Third Generation Wireless Systems

CW-1© Copyright Roshdy H.M. Hafez 1996-2000

3G Wireless

Third GenerationThird GenerationWirelessWirelessSystemsSystems


About the Instructor

Dr. Roshdy H.M. HafezDr. Roshdy H.M. Hafez

email: email: hafezhafez@@scesce..carletoncarleton.ca .ca


3G Wireless

4Motivation for 3G4IMT-2000 Development Procedure4Cdma20004UTRA/ARIB WCDMA4UWC-13643G Networks

Course Outline


Motivation for 3G

§ The second generation (2G) wireless systems

§ Motivations and drives for new standards

§ The business case for 3G

§ The case for broadband fixed wireless access


Second Generation Systems (2G)

Cell Size

Data Rate

Outdoor

indoor

CellularPCS

WirelessLAN

10 kbps

10 Mbps

l GSMl IS-136 (D-AMPS)l IS-95 (CDMA)

l Hiper LANl Ad-Hoc Networksl AT&Tl Olivettil IEEE802.11l … etc ..


2G Services

Voice – Required in all

wireless environment– Huge market

Data – Limited data

applications– Circuit-switched– Short Message

Systems (SMS)– The main drive for 3G

100 - 200%Coding

BER =0.1%

OrFER= 1%

Performance

20-ms frames

8 – 13 kbps

Format

Vocoder rate


2G Technologies

56 - 807150# / cell / 5 MHz

One cell7 cell4 cellsFrequency Re-use

BW / user ∼ 90 – 62.5 kHz10 kHz25 kHz

∼ 14 - 2038users/carrier

200 kHz

GSM

TDMA

30kHz

IS-136 IS-95

1,250 MHzBW / carrier

CDMA


2G Network Model

HLR

MobileStations

Base Stations &B.S. Controllers

Network Mgmt Subscriber Services

OMC

AuC

BSC

MSC

BS

VLR

EIR

PSTN

ISDNVLR = Visitor Location

Registry

HLR = Home Location Registry

EIR = Equipment Identification Registry

AuthenticationCenter

MSC = Mobile Switching Center

BS = Base Station OMC = Operation & Maintenance Center

BSC = Base Station Controller


2G Network Model (cont.)

BSC

BSC

MSC

IWF PacketOr IP-Network

PSTN

modem


Example of 2G Data Connection

BSC

MSUE

RLP Protocol

PPP Protocol

RS-232

MSC IWF

HDLC FR

Application

DataNet.


Example of 2G Voice Connection

BSC MSC

PSTN

BSC MSC

System A

System B


2G to 3G Evolution

MultimediaPCS

PCS

Cellular

BroadbandMultimediaWireless

3GIMT-20002.5 G

2ndGeneration


2G to 3G Evolution (cont.)

2G 3G

IS-95 IS-95-B Cdma2000

WCDMA

WCDMATDD

UWC-136

GSM

IS-136

IS-136+

EDGE 136HS


2G Limitations

● Designed primarily for mobile telephony§ Symmetric communications§ Circuit-switched§ Tolerate high error rates (up to 0.1%)§ Narrowband information (< 14.4 kbps)

● Too Many Standards§ Several incompatible air interfaces (GSM, TDMA.

CDMA, AMPS, DECT,…) § Wireless LANs and PCS are totally different and

incompatible

● Isolated Networks§ Two different networks: IS-41-C and GSM-MAP§ No direct communications between different

operators


Goals of 3G

l Wide range of operating wireless environmentsn Indoor / Outdoor

n High mobility (vehicular) / low mobility

l Wide range of transmission ratesn 1.2 kbps - 2 Mbps

l Support for different transmission modesn Circuit switched voice and datan IP-based application

l Support for a wide range of servicesl Multimedia QoS control capabilitiesl Compatibility and inter-operability with 2G systemsl Network interface standards


The Business Case for 3G

● Viable Applications§ E-Commerce§ email§ Internet browsing§ Entertainment

● Consumer Acceptance§ Ease of use§ Consumer dependency on Internet§ Widespread acceptance of cellular technologies

● Efficient Distribution§ Integration with other devices§ New car built-in options


The Business Case for 3G

CorporateApplications

&email

Data Services & Information

DatabasesWWW

browsing

Always-ONPre-paid

Wide-spread availability

Time


The Business Case for 3G (cont.)

50

100

150

200

250

300

350

1995 2000 2005 2010 2015

10%

20%

30%

40%

50%

60%

70%Million Subscribers Multimedia Penetration

among mobile users


How About Fixed Wireless Access

● Mobility§ The term "Personal" implies "Mobility"§ Mobility management and Signaling

● Physical Limitations§ Personal communication is more

challenging§ PCS antennas cannot be easily optimized§ PCS environment is highly variable

● Radio coverage§ FWA requires targeted radio coverage§ PCS requires total coverage

● Market§ PCS has much bigger market§ Billions of potential subscribers

PCS vs. FWA


The Business Case for FWA

● Viable alternative to cable, direct-to-home satellite and xDSL access over copper

● Easy to deploy with minimum infra-structure

● Very attractive solution for building-to-building high speed data links


IMT-2000 Development Process

§ History of IMT-2000 within the ITU

§ The IMT-2000 guidelines

§ The RTT proposals and technical evaluations

§ The harmonization efforts 3GPP and GHG


The Roots of IMT-2000

§ IMT-2000 = 3G

Race I

Race II

ACT

WRC 92

FPLMTS

IMT-2000

UMTS

1997


What is IMT-2000?

§ A process to establish "Global Standards" for wireless communications

§ The IMT-2000 process addresses:

Ø Air Interface

Ø Networks

Ø Services

§ It covers

Ø Personal wireless (PCS)

Ø Fixed Wireless Access (FWA)

Ø Satellite

IMT-2000

AirInterface

Networks Services

PCS FWA Satellite


IMT-2000 Data Model

CELLULAR

CORDLESS

IMT-2000

WLAN

Wired100.0

10.0

1.0

0.1

0.01

indoor outdoor

room building stationary walking car

Bit

rat

e M

b/s


The IMT-2000 Three Environments

Cell Size

Data Rateindoor

WirelessLAN

144 kbps

10 Mbps

2 Mbps

3G

384 kbps

Outdoor

PCS/CellularVehicular

Pedestrian

Indoor


Developing Air Interface Standards

Request for candidate RTT

proposals

Development of RTT Proposals

Self evaluation &Consensus building

Proposals & Evaluation reportsExamining proposed

RTT

RTT Synthesis & Consensus building

Recommendation

Implementation

VariousGroups

ITU

3GPP3GPP-2

1997

1998

1999

2000


Developing Air Interface Standards

l There are 15 proposals submitted to ITU:

u 1 (indoor only)u 9 (indoor/outdoor)u 5 (satellite)

l Out of the 9 indoor/outdoor proposals

u 1 TDMAu 1 Hybrid TDMA/CDMAu 7 CDMA

l The best known proposals were

u Cdma2000 North American based on IS-95

u W-CDMA UTRA/ARIB Japan

u UWC-136 GSM & IS-136


Harmonization

§ Global Partnerships:

