802.11-based wireless technology€¦ · at&t labs november, 1999 doc .: ieee 802.11-99/251...

AT&T LabsAT&T LabsNovember, 1999 doc.: IEEE 802.11-99/251

Slide 1Submission Harry Worstell, AT&T Labs

802.11-Based WirelessTechnology

to Enhance Premises Voice and Data Services



1996 Congress passed the Telecommunications Act, Longdistance carriers permitted local access again

1996-1999 Local exchange companies block long distancecarriers access to their lines

1998 AT&T purchased Tele-Communications Incorporated

1999 AT&T purchased Media1

AT&T to Provide Local Broadband Access



Rewiring the home for broadband distribution is veryexpensive and irritates customers

Now having broadband pipes to the edge of the home, it isnecessary to extend those pipes into and through the home.

With these cable acquisitions and other broadband accessmethods, AT&T anticipates being able to offer broadband

service to ~2/3 of the U.S households over the next 4 - 5 years.

Wireless is an extremely attractive solution for premisesbroadband distribution

AT&T to Provide Local Broadband Access



ACCESSPORT

ETHERNET

CABLE MODEM

Cable Television Headend

Hub

ETHERNET

CALL AGENT

C M T SDNS

DHCP

Eth

erne

t

To Network

CABLE MODEM

RJ11

InternetSurfing

Client Port

Customers Home

StreamingVideo

Client Port

Streaming VideoLaptop Computer

Client Port

Client Port

Client Port

Client Port

A Wireless Access Application



Data Communications Trends

Projected Volumes For Wide AreaCommunications In US By Type OfTraffic, 1994-2005

Source: IDC, AT&T Labs, GeopartnersAnalysis

Post Year 2000: “Transition from a voice focused network supporting data,to a data focused network supporting voice”

0

200

400

600

800

1000

1994 1996 1998 2000 2002 2004

Data

Voiceband - Voice, Fax & Modem

Average BandwidthGbits /Sec



Spanof Coverage

for ViableEconomics

ServiceInformation Rate

Demand

ServiceConcentration

Local(In-Building/

Campus)10,0001,000100101

(Miles)

1000

100

10

1

(Erlangs/Mi )

10M

1M

100K

10K

1K

(Bits/s)

2

Public(Neighborhood/

Urban)

Mobile(Suburban/Rural) Regional

Expansion of demand for wireless serviceshas caused migration of systems toward: Higher Teledensities Better Communication Quality More Throughput/User

2000+

1990's

1980's

1970's

Wireless Service Trends



Phase I(1997)

Phase III(2000+)

Phase II(1998)

Unified Broadband Wireless Access

Burstiness

Isochronous(Continuous Transmission,

Constant Low Delay)

Asynchronous(Bursty Transmission,

Load-Dependent, VariableDelay )

Max

imu

m T

hro

ug

hp

ut

(Mb

/sec

)

.1

1

10

100

0 .5.01

Wireless Local LoopFree-Space Optics

1

W-A

TM

IPv6

Phase 0(Pre-1997)Cellular

W-ISDN

V.3

2W

-ISD

N

PR

OTO

CO

LS

CDPD

H/S W-LAN

PR

OTO

CO

LS

TCP

/IPv4

UD

P

W-LAN

MultimediaSatellite

Future Multimedia / Wireless Technology Convergence



Transport Networksand Interfaces

HumanInterfaces

AccessMediation

VHF/UHF/MicrowaveRadio Subsystems

DigitalProcessing

EnergySystems

Antennas

Semiconductor& Freq ControlDevices

Unified Broadband Communications

Accommodation of RF BehaviorCellular Reuse ArchitecturesEarly Cellular/Cordless, T/R Phones

Management of RF Behavior,Separate System SolutionsAnalog Cellular/Cordless, ISDN

Adaptation to RF Environment,Merged Public/ PrivateMulti-Mode Systems,, EthernetDigital Cellular/ Wireless LANs

(1979-1985)

1986-1992

(1993-1997)

Packet ProtocolsIntegration of Wireless//Wired Services, MultimediaMulti-Access Terminals

(1998-2002)

(2003-2008)Unified Modulation,Coding, Formats

Service-TransparencyWired/Wiireless

AdvancedCoding

Unified Broadband Communications for outdoor and indoor use is a fusion of key technologies---Some are developing, others emerging...

The maturity of the various technologies dictates intermediate solutions whose capabilities satisfy the user service value judgment (cost, utility) at a particular point in time.

Technology “Superhighway On-Ramps” for Communications Networks



1 3

5

7

6

9

0

2

8

Multifunctional Communicators

4

* #

Rcl Sto Clr

Pwr Vol End

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Wireless =Central Theme

Wireless = Part of

Service "Bundle"

Handset +

Radio

Handset +

Modem +

Messaging Pager +

Conferencing Tool +

Computer +

Data Bank +

Remote Control +

Radio

New system environments and service demands have spurredfundamental architectural and technological progress:

Wireless “Y2K” Megatrends



Voice

Data

Distinct Media Typesw/Special Wireless Coding

ComputerData

NetworkAddressing

Video

ImageMultimedia SourceCoding Same asWired Network

Wired-Network Compatible Source Coding







DataData In = Data Out,Improved Error Control

Data

Data

InterferenceNoise

Blocking

Data

Wireless Connections Equivalent to Wired





Narrow Voice-RateData Pipe

More Bits/Hz

in Multipath

Environment

Higher Radio Frequencies,

Wider Channel BW

Wide

All-Purpose

Pipe

Wide-Bandwidth Wireless Connections



AnalogFront-End(Band 1)

