GSM-to-3G2

8/12/2019 GSM-to-3G2

1/45

1

GSM to 3G

A Journey of Wireless Communication

RTTC Pune presents

8/12/2019 GSM-to-3G2

2/45

2

1G ( Before 1990 )

Analog No roaming, no security, costly. 2G ( After 1990 )

Digital Mainly for voice communication Verity of standards like FDMA,TDMA,CDMA,DECT etc.

3G ( After 2000)

Main objectives: Integration of all standards and services. Higher data rate for multimedia applications

The Mobile Generations

8/12/2019 GSM-to-3G2

3/45

3

High data rates

(384kbps-14.4 Mbps)

+ 2ndgen. services

1990 2000

1stGeneration 2ndGeneration 3rdGeneration

Analog speech Digital speech +

low -rate data ( 64 kbps)

NMT450, AMPS,

TACS

C450

GSM, (IS-54)DAMPS,

JDC/PDC,

IS-136(TDMA),

IS-95(CDMA)

UMTS/IMT-2000

WCDMA

1980

The Mobile Generations

8/12/2019 GSM-to-3G2

4/45

4

1G Cellular Systems

Many Different Standards: AMPS (US) NMT (Northern Europe) TACS (Europe) NTT (Japan) many others...

Spectrum

around 800 and 900 MHz

8/12/2019 GSM-to-3G2

5/45

5

Frequency Division Duplex (FDD)

Forward Link

Reverse Link

Two separate frequency bands are used for

forward and reverse links.

Typically, 25 MHz in each direction.

e.g. in GSM-900 : 890915 MHz (forward)

935 -- 960 MHz (reverse)

mobile base station

8/12/2019 GSM-to-3G2

6/45

6

2G Cellular Systems

Four Major Standards: GSM (European, now Global) IS-54 (Later becomes IS-136, US)

JDC (Japanese Digital Cellular, now PDC) IS-95 (CDMA, US)

8/12/2019 GSM-to-3G2

7/45

7

Spectrum for 2G Systems

At present GSM is operating in

900 MHz band - 890-915 MHz Uplink935-960 MHz Downlink



8/12/2019 GSM-to-3G2

8/45

8

BTS Base Transceiver Station

BSC Base Station Controller

Typical 2G Architecture

MSC Mobile Switching Center

VLR Visitor Location Register

HLR Home Location Register

BTS

BSC

MSC/VLR

HLRBSC

GMSC

CO

BSC

BSCMSC/VLR

CO

PSTN

PLMN

CO

Tandem Tandem

SMS-SC

PSDN

8/12/2019 GSM-to-3G2

9/45

9

Low Data Bit Rates and Low voice QualityMainly designed to offer voice communication.

Connections setup too long & complicated

Inefficient resource utilization for bursty trafficSince it adopts Circuit Switching technique. No efficient method for packet switched services.

Failed to fulfil the growing demand from customers

i.e. Internet access not just at home/office but also when they are

on the move.

Multiple Standards and No common frequency Band.A wireless user can roam in only those networks that supports the

same standards.

Thus still it is not a Global system.

2G Limitations

8/12/2019 GSM-to-3G2

10/45

10

HSCSD( High Speed Circuit Switched Data):To increase the data rates a simple solution is to use

multiple time slots instead of one.

In GSM channel by using one TS provides speeds of

9.6-14.4 Kbps.

In HSCSD by using upto four TSs a speed of 57.6 Kbps

can be obtained. It requires minimum changes in thenetwork architecture;

But its flip side is that it uses circuit-switching.

The solution to this situation is GPRS.

Solution to 2G Limitations

8/12/2019 GSM-to-3G2

11/45

11

GPRS..

2.5 G system standardized by ETSI

Few changes to existing GSM infrastructure

No need to reorganize radio spectrum.

A new set of GSM-bearer services that provide packet mode

transmission within the GSM network & interconnects with

external packet data networks.

Offers data services (e.g. Internet access) by using

Packet -switching Domain.

Reserves radio resources only when there is data to send.

Uses 1 to 8 radio channels to offer speeds more than 115 Kbps

8/12/2019 GSM-to-3G2

12/45

12

Direct support for Data Network.

Better Billing Mechanisms.

Introduce packet-switched routing functionality

Better data transfer rates

Low cost and connectivity-oriented.

Migration Path to 3G NetworksBecause the core network components of GPRS

( e.g. SGSN , GGSN ) are an integral part of 3G core

network.

Though the software components in the entities of2.5G network and 3G network are different, the basic

network architecture and interfaces remains the same.

GPRS..

