UMTS and CDMA 2000

A Comparative Studyof

UMTS (WCDMA) and cdma2000 Networks

Neerav DalalAward Solutions, Inc.

IEEE METROCON-2001

Outline

! Current scene of Cellular Wireless! 3G Technology Landscape! Comparative Study

– Network Architecture– Air Interface– Network Interfaces– End-to-End Service Flow

! Beyond 3G! Summary

Evolution of Wireless Technologies

1st Generation (1G)

• Analog-based cellular technology• Services

" Voice

2nd Generation (2G)

• Introduction of digital technologies• Services

" Voice" Low-rate data

3rd Generation (3G)

• Next generation digital systems• Services

" Voice" High speed data services

2G Technologies

Frequency and Code

Frequency and TimeFrequency and Time

FrequencyChannel Separation

IS-41GSM-MAPIS-41IS-41Network Architecture

About 20831Users Per Channel

800 & 1900 MHz

900 & 1800 MHz (Europe)800 & 1900 MHz (US)

800 & 1900 MHz

800 MHzOperating Spectrum Frequency

CDMAGSMD-AMPSAMPS

1.25 MHz200 kHz30 kHz30 kHzChannel Width

GSM Network Architecture

BSC

GSM PLMN

HLR

MSC/VLR

MSC

BSS

A InterfaceBTS

SS7

PSTN

IS-95-Based 2G Network

BSC

BSC

Proprietary

VLR

HLR

AC

PSTN

IS-41SS7

IWF

Internet

IS-634(IOS)

MSC

CDMA(IS-95)

2G Limitations

Capacity

Limited roaming

capabilities

Limited support for packet data

Uni-service network

Bandwidth 14.4-64 Kbps

No multimedia

3G Requirements!Radio Network requirements

– Support up to 2 Mbps data rates– Support flexible operating environments– High spectral efficiency/capacity– Support multimedia services

!Core Network requirements– Packet Data Network and IP Mobility– Global Roaming– Virtual Home Environment– Quality of Service– Interoperability with 2G Networks

3G Network Architecture

PS-CN

RAN

CS-CN

Internet PSTNU

IM

IP Mobility! Ability to move with an IP address while the

connection using the IP address is active! IP Mobility may be provided by a combination

of “RAN mobility” and “CN mobility” ! Radio Access Network IP mobility

– Handoff/handover – Cell selection/reselection

! Core Network IP mobility– Mobile IP, GPRS

Always Connected

RAN Wireless Core

NetworkServices

e-mail

CC TV

IP

Application Logical Connection

CN Logical Connection

RAN Physical Connection

Physical Connection comes and goes

Logical Connections remain intact

Services Network

BTS

Packet Core Network

RAN

Services Network

PushServices

Location Based

Services

Billing

Customer Relationship Management

CS

PSBSC

Enterprise Services

M Commerce

IP Network

MSC

PDSN

PSTN

IS-41/MAP

IP Telephony ServicesGateway

IntelligentNetwork

Call Server

Circuit Core Network

3G Technology Landscape

GSM IS-136D-AMPS

Voice: IS-136 Data: EDGE

GPRS/EDGE

UMTS

IS-95A / B

AMPS

Voice: GSMData: GPRS

UMTS ?

1G

2G

3G

2.5G

FDMA TDMA CDMA

IS-2000(1x)

IS-2000(3x)

GSM # GPRS

Circuit Core Network (MSC/HLR/AuC)Air Interface (MS, BTS)A-Interface (BSC-MSC)

No Changes

BSC Hardware and SoftwareModification

Packet Core Network Nodes(SGSN, GGSN)

New Interface – Gb (BSC – SGSN)New

Summary of Changes

2.5G GSM/GPRS Networks

BSC

GPRS PLMN

GSM PLMN

HLR

MSC/VLR

MSC

SGSN

SGSN

GGSN

GGSN

Gb Interface

BSS

A InterfaceIP

BTS

IntraPLMN IP

Back boneSS7

GSM/GPRS # UMTS

MSC and SGSN for Iu InterfaceModification

WCDMA Air Interface (UE–Node B)RAN Interfaces

Iub (Node B – RNC), Iur (RNC – RNC)CN Interface – Iu (MSC–RNC & SGSN–RNC)

New

Circuit Core Network (HLR/AuC)Packet Core Network (GGSN)

No Changes

Summary of Changes

UMTS Networks

W-CDMA

UTRANNode B

Node BIub

Node B IubRNC

RNC

IurUE

GGSN3G SGSN

GPRS Internet

3G MSC/VLR

GSM

G-MSC

PSTN / ISDN

Iu

IS-95 # cdma2000

Air Interface (MS – BS)Network Interface (BS – MSC)

Modification

Packet Core Network (PDSN, AAA, HA/FA)

