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System Model

AUC

HLR EIR

SS

BSS

MSC

BTS

MS

NMC and OMC

Switching System

Signaling transmission

Call connections and

signaling transmission

Base Station System

Other

networks

BSC

GMSC

VLR

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Network elements in GSM

MS

PLMN

PSTN

ISDN

AUC

EIRHLR

VLR

MSC

BSC

BTS

GMSC

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SA2

MSC

VLR

MSCMSC

VLR

BSC BSC

LA1LA2

GMSC

MSC

BTS

SA1

HLR

AUC

EIR

SA - Service Area

LA - Location Area

BTS - Base Transceiver Station

BSC - Base Station Controller

MSC - Mobile Switching Center

VLR - Visitor Location Register

GMSC - Gateway MSCEIR - Equipment Identity Register

AUC - Authentication Center

HLR - Home Location Register

Mobile identity

SIM card

Network Hierarchy

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GSM interfaces

MS BTS BSC MSC

Um Abis A

The Um interface is the interface between the MS and the RBS. Other name of this interface is Air interface as the communication isin the air

The terms BSC and RBS are for the nodes in the BSS. Abis is the name of the interface connecting the two nodes. Various kinds of

information is transferred over the Abis interface like synchronization information, traffic (speech, data, fax, etc.), in-band signaling.

The interface separating the BSS from the MSC is called the A interface. It not only supports messages between the MSC and BSS,

but also messages between the MSC and MS.

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Macro, Mini, Micro and Indoor Cells

Antenna positions

Macro

Mini

MicroPico

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Relation Between Areas in GSM

GSM Service Area

PLMN Service Area

(one per operator)

MSC Service Area

Location Area

Cell

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Authentication Procedure

MSC/VLR

1. RAND

3. SRES

MS

2. MS calculates SRES using RAND + Ki(SIM-card) through A3 and Kc using RAND+Kithrough A8.

4. Compare SRES received fromMS with SRES in triplet. If theyare equal access is granted.

MSC/VLR Mobile service Switching CenterMS Mobile StationRAND Random number

SRES Signed Response

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Authentication in GSM

VLR

MSC

HLRAUC

Subscriber number (IMSI)Code key (Ki)

Random n umb er (RAND)Signal resp ons e (SRES)

RAND / SRES

RAND

SRES

Figure D.6.4

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Equipment Identification

MSC/VLR

MS

EIR

3. Check IMEI

4. Access/barring info

1. IMEI request

2. IMEI

IMEI International Mobile station Equipment IdentityEIR Equipment Identity RegisterMSC/VLR Mobile services Switching Center

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GSM Modes

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Operation Overview

Attached (On)

Detached (Off)

Idle

Busy

Roaming

Paging

Handover

Mr. Bond!!

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Monitoring BCCH Carriers

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Frequency bands for the different GSM-based

networks. (Values within brackets refer to E-GSM)

Network type

GSM 900 (880)890-915/(925)935-960 MHz GSM 900

GSM 1800 1710 - 1785/1805 -1880 MHz GSM 1800

GSM 1900 1850 - 1910/1930 -1990 MHz GSM 1900

EricssonsImplementations

Frequency bandUL/DL

WCDMA 1920 - 1980/2110 -2170 MHz UMTS

WiMax 2.5 - 66 GHz

Standard GSM 900 GSM 1800 GSM 1900

Duplex dist. 45 MHz 95 MHz 80 MHz

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Basic TDMA frame, timeslot, and burst structures

0 1 2 3 4 5 6 7

4.615 ms

3 57 1 26 1 57 3

Burst148 Bits

156.25 Bits0.577 ms

DataTrainingData