI and MSISDN) Current subscriber VLR (current location) Supplementary service information Subscriber status (registered/deregistered) Authentication key and AuC functionality Subscriber ID (IMSI and MSISDN) Current subscriber VLR (current location) Supplementary service information Subscriber status (registered/deregistered) Authentication key and AuC functionality

23 GSM Fundamentals Asiacell Telecom Platform Course 23 Visitor Location Register – VLR Mobile Status (IMSI detached/ attached / busy / idle etc) Location Area Identity(LAI) Temporary Mobile Subscriber Identity (TMSI) Mobile Station Roaming Number (MSRN) Mobile Status (IMSI detached/ attached / busy / idle etc) Location Area Identity(LAI) Temporary Mobile Subscriber Identity (TMSI) Mobile Station Roaming Number (MSRN)

24 GSM Fundamentals Asiacell Telecom Platform Course 24 IMEI Is Checked against White List IMEI Is Checked against Black/Grey List If NOT found EIR focus on the equipment, not the subscriber!! White List Black List Grey List Equipment Identity Register – EIR

25 GSM Fundamentals Asiacell Telecom Platform Course 25 Authentication Center (AuC) KI M) KI N) IMSI(m) RAND GENERATOR A8 A3 KI(IMSI) IMSIBUFFER RAND KC SRES TEMP DATA AUC HLR AUTH REQ RAND KC SRES RAND A8 A3 SRES EQUAL CKSN KC BSS KI(IMSI) VLR SIM RAND 16byte KI 16byte kc 8byte SRES 4byte CKSN low 3bits of 1byte IMSI(n) SRES

26 GSM Fundamentals Asiacell Telecom Platform Course 26 Rate Conversion Protocol Adaptation PSTN MSC EC IWF Inter-Working Function – IWF Eg. Fax, Modem

27 GSM Fundamentals Asiacell Telecom Platform Course 27 Echo takes place by GSM system delay caused by call processing,speech encoding and decoding etc. An Echo Canceller is used on the PSTN side of the MSC for all voice circuits 2-wire 4-wire 2-wire Hybrid Generation of Echo at 2-wire to 4-wire Interface Echo Canceller EC

28 GSM Fundamentals Asiacell Telecom Platform Course 28 NOC OMC Region2 Region 1 Region 3 Operation and Maintenance Sub System

29 GSM Fundamentals Asiacell Telecom Platform Course 29 OMC Functional Architecture OS MMI DB Event/Alarm Management Security Management Configuration Management Performance Management Fault Management

30 GSM Fundamentals Asiacell Telecom Platform Course 30 Example: Baghdad OMC

31 GSM Fundamentals Asiacell Telecom Platform Course 31 Contents Basic Concepts of Cellular Mobile System GSM Network Components Terrestrial Interface Service Area and Number Planning Channels on The Air Interface Radio Techniques The Future Development

32 GSM Fundamentals Asiacell Telecom Platform Course 32 HLR VLR MSC EIR AUC ECIWF TC VLR MSC IWF EC BTSBSC MS B H F G A E C D Um Abis GSM Interface

33 GSM Fundamentals Asiacell Telecom Platform Course 33 CM: Call Management MM: Mobility Management RR: Radio Resource Management LAPDm: LAPD modified LAPD: Link Access Procedure on D Channel BTSM: BTS Site Management MTP: Message Transfer Part SCCP: Signaling Connection Control Part BSSMAP: BSS Management Application Part GSM Protocol Stack

34 GSM Fundamentals Asiacell Telecom Platform Course 34 OSI Layers 7. Application 6. Presentation 5. Session 4. Transport 3. Network 2. Link 1 Physical CCS7 Levels MTP Level 1 2 Mb/s Trunk MTP Level 3 TUP SCCP BSSAP (DTAP+BSSMAP) ISUP MAP TCAP MTP Level 2 ITU Signaling System CCS7