Ø 3GPP (3G Partnership Project)

Ø 3GPP2

Ø UWCC (Universal Wireless Communications Consortium)

Ø OHG (Operators Harmonization Group)

§ Convergence of the technology

§ Emergence of technology groupings


3G Partnership Project (3GPP)

ITU

High Level Frame Work

3GPP

Project Coordination Group

Technical Specification Groups

PartnersOrganizations

Regulators

Marketing

Individual Members

TechnicalContributions

International Recommendations

Technical Specifications


3GPP

3GPP

Technical Specification Group

TSG-RAN

RadioAccessNetwork

TSG-SA

Servicesand

SystemsAspects

TSG-T

Terminal

TSG-CN

CoreNetwork


3GPP2

3GPP2

Steering Committee

TSG-A

A-Interface

TSG-C

cdma2000

TSG-P

PacketData

Network

TSG-R

NetworkInterface

IS-41

TSG-S

Serviceand

SystemAspect

TSG-N

ANSI-41WIN


Partnership Supporting Organizations

ITU - IMT-2000

3GPP

-ETSI-ARIB-Korea TTA-China CWTS

WCDMA Cdma2000

3GPP2

-TIA-ARIB-Korea TTA-China CWTS

UWC-136

-ETSI-US TR45.3-UWCC

DECT+

ETSI


ITU Air-Interface Recommendation


Cdma2000

§ Description of CDMA2000 physical layer

§ Data rates and signal processing blocks

§ Various deployment strategies

§ CDMA2000 MAC and LAC layers

§ Radio resource management

§ IP-based networking


Origin of Cdma2000

§ Cdma2000 is an evolution of the 2G CDMA standard IS-95

IS-95-A IS-95-B RTT-1X RTT-3X

CDMA2000

TIA/EIA-95-BEnhanced CDMA

2G CDMACell Phones


Cdma2000 Layered Architecture


Cdma2000 Layered Architecture (cont.)

LAC / MAC

Signaling

Logical Channels

Physical Channels

Configurationrecords

Broadcast Common Dedicated

ProprietyAlgorithms


RLP & QoS

§ Data applications are subjected to two processes:

Ø Radio Link Protocol (RLP):1. Transparent (no retransmission)2. Non-Transparent (with ARQ)

Ø QoS Control• Power allocation and Signal Format• Multiplex options• Priority enforcement• Congestion control


Traffic Channels and Data Rates

TIA/EIA/95-A TCH 14.4 kbps

TIA/EIA/95-B F-CH

Up to 7 Supp. Ch.

115.2 kbps

IS-2000-1X F-CH

Up to 2 Supp. Ch.

DCCH 307.2 kbps

IS-2000-3X F-CH

Up to 2 Supp. Ch.

DCCH 10368 kbps

Max. RateDedicated ChannelsModes

Cdma2000


Traffic Channels and Data Rates

4 RF Bandwidth = 1.25 MHz

4 Chip rate = 1.2288 Mcps

The IS-95-B Channel

OR

RTT-1X Channel

Multi-Carrier: RTT-NX

N=3, 6, 9, 12

4 Multiples of RTT-1X channels

4 RF Bandwidth = (N+1)*1.25 MHz

4 Chip rate = N*1.2288 Mcps

1.25 MHz 1.25 MHz 1.25 MHz 1.25 MHz

5 MHz

1.2288 Mcps 1.2288 Mcps 1.2288 Mcps


Deployment Options

1.25 MHz

5 MHz5 MHz

1.25 MHz1.25 MHz

1.25 MHz

80 MHz

Mobile Tx Mobile Rx

95-B

RTT-1X

RTT-3X


2G / 3G Compatibility

Carrier 1

95B or 1X

Carrier 1

Carrier 2

Carrier 3

MUX

Cdma2000-3X

5 MHz

3.6864 Mcps

1.25 MHz 1.25 MHz 1.25 MHz 1.25 MHz

5 MHz

1.2288 Mcps 1.2288 Mcps 1.2288 Mcps

D-MUX

Carrier 3

IS-95 N=1

Cdma2000x3

Carrier 2

Carrier 1

1.2288 Mcps

1.25 MHz

1.2288 Mcps

1.25 MHz


Composite CDMA Waveform

1.25 MHz

Different

codes

Frequency

Time

20 ms frame

5 ms frame


§ A physical resource is a Coded channel transmitted at a given level of Power for a certain time length "Frame"

§ Cdma2000 physical frame lengths [5 10 20 ms]

§ Tight power control:

Ø Open loop power controlØ Forward and Reverse closed loop power controlØ Outer loop power control

§ 9 Forward and 6 Reverse Radio Configurations

§ Many Channel Formats in every radio configuration

Major Characteristics


Downlink Radio Configurations

20 ms

5 ms

20 ms

5 ms

5, 20 ms

5, 20 ms

5, 20 ms

5, 20 ms

5, 20 ms

20 ms

20 ms

Frame

1/2

1/3

1/4

1/3

1/3

1/6

1/4

1/2

1/4

1/2

1/2

Rate

1.8/3.6/7.2/14.4/28.8/57.6/115.2/

230.4/460.8/1036.89

1.8/3.6/7.2/14.4/28.8/57.6/115.2/

230.4/460.88

1.5/2.7/4.8/9.6/19.2/38.4/76.8/

153.6/307.2/614.47

1.5/2.7/4.8/9.6/19.2/38.4/76.8/153.6/307.26

3X

1.8/3.6/7.2/14.4/28.8/57.6/115.2/230.45

1.5/2.7/4.8/9.6/19.2/38.4/76.8/153.6/307.24

1.5/2.7/4.8/9.6/19.2/38.4/76.8/153.63

1X

1.8/3.6/7.2/14.42

1.2/2.4/4.8/9.6195B

Data Rate, kbpsRC


Uplink Radio Configurations

5, 20 ms

5, 20 ms

5, 20 ms

5, 20 ms

20 ms

20 ms

Frame

1/4

1/2

1/4

1/3

1/4

1/4

1/2

1/2

1/3

Rate

1.8/3.6/7.2/14.4/28.8/57.6/115.2/230.4/460.8

OR

1036.8

6

1.2/1.35/1.5/2.4/2.7/4.8/9.6/19.2/38.4/76.8/153.6

OR

307.2/614.4

5

3X

1.8/3.6/7.2/14.4/28.8/57.6/115.2/230.44

1.2/1.35/1.5/2.4/2.7/4.8/9.6/19.2/38.4/76.8/153.6

OR

307.2

3

1X

1.8/3.6/7.2/14.42

1.2/2.4/4.8/9.6195B

Data Rate, kbpsRC


Forward Physical Channels

Common Dedicated

Common PilotCommon Transmit Diversity Pilot

Auxiliary PilotAuxiliary Transmit Diversity Pilot

SynchPaging

Quick PagingCommon Control

Common Power ControlCommon Assignment

Broadcast Channels

FundamentalSupplementalDedicated ControlDedicated Auxiliary Pilot


Reverse Physical Channels

Common Dedicated

AccessEnhanced AccessCommon Control

FundamentalSupplementalDedicated ControlPilotPower Control

Random Access Mode Circuit-Switched Mode


Processing the Physical Channels

CodingRepeat

PunctureInterleave

Decimator

MaskedLong Code

MUX

Bitselector

I/Q &Binary

toBipolarMap

WkComplex

PNSpreading

Filter

Filter

Cos ωt

Sin ωt

Data

QPSKModulat ionPN Cell

Identification

WalshChannelization

Power controlSub-channel

Scrambl ing(privacy)

Errorcontrol

Cdma2000-1X


Processing the Physical Channels (cont.)

