the future of wireless communications in and around the...

VIRGINIA POLYTECHNIC INSTITUTEAND STATE UNIVERSITY

TechVirginia

1 8 7 2

© 1999 T. S. Rappaport, All Rights Reserved

Prof. Theodore S. Rappaport

Engineers of the Capitol BuildingDecember 10, 1999

Mobile and Portable Radio Research GroupBradley Dept. of Electrical and Computer Engineering

Virginia Techhttp://www.mprg.vt.edu

The Future of WirelessCommunications In and Around

the Office

©1999 T. S. Rappaport

vWireless communications services proliferatingrapidly

vConsumers about to enjoy unprecedentedmobility and flexibility for tetherless officeapplications

vE-mail, file transfers, and voice/datacommunications soon commonplace for currentusers of cellular phones

v State-of-the-art and future directions of wirelesscommunications for in-building applications

Abstract Details


Emerging Web Access Technologies

Source: C. Mason, “Can You Find the Wireless Runners?,” America’s Network, February 1, 1999,http://www.americasnetwork.com/.


Broadband Subscribers by Technology:U. S. Market in 2003

LMDS9%

ISDN12%

Satellite12%

Cable Modem

26%

ADSL36%

Others5%

Source: Allied Business Intelligence Inc.; L. Luna, “Internet Access Most Likely Use for LMDS,” RCR, August 24,1998, p. 3+.


Emerging Wireless Services

• Unified Messaging

• Wireless Local Loop (WLL)

• E-911/Position Location

• Mobile Satellite Services

• World Wide Wireless Web & Wireless Web Tablets

• Wireless in Small Office/Home Office (SoHo)

• 3G (Third Generation)


Wireless LANs

“Introduction to Wireless LANs,” The Wireless LAN Alliance, http://www.wlana.com.

vWireless LAN (WLAN): implemented asextension to or alternative for wired LAN withinbuildings or campus

vElectromagnetic waves transmit and receive datathrough air, minimizing wired connections

vData connectivity and user mobility combined


Wireless LANs in the Market Place

vSmall Businesses

vCorporations

vEducation

vFinance

vHealthcare

vHospitality and Retail

vManufacturing

vWarehousing


Wireless LAN Marketplace:Future Growth Expectations

Revenue1:í 1999: just over $400 millioní 2000: $550 millioní 2001: $700 millioní 2002: $830 millioní 2003: $1.1 billion

1Source: Frost & Sullivan, “Clear Signals For Wireless LANs”, Information Week Online, October 11, 19992Source: Cahner’s In-Stat Group (Scottsdale, AZ), “Wireless Data Users to Reach 25 Million by 2003,” Wireless Design Online,November 3, 1999.

Shipments1:í 1999: just under 1.5 millioní 2000: 2.2 millioní 2001: 3.4 millioní 2002: 4.75 millioní 2003: 6.2 billion

Users2:í 1.7 million todayí 25 million by 2003


Wireless LAN Marketplace

Baystack 600 SeriesWireless LANProducts1

• Access Point $1,4993

• PC Card $4993 Aironet PC4800 Turbo DS Series2


• PC Card Adapter $5953

1 http://business.baynetworks.com/2 http://www.aironet.com/products/index.html3 http://www.gcn.com/vol18_no28/guide/514-2.html


Wireless LAN Marketplace (cont.)

Lucent WaveLANSeries (DSSS)1


• PC Card $4293

Nokia A020 Access Point2


• C020 Card $2953

1 http://www.wavelan.com/products/2 http://www.aironet.com/products/index.html3 http://www.gcn.com/vol18_no28/guide/514-2.html


Benefits of Wireless LANs

vMobility: improves productivity, service

v Installation: fast, simple, flexible

vCost of Ownership: reduced over costs of wiredLAN hardware

v Scalability: easily configured to narrow or broadarea

“Introduction to Wireless LANs,” The Wireless LAN Alliance, http://www.wlana.com.


