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    Gbo 001 E1 1 GSM Basic-40

    Uploaded by

    Clive Mangwiro
    (1) The document provides an overview of GSM including its history, architecture, interfaces and operation bands. (2) It describes key GSM events such as location update, handover, authentication, encryption and initialization. (3) The basic calling process is explained including location update process, outgoing and incoming calls from a mobile station to PSTN, and mobile station to mobile station calls.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PPT, PDF, TXT or read online from Scribd

    Gbo 001 E1 1 GSM Basic-40

    Uploaded by

    Clive Mangwiro
    103 views40 pages
    (1) The document provides an overview of GSM including its history, architecture, interfaces and operation bands. (2) It describes key GSM events such as location update, handover, authentication, encryption and initialization. (3) The basic calling process is explained including location update process, outgoing and incoming calls from a mobile station to PSTN, and mobile station to mobile station calls.

    Original Description:

    GSM basics for Planner a ZTE Document

    Original Title

    Gbo 001 e1 1 Gsm Basic-40

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    © Attribution Non-Commercial (BY-NC)

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    (1) The document provides an overview of GSM including its history, architecture, interfaces and operation bands. (2) It describes key GSM events such as location update, handover, authentication, encryption and initialization. (3) The basic calling process is explained including location update process, outgoing and incoming calls from a mobile station to PSTN, and mobile station to mobile station calls.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PPT, PDF, TXT or read online from Scribd
    Download as ppt, pdf, or txt
    103 views40 pages

    Gbo 001 E1 1 GSM Basic-40

    Uploaded by

    Clive Mangwiro
    (1) The document provides an overview of GSM including its history, architecture, interfaces and operation bands. (2) It describes key GSM events such as location update, handover, authentication, encryption and initialization. (3) The basic calling process is explained including location update process, outgoing and incoming calls from a mobile station to PSTN, and mobile station to mobile station calls.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PPT, PDF, TXT or read online from Scribd
    Download as ppt, pdf, or txt
    of 40

    GSM Basic

    ZTE University

    Objective

    At the end of this course, you will be able to:


    Understand GSM system architecture and function State GSM common events Describe basic calling process

    Content

    GSM System Overview GSM Common Events Basic Calling Process

    Mobile Telecommunication Technology Evolution


    1G Analog 2G Digital 3G IMT-2000

    AMPS
    Market Driving

    GSM CDMA IS95 TDMA IS-136 PDC UMTS WCDMA


    Market Driving

    TACS
    NMT Others

    CDMA 2000 TDSCDMA

    GSM History

    Technology Development 2000China Mobile 400 million subscribers Competitio n Custome r Demand

    1994GSM enter into China

    3 2

    1991GSM system launched commercially

    1989GSM Standard Take effect

    Development of mobile communication system

    UMTS

    2002
    1M

    2M

    Video

    EDGE 2001 GPRS 2000 GSM


    1999
    10 k

    l A

    a w

    s y
    115 k

    n o

    High quality

    384 k

    Mobile Office
    Graphics Medium quality

    56 k Voice Messaging SMS

    text

    Bit/s

    1k

    The way to 3G

    Meaning of GSM

    GSM: Group Special Mobile

    GSM: Global System for Mobile

    GSM specification

    Field 1: General Field 2: Services Field 3: Network Functions Field 4: MS-BS Interfaces and Protocols Field 5: Physical Layer on Radio Path Field 6: Speech Coding

    GSM specification

    Field 7: MS Terminal Adaptor Field 8: BS-MSC Interface Field 9: Network Inter-working Field 10: Service Inter-working Field 11: Equipment and Model Acceptance Specification Field 12: Operation and Maintenance

    GSM Network development

    1982: The group special mobile 1986: On-site test 1987: TDMA, RPE-LTP, GMSK 1988: MOU 1989: GSM took effect 1991: First GSM network was deployed 1992: GSM standard was frozen 1993: GSM phase 2 complete 1994: GSM phase 2+ for mobile data service

    GSM system architecture


    MS
    MS

    (Mobile Station)

    BTS

    BSS (Base Station System)


    BSC
    PSTN, ISDN...