CodingRepeat

PunctureInterleave

Decimator

MaskedLong Code

Bitselector

MUX

I/Q &Binary

toBipolarMap

W k1Complex

PNSpreading

Filter

Filter

Cos ω 1 t

Sin ω 1 t

Data

I/Q &Binary

toBipolarMap

W k2Complex

PNSpreading

Filter

Filter

Cos ω 2 t

Sin ω 2 t

I/Q &Binary

toBipolarMap

W k3Complex

PNSpreading

Filter

Filter

Cos ω 3 t

Sin ω 3 t

De

-Mul

tiple

xMUX

MUX

PowerControl

bits

+


Channelization Using Walsh Codes

]0[0 =A

=

=

10

00

00

001

AA

AAA

=

=

01

11

10

0010

00

10

00

11

112

AA

AAA

=+

mm

mmm

AA

AAA 1

General Form


The Pilot Channel [PN Cell Identifications]

• Transmitted at al l t imes on every CDMA carrier

• New mobiles use it to synchronize

• Receiving mobiles use it for channel estimation and RAKE combining

• Mobiles use it to detect new cells and request hand-off

• Each cel l has a unique pilot offsetthat identifies it.


The Pilot Channel [PN Cell Identifications]

Inserted zero

.. 0 0 0 1 …000 0 1

14 zeros

Zeroshift

1 2 3 511

Ts

215=32768 chips

32767 chips


Pilot in Different Cdma2000 Modes

1.2288 Mcps

1.25 MHz

1.25 MHz 1.25 MHz 1.25 MHz 1.25 MHz

5 MHz

1.2288 Mcps 1.2288 Mcps 1.2288 Mcps

5, 10 or 15 MHz

Nx1.2288 Mcps

Zeroshift

1 2 511

Ts

Zeroshift

1 2 511

N code cycles

Direct Spread

3X Multi-Carrier

95 or 1X

In MC, the pi lot is transmitted on every carrier with the same shift

512 shifts over N cycles


The Long Code

◆ The output is a shifted version of the long code.

◆ The shift is uniquely related to the 42-bit mask

◆ Each mobile unit has its own unique mask (Electronic Identification)

◆ Some masks are common for access and other signaling

1234142

MOD-2 ADDER

THE REFERENCE LONG CODE GENERATOR

42-B

IT M

AS

K

OUTPUT


Aligning the Long and Short Codes

● Absolute time reference is achieved by observing the states of the long and short codes

1

1

11 0 [15]

1 0 [15]

1 0 [41]

January 6, 1980

Zero offset I pilot

Zero offset Q pilot

Long code mask

26.66.. µs

approx. 41.425 days

1

1

11 0 [15]

1 0 [15]

1 0 [41]

approx. 37 centuries

● All base stations are synchronized through the GPS ● Time shifts of the I&Q pilot codes (short codes) identify

base stations● Time shifts of the long code identify individual users


Air Interface Features & Facilities

§ Signaling formats

Eb/No ßà FER (BER)

Convolutionor Turbocoding

SymbolRepeat

SymbolPuncture

BlockInterleaver

Qualityindicator

Trailbits

§ Auxiliary pilots


Air Interface Features & Facilities (cont.)

§ Different Frame Lengths

5 ms Efficient MAC signaling

For possible harmonization with WCDMA10 ms

20 ms Vocoders (IS-95 native)

20, 40 or 80 ms

[Logical] For efficient transmission of supplemental channels

§ Using the supplemental channels in burst format

Allocate-Lock-unlock approach



§ RCCCH & the Enhanced Access ChannelØ Quick re-connectØ Slotted modeØ Reservation mode

Reverse Access Transmission

Reverse Pilot

AccessPreamble

AccessMessages

Pilot

Multiples of1.25 ms

Access Probe



§ Common Assignment Channel

Designed for fast assignment in a random access packet mode.

§ Reservation



◆ Carries PC bits for several reverse common control and enhanced access channels

MUX

0

N-1

RepeatSignal

MappingGain

MUX

N

2N-1

RepeatSignal

MappingGain

decimator MaskLong code

Generator @3.6864 Mcps

offset

48200 bps

12800 bps

24400 bps

NUpdate rate

§ Common Power Control Channel


Quick Paging Channel

20 ms 80 msPCH slot

80 msQPCH s lot

Indicators for this slot


Orthogonal Transmit Mode

BasebandFilter

Pha

se r

otat

ion

Repeat++

Repeat++

Σ

Σ

+

-

-

+

Cosωt

BasebandFilter

sinωt

Σ

BasebandFilter

Pha

se r

otat

ion

Repeat++

Repeat++

Σ

Σ

+

-

-

+

Cosωt

BasebandFilter

sinωt

Σ

PN I

PNQ

S1(t)

S2(t)

Walsh

QOF +/-

Walsh

QOF +/-


Reverse Link Spreading & Multiplexing

ComplexPN

Spreading

Gain

Gain

Cos ωt

Sin ωt

Filter

Filter

Long code

PN I PNQ

[+ - - +]

[++ + + - - - -]

Gain

Gain

[+ -] 0r [+ - - +]

Gain

Gain

[+ + - -]

Pilot & PC bits

R-DCCH

R-SCH

second

R-SCHfirst

R-FCH


Radio Resource Management Issues

§ Call admission?§ Assessment of available resources§ Predicting the impact of admitting new users§ Accounting for soft hand-off§ Estimating the feasible data rate

§ Optimum allocation of resources§ Power§ Code/Interleave/Repeat/Puncture Format§ Spot beams

§ Managing traffic fluctuations§ Feasible bandwidth on demand§ Avoiding tying up radio resources§ Quick re-connect


UTRA/ARIB WCDMA

§ Description of the physical layer

§ Logical, transport and physical channels

§ Multiplexing and radio resource management

§ Synchronization and system acquisition

§ New features to improve signal detection

§ The MAC and LAC layers

§ The TDD and Asymmetric communications


What is WCDMA ?