Applications of Wireless LANs

M. Sullivan, “State of the Wireless LAN Industry,” The Wireless LAN Alliance, http://www.wlana.com.

MainstreamApplications:

•Data Collection

•Inventory

•Point of Sale

•Hard-to-WireBuildings

BurgeoningApplications:

•BedsideMonitoring

•ER Check-in

•Financial Trading

•Cargo Tracking

•Outdoor Events

•HospitalityCheck-in

•StudentNetworking

AnticipatedApplications:

•Project Team Setup

•Virtual Offices

•Consulting Teams

•On-Site Training

•Mobile Intranet

•Customer-ReadyRooms

•Home Networking


IEEE 802.11 WLAN Standard

vDefines protocol for two types of networks: ad-hoc and client/server networks

v Ad-hoc network: communications are establishedbetween multiple stations in given coverage areawithout use of access point or server

v Client/server network: uses an access point thatcontrols the allocation of transmit time for all stationsand allows mobile stations to roam from cell to cell

v 2.4GHz unlicensed frequency band for data ratesof 1 and 2Mbps

“The IEEE 802.11 Wireless LAN Standard,” http://www.wlana.com/intro/standard/


IEEE 802.11 WLAN Standard (cont.)

vDoes not specify technology or implementation

v Simply specifies for the physical layer and MediaAccess Control (MAC) layer

“The IEEE 802.11 Wireless LAN Standard,” http://www.wlana.com/intro/standard/


In-Building and Campus DeploymentTools

Deterministic tools like SitePlanner™ , developed by researchers at MPRGand marketed by Wireless Valley Communications, Inc., leverage raytracing and other algorithms to provide system designers with acomprehensive package for designing and deploying indoor andmicrocellular wireless systems, including WLANs. Seehttp://www.wvcomm.com for more information.

R. J. Boyle, “Wireless Communications and Multipath Propagation: The Love-Hate Relationship,” presented at 1998Meeting of the American Institute of Physics’ Corporate Associates, October 26-27, 1998.

R. K. Morrow, “Site-Specific Engineering for Indoor Wireless Communications,” Applied Microwave and Wireless,March 1999, Vol. 11, No. 3, pp. 30-38.


In-Building Wireless Market(Cellular & PCS)

vAnnual growth rate for in-building wireless voicemarket expected to be 34%

v In-building market should reach revenues of morethan $800 million by 2003

v 169,000 mobile handsets shipped in 1998 for in-building applications; expected to be 1.2 millionhandsets shipped by 2003

Source: Phillips Group InfoTech, 1999


Dominant PCS Technologies in theWorld

• GSM (Global System for Mobile communications)

• CDMA (Code Division Multiple Access)

• TDMA (Time Division Multiple Access)

0

100

200

300

400

GSM CDMA TDMA

19972003

Source of Chart Information: Strategis Group’s “World Cellular/PCS Markets: 1998;” “Half of World’s WirelessSubs to Use GSM by 2003, Strategis Says,” RCR, June 8, 1998, p. 17.

Mill

ions

of S

ubsc

ribe

rs


3G (Third Generation Wireless)

http://devices.internet.com/glossary/glossary__a-h/glossary__a-h.html#3g

3G Third Generation Networks:

vNewest generation of mobile communications

vBased on GSM core and CDMA core

vAllows greater bandwidth, opening the way toincreased data-over-wireless solutions such assmart phones

vNot expected to be fully operational until 2002


3G (Third Generation Wireless)

“Third Generation Wireless Standards to Shape Internet's Future,” A WirelessNOW Feature by Geoff Livingston,http://www.commnow.com/3rd_Generation.html

Criteria for 3G Cellular Standards:

vMobile data rate of 144 Kbits per second

vPortable data rate of 384 Kbits per second

v In-building fixed data rate of 2 Mbits per second


IMT-2000: The Evolution of theStandard

vOriginally, IMT-2000 was to embrace a singleworldwide wireless standard

vUnable to unite 2G systems under one 3Gtechnology

v IMT-2000 will now be seen as a “family ofstandards” to ensure both current investments andglobal compatibility