35 GSM Fundamentals Asiacell Telecom Platform Course 35 Abbreviation of CCS7 MTPMessage Transfer Part TCAP Transaction Capabilities Application Part SCCPSignaling Connection Control Part TUP Telephone User Part ISUP ISDN User Part MAP Mobile Application Part BSSAP Base Station System Application Part BSSMAP BSS Management Application Part DTAP Direct Transfer Application Part MTPMessage Transfer Part TCAP Transaction Capabilities Application Part SCCPSignaling Connection Control Part TUP Telephone User Part ISUP ISDN User Part MAP Mobile Application Part BSSAP Base Station System Application Part BSSMAP BSS Management Application Part DTAP Direct Transfer Application Part

36 GSM Fundamentals Asiacell Telecom Platform Course 36 Typical Configuration TS 0TS 1-15TS16TS TS = Time slot TS# Used for Synchronization / Clock Traffic CCS7 Signaling (Other TS may also the used) Traffic 2MBps Trunks

37 GSM Fundamentals Asiacell Telecom Platform Course 37 HLR MSC/VLR EIR AUC EC OMC MSC/VLR TC IWF EC BSC PSTN BTS SigL1: 2MBps Trunks

38 GSM Fundamentals Asiacell Telecom Platform Course 38 CCS7 Interface

39 GSM Fundamentals Asiacell Telecom Platform Course 39 LAPD Interface

40 GSM Fundamentals Asiacell Telecom Platform Course 40 Contents Basic Concepts of Cellular Mobile System GSM Network Components Terrestrial Interface Service Area and Number Planning Channels on The Air Interface Radio Techniques The Future Development

41 GSM Fundamentals Asiacell Telecom Platform Course 41 Service Area PLMN service area System area PLMN service area MSC service area... Location area... Base station area... Radio cell MSC service area... Location area... Base station area... Radio cell PLMN service area

42 GSM Fundamentals Asiacell Telecom Platform Course 42 MSC/VLR Number The format is CC+NDC+LSP CC Country Code. For example: The CC of Iraq is 964". NDC National Destination Code. For example: The NDC of AsiaCell is 770. LSP (locally significant part): is defined by Telecom operator. For example: CC NDCLSP MSC/VLR number

43 GSM Fundamentals Asiacell Telecom Platform Course 43 HLR Number The format is CC + NDC + LSP. CC Country Code. For example: The CC of Iraq is 964". NDC National Destination Code. For example: The NDC of Asiacell is 770 LSP (locally significant part): is defined by Telecom operator. For example: The format is CC + NDC + LSP. CC Country Code. For example: The CC of Iraq is 964". NDC National Destination Code. For example: The NDC of Asiacell is 770 LSP (locally significant part): is defined by Telecom operator. For example:

44 GSM Fundamentals Asiacell Telecom Platform Course 44 LAI Location Area Identification The LAI is the international code for a location area. MCC Mobile Country Code It consists of 3 digits. For example: The MCC of Iraq is 418" MNC Mobile Network Code It consists of 2 digits. For example: The MNC of Asiacell is "05" LAC Location Area Code It is a two bytes BCD code(hex). The value 0000 and FFFF is invalid. For example: AB MCC Mobile Country Code It consists of 3 digits. For example: The MCC of Iraq is 418" MNC Mobile Network Code It consists of 2 digits. For example: The MNC of Asiacell is "05" LAC Location Area Code It is a two bytes BCD code(hex). The value 0000 and FFFF is invalid. For example: AB MCC MNCLAC E.164 = CC + NDC + … (MSC/VLR, HLR, MSISDN) E.212 = MCC + MNC + … (IMSI)

45 GSM Fundamentals Asiacell Telecom Platform Course 45 CGI The CGI is a unique international identification for a cell The format is LAI+CI LAI: Location Area Identification CI Cell Identity. This code uses two bytes BCD code(hex) to identify the radio cells within an LAI. For example : AB-CD98 The CGI is a unique international identification for a cell The format is LAI+CI LAI: Location Area Identification CI Cell Identity. This code uses two bytes BCD code(hex) to identify the radio cells within an LAI. For example : AB-CD98 CGI: Cell Global Identification

