gprs and edge

7/29/2019 Gprs and Edge

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GPRS BACK GROUND

With Mobile penetration reaching its full potential, GPRS gives Mobile operators competitiveedge and optimum use of the infrastructure.

SMS is a good example of just how hungry users are for data services. The main Objective of GPRS is to offer the access to standard data networks, using protocols

e.g. TCP/IP and X.25

Transactions such as Credit Card checks and a variety of telemetric applications benefit fromthe fast session set-ups.

GPRS enables efficient use of radio resources by allowing many data users to share the sameinterface on a statistical basis.

The main benefits of GPRS are that it reserves radio resources only when there is data to be sent Mobile users doesnt have to connect to the network each time he wants to transfer the data,

he can stay connected all day.

MAIN ADVANTAGES FOR OPERATORS

More Revenue :By providing more than a mobile connection.

Also operator can charge on the basis of type and amount of content accessed.

Huge Potential Market for Data Sevices :


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Mobile Phone and Internet, both are fastest growing technologies and GPRS is the merger of

two.

Fast Roll-out and Continuous Network Expansion :GPRS is an integral part of GSM.

GPRS uses excess voice capacity for data :GPRS Packets are transmitted in short, free periods between busy hour calls.

GPRS Vs GSM

GPRS Vs GSM

1. SUPPORTS BOTH CKT. Only circuit switched.

SWITCHED as well as

packet switched service.

2. MS Utilizes Automatic No re-transmission is

retransmission (ARQ) at provided.

data link layer to re-transmit

error frames.

3. Multiple time slots can be Single time slot per user.

allotted to a single user

4. One time slot can be allotted Single time slot per user.

to several users.

5. Charging/ billing more complex Simple time-based billing.

(Volume based, Q.O.S. based)

TYPICAL GPRS SERVICES

* Communications- E-mail, fax,

intranet/ internet access.

* Value added services - Information services, games,

e-commerce.


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* Location-based applications - Navigation, traffic conditions,

airline/rail schedule, location finder.

* Vertical applications - Freight delivery, fleet management,

sales-force automation

* Location sensitive A user nearing a cinema hall or

Advertising - a restaurant receives flashes of

advertisement

GSM NETWORK ELEMENTS

The Main elements of GSM are:

NSS : MSC VLR HLR (Includes Authentication Center and Equipment Identity Register)

BSS : BSC BTS Transcoder

NMS Fault Management Configuration Management Performance Management

GPRS Network Elements

Network Element Software Hardware


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SGSN SG1 DX Platform GGSN G1 IP650 Firewall Checkpoint IP650 Ethernet Switch N/A Cisco Catalyst DNS HP-UX 11.00 HP 9000 A class CG HP-UX 10.20 HP K class Border Gateway BGP4 IP650 DHCP HP-UX 11.00 HP 9000 A class

GPRS Interface

SGSN Role

Authentication, Authorization GTP tunneling to GGSN Ciphering & compression Mobility Management Session Management

HLR

Air (Um)

Gb

GsGr Gf

Gn

GnInter-PLMN

GPRSBackbone

Gp

External

packetnetworkGi

SGSN

EIR

BSC

MSC/VLR

SMS-GMSC

Gd

GGSN

GGSN

Signalling and data

Signalling


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Interaction with HLR, MSC/VLR Charging & statistics NMS interfaces

GGSN Role

Interface to external data networks Encapsulate in GTP and forwards end user data to right SGSN Routes mobile originated packets to right destination Filters end user traffic Collects charging and statistic information for data network usage

Different GPRS Capacity Types

MS Class

CLASS A:Supports simultaneous attach, simultaneous activation, simultaneous monitor, simultaneous

invocation, and simultaneous traffic.

CLASS B:Simultaneous traffic shall is not supported. The mobile user can make and/or receive calls on

either of the two services sequentially but not simultaneously. The selection of the appropriate

service is performed automatically


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CLASS C:Supports only non-simultaneous attach. Alternate use only.

The status of the service which has not been selected is detached,

that is, not reachable

GPRS Channel Coding Schemes

Mobility Management State


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Routing Area


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RAI = MCC+MNC+LAC+RAC

GPRS Mobility Management

Routing Area :

The RA is a new concept for tracing the MS location.

Cell =< RA =< LA served by one SGSN

RAI = MCC + MNC + LAC + RAC

Every time the MS sees the new RAI is has to initiate the RA update procedure.

Mobility Management States :

The IDLE State is when the MS is not connected. The Standby State is when the MS is connected to the GPRS Network


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The Ready State is when the MS is ready to connect to the external IP Network.Changing between states can be initiated from the MS, from the network and from the timers set.

PDP Context Activation Accessing the HLR

SECURITY IN GPRS

GPRS SYSTEM HAS INHERITED THE GSM PH-2 SECURITY FUNCTIONS

Authentication of the subscriber IMEI Checking User Identity Confidentiality (TMSI in GSM, P-TMSI in GPRS) Ciphering of the data traffic between MS and SGSN

ADDITIONAL GPRS SECURITY FEATURES ARE

Private IP Addressing in the GPRS backbone. Ciphered links and authentication between nodes in the GPRS Backbone. Screening of packets coming from the external networks (Firewall).

(P-TMSI is used to derive the Temp Logical Link Identity (TLLI))


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EDGE Provide 3G services today

Provide 3G services with existing licenses New modulation optimized for wireless data services Link adaptation: Take highest possible rate Covered by existing GSM licenses Same channel structure, network infrastructure, frequency

planning and protocol as todays GSM


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What EDGE would mean to subscribers

Streaming Applications Very high speed downloads Corporate Intranet connections Quicker MMS Video Phone Vertical corporate applications Video

Conference, Remote presentations

gprs and edge

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