Source: Personal Communications Newsletter, January 12, 1998


Key Features of IMT-2000

vEmphasizing worldwide commonality in design

vCompatibility of services within fixed networksand within IMT-2000

vHigh quality

vUse of small pocket-terminal worldwide andaccommodation of a variety of other types ofterminals

Source: “Frequently Asked Questions,” http://www.itu.int/imt/7_faqs/index.htm


Key Features of IMT-2000 (cont.)

vMobile users can connect to other mobile or fixedusers

vRange of voice and non-voice services available tomobile users

vCoverage areas services by more than one network

v Introduction of advanced technologies anddifferent applications made easy due to openarchitecture

Source: Working Document of Security Principles for FPLMTS, 1994


IMT-2000

Source: “Frequently Asked Questions,” http://www.itu.int/imt/7_faqs/index.htm

vThird Generation Systems

vAim to unify the diverse systems of today intoradio infrastructure capable of offering widerange of services around the year 2000 in manydifferent operating environments


IMT-2000

“ITU Approves IMT-2000 Specification,” Wireless Design Online, Nov. 9, 1999, http://www2.wirelessdesignonline.com/


Current Status of IMT-2000

v 10 terrestrial and 5 satellite proposals werereceived at ITU -- June, 1998

vReports by 16 independent evaluation groupssubmitted to ITU Task Group 8/1 -- September,1998

v Final selection of technologies -- March, 1999

Source: http://www.itu.int/newsroom/press/PP98/Documents/Backgrounder2IMT2000.htmlandhttp://www.itu.int/newsroom/press/releases/1999/99-22.html#1


Current Status of IMT-2000 (cont.)

v ITU-R Task Group 8/1 approved a comprehensiveset of terrestrial and satellite radio interfacespecifications for IMT-2000 -- November 1999

v Formal approval of the November 1999 IMT-2000Recommendations at the ITURadiocommunication Assembly -- May 2000

vCommercial operation of IMT-2000 services --2001

Source: http://www.itu.int/newsroom/press/PP98/Documents/Backgrounder2IMT2000.htmlandhttp://www.itu.int/newsroom/press/releases/1999/99-22.html#1


CDMA

vCode Division Multiple Access

v Spread spectrum technology (Qualcomm)

v cdma2000: TIA standard for 3G technology,submitted to ITU as part of the IMT-2000 3Gprocess

http://www.cdg.org/frame_cdg.html


CDMA Benefits to Users

v Increased capacity to 8 to 10 times that of AMPSanalog system and 4 to 5 times that of GSMsystem

vCall quality improved

v System planning simplified through use of samefrequency in every sector of every cell



CDMA Benefits to Users (cont.)

vPrivacy enhanced

vCoverage characteristics improved, allowing forpossibility of fewer cell sites

vTalk time increased for portables

vBandwidth on demand



CDMA: Channel/Cell Use

“About CDMA Technology: The CDMA Revolution,” http://www.cdg.org/frame_cdg.html

Before CDMA With CDMA

CDMA solves the capacity problem!


TDMA

vTime Division Multiple Access

vEuropean TDMA (GSM)

v Japanese TDMA (PHS/PDC)

vNorth American TDMA (IS-136)


TDMA Advantages

vTransmission Efficiency

vEasily adapted to data as well as voice

vNo interference from simultaneous transmissions

vExtended battery life and talk time for mobiles

vEfficient utilizes hierarchical cell, allowingcoverage to be tailored to support specific trafficand service needs

vDual-mode Handsets

“Time Division Multiple Access (TDMA) Tutorial,” http://www.webproforum.com/tdma/topic04.html


TDMA Disadvantages

vUsers have pre-definedtimeslots

v Subject to multipathdistortion

vLimited bandwidth



TDMA Standards Evolution



LMDS

v Local Multi-Point Distribution Service at28GHZ -- campus distribution

v Wireless Communications Servicesv Two-way communicationsv High-speed communicationsv Datav Voicev Video


What are the benefits of LMDS?

v Low Cost:v bandwidth licenses inexpensive

v Fewer Environmental Issues:v air is medium, providing fairly constant environment;