8/12/2019 GSM-to-3G2

13/45

13

Packet-switched technique

vs. circuit-switched

In circuit-switching, resources (e.g. a channel) areallocated to user for duration of connection

Inefficient use of resources User pays for the whole connection

High QoS: channel maintains real-time connection

In packet-switching, resources are allocated to user

only for the time it takes to send each packet

A channel can serve many users User pays by the packet Ideal for bursty data connections

8/12/2019 GSM-to-3G2

14/45

14

Comparison

Packet-switched High bit rates (up to

170kbit/s)

Shared bandwidth

Variable access times Friendly bill (based onvolume)

Robust applicationsupport

Frequent transmission

of small volumes

Infrequent transmission

of small or medium

volumes

Circuit-switched Low bit rates

(14.4kbit/s)

Reserved bandwidth

Fixed access time Unfriendly bill (basedon duration)

Limited applicationsupport

Large volumes

8/12/2019 GSM-to-3G2

15/45

15

SS7

BTS

BSCMSC

VLR

HLRAuC

GMSC

BSS

PSTN

NSS

A

E

C

D

PSTNAbis

B

H

MS

BSS Base Stat ion System



NSS Networ k Sub-System

MSC Mobile-service Switching Controller



AuC Authentication Server

GMSC Gateway MSC

2G to 2.5G Architectural Changes

SGSN Serving GPRS Support Node

GGSN Gateway GPRS Support Node

GPRS General Packet Radio Service

IP

2G+ MS (voice & data)

PSDNGi

SGSN

Gr

Gb

Gs

GGSN

Gc

Gn

2G MS (voice only)

8/12/2019 GSM-to-3G2

16/45

16

GPRS Architecture - Components

New components introduced for GPRSservices:

SGSN (Serving GPRS Support Node) GGSN (Gateway GPRS Support Node) IP-based backbone network

Old components in GSM upgraded for GPRS

services:

HLR MSC/VLR Mobile Station

8/12/2019 GSM-to-3G2

17/45

17

GPRS ArchitectureSGSNServing GPRS Support Node

At the same hierarchical level as the MSC.

Transfers data packets between mobile stations and

GGSNs.

Keeps track of the individual MSs location andperforms security functions and access control.

Detects and registers new GPRS mobile stations

located in its service area

Participates into routing, as well as mobilitymanagement functions.

8/12/2019 GSM-to-3G2

18/45

18

GPRS ArchitectureGGSNGateway GPRS Support Node

Provides inter-working between PLMN and externalpacket-switched networks.

Converts the GPRS packets from SGSN into the

appropriate packet data protocol format (e.g., IP or X.25)

and sends out on the corresponding packet data network.

Participates into the mobility management.

Maintains the location information of the mobile stations

that are using the data protocols provided by that GGSN.

Collects charging information for billing purpose.

8/12/2019 GSM-to-3G2

19/45

19

GPRS ArchitectureBackbone Network

Tunnels of data and signaling messages

between GPRS support nodes.

Protocol architecture based on the InternetProtocol (IP).

GTP (GPRS Tunneling Protocol) used to

tunnel user data and signaling between

GPRS Support Nodes. All PDP (Packet DataProtocol) PDUs (Protocol Data Units) shall be

encapsulated by GTP.

8/12/2019 GSM-to-3G2

20/45

20

GPRS Architecture

Backbone Network (cont.)

Two kinds of GPRS backbone Network: Intra-PLMN backbone network: The IP network

interconnecting GSNs within the same PLMN.

Inter-PLMN backbone network: The IP network

interconnecting GSNs and intra-PLMN backbone networksin different PLMNs.

Two intra-PLMN backbone networks are connected via

the Gp interface using Border Gateways and an inter-

PLMN backbone network.

Border Gateway handles the packet transfer between

GPRS PLMNs.

8/12/2019 GSM-to-3G2

21/45

21

GPRS ArchitectureHLR

Enhanced with GPRS subscription data and

routing information.

Accessible from the SGSN via the Gr

interface and from the GGSN via the Gc

interface.

8/12/2019 GSM-to-3G2

22/45

22

GPRS ArchitectureMSC/VLR

Not needed for routing of GPRS data.

Needed for the co-operation between GPRS

and the other GSM services. e.g.,

Paging for circuit-switched calls that can beperformed more efficiently via the SGSN

Combining GPRS and non-GPRS location

updatesReceives location information from SGSN or

sends paging requests to SGSN via the Gs

interface.

8/12/2019 GSM-to-3G2

23/45

23

GPRS ArchitectureMobile Station

GPRS MS includes two components:

MT (Mobile Terminal). Typically a handsetused to access the radio interface.

TE (Terminal Equipment). Typically a laptop ora Personal Digital Assistant (PDA).