New Interface (R-P) – BS - PDSNNew

Core Network Nodes (HLR, AC)No Changes

Summary of Changes

Circuit Switched-CN

cdma2000 Network Architecture

HLR

BTSMS

RAN Packet Switched-CNBSC

PDSN/ FA HA

AC

Private IP Network

Internet

AAA Server

MSC/VLR IS-41

Signaling Data User Data

Radio Link Control (RLC)

Media Access Control (MAC)

Physical Layer

LinkLayer

PhysicalLayer

UpperLayers

Radio Resource Control (RRC)L3

Transports data over-the-air

W-CDMA Protocol Stack

Controls useraccess to the

medium

Increases reliability

UTR

AN L2

L1

ManagesRadio

Resources

cdma2000 Protocol Stack

SignalingTraffic

Upper Layers

Link Layer

Physical Layer Physical Layer – IS-2000.2

Medium Access Control (MAC) – IS-2000.3

Link Access Control (LAC) – IS-2000.4

Layer 3 – IS-2000.5 Packet Data

Service

Voice Services Circuit

Data Service

Signaling

CDMA Physical Layer Functions

Source ID Separation

Downlink BS

UserData

Digital CodingTechniques

Protect Data

Digital CodingTechniques

ChannelizationCode

Channel Separation

ChannelizationCode

Uplink

MS

Bandwidth and spreading

3.84 Mcps

1.2288 Mcps

Spreading

4-128 bits (1x)4-256 bits (3x)

1.25 MHz (1x)3.75 MHz (3x)

cdma2000

Channelization codes

Bandwidth

4-256 bits5 MHzUMTS

Air Interface Parameters (1)

Direct spread (1x)Multi-carrier (3x forward

link)

Direct spread configurationConfiguration

ConvolutionalTurbo

(Parameters fixed in the standard)

ConvolutionalTurbo

(Parameters flexible)Channel coding

Asynchronous

5 MHz

3.84 Mcps

UMTS

1.25 MHzBandwidth

1.2288 McpsSpreading rate

SynchronousSynchronization between cell sites

cdma2000

Air Interface Parameters (2)

Orthogonal Transmit DiversitySpace Time Diversity

Time Switched Transmit DiversitySpace Time Block Coded Transmit Diversity

Diversity schemes

FDD and TDD Mode

10 msec for physical layer10,20,40 and 80 msec for transport layer

QPSK in both directions

UMTS

5 (for signaling), 20, 40 and 80 msec physical layer frames

Frame size

QPSK in forwardBPSK in reverseModulation

Only FDD ModeModes

cdma2000

Channelization & Source Identification Codes

Unique scrambling codes assigned by sector

512 unique scrambling codes each identifying a

sector (38,400 bits)

Orthogonal Variable Spreading Factor (OVSF)

codes from 4-256 bits

UMTS

One PN code (32,768 bits)512 unique offsets are

generated using PN offsets

Source identification

code for Sector

Walsh codes (same as OVSF) codes from 4-128

bits

Channelization codes

One long PN code (242 bits). Unique offsets are generated based on ESN. Not assigned by sector

Source identification for

mobiles

cdma2000

Asynchronous Cell Operations

PNt0

PNt3

PNt4

PNt5

PNt6

PNt1

PNt2

PNt3

PNt7

S0

S3

S4

S5

S6

S1

S2

S3

S7

CDMA2000 UTRA-FDDGPS

PNt0-n - Time offset scrambling code! Cell sites transmission and reception

are synchronized through GPS timing! Adjacent cell sites use different time

offsets of same scrambling code for spreading

S1-n - Scrambling codes! Cell sites are not synchronized! Each cell site uses a different

scrambling code for spreading

Power Control

1500/sec

1500/sec

√√√√

UMTS

800/secForward link Power control

√√√√Open loop Power control for System Access

800/secReverse link Power control

cdma2000

UMTS Packet data Network Architecture

Signaling and Data Transfer InterfaceSignaling Interface

Other PLMN

GGSN

UTRANMTTE GGSN PDN

EIR

SGSN

TEGi

Gf

GpGn

IuUuR

SGSNGn

CGFBillingSystem

GaGa

L2

PDCP GTP-U

UMTS protocol modelApplication

E.g., IP, PPP, OSP

PDCP

RLC

MAC

UMTS RF UMTS RF ATM

UEUu

UTRANIu-PS

3G-SGSNGn

3G-GGSN

L1

RLC

MAC AAL5

UDP/IP

Gi

E.g., IP, PPP, OSP

GTP-U

L2

UDP/IP

Relay

ATM L1

UDP/IP

GTP-U GTP-U

Relay

AAL5

UDP/IP

cdma2000 Packet Data Network Architecture

BTSMS

HTTP/TCP/Others

MIP: RFC 2002

PPP: RFC 1661

IS-707: CDMAData Services

IS-2000 AIR I/F

RADIUS

MIP: RFC 2002

BSC

PDSN

AAA RADIUS Server

IP

HA

Services

3GPP2:IOS(R-P)