CATV and telephone systems have more difficulties

v Easy to Deployv Modern Network:v do not have to rely on or maintain legacy systems or

services

D. Sweeney, “LMDS: Finally Ready for Prime Time?,” America’s Network, August 1, 1998.


What are the negatives of LMDS?

v Lack of Mature Technology:v largely undeveloped; untried service; little equipment available

v Lack of Experienced Personnel:v both relevant business experience in many of licensees and

qualified engineers

v No Leverage:v most licensees do not have customer base or existing

infrastructure

v Service Limits:v licensees cannot feasibly deliver service everywhere in

their market due to line-of-sight restriction for LMDS

D. Sweeney, “LMDS: Finally Ready for Prime Time?,” America’s Network, August 1, 1998.


LMDS

Source: WAVTRACE, August 1999


Radio Wave Propagation at 38 GHz

View from Tx.

SCATTERINGREFLECTION

Burrus

Measurement Sites: Slusher - Whittemore Link (605 m)View from Rx.

H. Xu, T. S. Rappaport, R. J. Boyle, J. H. Schaffner, "38 GHz Wideband Point-to-Multipoint Radio Wave PropagationStudy for a Campus Environment," IEEE Vehicular Technology Conference, Houston, TX, May 16-19, 1999.



Measurement Results: Hail Attenuation Results

Attenuation due to hail: 25.7 dB.Hail size: 0.5-1.5 cm in diameter.




Weather conditions:

• Hailstorm : Rain rate: 40 mm/hr Wind speed: 6 mile/hr Hail Diameter: 0.5-1.5cm

• Rain: Rain rate: 7.6 mm/hr Wind speed: 7 mile/hr

Analysis on MP Occurrence: Comparison of PDPs for Different Weather



Bluetooth

Source: http://www.bluetooth.com/

vOpen specification for wireless communication ofdata and voice

vBased on low-cost short-range radio link

vBuilt into 9 x 9 mm microchip

v Facilitates protected ad hoc connections forstationary and mobile communicationenvironments


Bluetooth Benefits to End Users

vEasy, simple connectivity to wide range ofcomputing and telecommunications deviceswithout need to buy, carry, or connect cables

vOpportunities for rapid ad hoc connections

vPossibility of automatic, unconscious, connectionsbetween devices

vVirtually eliminates need to purchase additional orproprietary cabling to connect individual devices

“Frequently Asked Questions,” http://www.bluetooth.com/v2/faq/default.asp


Bluetooth Benefits to End Users(cont.)

vPotential replacement for multiple cableconnections via single radio link

vPossibility of using mobile data in a differentway, for different applications

vAllows users think about what they are workingon, rather than how to make their technologywork

“Frequently Asked Questions,” http://www.bluetooth.com/v2/faq/default.asp


Bluetooth Overview

vAllows for replacement of proprietary cablesconnecting one device to another with oneuniversal short-range radio link

vProvides universal bridge to existing datanetworks, peripherals, mechanisms to form smallprivate ad-hoc groupings of connected devicesaway from fixed network infrastructures



Bluetooth Overview (cont.)

vDevices designed to operate in noisy radiofrequency environment

vRadio uses fast acknowledgement and frequency hopping scheme to make linkrobust

vRadio modules avoid interference from othersignals by hopping to new frequency aftertransmitting or receiving packet



Bluetooth System Components

A Bluetooth system consists of the followingcomponents:

v Radio Unit

v Link Control Unit

v Link Management

v Software Functions



Bluetooth Network Topology

Image Source: Bluetooth – “The Universal radio interface for ad hoc, wireless connectivity.” TheTelecommunications Technology Journal – No. 3, 1998)

The topology can best be described as a multiplepiconet structure.