46 GSM Fundamentals Asiacell Telecom Platform Course 46 BSIC NCC PLMN network color code. It comprises 3 bit. It allows various neighboring PLMNs to be distinguished. BCC BTS color code. It comprises 3 bit. It allows distinction between different radio frequency channels using the same frequency in neighboring cells. NCC PLMN network color code. It comprises 3 bit. It allows various neighboring PLMNs to be distinguished. BCC BTS color code. It comprises 3 bit. It allows distinction between different radio frequency channels using the same frequency in neighboring cells. NCC BCC BSIC BSIC Base Station Identification Color Code)

47 GSM Fundamentals Asiacell Telecom Platform Course 47 CC Country Code. For example: The CC of Iraq is 964". NDC National Destination Code. For example: The NDC of Asiacell is 770. SN Subscriber Number. Format:H0 H1 H2 ABCD Example: CC Country Code. For example: The CC of Iraq is 964". NDC National Destination Code. For example: The NDC of Asiacell is 770. SN Subscriber Number. Format:H0 H1 H2 ABCD Example: MSISDN CC NDCSN National (significant) Mobile number Mobile station international ISDN number

48 GSM Fundamentals Asiacell Telecom Platform Course 48 MCC Mobile Country Code It consists of 3 digits. For example: The MCC of Iraq is 418" MNC Mobile Network Code It consists of 2 digits. For example: The MNC of Asiacell is "05" MSIN Mobile Subscriber Identification Number. H1H2H3 ABCDEFG For example: NMSI National Mobile Subscriber Identification MNC and MSIN form it together. For Example of IMSI : MCC Mobile Country Code It consists of 3 digits. For example: The MCC of Iraq is 418" MNC Mobile Network Code It consists of 2 digits. For example: The MNC of Asiacell is "05" MSIN Mobile Subscriber Identification Number. H1H2H3 ABCDEFG For example: NMSI National Mobile Subscriber Identification MNC and MSIN form it together. For Example of IMSI : Not more than 15 digits 3 digits2 digits IMSI MCCMNC MSIN NMSI IMSI

49 GSM Fundamentals Asiacell Telecom Platform Course 49 The TMSI is assigned only after successful subscriber authentication. The VLR controls the allocation of new TMSI numbers and notifies them to the HLR. TMSI is used to ensure that the identity of the mobile subscriber on the air interface is kept secret. The TMSI consists of 4 bytes( 8 HEX numbers) and determined by the telecom operator. The TMSI is assigned only after successful subscriber authentication. The VLR controls the allocation of new TMSI numbers and notifies them to the HLR. TMSI is used to ensure that the identity of the mobile subscriber on the air interface is kept secret. The TMSI consists of 4 bytes( 8 HEX numbers) and determined by the telecom operator. TMSI TMSI: Temporary Mobile Subscriber Identification)

50 GSM Fundamentals Asiacell Telecom Platform Course 50 IMEI TAC FACSNR SP IMEI TAC Type approval code, 6 bit. It is administered by the type approval center. FAC Final assembly code, 2 bit. It is administered by the manufacturer. SNR Serial number, 6 bits. It is issued by the manufacturer of the MS. SP 1 bit, Not used. TAC Type approval code, 6 bit. It is administered by the type approval center. FAC Final assembly code, 2 bit. It is administered by the manufacturer. SNR Serial number, 6 bits. It is issued by the manufacturer of the MS. SP 1 bit, Not used. IMEI: International Mobile Station Equipment Identification Check IMEI by *#06#

51 GSM Fundamentals Asiacell Telecom Platform Course 51 MSRN/HON The MSRN is used to route the call to the MSC which MS is currently located. The HON is used by the MSC-A to set up a connection to the MSC-B during handover process Usually, MSRN and HON share the same numbering plan. The format is CC+NDC+individual number. CC and NDC is the same as that of MSISDN. The individual number is taken from a pool of numbers specially reserved for MSRN. The MSRN is used to route the call to the MSC which MS is currently located. The HON is used by the MSC-A to set up a connection to the MSC-B during handover process Usually, MSRN and HON share the same numbering plan. The format is CC+NDC+individual number. CC and NDC is the same as that of MSISDN. The individual number is taken from a pool of numbers specially reserved for MSRN. MSRN: Mobile Subscriber Roaming Number HON: Hand-over Number

52 GSM Fundamentals Asiacell Telecom Platform Course 52 Contents Basic Concepts of Cellular Mobile System GSM Network Components Terrestrial Interface Service Area and Number Planning Channels on The Air Interface Radio Techniques The Future Development

53 GSM Fundamentals Asiacell Telecom Platform Course Multiple Access Technique Multiple Access Technique allows many subscribers to use the same communication medium. There are three kinds of basic Multiple Access Technique : FDMA, TDMA and CDMA. GSM system adopt FDD-TDMA (FDMA and TDMA together).