    MSC

    Voicemail Server SM-SC VLR


    OMC

    NSS
    HLR AuC
    OMC

    (Network Switching Subsystem)

    EIR

    NMC

    OMS (Operations & Maintenance GSM interfaces Management) X.25 links

    GSM network entities


    MS

    (Mobile Station)

    Mobile Equipment
    Subscriber Identity Module (SIM)

    BTS

    (Base Transceiver Station) (Base Station Controller)

    Provide radio channels

    BSC

    Radio resource management Transcoder

    GSM network entities


    HLR

    (Home Location Register)


    Subscriber data Subscriber location info.

    Database

    VLR (Visitor Location Register)


    Database
    MSRN (Mobile Station Roaming Number) TMSI (Temporary Mobile Subscriber Identification) Location area codeLAC Subscriber data related to supplementary service

    GSM network entities


    MSC

    (Mobile service Switching center) (Authenticate Center) :

    Circuit switching

    AUC

    Authenticate subscriber access

    EIR

    (mobile station Equipment Identity Register) :

    Identify terminal equipment

    OMC

    (Operation and Maintenance Center)

    Provide MMI to control and monitor system

    GSM service area


    GSM Service Area PLMN Service Area MSC Service Area
    Location Area

    Cell

    GSM interfaces

    G VLR Sm Um Abis A B D MS BTS BSC MSC E C HLR F EIR MSC VLR

    GSM operation band

    SYSTEM
    Frequencies - Uplink - Downlink Wavelength Bandwidth Duplex Distance Carrier Separation Radio Channels

    P-GSM 900
    890 - 915 MHz 935 - 960 MHz ~33 cm 25 MHz 45 MHz 200 kHz 125

    E-GSM 900
    880 - 915 MHz 925 - 960 MHz ~33 cm 35 MHz 45 MHz 200 kHz 175

    GSM 1800
    1710 - 1785 MHz 1805 - 1880 MHz ~17 cm 75 MHz 95 MHz 200 kHz 375

    GSM 1900
    1850 - 1910 MHz 1930 - 1990 MHz ~16 cm 60 MHz 80 MHz 200 kHz 300

    Absolute radio frequency channel NumberARFCN

    GSM900

    Fu (n) = 890 + 0.2n MHz Fd (n) = Fu(n) + 45 MHz01 n 124 Fu (n) = 1710.2 + 0.2(n-512) MHz Fd (n) = Fu(n) + 95 MHz512 n 885

    GSM1800

    Multiple Access Technology (MAT)

    Many subscribers share common telecommunication lines without interference to each other.
    MAT

    FDMA TDMA

    CDMA

    GSM

    FDMA

    FDMA

    Identify by frequency

    Time

    FDMA

    Frequency

    TDMA

    TDMA

    Identify by time

    Time TDMA

    Frequency

    CDMA

    CDMA

    Identify by code

    Time CDMA Code

    Frequency

    Content

    GSM System Overview GSM Common Events Basic Calling Process

    Subscriber status

    IMSI Attach

    IMSI Detach

    MS busy

    Location Update
    HLR

    Originated by MS Location info stored in SIM MS monitor system infooriginate location update once the new LAC is different from that in SIM

    MSC (old)

    MSC (new)
    VLR

    VLR

    Location Update

    Location Update

    Type

    Power on

    IMSI ATTACH/DETACH Location register MS power on/off

    ON
    M SC

    VL R

    Normal location update

    LA 1

    LA 2

    MS change LA

    Periodic location update

    Operator decide the period (timer) Location update when time out

    Handover

    Handover: Hand-over is a process that transfers a MS that is in setting up or busy status to a new traffic channel Why need handover

    Keep and save the call in progress Improve network service quality

    Decrease call drop rate Decrease congestion rate

    Who will be involved

    MSBTSBSCMSC

    MSmeasure downlink radio signal level BTSmeasure uplink radio signal level and quality and send the results to BSC BSCevaluate and decision of HO MSC routes the call to the other MSC during Inter-MSC HO

    Handover classification

    Reason:
    PBGT Signal level

    TA:
    Synchronous Asynchronous

    Signal quality
    Distance Traffic

    Position:
    Intra-cell
    Inter-cell Intra-BSC Inter-BSC

    Inter-MSC

    Cell selection and Reselection

    After a MS is turned on, it will attempt to contact a common GSM PLMN, so the MS will select an appropriate cell, and extract from it the parameters of the control channel.