AnalogBack-End(IF BW 2)

Digital ChannelProcessing

(Std 2)




(Std 1)




(Std 3)

General-Coverage RadioTechnology

Unique Radio Design for

Each Radio Service

Band-AgileFront-End

Single Radio

Platform Designfor Multi-Band,

Multi-Mode Use

Multi-Band, Multi-Mode Radio Equipment

Wireless “Y2K” MegatrendsNew system environments and service demands have spurredfundamental architectural and technological progress:



Wireless “Y2K” MegatrendsNew system environments and service demands have spurredfundamental architectural and technological progress:

Distributed-Intelligence Wireless Networks

Distributed Adaptive Wireless

Network Processing & Control

Centralized Wireless

Network Processing & Control

Wire

d N

etw

ork

MT

SO





Capacity/Quality Increases Via Adaptive Antennas

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Antenna Processor

AdaptiveArray Antennasfor MaximizedFrequencyRe-Use

Omni or SectorAntennas inCenter or Edge-Excited Cells

"Beams"Replace"Cells"

R/T R/T R/T R/T R/T





Circuit-Switching

Packet-Switching

Switched-Circuit and Packet Mode Depending on Media





Open Interfaces

SS7

Closed Proprietary

Architectures

H323

CTI

IEEE802.11

MGCP

Open Interfaces Required



Although easy to install, W-LANs provide spot coverage, withoutthe range, reuse, contiguous coverage, and isochronous traffic-handling benefits characteristic of cellular CAIs and networkarchitectures.

W-LAN Radio Access PointsRouter

PacketNetwork

Current Indoor Wireless LANs



• Peer/Peer and Client/Server• Small User Population• Isolated "Cells" and User Groups• Non-Contiguous Coverage• Indoor Operation• Limited Mobility• Mostly Asynchronous Traffic• Slower than Ethernet

A

A

A

Today’s Wireless LANs

• InterNet/IntraNet • Ethernet-Compatible Speeds• Multiple RF Bands to operate

Second-Generation Wireless LANs

A

C

BA

• Larger User Population• Full Roaming/Handoff Capability• Contiguous Coverage in Dense Areas• Wider Area Coverage for Community LANs• Mobility (Follow-Me Service)• Mix of Async and Isochronous Traffic• Higher System Utilization• Enhanced Security

IEEE 802.11Fourth-Generation ofWireless Communications

Third-Generation Wireless Communications•TDMA•EDGE•Wideband CDMA

Indoor Wireless LANs Migration



Enhanced IEEE 802.11 MAC

Present 802.11 MAC Enhanced 802.11 MAC



For the past several years, AT&T Labs has been evaluating and developinghardware and software platforms. These platforms evaluate:

•Enhanced network solutions based on extensions to the IEEE 802.11 Standard

• Mixed and simultaneous Isochronous / Asynchronous traffic management

•Full Roaming/Handoff Capability

•Contiguous Coverage in Dense Areas

•Wider Area Coverage for Community LANs

•Mobility (Follow-Me Services)

•Higher System Utilization

• Enhanced security

All while maintaining the Quality-of-Service that the AT&T brand is noted

Ongoing Labs Efforts



Managing Multimedia Content and Throughput

Unified Protocol/MAC

The packet communication challenge: how to provideconcentration of users with various media, preserving QOS...

FDMA, TDMA, CDMA Packet (ALOHA, PRMA, etc.)

Reservation Techniques(Circuit-Switched, Control at Base)

Contention Techniques(Packet-Switched, Control at User and Base)

Knowledge base and modeling of access methods are fundamental to engineering asystem which optimizes cost, system capacity, data latency, frequency use, etc.

Hz

1

2

3

4

1234

1 2 3 4

56

5 6

Time

1,2,3,4,5,6

Time Time

431

42 3

0 1 e e 1FB

Reserved

Contending

FB

1 423

Frame

e 1 1 e21 1

1 4

35

Frame

UserUserUserUserUserUserChannel

ChannelChannelChannelChannelChannel

Slot Slot Slot Slot

Slot SlotSlot

42

e

SlotSlot Slot Slot SlotSlot Slot SlotSlot Slot

Frame

Channel

A set of users (transmitters) wish to communicate with a radio node or coaxial head-end facility (receiver)Users must share a communication channel

Problem: How to coordinate channel usage by the users so that the channel is used efficiently?

e1

Mini-Slots Bearer-SlotsMini-Slots for Payload Management

Synchronous Media ReservationsAsynchronous Media Contention ResolutionSignaling and System Control

Bearer-Slots for Payload Communication



Merging of Wired & Wireless

The Future.....

Telephony, Multimedia, Paging, High Speed Internet/Intranet Services



Conclusion

We at AT&T Labs support the IEEE 802.11 study group in their efforts toenhance the Standard with respect to adding extensions to the MAC and movethe Standard to a 4th Generation Standard that includes a wireless networkingsolution.

We encourage the Study Group / Working Group to look at enhancements thatprovides true network based solutions that will support simultaneousMultimedia, Telephony, Streaming Video, and High Speed Internet / Intranetaccess with a cellular like CAI and enhanced security.

We are pleased to be a participant in the IEEE 802.11 committee and hope tocontinue to contribute to and support the efforts of the IEEE 802.11 StandardsCommittee and this Study Group.

802.11-based wireless technology€¦ · at&t labs november, 1999 doc .: ieee 802.11-99/251...

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