3G mobile services

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Third Generation MobileServices


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September 30, 2005 Girish Kumar Patnaik 2

Third Generation Mobile (3G)

Offering data rates greater than ISDN (144kbps),

typically thought to be 384kbps and perhaps upto

2 Mbps when stationary near a base station. Six types of services:

Interactive multimedia (video conferencing)

High speed multimedia (broadcast TV)

Medium speed multimedia (web browsing)

Circuit switched data (FAX)

Speech (telephony)

Messaging (e-mail, SMS, )


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Paradigm shifts

voice-centric data centric

shift to packet switching

problems: QoS, streaming media

continually evolving terminals and dataapplications - end users expect the same

services (and more) from wireless systems

as they expect from wireline systems


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W-CDMA and cdma2000Technology W-CDMA CDMA2000

Chip Rate 4.096 MCps 3.6864 MCps

Forward Link Pilot

Structure

Dedicated Pilot with

TDM

Common Pilot with

CDM

Base Station TimingSynchronization

Asynchronous Synchronous

Forward Link Modes A multicarrier mode

capable of overlay onto

IS-95 carriers

Comparison of W-CDMA and cdma2000


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W-CDMA and cdma2000

MODE FDD (DS) FDD (MC) TDD

Chip Rate 3.84 MCPs 3.6864 MCPs 3.84 MCPs

Common Pilot CDM CDM To be determined

Dedicated Pilot TDM CDM To be determined

Base StationSynchronization

Asynchronous/Synchronous

Synchronous ascdma2000

To be determined

Harmonization Agreement of the 3G CDMA Modes

I C N k


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Improvement on Core Network

Network related procedures are optimized to reduce signalingtraffic

Introduces a Gateway Location Register (GLR) between theVLR/SGSN and the HLR

From the view point of the VLR/SGSN at the visited network, theGLR is treated as the roaming users HLR located at the homenetwork

From the view point of the HLR at the home network, the GLR actsas the VLR/SGSN at the visited network

HLR and GLR communicate through the D interface

After the first registration, all subsequent registration operations ina visited network are performed locally between the VLRs and theGLR; the remote HLR is not involved.

GLR is physically located in the visited network and interacts with

all VLRs in the visited network.

M fl f th fi t


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Message flow for the firstregistration with GLR


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Message flow for a subsequentregistration with GLR

M fl f h l i


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Message flow for the locationcancellation with GLR

M fl f bil


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Message flow for mobiletermination call with GLR


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Quality of Service in 3G

3G QoS control mechanism should

Efficient utilize resources based on the ability to dynamicallychange QoS parameters during a communication session

Interwork with current QoS schemes

Present end-to-end Qos to the users with appropriate mapping

The end-to-end service on the application level uses thebearer services for the underlying networks, portionedinto three segments

Local bearer service provides a connection between TE and

MT

3G bearer service provides 3G QoS

External bearer service provides the connection to the the other

party in the call


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3G bearer service consists of two parts

Radio Access bearer service provides confidential

transport of signaling and user data for moving usersover the radio interface

Core Network bearer service utilizes a 3G backbone

network service that covers layer 1 and layer 2

functionality (eg. ATM or IP-based)

Q lit f S i i 3G


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Four QoS classes:

7 QoS parameters: max/min/guaranteed bit rates, max.packet size, reliability,

Major problems with how to map between the QoS of

different systems.

O


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Wireless Operating System

for Handsets

Wireless OS should satisfy the followingrequirements:

Immediate access to applications

Modular software

Support low-powered CPUs

Be protected in a read-only-memory chip


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Wireless OS Examples

Windows Consumer Electronics (WinCE) OS

Developed by Microsoft

Subset of Windows NT

EPOC OS

Developed by Psion

Symbian uses EPOC

PalmOS Developed by 3Com


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EPOC

EPOC provides communication to the outside worldthrough serial and sockets, dial-up, TCP/IP, and PCconnect

Components Base Component

Consists of portable runtime system, kernel, file server,

user library and file server APIs Engine support Component

Provides APIs for data manipulation, an application

architecture, resource files and utilities, standard Clibrary and text tools

Graphics Component GUI


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EPOC

EPOC kernel is light weight

Kernel supports preemptive multitasking,enabling context switching between

threads

A power model is used by the kernel and

device drivers to turn off devices and

power sources when they are not active

3G mobile services

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