54 GSM Fundamentals Asiacell Telecom Platform Course FDMA FDMA uses different frequency channels to accomplish communication. The whole frequency spectrum available is divided into many individual channels (for transmitting and receiving) every channel can support the traffic for one subscriber or some control information. Frequency Time

55 GSM Fundamentals Asiacell Telecom Platform Course TDMA TDMA accomplishes the communication in different timeslot. A carrier is divided into channels based on time. Different signals occupy different timeslots in certain sequence, that is, many signals are transmitted on the same frequency in different time. Time Frequency

56 GSM Fundamentals Asiacell Telecom Platform Course CDMA CDMA accomplishes the communication in different code sequences. Special coding is adopted before transmission, then different information will lose nothing after being mixed and transmitted together on the same frequency and at the same time. Time Frequency Code

57 GSM Fundamentals Asiacell Telecom Platform Course 57 Physical Channel and Logical Channels The physical channel is the medium over which the information is carried: 200KHz and 0.577ms 01 TDMA FRAME Timeslot The information carried in one time slot is called a burst The information carried in one time slot is called a burst The logical channel consists of the information carried over the physical channels TDMA FRAME

58 GSM Fundamentals Asiacell Telecom Platform Course Two types of Logical Channel Traffic Channel (TCH) : Transmits traffic information, include data and speech. Control Channel (CCH) : Or Signaling Channel, transmits all kinds of control information.

59 GSM Fundamentals Asiacell Telecom Platform Course 59 Traffic Channel (TCH) TCH Traffic Channels Speech TCH/FS Data TCH/HS TCH/9.6TCH/2.4 TCH/4.8 Normal Burst TCH Traffic Channel TCH/FS Full rate Speech Channel TCH/HS Half rate Speech Channel TCH/9.6 Data Channel 9.6kb/s TCH/4.8 Data Channel 4.8kb/s TCH/2.4 Data Channel 2.4Kb/s

60 GSM Fundamentals Asiacell Telecom Platform Course 60 FCCH SCH CCH Control Channels DCCH SDCCH BCCH Synch. CH. ACCH SACCHFACCH CCCH RACH CBCH PCH/AGCH Broadcast Control Channel – BCCH Common Control Channel – CCCH Dedicated Control Channel – DCCH Associated Control Channel – ACCH Control Channel (CCH)

61 GSM Fundamentals Asiacell Telecom Platform Course 61 CCH BCCH downlink only BCCH Synch. Channels SCHFCCH The information carried on the BCCH is monitored by the MS periodically when it is in idle mode BCCH: Broadcast Control Channel FCCH: Frequency Correction Channel SCH: Synchronization Channel The information carried on the BCCH is monitored by the MS periodically when it is in idle mode BCCH: Broadcast Control Channel FCCH: Frequency Correction Channel SCH: Synchronization Channel Broadcast Control Channel – BCCH

62 GSM Fundamentals Asiacell Telecom Platform Course 62 CCH CCCH RACH uplink CBCH downlink PCH/AGCH downlink The CCCH is responsible for transferring control information between all mobiles and the network. RACH: Random Access Control Channel PCH: Paging Channel AGCH: Access Grant Control Channel CBCH: Cell Broadcast Channel The CCCH is responsible for transferring control information between all mobiles and the network. RACH: Random Access Control Channel PCH: Paging Channel AGCH: Access Grant Control Channel CBCH: Cell Broadcast Channel Common Control Channel – CCCH

