Slide thông tin di động đại học bách khoa hà nội chương 6 general packet radio service

3 3 General Packet Radio Service GPRS 2/17/2014 GPRS Network Architecture SMSC MSC/VLR HLR Packet Control Unit PCU SGSN SGSN GGSN Charging Gateway Function Billing PDN RF air interfac

Trường Đại học Bách Khoa Hà Nội

Khoa Điện tử Viễn thông

Thông tin di động Mobile Communications

TS Đỗ Trọng Tuấn

Bộ môn Kỹ thuật thông tin

Hà Nội, 9-2010

2/17/2014

General Packet Radio Service

(GPRS)

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3 3

General Packet Radio Service

(GPRS)

2/17/2014

GPRS Network Architecture

SMSC MSC/VLR HLR

Packet

Control Unit

(PCU)

SGSN

SGSN GGSN

Charging Gateway Function Billing

PDN

RF air

interface

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GPRS system architecture

2/17/2014

How is GPRS seen by external networks and

GPRS users?

Local area network

Router Corporate 2

Local area network

Router

Corporate 1 Packet

network Data network

(Internet)

GPRS SUBNETWORK SUBNETWORK 155.222.33.XXX

SUBNETWORK 131.44.15.XXX SUBNETWORK

191.200.44.XXX

HOST

191.200.44.21

HOST 131.44.15.3

HOST

155.222.33.55

"Router"

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Salient Features of GPRS

 Important step on the path to 3G

 Standardized by ETSI

 GPRS is an overlay network over the GSM

 Provides Data Packet delivery service

 Support for leading internet communication protocols

 Billing based on volume of data transferred

 Utilizes existing GSM authentication and privacy

procedures

2/17/2014

Advantage of GPRS

 Use of packet-switching technology

 Enables multiple users to share air interface

resources

 Users feel their services to be “always on”

 GPRS is primarily for data communication and

not for voice communication

 GPRS communicates using TCP/IP protocol

similar to the internet

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GPRS

Tốc độ truy nhập

Tốc độ truy nhập

t t

t

Không truy nhập

2/17/2014

Applications

Standard data network protocol based

IP based applications

• WWW, FTP, Telnet,

• Any conventional TCP/IP based applications

X.25 based applications

• Packet Assembly/Disassembly (PAD) type approach

GPRS specific protocol based

Point-to-point applications

• Toll road system, UIC train control system

Point-to-multipoint applications

• Weather info, road traffic info, news, fleet management

SMS delivery (GPRS as a bearer for SMS)

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Mobility Management state model in GPRS

2/17/2014

QoS Profile for GPRS Bearers

 Describes applications characteristics and QoS

requirements

 4 parameters:

• Service precedence

 3 classes

• Reliability parameter

 3 classes

• Delay parameters

 4 classes

• Throughput parameter

 Maximum and mean bit rates

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QoS Precedence classes (from [GSM 03.60])

Reliability classes (from [GSM 02.60])

SDU (Service Data Unit)

2/17/2014

Delay classes (from [GSM 02.60])

Peak throughput classes (from [GSM 03.60])

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Mean throughput classes (from [GSM 03.60])

2/17/2014

PDP and PDF contexts

PDF : Packet Data Flow PDP : Packet Data Protocol

NSAPI : Network layer Service Access Point Identifier

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Channel coding schemes applied per time slot

• The Packet Data Traffic Channels ( PDTCH s) use four different channel

coding schemes, described in [GSM 04.60] to transfer the packet data

traffic Above table lists the used channel coding schemes and the data

rates that can be obtained by using these coding schemes per time slot.

• The maximum data rate that can be obtained on PDTCH channels is

8*21.4 kb/s = 171.2 kb/s

i.e., (8 time slots) * (Maximum data rate for CS-4 for a time slot).

2/17/2014

PDP Context

used by an external packet data network interfacing to

GPRS.

for a PDP address

integer value in the range [0; 15], identifying a certain

PDP Context

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PDP Context Activation Procedure

+ IP assignment + Roaming

2/17/2014

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SIM300

Features

 Tri or Quad-Band GSM/GPRS

 40x33x2.85mm 60-pin ENTERY board to board connector

 Support sleep mode(about 3mA)

 Embeded TCP/IP protocol

 Autobauding

 Support RTC function

 Over-temperature automatic shutdown

 Operation temperature -20~55Ԩ

 Supply voltage 3.4-4.5V

 Support FAX and USSD

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SIM508 and SIM548

Features

 Tri or quad-band GSM/GPRS+GPS

 80PIN CONNECTOR

 GSM part based on SIM300C

 GPS receiver with SiRFstar III GSC3f chip set

 Processor type ARM7/TDMI

 Software version: SiRF GSW3

 Two serial GPS interfaces

 Size: 55±0.15 x 34±0.15 x 2.9±0.3 mm

2/17/2014

SIM508 and SIM548 Application

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