GSM GLOBAL SYSTEM FOR MOBILE COMMUNICATION

GSM NETWORK ARCHITECTURE

BY: ENG. Waleed ElsafouryCopyright 2013 Waleed ElsafouryGSM NETWORK ARCHITECTURE GSM NETWORK ARCHITECTURE

GSM NETWORK ARCHITECTURE

GSM NETWORK ARCHITECTURE-The Mobile station (MS)

Modes of MSattacheddetachedIMSI de.Implicit de.idleactiveregistrationLA UpdatingpagingroamingOngoing callHandoverMonitoring power of neighboring BTSsMonitoring power & quality of its BTSTypes of MSsVehicle mounted MS Mounted to dashboard of vehicle. Antenna mounted on outside. More powerful.

Transportable MS Can be handheld. Antenna is not connected to handset.

Handheld MS Hand carried Antenna connected to handset. Pocket-sized. Can be vehicle mounted.GSM NETWORK ARCHITECTUREGSM NETWORK ARCHITECTURE-The Mobile station (MS)

1- Mobile equipment (ME)

it is the terminal used by user

Can be purchased from any store

Without SIM no calls can be made

It has an International Mobile Equipment Identity (IMEI)

IDENTITY NUMBERS

GSM NETWORK ARCHITECTURE 2- Subscriber identity module (SIM)

An electronic microchip for storing information

GSM NETWORK ARCHITECTURE 2- Subscriber identity module (SIM)

GSM NETWORK ARCHITECTURE 2- Subscriber identity module (SIM)

IDENTITY NUMBERS

IDENTITY NUMBERS

IDENTITY NUMBERS

IDENTITY NUMBERS

IDENTITY NUMBERS

GSM NETWORK ARCHITECTURE-The base station subsystem (BSS)

1- The Base Transceiver station (BTS)

BS contains the RF transmission equipment

Each cell has one BS

It has an International cell global Identity (CGI)

It performs Power amplification,channel coding, ciphering and modulation

GSM NETWORK ARCHITECTUREThe Site:

The TowerThe ShelterBase Transceiver station

GSM NETWORK ARCHITECTURE

Base Transceiver station

GSM NETWORK ARCHITECTUREBase Transceiver station

GSM NETWORK ARCHITECTURE

Site Controller (HIISC)CTU2Cooling FansPower Supply Units (PSU)Circuit Breaker Card (CBC)Alarm Board21Cooling fans: Two Fans - respond to temperature changes one fails the other compensate.

Tx BlocksPower SupplyBase Transceiver station

GSM NETWORK ARCHITECTUREBase Transceiver station

GSM NETWORK ARCHITECTUREBase Transceiver station

GSM NETWORK ARCHITECTUREGSM NETWORK ARCHITECTURE

GSM NETWORK ARCHITECTURE

GSM NETWORK ARCHITECTURE

GSM NETWORK ARCHITECTURE

GSM NETWORK ARCHITECTURE2- The base station controller (BSC)

-It carries out all control functions in the BSS as:

Paging

Channel allocation

Dynamic power control

Handover

Frequency hoppingThe base station controller (BSC)

BTSGSM NETWORK ARCHITECTUREThe base station controller (BSC)

BSCBTSRemote BTSCo-located BTSThe base station controller (BSC)

The base station controller (BSC)

The base station controller (BSC)

The base station controller (BSC)

BSS Link configurationGSM NETWORK ARCHITECTUREBTSBSCBTSBTSBTSBTS- CascadeBTSBSS Link configurationGSM NETWORK ARCHITECTUREBSCBTSBTSBTS- loopBSS Link configurationGSM NETWORK ARCHITECTUREBTSBSCBTSBTSBTSBTS- StarGSM NETWORK ARCHITECTURE3- The transcoding and rate adaptation unit (TRAU)

It is used for speech compression/decompression

Also adaptation of data to the requirement of the air interface MSCVLRBSC1616161664646464

1616161613TRAUTranscoding and rate adaptation unit

GSM NETWORK ARCHITECTURE - The Mobile service switching center (MSC)

-It is an electronic computerized exchange provides the interface between MS and the fixed network -It will not contain any subscriber parameters

Switching

Charging

call routing

Communication with HLR and VLR

Communication with other MSCs

Control of connected BSCs

Mobile Services Switching CentreGSM NETWORK ARCHITECTUREThe MSC is connected to:HLR (Home location register)VLR (Visitor location register)AUC (Authentication Center)EIR (Equipment identity register)

GSM NETWORK ARCHITECTUREHLR (Home location register)

The centralized database that stores and manages all mobile subscription parameters

HLR contains :

Subscriber identification numbers (IMSI,MSISDN)

Subscriber current location information (MSC/VLR)

Subscriber authentication information

Charging

Billing method

GSM NETWORK ARCHITECTUREHLR (Home location register)

GSM NETWORK ARCHITECTURE2. VLR (Visitor location register)

A temporary storage location for subscription information for MSs which are within MSC service area

VLR contains :

Mobile status (free, busy,etc)

Temporary MS identity (TMSI)

Temporary MS roaming number (MSRN)

Supplementary service informationGSM NETWORK ARCHITECTUREAuthentication - It is a processor system that performs the authentication function

AUCRANDDatabaseIMSI,KiA8A3RANDSRESKcTripletKiIMSITripletRequest for Triplet from HLR,VLRGSM NETWORK ARCHITECTUREAuthentication

GSM NETWORK ARCHITECTURE4. EIR (Equipment identity register)

As the subscriber and equipment are separate in GSM so we use a separate authentication process for MS equipment

EIR is a centralized database for validation of international mobile equipment identity (IMEI)

EIR contains 3 lists:

White list (for valid MS equipment)

Black list (for stolen or denied service MS)

Gray list (for mal-performance MS [e.g. faulty software] )

EIRBlack listWhite listGray listGSM NETWORK ARCHITECTURE

3-The Operation and maintenance center (OMC):-

A-The Operation and Maintenance Center for Radio part (BSS) (OMC-R)

B-The Operation and Maintenance Center for switching parts (OMC-S) GSM NETWORK ARCHITECTURE

- Geographic network areas

GSM NETWORK ARCHITECTURE

GSM NETWORK ARCHITECTURE

GSM NETWORK ARCHITECTURE

IDENTITY NUMBERS

GSM NETWORK ARCHITECTURE- Cell

IDENTITY NUMBERS

Vodafone 2G Coverage

Mobinil 2G Coverage