§ WCDMA is a wideband CDMA access system

§ There are several versions of WCDMA developed separately by ARIB (Japan), UTRA (Europe), Korea and NA.

§ All these proposals were harmonized earlier and now are presented as WCDMA

§ WCDMA has two modes:

Ø Frequency Division Duplexing (FDD)

Ø Time Division Duplexing (TDD)

§ WCDMA is strongly sponsored by the UMTS forum


WCDMA Layered Protocol

Network Layer

Link Access Control (LAC)

Media Access Control (MAC)

Physical LayerTransportChannels

PhysicalChannels

LogicalChannels

What is being transmitted

How will it be transmitted

Coding, interleaving, multiplexing..etc.

Physical data stream

One transport channel Could be transmitted on

several physical channels

Protocol Layers


Transport Channels

Up Link Transport Channels

Mobile

Dedicated Channel

Base

Dedicated Channel

Forward Access Channel

Broadcast Access Channel

Paging Access Channel

Random Access Channel

Common Packet Channel

Downlink Shared Channel

Down Link Transport Channels

Common

Dedicated


Processing the Transport Channels

CodingStatic Rate Matching

OptionalFrame-to-

FrameInterleaving

TC

Mul

tiple

x

In-FrameInterleaver Down Link

ToPhysicalFrames

CodingStatic Rate

Matching

OptionalFrame-to-

FrameInterleaving

TC

Multiplex

In-FrameInterleaver

Dynamic Rate

Matching

Up Link

ToPhysicalFrames


Flexible Transport to Physical Mapping

TC

De

-Mul

tiple

x

Map

per

TC

Mul

tiple

x

Map

per

One High Data Rate Transport

Channel

Transmitted on several

Physical channels

Several Low Data Rate Transport Channel

Transmitted on One Physical

channel

Transport Physical


Mapping Transport to Physical Channels

Downlink

Map

Map

Dedicated Channel

Forward Access Channel

Broadcast Access Channel

Paging Access Channel

Downlink Shared Channel

Dedicated Physical Channel

Synchronization Channel

Common Pilot Channel

Common Control Physical Channel

Physical Downlink Shared Channel

Acquisition Indication Channel

Paging Indication Channel

Dedicated Channel

Random Access Channel

Common Packet ChannelDedicated Physical Control Channel

Physical Random Access Channel

Dedicated Physical Data Channel

Physical Common Packet Channel Uplink


Highlights of Downlink Physical Channels

Indicates to the mobile that it has a paging message

PICHPaging Indication Ch.

Signals the mobile to transmit on common uplink channels

AICHAcquisition Indication Ch.

Common packet channelPDSCHPhysical Downlink Shared Ch.

Carries system information broadcast

CCPCHCommon Control Physical Ch.

Allows the mobile to search the cell and synchronize

SCHSynchronization Ch.

Facilitates the coherent detection mode

Carries user information

CPICHCommon Pilot Ch.

DPCHDedicated Physical Ch.


Highlights of Uplink Physical Channels

Carries user's packet dataPCPCHPhysical Common Packet Ch.

Carries control signalsDPCCHDedicated Physical Control Ch.

Slotted ALOHA acess

Carries user information

PRACHPhysical Random Access Ch.

DPDCHDedicated Physical Data Ch.


What is A Physical Channel?

§ A WCDMA physical channel is a coded stream of symbols transmitted within one slot in a frame.

§ All the slots of a given frame have the same channelization code but may carry different Transport Format

§ The transport format of each slot is signaled within the slot

TPC TFI Data

Time Slot

TFI = Transport Format IndicatorTPC = Transport Power Control


WCDMA Frame Structure

Frame 1 Frame 2 Frame i Frame 72

Super Frame = 720 ms

Slot 1 Slot 2 Slot k Slot 15

Frame = 10 ms

Symbol

Chip0.26 µs

For 5 MHz BW

Slot = 0.666… ms


Physical Layer Characteristics

1. Minimum Bandwidth

Ø 5 MHZ à TDD

Ø 2x5 MHz à FDD

Mobile Tx and Rx

Mobile RxMobile Tx

Frequency

Frequency

80 MHz 5 MHz

5 MHz

TDD

FDD


Physical Layer Characteristics (cont.)

2. Chip rate is fixed at:

Ø 5 MHz à 3.84 Mcps



3. WCDMA uses a "Variable Processing Gain" approach. The chip rate is fixed while the data rate is variable.

4. Minimum processing gain = 4

bit

chip Min. Processing Gain = 4


Transmitted Waveform

15 time slots = 10 ms

5 MHz

Different

codes

Frame

One user may consume: • One or more time slot on a code• The whole code (15 slots), or• Several codes


The FDD Mode

The DS mode uses Frequency Division Duplexing (FDD)

5 MHz

Frame

5 MHz

80 MHz

MobilesTo

Base

BaseTo

Mobiles


The TDD Mode

The TDD mode uses Time Division Duplexing

5 MHz

Frame

Mobiles To Base

Base To Mobiles


Error Correcting Codes

Three Options

(1) Convolutional coding

1/3 CC(3,1,9,557,663,711)

1/2 CC(2,1,9,561,753)

(2) Turbo Coding

1/3 or 1/2

(3) Service-Specific Coding

-310 BERRequired =

-610 BERRequired =

32kbps Speed High >


Rate Matching

STATIC DYNAMIC

Up Link & Down Link

Matched the total symbol rate to the rate of the physical data stream.

Up Link Only

Slow. Activated when adding or removing Transport Channels

Fast. Every 10 ms

Puncturing

Symbol repetition

Matched the total instantaneous symbol rate to the rate of the physical data

stream.

Unequal symbol Repetition

Links

Speed

Why ?

How ?


Downlink Spreading and Modulation

Serialto

Parallel

p(t)

p(t)

Channelizationcode

Scramblingcode

Cos(ωt)

Sin(ωt)

Pulse shapingFilter

(RC with 0.22 Roll-off)

Data

DPDCH&

DPCCH

Dedicated Physical Channel


Spreading and Scrambling

4The I & Q channels are spread by the same code.

4 It is one of a set of orthogonal codes known as the "channelization codes".

4The I & Q channels are also scrambled using the same scrambling code

4The scrambling code is "Cell Specific"


Channelization Codes

C1,1 = (1)

C2,1 = (1,1)

C2,2 = (1,-1)

C4,1 = (1,1,1,1)

C4,2 = (1,1,-1,-1)

C4,3 = (1,-1,1,-1)

C4,4 = (1,-1,-1,1)

C8,1 = (1,1,1,1,1,1,1,1)

C8,2 = (1,1,1,1,-1,-1,-1,-1)

C8,3 = (1,1,-1,-1,1,1,-1,-1)

C8,4 = (1,1,-1,-1,-1,-1,1,1)

C8,5 = (1,-1,1,-1,1,-1,1,-1)

C8,6 = (1,-1,1,-1,-1,1,-1,1)

C8,7 = (1,-1,-1,1,1,-1,-1,1)

C8,8 = (1,-1,-1,1,-1,1,1,-1)

SF=1 SF=2 SF=4 SF=8 SF=16


Channelization Codes (cont.)

