gsm towards lte networks lecture # 2. cellular generations first generation wireless : analog second...

GSM TOWARDS LTE NETWORKS

Lecture # 2

CELLULAR GENERATIONS First Generation Wireless : Analog Second Generation Wireless (2G): Digital Second Generation Wireless + (2G+): More Data Third Generation Wireless (3G):

Universal Global Wireless Voice and Data System Worldwide Effort Toward 3G

International Standard Underway: IMT-2000

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1st GENERATION CELLULAR SYSTEM Widespread introduction in early 1980s.

Analogue modulation.

Frequency division multiple access.

Voice traffic only.

No inter-network roaming possible.

Insecure air interface.

Examples :

AMPS (Advance mobile Phone System, American based,800MHz)

TACS (Total Access Communications System, UK based,900MHz)

C-450 (German standard, 450MHz)

JTACS (Japanese Total Access Communications System,900MHz).

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2nd GENERATION OF CELLULAR NETWORKS

Widespread introduction in 1990s.

Use digital modulation.

Variety of multiple access strategies.

More efficient use of radio spectrum.

International roaming capability.

Secure air interface.

Compatibility with ISDN.

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GSM ARCHITECTURE OVERVIEW

A GSM system is made up of three subsystems:

The mobile station (MS) The Base station subsystem (BSS) The Network and switching subsystem (NSS)

The interfaces defined between each of these sub systems include:

“A” interface between NSS and BSS “Abis” interface between BSC and BTS (Within the BSS) “Um” air interface between the BSS and the MS

GSM ARCHITECTURE OVERVIEW

Main components of GSM

The mobile station (MS) BSS Base Station Subsystem (BTS+BSC) MSS Mobile Station Subsystem (MSC/HLR, ..)

BSCBTS MSC

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Abis Interface

Interface

GSM NETWORK / DEPARTMENT OVERVIEW / 2G NETWORK

BTS

BSC

MSC

VLR HLR AuC EIR

PSTN,ISDN...

OMCOMC

NMCX.25 links

GSM interfaces

Voicemail Server

SM-SC

MS (Mobile Station)

BSS (Base Station System)

NSS (Network Switching Subsystem)

OMM (Operations & Maintenance Management)

MS

RAN department

RF department

NSS department

Transmission department

NMC and OMC

BSS

Signaling transmission

Call connections and signaling transmission

AUC

VLR

HLR

EIR

SSSwitching Systems

Base Station Systems

MS

Other Networks

GSMOverview 00/9

GMSC MSC

BTS

BSC

GSM system

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GSM Call GSM Call SetupSetup

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MS Mobile Station = phone + SIM card

BTS Base Transceiver Station BSC Base Station Controller HLR Home Location Register MSC Mobile services Switching

Centre VLR Visitor Location Register AUC Authentication Centre

Stand-alone or integrated in HLR

EIR Equipment Identity RegisterFor blacklisting stolen and

unwanted equipment SMSC Short Message Service

”Support” Centre VMS Voice Messaging System PrePaid Node Hosting prepaid service

system IN Intelligent Network services PSTN Public Switched Telephone

Network PABX Private Automatic Branch

Exchange

MSC/VLRWarid

Telenore

BSC

SMSC

EIR

INTERNET

MobilinkPSTN

BSC

PrePaidNode

VMS

HLR

MSCw

AUC

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MSC SMSC

EIR

INTERNET

PABXPSTNInternational

PSTNFixed Network

BSC

IN

PrePaid

VMSVoicemail

HLR

MSC BSC

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MSC SMSC

EIR

INTERNET

BSC

IN

PrePaid

VMSVoicemail

HLR

MSC BSC


PSTNFixed Network

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MSC SMSC

EIR

INTERNET

BSC

IN

PrePaid

VMSVoicemail

HLR

MSC BSC


PSTNFixed Network

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MSC SMSC

EIR

INTERNET

BSC

IN

PrePaid

VMSVoicemail

HLR

MSC BSC


PSTNFixed Network

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BSCBSC

Base Station ControllerBase Station Controller

The call request reaches the BSC from the The call request reaches the BSC from the BTS and is forwarded to MSC.BTS and is forwarded to MSC.

After call is established, the BSC will perform After call is established, the BSC will perform decodingdecoding of the call (in typical config.) of the call (in typical config.)