Could be one unit combing the functionalitiesof a MT and a TE.

8/12/2019 GSM-to-3G2

24/45

24

GPRS ArchitectureMobile Station (cont.)

Three types of MS:

Class-A: Could be attached to both GPRS andother GSM services, and the MS supports

simultaneous operation of GPRS and other

GSM services.

Class-B: Could be attached to both GPRS andother GSM services, but the MS can only

operate one set of services at a time.

Class-C: Could be exclusively attached to oneservice type at a given time.

8/12/2019 GSM-to-3G2

25/45

25

Packet transfer

Intra-PLMN backbone

PLMN

8/12/2019 GSM-to-3G2

26/45

26

Packet Transfer

A laptop connects with a GPRS-capable handset.The handset communicates with GSM base station.

Base station sends the GPRS packets to SGSN.

SGSN encapsulates packets

Handset location information is updated in otherGSM components, such as HLR.

SGSN sends encapsulated packets to GGSN.

GGSN decapsulates and sends to PDNs.

GPRS summary

8/12/2019 GSM-to-3G2

27/45

27

GPRS summarySGSN :

Mobility Management

Random access detection and Authentication Gathers Charging Information

GGSN :

Gateway between UMTS Core Network and externalnetworks

Address allocation for MS Gathers Charging Information

Filtering and format conversions.BSS : BSC , BTS , MFS.

call processing R/R/M,

T/F synchronisation,

G S

8/12/2019 GSM-to-3G2

28/45

28

GPRS Limitations

Speeds Much Lower in Reality.

Data packets can traverse different routes/nodes leadingto potential transit delays affecting the Quality of Service.

Operators may decide to charge based on time rather

than volume, which may destroy the cost advantage that

GPRS provides today.

Requires major network modifications:

Many network elements to be upgraded and totally

new to be introduced.

Expensive:

Not much time for invest to be returned due to

upcoming 3rd generation technology.

3G (UMTS)

8/12/2019 GSM-to-3G2

29/45

29

3G (UMTS) IMT-2000 Goal : to have a single radio interface that provide

global roaming.

But due to technical/other reasons, different countries/bodiesstarted developing their own 3G radio interface systems using

various standards like :

WCDMA

WTDMA

TDMA/FDMA

OFDMA

ODMA

ETSI selected two systems :

WCDMA for paired frequency bands for FDD operation and

WTDMA for unpaired frequency bands for TDD operations.

8/12/2019 GSM-to-3G2

30/45

3G Systems

8/12/2019 GSM-to-3G2

31/45

31

3G Systems High quality and integrity comparable to to the fixed network.

High bit rates : ranging from 144 Kbps -2 Mbps.

Variable bit rates to offer bandwidth on demand.

Multiplexing of services with different quality requirements on a

single connections e.g. speech, video and packet data.

A modular and open structure to allow to grow in size andcomplexity and permit easy introduction of new applications.

Coexistence of second and third generation systems and inter

system handovers for coverage enhancement and load

balancing.

Support of asymmetric uplink and downlink traffic, e.g. web

browsing causes more loading to downlink than to uplink.

Use of small pocket terminal world wide.

8/12/2019 GSM-to-3G2

32/45

32

Spectrum for 3G Systems

The IMT 2000 band has been identified in

most of the countries for the launch of 3G

services- Uplink- 1920-1980 MHz, Downlink- 2110-2170 MHz.

There have been some dispute which has

been raised by CDMA operators for the useof PCS 1900 band 1850-1910 and 1930-

1990.

8/12/2019 GSM-to-3G2

33/45

33

Spectrum Bands

The PCS-1900 band is in direct conflict with the IMT-2000

bands

If the PCS-1900 band is allocated to cdma players there is

a clear risk that WCDMA cannot happen in India.

1710 1785 1805 1880

1850 1910

1920 1980 2110 2170

1700 1800 1900 2000 2100

1930 1990

GSM 1800 Uplink

PCS-1900 Uplink60 MHz

PCS-1900 Downlink60 MHz

IMT-2000 Uplink60 MHz

IMT-2000 Downlink60 MHz

GSM 1800 Downlink75 MHz75 MHz

8/12/2019 GSM-to-3G2

34/45

34

Two main evolution paths into 3G

cdmaOne CDMA2000 1X

2G First Step into 3G 3G phase 1

GSM/GPRSGSM

64 - 144 Kb/s

Evolved 3G

384 Kb/s3.6 Mb/s Up to 14Mb/s+28.8 kb/s

EDGEExisting

Spectrum

WCDMA/WCDMA-ENew

Spectrum

CDMA2000 1xDO Rev 0/A

New+Existing

Spectrum

TDMA

PDC

WCDMA Evolution

8/12/2019 GSM-to-3G2

35/45

35

GSM Evolution for Data Access

1997 2000 2003 2003+

GSM

GPRS

EDGE

UMTS

9.6 kbps

115 kbps

384 kbps

2 Mbps

GSM evolution 3G

8/12/2019 GSM-to-3G2

36/45

36

WCDMA

TECHNOLOGY CHOSEN BY BSNL

FOR THE LAUNCH OF 3G(UMTS)