C1,1 = (1)

C2,1 = (1,1)

C2,2 = (1,-1)

C4,1 = (1,1,1,1)

C4,2 = (1,1,-1,-1)

C4,3 = (1,-1,1,-1)

C4,4 = (1,-1,-1,1)

C8,1 = (1,1,1,1,1,1,1,1)

C8,2 = (1,1,1,1,-1,-1,-1,-1)

C8,3 = (1,1,-1,-1,1,1,-1,-1)

C8,4 = (1,1,-1,-1,-1,-1,1,1)

C8,5 = (1,-1,1,-1,1,-1,1,-1)

C8,6 = (1,-1,1,-1,-1,1,-1,1)

C8,7 = (1,-1,-1,1,1,-1,-1,1)

C8,8 = (1,-1,-1,1,-1,1,1,-1)

SF=1 SF=2 SF=4 SF=8 SF=16


Scrambling Codes

1

2

3

32

0 1 2 15

16 17 18 31

32 33 34 47

496 497 498 511

512 codes

32 Groups x16 codes per group

1 2 3 16

18 stage m-sequence

18 stage m-sequence

1+x7+x18

1+x5+x7+x10+x18

xn

y

Cn


Uplink Scrambling and Modulation

Dedicated Physical Channel DPDCH/DPCCH

p(t)

Cos(ωt)

Sin(ωt)

DPDCH

DPCCHp(t)

Re [ Cscramb] Im [ Cscramb]

CD

CC

+

-

+

+

Channelizationcodes


Uplink Scrambling Codes

SHORT LONG

complex

Extended Kasami Set

complex

256 chips10 ms (one radio frame)

e.g. 40960 chips @1.096 Mcps

Identifies the mobile

Segments of sets of Gold sequences

Length

Class

Purpose Identifies the mobile

Short codes simplifies muti-user detection

Used in cells without mutli-user detection


Initial Synchronization

Power ON

Slot Synchronization

Frame Synchronization& Group Identification

Scrambling CodeIdentification

Super Frame Synchronization& Read BCCH

Primary Synch code

Secondary Synch code

Primary CCPCH

Primary CCPCH

SCH

P-CCPCH


The Synchronization Codes

16 Slots

Cp

Cs(k,1)

Cp

Cs(k,2)

Cp

Cs(k,16)

2560 chips(Slot)

256chips


Properties of the Secondary SCH

A set of 17 orthogonal Gold codes of length 256 chips

{ C1,C2 ,C3 ,C4 ,C5 ,C6 ,C7 ,C8 ,C9 ,C10 ,C11 ,C12 ,C13 ,C14 ,C15,C16,C17 }

A secondary SCH SEQUENCE is made of 16 codes selected out of the set of 17 codes

e.g. ( C1C1C2 C11C6C3C15C7 C8C8C7C15C3C6C11C2 )

There are 32 sequences

They are selected carefully to have the following properties

Cyclic shift of any sequence does not look like any other sequence

Any cyclic shift of a sequence does not look like itself with any other cyclic shift

The 32 sequences are used for the initial cell search


Properties of the Secondary SCH

4The Primary SCH is the same in all cells (sectors)

4The "mobile" searches for the unique code of the P-SCH

time

Slot2560 chips

Primary synch code256 chips

Base "b"

Base "a"

Cp


Processing the Primary SCH

Matched FilterCp (256 chips)

Rx signal Accumulateover Tslot

Non-coherent

SelectMax.

Slottiming

Tslot Tslot

Tslot

BaseA

BaseB

BaseC


Frame Synchronization

4The mobile uses the secondary SCH for frame synchronization

4In this stage, the slot timing is known

time

Frame

Ck,1 Ck,2 Ck,3 Ck,4Ck,16 Ck,16 Ck,1

TT/10


Processing the Secondary SCH

MF C1

MF C2

MF C3

MF C17

16 Slots

SelectLargestin each

slot

C i Ck Cm Cn

Most Likely Code Sequence


Processing the Secondary SCH (cont.)

16 Slots

C i Ck Cm Cn

Most Likely Code Sequence

16 cyclicshifts

32Groups

Compare to all512 Sequences

Group&

ShiftIdentified


Processing the Secondary SCH (cont.)

10 ms (4096 chips @ 4.096 Mc/s)

8 12 8 12 8 12 8 12 8 12 8 12 8 12 8 12 8 12 8 12 8 12 8 12 8 12 8 12 8 12 8 12

One cycle of the scrambling code

Pilot Data

Integrate over a symbol period

Candidate scramble code #1





P-CCPCH

Magnitude Accumulate



Sel

ect L

arge

st


The Random Access Channel

• Collision Risk• with some code division• protection


The Random Access Burst

Random access burst

Offset

11.25 ms1.25 ms

Message = 10 ms

Idle time = 0.25 msPreamble = 1 ms

One burst


Spreading and Modulation of the Random Access Channel

p(t)

Cos(ωt)

Sin(ωt)DataPart

Complexspreading

p(t)

CD

CC

R

I

ControlPart

Complex cell-specificscrambling code

Real [signature]

Cpreamb

Imag [signature]

1

2

3

1

2

3Position 1: 1 ms

Position 2: 0.25 ms

Position 3: 10 ms


WCDMA vs. CDMA2000

Spreading and Identifying individual users:

• Both systems use scrambling codes (long) and channelization codes (short & orthogonal).

Identifying Cells:

• Cdma2000 uses the shifted complex short code

• Cells operate in an asynchronous mode. Cells are identified by groups of orthogonal Gold codes

Power Control:

• Both systems propose forward and reverse link closed loop power control using pilots

• Cdma2000 uses 800 bps & continuous pilot

• W-CDMA uses 1600 bps and pilot symbols

Coding & Modulation:

• Similar techniques with different framing parameters


UWC-136

§ The four modes of UWC-136

§ North American TDMA, IS-136 and IS-136+

§ Enhanced air interface

§ The high speed outdoor mode

§ The high speed indoor mode

§ High speed packet mode


What is UWC-136?