Bluetooth: Establishing NetworkConnections


UnconnectedStandby

ConnectingStates

Active States

Low PowerModes PARK HOLD SNIFF

Ttypical=0.6s

Detach Ttypical=2s

Standby

Inquiry(unknown address)

Page(known

address)

TransmitData

Connected

Ttypical=2 m s Ttypical=2 m s

ReleasesMAC

Address

Keeps MAC Address


Wireless Devices

E-PagerWireless Device(Internet e-mailaddress insteadof phonenumber)3

Ericcson’sBluetooth headset1

Qualcomm’s pdQ(cell phone andPalm Pilot)2

1 http://www.gadgetguru.com/CO---001971.HTML2 http://www.cnn.com/1999/TECH/ptech/12/03/qualcomm.pdq/index.html3 http://www.gadgetguru.com/CO---001926.HTML


Wireless Devices (cont.)

3Com/Palm’sPalm VII 3

Samsung Dual BandSCH 35001

Handspring’s VisorHandheld2

1 http://www.gadgetguru.com/CO---001981.HTML2 http://www.handspring.com/products/vgallery_visorincradle.asp3 http://www.palmpilot.com/custsupp/palmvii.html


Wireless Devices (cont.)

Qubit WebTabletAppliance 3

NeoPoint'sNP1000 DigitalSmart Phone1

Motorolai1000plus SmartPhone2

1 http://www.gadgetguru.com/CO---001882.HTML2 http://www.gadgetguru.com/CO---001882.HTML3 http://gadgetguru.com/CMPLM001777.HTML


Emerging Wideband WirelessSpectrum

Cellular, 50 MHz, 1983

PCS, 150 MHz, 1995

UNII, 300 MHz, 1997

LMDS, 1300 MHz, 1998

60 GHz Unlicensed, 5000 MHz, 1998

• A voice channel occupies » 10 kHz of spectrum.• A TV channel occupies » 5 MHz of spectrum.


5.85 GHz Residential Measurements: 5.85 GHz Applications

•January 1997: FCC allocated 300 MHz of spectrum in 5-6 GHz frequency bands•Unlicensed National Information Infrastructure (NII) devices•Applications for wide-bandwidth wireless local loops, public and private switched

telecommunications, and internet access•Similar spectrum in Europe allocated for HIPERLAN applications. MPRG did extensive

propagation study at 5.85 GHz and anticipates the development of lucrative consumer applicationsfor these frequencies

G. Durgin, T. S. Rappaport, H. Xu, “Measurements and Models for Radio Path Loss and Penetration Loss in and AroundHomes and Trees at 5.85 GHz,” IEEE Transactions on Communications, Vol. 46, No. 11, November 1998, pp. 1484-1496.

e

Houses

Moderately Wooded Yards

(160 m from Tranter Home)

tirie e v

oc oR c eL a ns

e

TxStreet

Trees

Trees

Trees

Trees

Tree

s

Trs


5.85 GHz Residential Measurements: Transmitter Configurations for

Residential Measurements


150-210 m30-45 m

1.5 m5.5 m

T Tx1 x2

Rx• One near transmitter (30-45m

from home) at 5.5m height

• One far transmitter (150-210m)from home at 5.5m height

MPRG Researcher GregDurgin sets up a 5.85 GHztransmitter unit from the backof the measurement van. Alltransmitters emulate curbsideneighborhood base stationsmounted atop 5.5m utilitypoles.


5.85 GHz Residential Measurements: Aggregate Penetration Loss Into a Home

This table provides typical5.85 GHz penetration lossthat are calculated from thedifference between indoorand outdoor measurements.

Shadowing LossHome TR sep 5.5 RX (dB) 1.5 RX (dB) APL (dB)Rappaport 30m 19.1 23.2 13.3

150m 10.8 11.9 16.4Woerner 30m 14.1 27.8 13.1

210m N/A N/A 7.2Tranter 48m 17.2 19.0 21.1

160m N/A N/A 15.316.3 23.6 16.3Linear Average

dB Average 15.3 20.5 14.4



5.85 GHz Propagation Modeling : The Need for 5.85 GHz Propagation Models

Statistical/EmpiricalModeling

Pseudo-DeterministicPropagation Modeling

DeterministicPropagation

Modeling

Computation Time

Site-Specific Information

Error/Standard Deviation

Measured Data

Future deployment of wireless 5-6GHz NII and HIPERLAN devices willrequire accurate propagationprediction models.