7

1

3

4

5

4

62

UMTS Call Flow

SGSN

UE

GG

SN

UTRAN

Logical connection

between UE and UTRAN1. Establish RRC

Connection 2. Establish Iu Signaling Connection

Logical connection UE

and SGSN IPATM

3. Authentication

4. Attach

UMTS Call Flow

SGSN

UE

GG

SN

UTRAN

Request dynamic IP

address

5. Activate PDP Context

IPATM

6. Establish Radio Bearer

6. Establish Iu Bearer

6. Establish PDP Context

7. Allocate IP Address

Radio Bearer GTP GTP

8. PDP Response

9. UE can now send and

receive IP datagrams

cdma2000 call flow

MS

BSC/ BTS

Service Connect and Synchronization

Radio Channel R-P Session Link

MSC

Radio Link SetupR-P Session

SetupPD

SN

Origination CM Service Request

RAN Authentication

Point-to-Point Connection Setup

HAIP

Network

Mobile IP related connection/setup (if required)

IS-41

HLR/AC

Status of UMTS standards

R 4 R 5R 99Release ’99Voice Services

Emergency CallsShort Message Service

Internet Access

Release 4Optimization of UTRA

Quality of ServicePreparation for All-IP

Release 5Open Services Architecture

All-IP Multimedia SubsystemAll-IP UTRAN

High Speed Downlink Packet AccessQuality of Service

Developed by 3GPP

Status of cdma2000 standards

1x/3x RTTProposal

IS-856

1xEV-DO (HDR)

IS-XXXX

1xEV-DV

IS-2000B

IS-95A/IS-95B

cdmaOne

IS-2000A

IS-2000cdma2000

Developed by 3GPP2

Spectrum allocation

600 800 1200 14001000 1600 1800 2000

PCS (2G)

Planned Auction (10-20 M

Hz)

Proposed Auction

Cellular (2G)

Satellite

Satellite

Terrestrial paired band

Terrestrial paired band

Terrestrial unpaired band

Terrestrial unpaired band

1885 1980 2010 21702025 211019201900 2200MHz

North America

Europe and Asia

3G DeploymentNew Operator, New Spectrum

2G 2G

Core Network

3G

Core Network

2G

3G3G

3G

Operator A Operator B

2G Operator

3G Operator

2G

Core Network

3G

3G

3G

2G Operator, New Spectrum

GSM → UMTS Clear some part of the spectrum

3G Deployment

! Shared Infrastructure (Core Network, Management Systems, Billing System)! Dual Mode phone (2G and 3G)

2G Operator, Existing Spectrum

IS-95 → cdma2000 Same Spectrum

200 kHz

200 kHz

200 kHz

200 kHz

1.25MHz

GSM

UMTS

IS-95

cdma2000

Deployment Status

UMTS in 2002

UMTS Not announced

2001GPRS in trials

USA

GPRS Started

2003

Oct-2001

UMTS

SKT – Oct 2000KTF – Dec 2000

Korea

2002Japan

Not announcedEurope

cdma2000

Major Players

! UMTS (3GPP)– Vendors

! Ericsson! Nokia! Nortel! Motorola! Alcatel, Lucent, …

– Operators! NTTDoCoMo! Vodafone, …

! cdma2000 (3GPP2)– Vendors

! Qualcomm! Lucent! Nortel! Motorola! Samsung, Ericsson, …

– Operators! Sprint PCS! Verizon, KDDI, SKT…

3G and Beyond - UMTS

WCDMA (FDD)

Air Interface

TD-CDMA (TDD)

High Speed Downlink Packet Access (HSDPA)

MSC & SGSN/GGSN

Network

IP to RAN

All-IP Multimedia

3G and Beyond – cdma2000

cdma2000 (1x)

Air Interface

cdma2000 (3x)1x Evolution (Data Only) –

1xEV-DO

MSC & PDSN/AAA

Network

IP to RAN

All-IP Multimedia1x Evolution

(Data & Voice) –1xEV-DV

Summary – Air Interface

Backward Compatible

w/IS-95

GSM – UMTS HandoverInteroperability

614 kbps2 MbpsPeak Data Rate

Asynchronous

3.84 Mcps

WCDMA(5 MHz)

UMTS

1.2288 McpsChip Rate

CDMA(1.25 MHz)

Technology (Bandwidth)

Synchronous (GPS)Mode of Operation

cdma2000

Summary – Core Network

Limited (R-UIM)SIM CardGlobal Roaming

Yes

GPRS BasedSGSN/GGSN

GSM-MAP MSC/HLR/AuC

UMTS

IETF BasedPDSN/AAA/HA/FA

Packet Switched

IS-41MSC/HLR/ACCircuit Switched

YesMultimedia

cdma2000