Generations of wireless technologies and networks

Generations of Wireless■ First generation wireless systems used Analog technologies to provide circuit-switched access for mobile voice telephony • AMPS Advanced Mobile Phone System • MT

Generations of Wireless Technologies and Networks

Generations of Wireless Technologies and Networks

Course 331

Generations of Wireless

■ First generation wireless systems used Analog technologies to provide circuit-switched access for mobile voice telephony

• AMPS (Advanced Mobile Phone System)

• MTS, IMTS, NMT, TACS, ETACS, JTACS, others

■ Second generation wireless systems use the earliest digital technologies

to provide mainly circuit-switched access for mobile voice telephony

• GSM (Global System for Mobile Communications) TDMA

• IS-54, IS-136 TDMA

• IS-95 CDMA

■ Third generation wireless systems use improved digital technologies to provide packet-switched access for advanced voice and data applications

• wider-bandwidth, higher-capacity, more features and applications

• CDMA2000 1xRTT, 1xEV DO, DV, 3xRTT - migration path from IS-95

• GPRS & UMTS - migration path from GSM and IS-136 TDMA

• EDGE - migration path from TDMA, but will anybody use it?

■ Fourth Generation technologies are erupting into the marketplace, a

revolution that could topple (or be absorbed by) the established players

2G Wireless Data:

S L O W !

■ Each wireless technology offers

limited data capability today

■ One or more circuit-switched

traffic channels are dedicated to

fast data instead of voice

• Dial-up modem emulation is

provided at the wireless

switch

• Packet data access may be

provided by a router at the

switch, but the RF link is

circuit-switched

• Data rates are slow;

compression may be provided

■ Even 2G CDPD and Mobitex

Data-Only technologies are slow!

■ 3G technologies are much better!

• Much faster RF traffic

IP Packets

CDMA2000

1xEV

2.4 M 5+M

IP Packets

WCDMA UMTS

1M 2M

IP Packets

GPRS

9000 115K

IP

3G

TDMA IS-136

9600

Circuit Switched

14400

Circuit Switched

IDEN Circuit 19200

Switched

CDMA IS-95

9600

Circuit Switched 14400 64K

14400

Circuit Switched

2G

Packets

What’s Interesting in 3G?

3G is a multi-ring circus, with two big areas of improvement:

■ Radio: New Air Interface Technologies and Adaptations

• Higher bandwidth, faster data

• More flexible channel architectures and call processing

protocols

• True packet data access with multiple IP sessions

• CDMA technology is predominant!

■ Data: New Back-Side Packet-switched networks

• New architecture provides direct connection from wireless network to IP networks including Internet!

• The new data network architecture parallels existing voice connections and will surpass the traffic volume of the voice network

• New functional blocks, protocols, connectivity!

3G Perspectives: Operators & Manufacturers

■ System Operator

• What do our customers want?

– What are our competitors doing with 3G, and when?

– What are the features and services we can offer?

• Which 3G technology should we deploy?

• Do we need more spectrum?

• What parts of our network can be used with 3G - what must be new?

• How soon can we get 3G, and how long will it take to install it?

• How can we make money with this?

• Can we get financing?

■ Network Manufacturer

• Which 3G technologies do we have to provide?

• When are customers expecting this, and how much will they order?

• How do we implement - can we add this to existing network products?

• What will it cost to manufacture, are there any IPR dollar swamps?

• Where will we get capital?

• Will customers expect us to finance their purchases?

3G Perspectives: Handsets & Test Equipment

■ Handset Manufacturer

• What are the technologies? What are the features?

• What is the demand, and when?

• Can we make distinctive products and get major market share?

• Whose chipsets will I use? What will it cost to manufacture?

• Can we make money in this framework? What are the risks?

• Where can we get capital?

■ Test Equipment Manufacturer

• What are the technologies?

• What do operators need to see to test and optimize their networks?

• Whose handsets will I use as my front-end?

• What will IPR and handset agreements cost?

• When is the market window? Can we make money with this?

• Where can we get capital?

3G Perspectives: End-Users and Technical

■ End-User

• This is cool! What applications will I get? Will it change my lifestyle?

• Will the battery last long enough for my style of use?

• Will the screen be big enough?

• Will it cost too much?

• Will I be able to use it where I need it?