63 GSM Fundamentals Asiacell Telecom Platform Course 63 CCH DCCH SDCCH FACCH SACCH DCCH is assigned to a single mobile connection for call setup or for measurement and handover purpose. SDCCH: Standalone Dedicated Control Channel ACCH: Associated Control Channel SACCH: Slow Associated Control Channel FACCH: Fast Associated Control Channel DCCH is assigned to a single mobile connection for call setup or for measurement and handover purpose. SDCCH: Standalone Dedicated Control Channel ACCH: Associated Control Channel SACCH: Slow Associated Control Channel FACCH: Fast Associated Control Channel ACCH Dedicated Control Channel – DCCH

64 GSM Fundamentals Asiacell Telecom Platform Course Uplink Logical channel RACH CCCH CCH SDCCH SACCH FACCH TCH/F TCH/H DCCH TCH DCH

65 GSM Fundamentals Asiacell Telecom Platform Course Downlink Logical channel FCCH SCH BCCH PCH AGCH BCCH CCCH CCH SDCCH SACCH FACCH TCH/F TCH/H DCCH TCH DCH

66 GSM Fundamentals Asiacell Telecom Platform Course 66 Search for frequency correction pulse Search for synchronous pulse Unscramble system information Snoop into paging message Send access pulse Allocate signaling channel Set up the call Allocate voice channel Conversation Release the call FCCH SCH BCCH PCH RACH AGCH SDCCH FACCH TCH FACCH Power-off state Idle state Dedicated mode Idle state How to use these channel?

67 GSM Fundamentals Asiacell Telecom Platform Course 67 GSM Logical Channel Channel Combination Main BCCH combination – BCCH + CCCH SDCCH combination – SDCCH8 + SACCH8 Combined BCCH – BCCH + CCCH +SDCCH4 + SACCH4 TCH combination – TCH/FACCH + SACCH

68 GSM Fundamentals Asiacell Telecom Platform Course 68 TDMA Frames – Frame Multiframes CONTROL CHANNELS GSM Multiframe

69 GSM Fundamentals Asiacell Telecom Platform Course 69 BCCH/CCCH Multiframe FS BBBB CCCCF FSCCCCCCCC I Downlink S C C.. F S C C.. F S C C.. RRRRRRRRRRRRRRRRRRRRRR Uplink R R R.. R R R..R R R F = FCCH (Frequency) S = SCH (Sync.) C = CCCH (Common) I = Idle R = RACH (Random)

70 GSM Fundamentals Asiacell Telecom Platform Course 70 D0D1D7A0A3III D0D1D6D7A4A7III A5A6D0D7A0A7III A1A2D0D7A4A3III Downlink Uplink D = SDCCH/8 (Dedicated) A = SACCH/C8 (Associated) I = Idle D6 SDCCH Multiframe

71 GSM Fundamentals Asiacell Telecom Platform Course 71 Timeslots and TDMA Frames Higher Capacity Cell Broadcast Traffic Dedicated Traffic Low Capacity Cell Combined Traffic

72 GSM Fundamentals Asiacell Telecom Platform Course 72 Combined Multiframe

73 GSM Fundamentals Asiacell Telecom Platform Course 73 GSM Multiframe TDMA Frames – Frame Multiframes TRAFFIC CHANNELS

74 GSM Fundamentals Asiacell Telecom Platform Course 74 TCH Multiframe IDLE SACCH IDLE SACCH This is used to transmit a Traffic Channel Combination (TCH/ SACCH/FACCH). The FACCH is not showed in the diagram as it does not receive its own time allocation. The FACCH steals a time period from the TCH is required. The 13th frame is used by the SACCH which carriers link control information to and from the mobile and BTS. The 26th frame is idle. This is used to transmit a Traffic Channel Combination (TCH/ SACCH/FACCH). The FACCH is not showed in the diagram as it does not receive its own time allocation. The FACCH steals a time period from the TCH is required. The 13th frame is used by the SACCH which carriers link control information to and from the mobile and BTS. The 26th frame is idle. DownlinkUplink

75 GSM Fundamentals Asiacell Telecom Platform Course 75 Superframe and Hyperframe

76 GSM Fundamentals Asiacell Telecom Platform Course 76 Contents Basic Concepts of Cellular Mobile System GSM Network Components Terrestrial Interface Service Area and Number Planning Channels on The Air Interface Radio Techniques The Future Development