UWC-136

Circuit&

Packet

North-America'sTDMA

GSM


The Modes of UWC-136

136 136+GPRS

136HS-O HS-I

GSM GPRS EDGE

UWC-136

200 kHz

30 kHz 1.6 MHz200 kHz


Basic Characteristics of IS-136 / IS-136+

§ The RF channel bandwidth is 30 kHz

§ RF channels are paired for full duplex operation (FDD)

§ Each channel is divided into 40 ms time frames

§ Each frame has 6 time slots

IS-136

30 kHz

40 ms frametime

frequency


Full Rate Frame Format

Slot 1 Slot 2 Slot 3 Slot 4 Slot 5 Slot 6

972 symbols per frame @ 24.3 ks/s = 40 ms

1 2 3

§ Three users share a carrier§ Each user is assigned two time slots§ The slots for the three users are interleaved


Half, Full, Double and Triple Rates


972 symbols per frame @ 24.3 ks/s = 40 ms


Full Rate


Double Rate


Triple Rate


Half Rate


IS-136 Modulation Methods

§ Two modulation methods are allowed:

1. π/4-DQPSK [45-degrees-Differential Quadrature Phase Shift Keying]

2. 8-PSK [8 phases Phase Shift Keying]

§ The first method, π/4-DQPSK, yields 2 bits per transmitted symbol

§ The second method, 8-PSK, yields 3 bits per transmitted symbol [50% increase in data rate]


ππ/4-DQPSK

-π/401

π/400

3π/410

-3π/411

∆ΦYX

S/PDifferential

PhaseEncoder

LPF

LPF

A cos ωt

-A sin ωt

Data S(t)

X

Y

I

Q

nnn

ntAtS

φ∆+φ=φ

φ+ω=

−1

)cos()(


ππ/4-DQPSK Phase Trajectory

0

45

90

135

180

-180

-135

-90

-45

1 2 3 4 5 6 7 8 9 10 11

1 1 0 1 0 0 1 0 1 1 1

1 0 1 0 0 1 0 1 1 1 0

X

Y

12

3

4

5

6

7

89 10

11-45o-135o

+135o +45o


8-PSK Modulation

8-PSK phase constellation

§ 3 bits per phase (symbol)

§ All phase transitions are allowed

§ Absolute bits-to-phase mapping

§ Grey coding is used


8-PSK Modulation

−π/4011

−π/2001

−3π /4101

π100

3π/4000

π/2010

π/4110

0111

ΦZzYkXk

)],,(cos[ kkkk zyxI Φ=

)],,(sin[ kkkk zyxQ Φ=


IS-136 Channels

Channels

Digital Control Channel

DCCH

BCCH

SPACH

RACH

SCF

Digital Traffic Channel

DTC

Voice

Data


The DCCH

TDMA frame = 40 ms

§ The DCCH occupies slots #1 and 4 on one carrier in a sector.

§ At the RF level, it appears as any other full-rate TCH.

DCCH

TCH

Analog

f1

f2

fN

fM


The IS-136 Super Frame

§ Super frame is a group of 16 TDMA frames.

§ It has 96 time slots.

§ The DCCH occupies 32 TDMA slots.

§ The purpose of the super frame is to organize the DCCH logical channels in a recognizable pattern.

§ The first slot of a super frame is always a “Fast” broadcast message.

Super frame = 640 ms = 16 TDMA frames

TDMA frame = 40 ms


Multiplexing Different DCCH Channels

One Super Frame

F

TDMA frame

F E E E E RF

SPACH channelsReservedBCCH


Uplink/Downlink Arrangement

One Super Frame

SPACH channelsRSVD

BCCH

EF

RACH

Downlink

Uplink


Some Enhanced Characteristics of IS-136

§ Three Vocoder techniques

§ Two interleaving schemes:

− Robust 2-block interleaving

− Low-delay one block interleaving

§ The RF channel bit rate is:

− 72.9 kbps on coherent 8-PSK

− 48.6 kbps on coherent DQPSK

§ A high data rate user can use more than one full rate channel (i.e. more than two slots per frame)

§ Power control is provided

§ Pilot symbols for coherent detection


Uplink Frame Format

FullRate

DoubleRate

TripleRate

π/4 DQPSK

8-PSK

Primary

Secondary

Initial Primary

Subsequent Primary

Secondary


Downlink Frame Format

Full Rate


Downlink Frame Format (cont.)

DoubleRate

TripleRate


IS-136-HS-O High Speed for Outdoor

§ IS-136-HS-O targets low-speed outdoor users

§ It is a derivative of the GSM standard

§ The RF bandwidth is 200 kHz/carrier

§ It is a "Packet-oriented" technique

§ It uses three different modulation methods:

1. GMSK

2. 8-PSK


Slot 0 Slot 1 Slot 2 Slot 3 Slot 4 Slot 5 Slot 6 Slot 7

One TDMA frame = 1250 symbols = 4.615 ms

§ 8 Slots per frame

§ The slot duration is 576.92 µµs

§ Number of bits/frame depends on the modulation:

- GMSK à 1250 bits

- 8-PSK à 3750

§ Transmission rate = 270.833 ks/s

§ IS-136-HS-O operates in a packet mode

§ The parameters are adopted from GSM

IS-136-HS- Frame


RB0 RB1 RB2 X RB3 RB4 RB5 X

Slot 0 Slot 2 Slot 3 Slot 4 Slot 5 Slot 6 Slot 7Slot 1

One TDMA frame = 1250 symbols = 4.615 ms

26 Sub-Multi-Frame Structure

Radio Block

RB0-RB2 X RB3-RB5 X RB6-RB8 X RB9-RB11 X

52 Sub-Multi-Frame Structure

IS-136-HS-O Multi-Frame Structure


§ This is very similar to the GSM burst format

§ Coding and interleaving are done across 4 bursts

TS = Trail SymbolsIS = Information SymbolsTSS = Training Sequence SymbolsGP = Gap Symbols

TS IS ISTSS TS GP

576.92 µs

3 58 26 58 3 8.25

IS-136-HS-O Burst Format


2--1612313591 PCS-6

926231061612311491/2PCS-5

692207661612310321/2PCS-4

27816626161238251/2PCS-3

013846161236861/2PCS-2

213866161234561/3PCS-1

8-PSK

0--161234311GCS-4

2206764161233151/2GCS-3

1325884161232711/2GCS-2

0456440-31841/2GCS-1

Punct.

bits

Coded

bits

Tail

bits

BCS

bits

Coded

USF

USF

bits

Input

bits

Mother

code

Coding

bits

GMSK

IS-136-HS-O Coding & Interleaving


1.0

0.73

0.64

0.49

1.0

0.829

0.746

0.596

0.496

0.329

69.269.28-PSKPCS-6

11.222.8GMSKGCS-1

14.522.8GMSKGCS-2

16.722.8GMSKGCS-3

22.822.8GMSKGCS-4

57.3569.28-PSKPCS-5

51.669.28-PSKPCS-4

41.2569.28-PSKPCS-3

34.369.28-PSKPCS-2

22.869.28-PSKPCS-1

Radio Interface Rate/Slot (kb/s)

Gross Rate (kb/s)

ModulationEffective Code Rate

Service Name

Information Rates


datablockheader

CRC

Coding

Puncturing

Interleaving

0 2 3 4 5 6 71 0 2 3 4 5 6 71 0 2 3 4 5 6 71 0 2 3 4 5 6 71

Mapping Data Onto the Physical Layer


§ IS-136-HS-I targets indoor users

§ The RF channel bandwidth is 1.6 MHz/carrier, which is 8 times wider than GSM

§ Frames have GSM structure but are clocked 8 times faster.