■ System Design and Operations Personnel

• What are the technology choices?

• How do they work?

– How much capacity will they have?

• What’s involved in designing and implementing a 3G network?

– Is any of my old equipment usable? Can 3G coexist or overlay? – What new equipment is available, when, and what will it cost?

• What’s the “feel” of a 3G network?

– What’s involved in optimizing 3G networks?

• How soon do we have to do this?

■ What’s after 3G? Is there a 4G?

4G – Evolution or Revolution? When?

■ There’s a revolution going on out there!

• New 2.5G services arriving now, new 3G arriving 2002 through 2005

• A groundswell of commercial (and even free!) WILAN deployment

■ Who owns it? Who drives it? Who benefits from it? Fear it?! Love it?!

■ Ultimately 3G and 4G will be integrated - by operators, users, manufacturers?!

Wireless Development and the

Recent History of 3G Wireless Development and the

Recent History of 3G

The Age of Science and Technology

The Telecommunications Age

The Wireless Age

Ohm Volta Ampere

Rayleigh

U

N S

The Telecommunications Age

Strowger

Commercial Television

De Forest

Armstrong Farnsworth

ASICs

Bardeen Brattain Shockley

Digital Transmission Digital Switching

Nipkow Zworykin

Fleming

The Age of Wireless Telephony

1980s

89 88 87 86 85 84 83 82 81 80

1990s

99 98 97 96 95 94 93 92 91 90

Communications Technology Family History

A Story of Births, Weddings and Funerals

■ Commercial telegraphy gave birth to telephony, then died

■ Telephony and Land Mobile Radio married, giving IMTS & Cellular

■ IP networks developed, their usage and bandwidth are increasing

■ 3G is the wedding of IP and Wireless!

Commercial Switched Telephony

Wireless Voice and IP Data

40 50

Digital Switching IMTS-Cellular-GSM-GPRS-WCDMA

IP Networks

The Internet Voice over IP

Land Mobile Radio

HF, VHF, UHF, Trunked

Extinction!

Extinction?

Extinction?

Wireless Standards Organizations

Each of these groups is a forum for global wireless

operators, network manufacturers, and handset

Korea

IMT2000 Consortium

ARIB

Association of Radio Industries and Businesses

Japan

TTC

Telecommunications Technology Council

Japan

TIA

Telecommunications Industry Association

USA

CDG (IS-95)

CDMA Development Group (USA)

UWCC (IS-136)

Universal Wireless Cellular Communications

ITU Third Generation Process Phases and Terminology

■ The ITU defined objectives for next-generation mobile systems in a 1998 request for proposals

■ Sponsoring organizations submitted details of proposed radio

transmission technologies in mid-1998

■ Technology developers were inflexible and could not reach compromises

to select one common proposal

■ The system operators led the process of “harmonizing” the proposals in to three main versions for commercial deployment, “Global Third Generation”

IMT-2000

G3G

Global Third Generation

Original ITU RTT Submissions Mid-1998

Each item above was submitted to the ITU-R in mid-1998 as a candidate radio transmission technology for third generation systems Eight of the

submissions proposed some form of wideband CDMA; the other two were TDMA-based.

TD SCDMA W-CDMA CDMA I CDMA II W-CDMA WCDMA/NA cdma2000

TDMA TDMA CDMA CDMA CDMA CDMA CDMA CDMA CDMA CDMA

Digital Enhanced Cordless Telecommunications Universal Wireless Telecommunications Wireless Multimedia & Messaging W-CDMA Time Division Synchronous CDMA

Wideband CDMA Synchronous Direct Sequence CDMA Asynchronous Direct Sequence CDMA UMTS Terrestrial Radio Access Wideband CDMA North America Wideband CDMA Synchronous Direct Sequence & Multicarrier CDMA

Proponent

Contrasting US/International CDMA

Viewpoints

■ Should we have one worldwide 3G standard?

• Great idea, but is anybody willing to compromise?

