gprs edge techniques

7/29/2019 Gprs Edge Techniques

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General Packet Radio Service

BSNL


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Evolution from GSM to 3G

GSM

2G

HSCSD

GPRS

2.5G

EDGE

3G


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GSM Evolution

GPRS200 KHz carrier115 Kbps peak data rates

EDGE200 KHz carrierData rates up to 384 Kbps8-PSK modulationHigher symbol rate

UMTS5 MHz carrier2 Mbps peak data ratesNew IMT-2000 2 GHz spectru

GSM200 KHz carrier8 full-rate time slots16 half-rate time slots

GSM GPRS EDGE UMTS

3G2.5G2G

HSCSD

HSCSDCircuit-switched data64 Kbps peak data rates


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Mobile Data Technologies

HSCSD

GPRS

EDGE

UMTS


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HSCSD

GPRS

EDGE

UMTS

High Speed Circuit Switched Data

GSM Phase 2+ service (2.25 G)

Using Multiple Time slots

14.4 Kbps to 57.6 Kbps


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HSCSDGPRS

EDGE

UMTS

General Packet Radio Service

GSM Phase 2+ service (2.5G)

From 9.05 Kbps to 171.2 Kbps


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Enhanced Data Rates for GSM Evolution (2.75 G)

14.4/28 Kbps to 384/512 Kbps

EGPRS

HSCSD GPRS

EDGE

UMTS


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HSCSD GPRS

EDGE

UMTS

Universal Mobile Telecommunication System

3G standard

Using W-CDMA technology

Data rates up to 2 Mbps


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GSM Conventional Data Service Problems

Low Speed 9.6 Kbps Data rates (High Data rates with HSCSD)

Long connection setup time

Long connection setup time up to half a minute.

Circuit Switched Data Service Charging is based on amount of time not amount of data

Channels are occupied continuously during the operation.

No GSM standard is defined for direct connection to

the Internet.


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GSM Conventional Data Service Problems

Separate agreement with an ISP. Internetconnection may not be available duringroaming.

SMS is also a data service but it is designed

to carry 160 characters long short textmessages not continuous data. It usescommon channel signaling channels notTraffic channel.

Transmission of music samples, pictures,graphical short messages, MMS notsupported


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Operator Requirements

Better utilization of Radio Resources

Get more users = More Money

Simplified Access to data networks

Divide Users to Categories

Operators will become ISP's

Minimum modifications on the existing

infrastructure


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User Expectations

Cheaper Access to Data Networks

Higher Data Transfer Rates

Shorter Connection Setup Time

Better Support for Roaming

Less Connection Drops


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What is GPRS ?

Packet Data Network overlaid on todaysGSM Circuit Switched architecture

Circuit Switching is wasteful of valuable

spectrum - packet data is more efficient Subscribers will be permanently connected

- just like PC in the office LAN

The Mobile Phone will become a window onthe Internet and Corporate Intranets


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Channel Sharing

BTS

BCCH GPRS GPRS GPRS GPRS GPRS GPRS GPRSUser rate atCS2 = 93.8 kbps

BTS

BCCH GPRS TCH TCH TCH TCH TCH User rate atCS2 = 13.4 kbps

TCH

Dynamic allocation of channels between circuit and packet:

One timeslot allocated to GPRS


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Data Rate & Coding Schemes for GPRS

Scheme Code Rate Data Rate Max. Data

Per Timeslot Rate

CS-1 1/2 9.05kbps 72.4 kbps

CS-2 2/3 13.4kbps 107.2 kbps

CS-3 3/4 15.6kbps 124.8 kbps

CS-4 1 21.4kbps 171.2 kbps


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Network Area Routing Area (RA) can consist of one or more

cells and is always served by only on SGSN.

However, one SGSN could serve more than

one Routing Area.

Location Area (LA) can contain one or moreRouting Areas, but one Routing Area could

not span more than one Location Area.


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Classes of GPRS Mobiles Class A

Simultaneous execution of circuit switched and GPRSoperation (including SMS) is possible

user can make/receive calls on both services simultaneously

Class B Simultaneous execution of signaling for both circuit switched

and GPRS operation is possible

GPRS traffic will be suspended during an established orpending circuit switched connection

can be attached to both services but only one type of serviceat a time

Class C Alternate use of circuit switched and GPRS operation

User can receive/make calls from default/manually selectedservice


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GPRS Network

Internet

X.25 Network

GSM Network

With GPRS

Capability

MS

BSNL


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GPRS Architecture

Radius

Server

Charging

Gateway

WAP

Server

Mediation

Billing

MS

GGSN

GGSN

SGSN

MSC

BSC PCU

PSTN

GPRS

Network

Intranet

Internet

BSNL


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GPRS Architecture

EIR

SGSN HLR

AUC

GGSN

ISDN / PSTN / PLMN

Network

IP-Backbone

Network

ExternalIP Network

External

X.25 Network

GMSC

MSC/VLR

A

Gb

Gs

Gn

Gf

Gr

Gi

Gi

Gn

BTS

BSC

Abis

BSS

Um

TE

MT

MS

A GSM Interface

Abis GSM Interface (Proprietary of M/s Ericsson)

AUC Authentication Center

BSC Base Station Center

BSS Base Station System

BTS Base Transceiver Station

EIR Equipment Identity RegisterGGSN Gateway GPRS Support Node

GMSC Gateway Mobile services Switching Center

Gx GPRS Interfaces

HLR Home Location Register

MS Mobile Station

MSC Mobile services Switching Center

MT Mobile Terminal

SGSN Serving GPRS Support Node

TE Terminal Equipment

Um Air Interface

VLR Visitor Location Register

GPRS Network ElementsGSM Network Elements Traffic & Signaling Signaling


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EDGE (2.75G)

BSNL


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The Abbreviation

GPRS = General Packet Radio System

EGPRS = GPRS + EDGE modulation


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M

SBTS

P

U

C

BSC MSC/VL

R

HLR

SGS

N

GGSN

Backbone

Network

ISP

Network

CorporateNetwork

AUC

SMS G/IW MSC

Gb

Gd

Gs

Gn

Gr

Gn

GiEDGE

TRUM

S

Evolution to EDGE


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voice voice voice voice voice

voice voicevoicevoice voiceFree

TS DataFree

TS

Standard GSM Transceiver

EDGE Transceiver

EDGE increases capacity


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System upgrade forEDGE

B

S

C

BSC Software Upgrade

R

B

S

EDGE TRU

EDGE enabled RBS


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What JKJDFDSSWWhat EDGE would mean to subscriber ?

Streaming Applications Very high speed downloads

Corporate Intranet connections

Quicker MMS Video Phone

Vertical corporate applications Video

Conference, Remote presentations


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Enhanced Data for GSM Evolution

Next step towards 3G for GSM/GPRS Networks

EDGE adopts the GSM standards such as

same frequency plan, meaning that 200kHz will stillseparate carriers

TDMA structure supported by GSM will remain intact ateight timeslots per frame

same relationship between logical and physicalchannels.

Increased data rate up to 384 Kbps by bundling up to 8channels with 48 Kbps/channel

GPRS is based on modulation technique known as GMSK.

EDGE is based on a new enhanced modulation scheme thatallows a much higher bit rate across the air-interface called8PSK (OPSK) modulation.


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Enhanced Data for GSM Evolution

EDGE maintains a good quality link byautomatically adapting to the radio

interference conditions and thereby

provide the highest possible rate.

Since 8PSK will be used for UMTS,

network operators will be required to

introduce this at some stage before

migration to 3G.


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gprs edge techniques

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