§ It is a "Packet-oriented" technique

§ It uses two different modulation methods:

1. Quaternary Offset QAM (Q-O-QAM)

2. Binary Offset QAM (B-O-QAM)

IS-136-HS-I High Speed for Indoor


0

Hyper frame = 2048 super frames = 3 Hr. 28 min. 53 s. 760

1 2 3 4 5 2045 2046 2047

0 1 2 3 48 49 50

Super frame = 1326 TDMA frames

0 1 2 3 23 24 25

26 Multi-frame = 26 TDMA frames

1 TDMA frame = 64 short frames = 16 long frames = 4.615 ms

IS-136-HS-I Frames


Short burst = 1/64 of TDMA = 72.1 µµ s

T3

Data72

Training27

Data72

T3

GP10.5

long burst = 1/16 of TDMA = 228 µµ s

T3

Data353

Training27

Data353

T3

GP11

IS-136-HS-I Long and Short Bursts


IS-136-HS-I Coding Parameters


Binary-Offset-QAM Quaternary-Offset-QAM

IS-136-HS-I Modulation Methods


Summary of UWC-136 Environments

IndoorIS-136HS-I

1.6 MHz

OutdoorSmall cells

IS-136-HS-O200 kHz

EverywhereIS-13630 kHz


UWC-136 Packet Mode

§ The "Packet Mode" is over 200-kHz RF channels

§ For GSM operators, the transition is simple

§ For IS-136 operators, some 30-kHz voice channel must be replaced by GSM-like channels

§ The packet mode uses EDGE (Enhanced Data rate for GSM evolution).

§ The packet network is called GPRS (Generalized Packet Radio System).


Generalized Packet Radio System (GPRS)

MobilityManagement

MediaAccessControl

RadioResource

Management


GPRS Network Model

OtherPLMN

SGSN

SGSN

SGSN

GGSN

GGSN

GGSNPublic Data

Network

IPNetwork

Radio AccessNetwork


GPRS Protocol Stack

Application

IP/X.25

SNDCP

LLC

RLC

MAC

SNDCP

Physical

MAC

Physical

Networkservice

L1bis

BSSGPRLC

Relay

NetworkService

L1bis

L2

L1

BSSGP

LLC

GTPSNDCP

Relay

UDP/TCP

IP

L2

L1

UDP/TCP

IP

Application

IP/X.25

GTP

MS BSS SGNS GGNSUm Gb Gn


1. Initial Systems Acquisition

2. Hierarchical Cell Structures

3. DCCH Selection and Camping

4. DCCH Reselection

5. Registration

6. Mobile Assisted Channel Assignment

7. Mobile Assisted Hand-Off

IS-136 Network Procedures


§ At "service activation", the mobile may download what is known as: Intelligent Roaming Database (IRDB)

§ The Mobile also maintains a History List of last used DCCH frequencies

SID'sSOC's

Preferred systemsParameters

BandsEtc….

IRDB

HistoryList

Recent DCCH's

Initial System Acquisition


§ Upon "power up", the mobile searches for service

§ The mobile follows the simplified flow chart shown

Power Up

CheckHistory List

Check all bandsIn IRDB

Camp&

Register

Y

Y

N

N

CellularPCS

DigitalAnalog

Own service providersOther service providers

No Service

Check otherpossible bands

N

Y

Initial System Acquisition (cont.)


SSYNC SCF SCFCSFPData

28 12 130 12 130 10 2

Data

CDLSYNC SACCH SCDVCCData Data

28 12 130 12 130 1 11

DCCH

DTC

Detecting the DCCH


Power

Scan History List DCCH?

Scan remaining probability

blocks

Camping?

Camp & Register on DCCH

DTC?

Scan forACC

Y

N

Y

N

ACC?Y

N

DCCHPointer ?

Camping?

Camp & Register on ACC

DCCH? Camping?Y

N

YN

N

Scan remaining CDL

frequenciesDCCH? Camping?

Y

NNo Service

Y

N

Y

N

Scanning and Camping


Umbrella

Macro

Micro

§ In any given location, the mobile may be covered by several cells of different sizes

§ IS-136 supports the notion of establishing hierarchy of preferences

Hieratical Cellular Structure


Assign

Is there a preferred cell with adequate

camping?

Is there a regular cell with adequate

camping?

Is there a non-preferred cell with

adequate camping?

Noservice

Y

Y

Y

N

N

N

Preferred, Regular & Non-Preferred Cells


§ The mobile is constantly evaluating The DCCH channels in neighboring cells (sectors)

§ The mobile uses "Broadcast Neighboring Lists" to find the location of neighbor's DCCH.

§ The decision to "Reselect" a DCCH depends on many factors, including the hieratical preference

BNList

Reselecting the DCCH


DCCH800 MHz

DCCH1900 MHz

ACC

DCCH800 MHz

DCCH1900 MHz

ACC

Known LocationsPointers

Digital verification color codeDVCC

Private System Identification (option)PSID

Parameters related to hand-offThreshold values

Public or private Network

Cell preferenceCell descriptors

RF channelChannel Number

FunctionParameter

Example of Neighbor List

Neighbors Cell List


§ IS-136 honors AMPS and IS-54 registration schemes, but it adds new features

§ Two channels are involved:

- RACH: Uplink

- ARCH: Downlink

• Power up• Periodic• Location Area

• Power down• New system• Reselection of DCCH/ACC• Forced• User group• Change of frequency band• TMSI timeout• Deregistration

AMPS/IS-54 Additional

Registration Types

System Registration


§ In the DCCH camping state, the mobile monitors a range of frequencies and determine their signal quality

§ The mobile periodically reports the measurements back to the base station.

§ The accumulated knowledge about the mobile environment is used to select the traffic channel.

§ The MACA functions fall into two categories:

- Long-Term

- Short-Term

Mobile Assisted Channel Selection


RI I I R I I R I TI I

f1 f2 f3

Frequencies to be scanned

Command to measure RSSI on some frequencies

Report every second

Mobile Assisted Channel Hand Off


3G Networks

§ The concept of core networks

§ Families of core networks with universal interfaces

§ IP-based network models

§ Internet traffic models

§ Wireless Internet proxy communications

§ Future directions


Evolution of Wireless Networks

Present Future

• Wideband• Narrowband

• Multimedia• Voice

• High data rates• Low data rate

• IP-centric• Circuit-switched

• Harmonized standards

• Multi-standards

• Hierarchical, isolated networks

• Integrated Networks


Key Network Characteristics

§ Backward compatibility to 2G services

§ Support for Multi-mode terminals

§ WRC-99 outlined the need for Global Radio Control Channel (RCC) to help in international roaming.

§ The global RCC is expected to broadcast helpful information, including:

§ IMT-2000 bands

§ Clocks and timing references

§ Identifications of public and private networks

§ Availability of services …etc

§ 3G networks will evolve from existing networks

§ It is expected that the network aspects will converge over the next three years


3G Network Interface Model

RAN CNOtherCN's

l The CN-CN interface is key for global roaming :

l ITU study group 11 (ITU-T-SG-11) is currently investigating a common signaling protocol for this interface.