■ North American IS-95 CDMA perspective

• New chip rate should be a multiple of our current rate so 3G signals will be synchronous and can be overlaid

2G-• Channel structure, system architecture should be logical

extension of our existing IS-95 technology

■ International CDMA perspective

• New signal should be a logical extension of existing GSM

system architecture, the GSM-MAP specification

– Logical extension of GPRS (General Packet Radio Service)

• Fear of depending on US-based GPS system for timing

– A military system, may be withdrawn during conflicts

Harmonization: From Dark Ages to Cooperation

1998: “Dark Ages”

■To converge from 13

modes to one mode

First OHG meeting in Beijing

Harmonization framework agreed

Second OHG meeting in San Francisco

Third OHG meeting in London

Baseline Technical Agreement

Fourth OHG meeting in Tokyo

Fifth OHG meeting in Toronto

Final Technical Agreement

3G Technical Agreement Ratified

The commercialization era begins!

OHG Operator Harmonization Group formed

Categorizing the Harmonized CDMA ITU Submissions

■ The original 13 wideband CDMA RTT submissions to the ITU were refined and converged into three main radio access specifications

■ The ITU Global Third Generation CDMA Radio Access Specification

includes the three converged specifications

Only 3 final modes!!

DS-FDD TDD, DS-FDD & MC-FDD

Direct-Sequence Frequency Division Duplex (UMTS)

Multi-Carrier Frequency Division Duplex (CDMA2000)

Further Harmonization Work

■ cdmaONE systems have been structured around the IS-41-based HLR and VLR paradigm for intersystem handoff and call delivery

■ IS-2000 CDMA systems will be further harmonized to achieve

operability on the GSM-MAP (Group Speciale Mobile Mobile

Application Part), the network architecture of GSM

• Protocol stacks of both IS-2000 and UMTS have been largely harmonized already

CDMA Development & Deployment Leading up to Third Generation

TIA formally accepts CDMA

As a standard in the USA

Hong Kong and Los Angeles IS-95 commercial launch

Korea IS-95 Commercial Launch

Korea passes Million customers

Ericsson, NTT Promote 3G ITU 3G team formed

ETSI selects CDMA For GSM>3G migration!

US CDMA2000 Specs finished

ITU receives 10 IMTS2000 proposals

Harmonization ratified

1xRTT Trials

UMTS Trials

1xRTT Launch? UMTS Launch?

Migration Paths from 2G Technologies to 3G

Migration Paths from 2G Technologies to 3G

Global Wireless Users by Technology

■ The GSM family already includes approximately 500 million users

• Their migration paths will be a major 3G business opportunity

■ The IS-95 CDMA and IS-136 TDMA families are also considerable

Global Wireless Users by Technology (millions)

488

65.8

80.4

GSM IS-136 TDMA IS-95 CDMA

2G to 3G Technology Migration Paths

136 HS indoor

VoiceStream 5,315,000

AT&T Wireless 2,728,000

Sprint PCS 14,000,000

136HS

WCDMA UMTS UTRA

PacBell Wireless 2,000,000

Verizon 2,000,000

1xRTT cdma2000

??!

Leap WirelessCricket Comms

EDGE

X$?

GPRS

Other CDMA1,990,397

US Operators’ 3G Migration Plans

TDMA CDMA GSM iDEN Total Total 45,629,010 59,153,547 5,423,000 8,058,900 118,264,457

Cellular TDMA CDMA GSM iDEN Total PCS TDMA CDMA GSM iDEN Total

AT&T Wireless 15,172,000 15,172,000 AT&T Wireless 2,728,000 2,728,000 Cingular Wireless 21,200,000 21,200,000 Sprint PCS 11,200,000 11,200,000 Vodafone Airtouch 9,000,000 9,000,000 Verizon Wireless 2,000,000 2,000,000 Verizon Wireless 26,000,000 26,000,000 Nextel Communications 7,700,000 7,700,000 Alltel 6,400,000 6,400,000 VoiceStream Wireless 5,315,000 5,315,000

US Cellular 1,650,000 1,650,000 3,300,000 Qwest Communications 1,000,000 1,000,000 Western Wireless 1,087,000 1,087,000 Leap Wireless 472,000 472,000 CenturyTel Inc 707,486 707,486 TeleCorp Holdings 385,000 385,000 Dobson Cellular 485,600 485,600 971,200 Triton PCS 374,000 374,000 Centennial 262,550 262,550 525,100 Nextel Partners 358,900 358,900 Price Communications 450,000 450,000 Tritel Communications 190,000 190,000 Rural Cellular 258,247 258,247 DigiPH PCS 82,000 82,000 Triton Cellular Partners 209,000 209,000 US Unwired Inc 77,000 77,000 Wireless One 177,000 177,000 Alamosa PCS 180,000 180,000 Cellcom Cellular 165,000 165,000 CFW (NTELOS) 62,500 62,500 Midwest Wireless 158,974 158,974 Airadigm Communications 26,000 26,000 Plateau Wireless 68,354 68,354 Airgate PCS 179,000 179,000 Bluegrass Cellular 65,799 65,799 Amica Wireless 10,000 10,000