    MS change its service cell in IDLE state

    Authentication and Encryption

    Triplet

    RAND: the question asked by the network side Ki: stored in the SIM card and AUC in a very confidential way SRES: signed response. It is obtained through the calculation of subscribers unique key parameter Ki.

    Authentication process

    Execute authentication when

    MS registersetup calllocation update and active/deactivate supplementary service It is optional A3 algorithm Mobile Terminal Network
    Random number generator Ki RAND Ki A3 algorithm A3 algorithm

    SRES' SRES

    Encryption process

    Kc: Encryption key 64-bits (A8 algorithm) A5 algorithm (exclusive or) It is optional.
    Frame No. Kc (64-bit) (22-bit) Frame No. Kc (64-bit) (22-bit)

    Mobile Terminal

    Network

    Ki

    Random number generator RAND Ki A8 algorithm A8 algorithm

    A5
    S1 (114-bit) S2 (114-bit) S1 (114-bit)

    A5
    S2 (114-bit)

    Kc

    Kc

    MS

    BTS

    Content

    GSM System Overview GSM Common Events Basic Calling Process

    Initialization
    Initialization is a random access process
    MS Ch request (RACH) TA, access reason ACTSDCCH ACT ACKSDCCH

    BTS

    BSC

    Imm Assign SDCCHAGCH

    Imm Assign SDCCHAGCH

    Initial messageSDCCH

    Location update process

    (1) MS moves from one BTS to another BTS


    (2) Learn to the broadcasting information (3)(4) MS sends the LU request to MSC-A. (5) MSC-A sends the LU message to HLR (6) HLR sends back subscriber data.

    (7)(8) Subscriber data registration in the VLR.


    (9) Sending LU response message (10) Notifying the original VLR to delete subscriber data.

    Outgoing call from MS to PSTN


    (1) Random access channel. (2) Set up signaling connection between

    MS and MSC.
    (3) Authentication and encryption and enter the call setup starting phase. (4) Service channel allocation (5) Send ringing to the called subscriber, and send back the call connection acknowledgment signal to MS. (6)The called subscriber offhooks to reply, in which case a response (connection) message is sent to MS, thus entering the ultimate call session phase.

    Incoming call from PSTN to MS


    (1) Send MSISDN number to GMSC (2) Requests HLR for the MSC address (3) HLR requests VLR to assign MSRN (4) GMSC re-search for routes to set up connection to the visited MSC by MSRN. (5)(6) MSC obtains related subscriber data (7)(8) MSC sends paging messages (9)(10) The MS sends back the paging response messages, then carries out the same steps of (1), (2), (3), (4) as shown in the above outgoing call flow till the mobile station rings.

    (11) The mobile subscriber offhooks to answer,


    thus the response (connection) message is sent back to the fixed network

    MS to MS call

    (1) MS1 dials the phone number of MS2. BSS informs MSC1 of the call. (2) MSC1 analyzes the phone number of MS2, finds out the HLR of MS2 and sends the route application to HLR. (3) HLR queries the current location information of MS2 and obtains MSRN from the MSC2/VLR2. (4) MSC2/VLR2 allocates the route information, that is, MSRN and submits the MSRN to the HLR. (5) HLR sends the MSRN to the MSC1. (6) MSC2 sets up the call with MSC2 according to the MSRN. (7) MSC2/VLR2 sends the paging message to MS2. (8) MSC2/VLR2 receives the message, indicating the access of MS2 is allowed. (9) The call between MSC2 and MSC1 is set up. (10) MSC1 sends the successful connection signal to MS1. MS1 and MS2 can talk over the phone.

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