Key Question: How can weaccurately model signal power andinterference levels without invokingcomputational complexity or the needfor highly-detailed site information?

Solution: SitePlannerTM, a site-specific management tool spun out ofMPRG



5.85 GHz Propagation Modeling : Site-Specific Path Loss Map

40.2 45.0

31.3

51.4

33.4

52.6

32.4

51.3

33.7

54.4

31.8

53.6

32.0

29.6 33.0 48.5

31.3

50.7

25.9

51.0

27.3

57.9

32.1

56.5

32.0

1.5m Rx Ant. Path Loss

Indoor Path Loss

5.5m Rx Ant. Path Loss

Key

all values in dB w.r.t.1m FS

Rappaport Home - 30m TX Results

Tx

41.639.6

40.1

42.5 51.251.9

57.7

45.8

43.7

46.7

44.4 40.6

46.651.7

51.2Kitchen

Deck

First Floor

Second Floor

Garage

Tree

Tree

FrontBedroom

Rear Bed. 1

MasterBedroom

Rear Bed. 2Family Room

LivingRoom

DiningRoom

Office



5.85 GHz Propagation Modeling : Comparison of Standard Deviation

TR ConfigurationPL Exp.

nStd. Dev.σ (dB)

# of Meas.Points, Ν

# ofHomes

IndoorOverallFirst FloorSecond Floor

3.43.53.3

8.08.37.3

965838

333

OutdoorOverall1.5m5.5m

2.92.93.0

7.99.06.4

1477374

333

RappaportFirst FloorSecond Floor1.5m Outdoor5.5m Outdoor

3.53.53.13.0

9.77.410.26.5

23102627

1111

WoernerFirst FloorSecond Floor1.5m Outdoor5.5m Outdoor

3.23.32.93.1

6.27.78.26.2

8222220

1111

TranterFirst FloorSecond Floor1.5m Outdoor5.5m Outdoor

3.63.42.72.8

6.93.16.45.3

8272626

1111

PartitionLoss(dB)

TreeExterior WallInterior WallCinderblock/Basement

8.212.64.124

Standard Deviation 3.5

The above partitions resultfrom optimizing over allhome measurements withonly four basic partition types(tree, interior & exterior wall,and Cinderblock/Basement).

Path Loss Exponent ModelStandard Deviation: 8.0 dB

Partition-Based ModelStandard Deviation: 3.5 dB



Wireless Application Protocol (WAP)

“Frequently Asked Questions,” The Wireless Application Protocol Forum, http://www.wapforum.org/faqs/index.html.

vOpen, global specification

vEmpowers mobile users with wireless devicesto easily access and interact with informationand services instantly


WAP (cont.)

“Frequently Asked Questions,” The Wireless Application Protocol Forum, http://www.wapforum.org/faqs/index.html.

vWAP devices: handheld digital wireless

vWAP network compatibility: includesCDMA, GSM, TDMA, DECT and mostothers

vWAP complies with Third Generation (3G)wireless standards


WAP Benefits to Subscribers

vAccess from wireless handsets is quick andefficient for essential information.

vTransactions are secure.

v Interface is easy to use and meets the user’sneeds within the restrictions of a constrainednetwork device.

“WAP: Wireless Internet Today,” White Paper from The Wireless Application Protocol Forum,http://www.wapforum.org/what/WAP_white_pages.pdf.


WAP Benefits with WidespreadAdoption

vCommon user interface

vUbiquity of service

vWide selection of devices

vLarge selection of applications

“WAP: Wireless Internet Today,” White Paper from The Wireless Application Protocol Forum,http://www.wapforum.org/what/WAP_white_pages.pdf.


Conclusions

vNumerous specifications and standards aredeveloping to make devices more universaland compatible

vWireless Offices are no longer just an idea forthe future but are available today

vWireless, computing and the internet are allconverging rapidly into personal workappliances