gprs e.pptx

7/25/2019 GPRS e.pptx

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What is GPRS?

A new bearer service for GSM thatgreatly improves and simplieswireless access to packet datanetworkse!g to the internet!


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Motivation

Speed

"mmediacy

#ew and better applications

$ser friendly billing


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GSM Architect%re

&'SMS

&'S

&'S

MS

&S(

&S(

MS(

GMS(

MS

)"R

*+R

,+R

A$(

PS'#P-#

"S-#


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GPRS Architect%re

&'S

&'SMS

&S( Gb

SGS#

Gf

GsGr

-)"R

MS(.*+R

,+R

Gc

Gn

GGS#Gi

P-#

Gp GGS#

/ther GPRS

P+M#


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GPRS (/MP/#)#'S

SGSN : (Serving GPRS Support Node))0%ivalent to MS( in GSM

GGSN : (Gateway GPRS SupportNode)

)0%ivalent to GMS( in GSM

PCU : (Packet Coding Unit)1ragmentation of the packets into radioblocks


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GPRS "#')R1A()S

GPRS Core Network : IP basednetwork(1)

Gn interface between 2GS#sGp interface to other GPRS P+M#Gi interface to other PS-# 3 "nternet Wap Gateway )nterprise +A#s4

GPRS ccess NetworkGb interface 3 from SGS# to P($s&ased on 1rame Relay

P($5&S( 3 proprietary interface(alled A5ter A5bis GPRS A5GPRS4678


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GPRS "#')R1A()S

Signa!ing Inter"aces to GS# network(SS$ based) :

Gr interface from SGS# to ,+RGs interface from SGS# to MS(.*+RGd interface from SGS# to GMS(Gc from GGS# to ,+R

Gf from SGS# to )"R4


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Registration of a Mobile

#odeA mobile station m%st register itself

with GPRS network!

GPRS attach

GPRS detach

GPRS detach can be initiated by theMS or the network!


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Session Management

After S%ccessf%l attach a MS gets one ormore Packet -ata Protocol6P-P8

address!'his address is %ni0%e only fora partic%lar session!

"t consists ofP-P type

P-P address assigned to MSRe0%ested 9oSAddress of the corresponding GGS#


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Session

Management6(ontd!8P-P5Address allocation3

Static3Assigned by network

operator of $ser:s home P+M#!

-ynamic3Assigned by(orresponding GGS#!


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P-P (onte2t Activation

MS SGS# GGS#Activate P-P (onte2tRe0%est

Sec%rity 1%nctions

Activate P-P (onte2t Accept

(reate P-P (onte2t Re0%est

(reate P-P (onte2tResponse

P-P typeP-P Address

9oS Re0%estedAccess Point4

P-P typeP-P Address9oS #egotiatedAccess Point4

P-P type9oS #egotiated4P-P typeP-P Address9oS #egotiated4


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+ocation Management

MS fre0%ently sends location%pdate messages to inform the

SGS# where it is!-etermining fre0%ency of %pdate

messages is non5trivial!

'he location %pdate fre0%ency isdependent on the state of the MS!


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%rans&ission P!ane

'he protocols providetransmission of %ser data

and its associated signalling Signa!!ing P!ane

(omprises protocols for the

control and s%pport off%nctions of the transmissionplane

Protocol Architecht%re


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GPRS +ogical (hannels

Gro%p (hannel 1%nction -irection

Packet data'ra;c channel

P-'(, -ata 'ra;c MS &SS

Packet broadcastcontrol channel

P&((, &roadcast (ontrol MS &SS

Packet common(ontrol (hannel6P(((,8

PRA(,

PAG(,

PP(,

P#(,

Random Access

Access Grant

Paging

#otication

MS &SS

MS &SS

MS &SS

MS &SS

Packet -edicated(ontrol (hannels

PA((,

P'((,

Associated (ontrol

'iming Advance (ontrol

MS &SS

MS &SS


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$plink -ata 'ransferMS BSSPRACH or RACH

PAGCH or AGCH

Random Access

Transmission

Packet channel Request

PACCH

PACCH

PDTCH

PACCH

PDTCH

PACCH

Packet Immediate assignment

Packet resource Request

Packet resource assignment

Frame Transmission

egati!e Ackno"ledgement

Retransmission o# $locks in error

Ackno"ledgement


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-ownlink -ata 'ransfer

PRACH or RACH

PAGCH or AGCH

Paging

Transmission

Packet channel Request

PACCH

PACCH or PAGCH

PDTCH

PACCH

PDTCH

PACCH

Packet Immediate assignmentPacket %aging res%onse

Packet resource assignment

Frame Transmission

egati!e Ackno"ledgement

Retransmission o# $locks in error

Ackno"ledgement

Packet %aging requestPPCH or PCH

MS BSS


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M%lti Slot /peration

GPRS allows a mobile to transmit datain %p to < P-(,s 6eight5slot operation8

=5bit $S1 at beginning of each radioblock in downlink points to ne2t %plinkradio block

(omparison with single5slot GSM ,igher delay at higher load

+ow blocking rate

"mproved 'hro%ghp%t


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gprs e.pptx

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