SERVICES

3G (UMTS) Network Architecture

8/12/2019 GSM-to-3G2

37/45

37

3G (UMTS) Network Architecture

Access Network

(AN)

Core Network

(CN)User equipment

(UE)

PSTNand

other

networks

UMTS architecture is similar to that of GSM/GPRS.

but the actual protocols residing in these entities are quite

different. This difference is created by WCDMA based air

interface in UMTS AN .

Significant changes in the protocols residing at the UE and AN.

Thus GSM/GPRS Handsets will not support UMTS.

However CN entities( like HLR,VLR,SGSN,GGSN etc) of GSM

or GPRS is almost entirely reused in the UMTS.

3G (UMTS)

8/12/2019 GSM-to-3G2

38/45

38

User Equipment : ( UE )

To access the services provided by the N/W.Uu interface: WCDMA air interface to connect with the AN.Two modes of operation over Uu interface :FDD mode for the paired spectrum andTDD mode for the unpaired spectrum.

Access Network : ( AN )Functions specific to WCDMA air interface.BTSterminates the radio connection with the UE.BSCcontrols the resources of the BTS.

Core Network : ( CN )Core Functions :

Mobility management, Call control , Switching and Routing.Also manages the subscription information of a subscriber andprovides the services accordingly.

3G (UMTS) ...

Logical Structure

8/12/2019 GSM-to-3G2

39/45

39

Logical Structureof User Equipment

UniversalSubscriber

Identity Module

( USIM )

User Equipment (UE)

Mobile Equipment ( ME )

Mobile Termination

( MT )

Terminal

Equipment

( TE )

3G(UMTS) User Equipment (UE)

8/12/2019 GSM-to-3G2

40/45

40

UEis divided into two logical parts :

1. Mobile Equipment (ME)

2. Universal SIM (USIM) MEis divided into two distinct functional groups :

1. Mobile Termination (MT) :

Performs Radio transmission/termination, authentication

and mobility management.

2. Terminal Equipment (TE) : Laptop, Camera etc.

Manages the hardware( speaker, microphones, video

cameras) and hosts user applications like Web browser.

Universal SIM (USIM):

USIM application resides on a smart card called UICC

which contains logic required to securely identify the user.

For this it contains permanent identity of user i.e. IMS, Secrete

key for authentication phone book and other information's.

UE is also referred to as MS.

3G(UMTS) User Equipment (UE)

3G rel99 Architecture (UMTS)

8/12/2019 GSM-to-3G2

41/45

41


- 3G Radios

SS7

IP

BTS

BSCMSC

VLR

HLRAuC

GMSC

BSS

SGSN GGSN

PSTN

PSDN

CN

CD

GcGr

Gn Gi

Abis

Gs

B

H




RNS Radio Network System

RNC Radio Network Controller

CN Core Network





GMSC Gateway MSC



AE PSTN

2G MS (voice only)


UMTS Universal Mobi le Telecommunic at ion System

Gb

3G UE (voice & data)

Node B

RNC

RNS

Iub

IuCS

ATM

IuPS


8/12/2019 GSM-to-3G2

42/45

42


- Soft Switching

SS7

IP/ATM

BTS

BSCMSC Server

VLR

HLRAuC

GMSC server

BSS

SGSN GGSN

PSTN

PSDN

CN

CD

GcGr

Gn Gi

Gb

Abis

Gs

B

H




RNS Radio Network System

RNC Radio Network Controller

CN Core Network





GMSC Gateway MSC



ANc

2G MS (voice only)


Node B

RNC

RNS

Iub

IuCS

IuPS

3G UE (voice & data)

Mc

CS-MGW

CS-MGWNb

PSTNMc

ATM

8/12/2019 GSM-to-3G2

43/45

43

Element

management

WCDMA RAN

8/12/2019 GSM-to-3G2

44/45

44

3G at home:

PSTN telephony line

FAX line

Internet Access, up to 2Mbps

Low-cost alternative to the landline network based on WCDMA

Mobile BroadbandAn alternative for broadband at home

8/12/2019 GSM-to-3G2

45/45

THANK YOU&Have a Nice Time

Documents

GSM-to-3G2