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BSC HLR

MSC SMSC

EIR

INTERNETIN

PrePaid

VMSVoicemail

MSC BSC


PSTNFixed Network

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BSC HLR

MSC SMSC

EIR

INTERNETIN

PrePaid

VMSVoicemail

MSC BSC


PSTNFixed Network

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BSC HLR

MSC SMSC

EIR

INTERNETIN

PrePaid

VMSVoicemail

MSC BSC


PSTNFixed Network

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Checks A number.Checks A number. To whom is A subscriber calling?To whom is A subscriber calling?

(Checks B number)(Checks B number) Example : A subscriberExample : A subscriber has has

prepaid number.prepaid number.

MSC MSC

Mobile Switching CentreMobile Switching Centre

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BSC HLR

MSC SMSC

EIR

INTERNETIN

PrePaid

VMSVoicemail

MSC BSC


PSTNFixed Network

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BSC HLR

MSC SMSC

EIR

INTERNETIN

PrePaid

VMSVoicemail

MSC BSC


PSTNFixed Network

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BSC HLR

MSC SMSC

EIR

INTERNETIN

PrePaidPrePaid

VMSVoicemail

MSC BSC


PSTNFixed Network

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Does the A subscriber have Does the A subscriber have money left on his/her account?money left on his/her account?

When the call is established When the call is established and on-going the subscriber’s and on-going the subscriber’s account is decremented account is decremented accordingly.accordingly.

PrePaid NodePrePaid Node

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BSCHLR

MSC SMSC

EIR

INTERNETIN

PrePaid

VMSVoicemail

MSC BSC


PSTNFixed Network

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BSCHLR

MSC SMSC

EIR

INTERNETIN

PrePaid

VMSVoicemail

MSC BSC


PSTNFixed Network

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BSCHLR

MSCMSC SMSC

EIR

INTERNETIN

PrePaid

VMSVoicemail

MSC BSC


PSTNFixed Network

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Where is the B subscriber?Where is the B subscriber? MSC interrogates in HLR.MSC interrogates in HLR.

(HLR = Home Location (HLR = Home Location Register)Register)

MSCMSC Mobile Switching CentreMobile Switching Centre

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BSCHLR

MSCMSC

IN

PrePaid

VMSVoicemail

MSC BSC


PSTNFixed Network

SMSC

EIR

INTERNET

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BSCHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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HLR says ’I am the home of the B HLR says ’I am the home of the B subscriber and I know where he/she is subscriber and I know where he/she is right now’ (i.e. which VLR)right now’ (i.e. which VLR)

Tells this VLR ’Give me a visitor address Tells this VLR ’Give me a visitor address for this subscriber’ (Roaming Number) for this subscriber’ (Roaming Number)

HLRHLRHome Location Register

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSCMSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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Hosting MSC/VLR returns Hosting MSC/VLR returns TEMPORARILY assigned TEMPORARILY assigned visitor/roaming address for B-visitor/roaming address for B-subscriber to HLR.subscriber to HLR.

MSCMSC


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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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’’Thanks for the visitor address!’Thanks for the visitor address!’ ’’I will send this address to the I will send this address to the

MSC that requested for it.’ MSC that requested for it.’

HLRHLRHome Location Register

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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’’Thank you, HLR!’Thank you, HLR!’ Speech connection path will set Speech connection path will set

up now towards the MSC/VLR up now towards the MSC/VLR where the B subscriber is where the B subscriber is presently located.presently located.

MSCMSC


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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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Sets up a speech connection towards Sets up a speech connection towards BSC.BSC.

Delivers B-subscriber ID to BSC and asks Delivers B-subscriber ID to BSC and asks to page for the subscriber using that ID.to page for the subscriber using that ID.

MSCMSC


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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

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BSC now sends a PAGING MESSAGE to all the BTSs that BSC now sends a PAGING MESSAGE to all the BTSs that it covers/controls.it covers/controls.

Carrys PAGING RESPONSE from called MS back to MSC.Carrys PAGING RESPONSE from called MS back to MSC. Allocates a RADIO channel through a BTS with best Allocates a RADIO channel through a BTS with best

available and allowable SIGNAL STRENGTH for called available and allowable SIGNAL STRENGTH for called MS.MS.

Performs SPEECH CODING when call is established.Performs SPEECH CODING when call is established.

BSCBSC

Base Station ControllerBase Station Controller

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BSCHLRHLR

MSCMSC

MSC BSC


PSTNFixed Network

IN

PrePaid

VMSVoicemail

SMSC

EIR

INTERNET

THANKS

gsm towards lte networks lecture # 2. cellular generations first generation wireless : analog second...

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