CN-CNRAN-CNMT-RANUIM-MT

UIM MT RAN CN CN

UIM =User Interface ModuleMT = Mobile TerminalRAN= Radio Access NetworkCN =Core Network

RTT


Interworking Scenarios

l Ultimate goal

l No Interworking facilities

l Unlikely

C

A B

Common NNI

CommonNNI

CommonNNI

CommonNNI

A

B

IWF IWF C

IWF

l Different network protocols

l One IWF per network

l The IWF converts into a common protocol

A

B

C

l Different network protocols

l One IWF per Interface

l IWF's are different

IWF IWF

IWF


Two Major Network Models

IS-41-C GSM-MAP

SS7

North AmericaIS-95

IS-136AMPS

EuropeMany other countries

GSM


The GSM Network Model

VLR EIRHLRVLR

MSC

BSC

MSC

BS

BSBS

PSTN

G

E

B F

DC

A

Um

Ai

MS

AC

H

ISDNDi

Abis

MS= Mobile StationBS = Base StationBSC = Base Station ControllerMSC= Mobile Switching CenterHLR= Home Location RegistryVLR= Visitor Location RegistryAC = Authentication CenterEIR= Equipment Identity RegistryPSTN= Public Switched Telephone NetworkISDN= Integrated Services Digital Network


The GSM System Architecture (cont.)

4The Public Land Mobile Network (PLMN) covers a large area.

4 It interfaces with other networks through Gateway MSC

4The PLMN is divided into sub-areas, each is served by one MSC.

4The MSC could be internal to the PLMN or could be a gateway MSC

PLMN

G-MSC

G-MSC

MSC

MSC

G-MSC


The MSC Area

4The MSC area consists of one MSC and several BSS's

4The MSC provides the external interface, either directly or through a Gateway MSC

4Each MSC is connected to a Visitor Location Registry (VLR)

4The MSC also has access to a Home Location Registry (HLR) and Equipment Identification Registry (EIR)

MSC

VLRHLREIR

BSS BSS

BSS BSS

BSS


The MSC Area (cont.)

4Each MSC is connected to only one VLR.

4But one VLR could serve more than one MSC

4There are few HLR is the PLMN. One HLR usually serves several MSC's

4EIR is usually linked to the HLR. There are few EIR's in the entire PLMN

MSC

VLRHLREIR

MSC

MSCMSC

MSC

VLRVLR

VLR


The IS-41-C Network Model


3G Mobile IP

•• Multitude of applicationsMultitude of applications

•• Communication amongst “things”Communication amongst “things”

•• Varying QoS requirementsVarying QoS requirements

•• Differing performance Differing performance

characteristicscharacteristics

•• Different devicesDifferent devices

•• Distinct capabilitiesDistinct capabilities

•• Battery lifeBattery life

Voice

E-mail

Web

Conferencing

E-commerce

Audio InternetWirelessAccessNetwork


Transcoding

§ Application: WWW browsing

§ Problems:

Ø varying device characteristics

Ø limited and changing bandwidth

§ Solution:

Ø Adaptive transcoding techniques

• Image characteristics

• Device constraints

• Bandwidth limitations

• User preferences

Ø Optimize the document Format

WirelessProxy Server

Internet

Web


Deployment Models

§ Evolving 2G into 3G

§ Spectrum requirements

§ Enabling technologies:

Ø Software Radio

Ø Adaptive antennas

Ø Advanced power control and hand-off strategies


Evolving 2G into 3G

§ Cdma2000

Ø Existing 1.25 MHz channels can be used by 2G and 3G terminals

ØConversion does not prematurely sacrifice revenue producing 2G voice for the developing 3G data market

ØCdma2000 will experience the smoothest transition from 2G to 3G

ØMutli-Carrier can be deployed by grouping existing 2G carriers.


Evolving 2G into 3G (cont.)

§ UWC-136

Ø GSM operators will have easier time introducing 3G services. The deployment will follow the GPRS model

ØGPRS 200 kHz packet channels are fully compatible with the GSM system

Ø IS-136 operators will have difficult dilemma. They need to remove several 30 kHz channels to introduce one 200 kHz GPRS channel

Ø The IS-136 operators put a limit of 1 MHz on the converted voice channels


Evolving 2G into 3G (cont.)

§ WCDMAØWCDMA requires new band

Ø The minimum frequency band needed is 5 MHz (TDD mode)

Ø WCDMA is not backward compatible with any existing system

Ø Spectrum availability is important

Ø Japan will likely be the first country to fully implement WCDMA


IMT-2000 Spectrum Allocation

§ WRC-92 identified the spectrum requirements of IMT-2000

§ The required spectrum was estimated at 230 MHz for both terrestrial and satellite segments.

1885 – 2025 & 2110 – 2170 MHz [Terrestrial]

1980 – 2010 & 2170 – 2200 MHz [Satellite]

§ Subsequence decision in WARC-97 led to some modifications in region 2


IMT-2000 Spectrum Allocation (cont.)


Spectrum Plans for Europe [UMTS Forum]


WRC-2000

§ WRC-2000 will consider allocating additional spectrum

§ It is expected that additional 160 MHz will be designated for 3G

World Radio Communications 2000World Radio Communications 2000Istanbul, TurkeyIstanbul, Turkey

May 8 May 8 –– June 2, 2000June 2, 2000


Enabling Technologies

§ Smart Antennas

§ Software Radio

§ Advanced MAC layer

§ Transcoding and proxy communications


New Applications

BroadbandB-ISDN

IMT-2000 NetworkIMT-2000 Network

BSC

BSC

ATMSwitch

ATMSwitch

MATMSwitch

1 2 3 46

0D

# *1

B1C

A7 8

95

1 2 3 46

0D

# *1

B1C

A7 8

95

1 2 3 46

0D# *

1B

1CA7 8

95

MSC


References[GW96] V.K.Grag and J.E.Wilkes, "W ireless and

Personal Communications Systems", Prentice Hall,1996

[Dix94] R.C.Dixon,"Spread spectrum systems withcommercial applications", third edition, Wiely inter-science, John W iley, 1994

[Pro89] J.G.Proakis,"Digital Communications", secondedition, McGraw Hill, 1989

[Rap90] T.S.Rappaport et.al,"900 MHz multipathpropagation measurements for US digital cellularradiotelephone", IEEE Trans. on Veh. Tech., pp.132-139, May 1990

[Rap95] T.S.Rappaport,"W ireless communications:principles and practice", IEEE press and PrenticeHall PTR, 1995.

[Red95] S.M.Redl et.al.,"An introduction to GSM",Artech House Publishers, 1995

[Sim94] M .K.Simon et.al.,"Spread spectrumcommunications handbook", the revised edition,McGraw Hill, 1994

Documents

Third Generation Wireless Systems