77 GSM Fundamentals Asiacell Telecom Platform Course 77 Modulation Techniques – phase modulation can be implemented easily for digital signals, this is the method which is used for the GSM air interfaces. Phase Modulation is known as Phase Shift Keying when applied to digital signals Amplitude Modulation (AM) Frequency Modulation (FM) Phase Modulation (PM)

78 GSM Fundamentals Asiacell Telecom Platform Course Gaussian Digital Filter Phase Modulator Gaussian Minimum Shift Keying (GMSK)

79 GSM Fundamentals Asiacell Telecom Platform Course 79 Power Control Saves radio battery power Reduces co-channel and adjacent channel interference 8W 0.8W 5W Both Uplink and Downlink power settings can be controlled independently and individually.

80 GSM Fundamentals Asiacell Telecom Platform Course VAD and DTX Voice Activity Detection – VAD Discontinuous Transmission – DTX Battery Saving Interference reduction

81 GSM Fundamentals Asiacell Telecom Platform Course 81 Multipath Fading Diversity Frequency Hopping Time Dispersion

82 GSM Fundamentals Asiacell Telecom Platform Course 82 Diversity When diversity is implemented two antennas are situated at the receiver. These antennas are placed several wavelengths apart to ensure minimum correlation between the two receive paths. The two signals are then combined, this ensures that a low signal strength is less likely to occur. Compare or add signals Resultant Signal Approx. 10 wavelengths

83 GSM Fundamentals Asiacell Telecom Platform Course 83 Frequency Hopping Synthesizer Hopping:each timeslot on a given transceiver can transmit at a different frequency Baseband Hopping: each transceiver stays at the same frequency and the data is switched to the appropriate transceiver. Each time the BTS or mobile transmits a burst, it does so on a different RF carrier frequency. time frequency

84 GSM Fundamentals Asiacell Telecom Platform Course 84 Contents Basic Concepts of Cellular Mobile System GSM Network Components Terrestrial Interface Service Area and Number Planning Channels on The Air Interface Radio Technologies The Future Development

85 GSM Fundamentals Asiacell Telecom Platform Course 85 GSM User World Wide Millions Fixed line (dial-up) subscribers Mobile subscribers PC/NC Internet users Mobile Internet users Mobile Internet access overtakes fixed 500m Mobile users Mobile usage overtakes fixed Mobile will be the most prolific form of access to internet-based information, content and services Source: Ericsson Business Consulting

86 GSM Fundamentals Asiacell Telecom Platform Course 86 Number of Wireless Subscribers* *Update Q1, 2009 from Iraq Asiacell6,686,140 Zain10,111,000 Korek Telecom665,361 Sanatel361,431 Thailand AIS27,581,800 DTAC18,945,227 TRUE15,004,000 China China Mobile477,160,000 China Unicom133,365,000 World 4,153,784,344

87 GSM Fundamentals Asiacell Telecom Platform Course 87 Technology Roadmap TECHNOLOGY DATA SPEED Kbit/s Up to 2Mb/s? DEVICES GSM (2G) WAP HSCSD GPRS (2.5G) EDGE (2.75G) UMTS (3G)

88 GSM Fundamentals Asiacell Telecom Platform Course 88 Mobile Service Evolution Basic text messaging Hi, Ill see you at 6 PM Regards, Bob Messaging Black and white screens, simple graphics Browsing Instant connectivity, color screen, WAP Push xHTML for WAP and web integration, animated content Ringing tones, icons, screensavers, business cards Downloading Downloadable applications, MIDI sounds Video content (MMS, streaming) Multimedia messaging with video Dial-up connection s Accelerated connections, voice and data multitasking Corporate access Always-on, performance and security enhancements Multimedia messaging with pictures and audio

89 GSM Fundamentals Asiacell Telecom Platform Course 89 Basic Concepts of Cellular Mobile System GSM Network Components Terrestrial Interface Service Area and Number Planning Channels on The Air Interface Radio Techniques The Future Development Summary

90 GSM Fundamentals Asiacell Telecom Platform Course 90 By [Technical Trainer] Thank You


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