Ubiquitel 9,897 9,897

Wireless Industry Subscribers 2Q2001

Wireless Operators’ Internet Plans

Operator Data Offerings High Speed Data Plans

Verizon Wireless

Mobile Web phone browsing 1x rollout in limited markets 4Q Circuit-switched data using phone as modem 1x nationwide rollout 2002 Mobile IP CDPD service

As reported in RCR August 13, 2001

The Path to 3G from IS-95 CDMA

The Path to 3G from IS-95 CDMA

The CDMA Technology Path to 3G

&

Handoffs

None, 2.4K by modem

2G IS-95A/J-Std008

1250 kHz.

20-35

First CDMA, Capacity, Quality 14.4K

2G IS-95B

1250 kHz.

25-40

•Improved Access

•Smarter Handoffs 64K

•Enhanced Access

•Channel Structure

153K 307K 230K

3G 1xEV: HDR or 1Xtreme

1250 kHz Many packet users

Faster data rates on dedicated 1x RF data carrier

3 carriers

Faster data rates on shared 3- carrier bundle

1.0 Mb/s

2G CDMA Beginnings: IS-95A and J-Std 008

■ Original commercial CDMA systems in the 800 MHz band

complied with IS-95A, and 1900 MHz Systems complied with the Joint Standard 008 Both had the following common features

■ Signal structure:

• 1.2288 MCPS spreading, signal ∼ 1.25 MHz Wide

• BTS Sectors have short PN offsets, channels are Walsh codes

• Mobiles have long PN offsets and transmit one channel only

■ Traffic Channel Capabilities:

• Rate Set 1: 9600-bps traffic channels for 8 kb/s vocoders

• Rate Set 2: 14400-bps traffic channels for 13 kb/s vocoders and other 14400-max data applications

IS-95B: CDMA 2G Enhancements

■ IS-95B is still considered Second Generation, but offers some needed enhancements to the original IS-95A and J-Std008

■ Improved Access Methods

• Mobiles originally could use only one sector during an access attempt

– Multipath fading causes roughly 2% failed accesses!

• IS-95B allows mobiles to use alternate sectors as “backup” during access in case the original sector fades

■ Improved Handoff Methods

• Original CDMA provided only fixed-threshold handoff triggers

– Inflexible, can skip needed handoffs but waste unneeded ones

• IS-95B uses slope and intercept-based thresholds to tailor handoff action to what is really needed for call survival

■ Faster Data Services

• Original CDMA allowed data only at the rate of a single traffic channel

• IS-95B/IS-707 allows aggregation of traffic channels for faster data, but not at the rates provided by 3G cdma2000

RF Perspective:

3G Phase One: cdmaONE to cdma2000 1xRTT

■ 1xRTT Keeps same chip rate and carrier

bandwidth

■ Splits I and Q phase planes, 2x cap!

■ Keep existing IS-95-based channels for

backwards compatibility with IS-95 mobiles

• IS-95B enhancements retained

■ Adds new radio configurations, adds new

FWD and REV channels

• New optional control channels

• New fundamental traffic channels

• New supplemental traffic channels for

faster data

• New codes and spreading techniques

■ Operators can deploy 1xRTT with no

additional spectrum and minor equipment

upgrading

IS-95B Today

•Single Carrier 1.2288 MCPS

•Sectors different short PNs

•Mobiles different Long PNs

•9600, 14400 rate sets

Next: 1xRTT

•Single Carrier 1.2288 MCPS

•Sectors different short PNs

•Mobiles different Long PNs

•Backward compatible IS-95

•Independent Short PN I & Q

• ∼∼∼∼ 70 max users/sector/carrier

•More rates, modes, channels

•Better administration

3G Phase Two: cdma2000 1xRTT to 3xRTT

■ Forward link expanded to 3 carriers,

each 1.2288 MCPS for 1.25 MHz BW

• Active walsh codes are not

duplicated on the carriers so they

maintain orthogonality and share

capacity as traffic loading changes

■ Reverse link expands to 3x current

chip rate, 3.6864 MCPS, fits in 5 MHz.

■ Adds new radio configurations and new

supplemental channels faster than

possible in 1xRTT

■ Increased spreading rate requires new

reverse short codes, other refinements

1xRTT

Next: 3xRTT

•Forward Link 3 1x carriers

•Rev Link 1 3x carrier

•Sectors different short PNs

•Mobiles different Long PNs

•Independent Short PN I & Q

•More rates, modes, channels

•Better admin & pwr Ctrl.

•New Features/enhancements

FWD

REV

3G Phase Two Alternatives: 1xEV

■ 1x alternatives are available offering data rates just as fast as 3x!

• 1xEV - 1x EVolution - is the term used to describe them

■ Qualcomm’s proprietary HDR (High Data Rates) technology dedicates a 1x carrier for fast data use only - no voice.

• This is called 1xEV DO (Data Only)

■ Motorola and Nokia have teamed up to develop and promote an

alternative 1x technology under the trade name 1Xtreme

• Uses more complex modulation techniques

• offers up to 4.9 Mb/s data rates

• backwards compatible with voice and data on same carrier

• This is called 1xEV DV (Data and Voice)

■ Both 1xEV DO and 1xEV DV use fragile modulation schemes

• Maximum claimed rates will be available only under ideal conditions (near unloaded base stations)

• 1xEV development is continuing - deployment probable in late 2002

■ Despite drawbacks, 1xEV is still more attractive to operators than 3x

• 3xRTT requires three physical carriers and substantially more BTS equipment than 1xEV!

Understanding the foundation of 3G Networks:

Basic 2G CDMA Network Architecture

SBS

Vocoders Selectors

CDSUCDSUCDSUCDSUCDSU

CMSLM

LPP ENET LPP

DTCs

DMS-BUS

Txcvr A Txcvr B Txcvr C

RFFE A RFFE B RFFE C

TFUGPSR

IOC

PSTN

CDSU DISCOCDSU

DISCO 1DISCO 2

The selector assembles packets going to the BTS and disassembles packets coming from the BTS.

A channel element turns packet bits into CDMA chips to the mobile, and chips from the mobile into packets to the BSC.

Channel Element

Existing 2nd Generation CDMA Voice Networks

■ 2nd Generation CDMA Networks were designed primarily to handle voice

■ The CDMA voice conversation’s 20-ms frames are carried as packets

between mobile and the Selector

• The selector assembles frames being sent to the mobile and

disassembles frames coming from the mobile

• Frame contents normally include voice and occasional signaling; may also include data if additional equipment is included (not shown)

■ The vocoders in the BSC and the mobile convert the packet stream into continuous DS-0 audio for the end-users

• The MSC makes a circuit-switched connection for call

PSTN

POINT-TO-POINT PACKETS

14400 bps max

Data Capability Today on a 2G CDMA Network

■ Additional hardware is needed to carry data on a 2G network

■ Data to/from the user connects near the selector in the BSC

• Passed through the switch as 56kb/s data links in 64kb/s DS-0s

■ Data connection to outside world handled by IWF Interworking Function

• Includes modems to convert data stream into DS-0 for dial-up uses

• Can contain data routers to access IP or PPP networks

• May include capability for FAX and other communications modes

Backbone Network

More about Today's InterWorking Function

■ The InterWorking Function (IWF) was introduced in 1998.

• collocated with MSC

• CDMA data calls can interwork with PSTN & packet data networks

• based on industry standards IS-95, IS-707, IS-658

• initial data service offering is rather limited, but provides valuable experience using data service without major capital investment

■ IWF allows:

• Data transmission rates to 14.4 Kbps (13,350 kbps considering overhead bits)

• Traffic Primary mobile-originated; Mobile-terminated service available but rare

■ IWF provides circuit switched service, not packet-switched

• No provision for multiple data calls to share a CDMA code channel

• proprietary Quick Net Connect allows packet connection to a public packet data network

Backbone Network