2001 Prentice Hall, Inc. All rights reserved. 1 Chapter 9, Wireless Communications Technologies: Part 1 Outline 9.1 Introduction 9.2Hardware 9.2.1Handsets

2001 Prentice Hall, Inc. All rights reserved.

1

Chapter 9, Wireless Communications Technologies: Part 1

Outline9.1 Introduction9.2 Hardware

9.2.1 Handsets 9.2.2 Pagers9.2.3 Personal Data Assistants (PDAs)9.2.4 Convergence Devices and Other Wireless Options

9.3 Wireless Carriers and Service Providers 9.3.1 Mobile-phone Service Providers9.3.2 Wireless Internet Service Providers (WISPs)9.3.3 SMS and Other Messaging Services9.3.4 Wireless Internet and Other Wireless Services


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Chapter 9, Wireless Communications Technologies: Part 1

Outline9.4 Wireless Networks

9.4.1 Wireless Local Area Networks (WLANs)9.4.2 Wireless Wide Area Networks (WWANs)

9.4.3 Wireless Personal Area Networks (WPANs)

9.4.4 Fixed Wireless

9.5 Radio Frequency, Laser, Infrared and Bluetooth Wireless Technologies

9.5.1 Radio Frequency (RF)9.5.2 Laser and Infrared Technologies

9.5.3 Bluetooth Wireless Technology

9.6 Satellite Communications 9.7 Future of Wireless Communications9.8 Internet and World Wide Web Resources


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9.1 Introduction

• Millions of people worldwide use wireless services and devices

• Wireless communications– Hardware

– Wireless carriers

– Networks

– Satellites


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9.2 Hardware

• Mobile phones, PDAs and laptop computers allow wireless access to the internet from remote locations

• Outside US, mobile phones are preferred medium for information and e-business transactions


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9.2.1 Handsets

• Handsets: devices to send/receive voice calls and data messages– Antenna – transmission

– Number pad – dialing

– Speaker and microphone – voice communications

– Operating system – operation

– Computer chips – other functions

• Flip-phones– Compact handsets


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9.2.1 Handsets

• Cell phone features– Digital and analog signals

– Phone books

– Caller ID and voicemail

– OEL color display screen

– Voice-activated technology: operation through voice commands

– Internet access

– Manufacturers developing disposable phones and other low-cost alternatives

• The term handset is used interchangeably with mobile phone, cell phone and wireless phone.


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9.2.1 Handsets

• Telespree: low-cost no-activation phones– Purchased from drug/grocery store at 1/3 price of regular

phones

– Once prepaid minutes used:• Can replace AirClip cartridge

• Can buy new phone

• Telespree works on GSM network– Current phones can send but not receive calls

– Access internet and use voice commands for dialing

– Handle numbers: allow for phone use without registering wireless service


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9.2.1 Handsets

Motorola’s V series™ Phone model 66, Nokia’s 3390 and 5165 series are examples of handsets available on the market. ©2001 Nokia Mobile Phones., ©2001, Motorola, Inc.


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9.2.2 Pagers

• Pagers were one of first widely used wireless communications methods– Store messages

– Alert user of new messages

– Show caller ID and message information

• Rates based on number of messages sent/received and messages stored

• 3 messaging types– One-way numbering paging: Transfer of numbers only

• Telephone numbers

• Some numbers used as codes for messages


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9.2.2 Pagers

• 3 messaging types (cont’d)– Text-based messaging: receives text and voice mail

notification (one-way text messaging)

– Two-way interactive communication: send/receive text messages between two individuals

• RIM’s BlackBerry handheld device: wireless e-mail solutions– Supports both DataTAC and Mobitex data network protocols

– In-building and roaming service, messaging and guaranteed reliability

– E-mail, desktop and server software available

– E-mail access without dialing into an ISP


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9.2.2 Pagers

BlackBerry home page. (Courtesy of Research In Motion Limited. The BlackBerry and RIM families of related marks, images and symbols are the exclusive properties of, and trademarks of Research In

Motion Limited, used by permission.)


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9.2.3 Personal Digital Assistants (PDAs)

• PDA popularity in wireless market growing– Access web, e-mail, travel arrangements, directions,

reservations, shopping, etc…

– Organizers: store information, appointments and personal information

– Infrared technology allows information sharing between devices

• PDA opportunities for businesses and consumers• Security and privacy concerns

– Access conflicts


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9.2.4 Convergence Devices and other Wireless Options

• Convergence Devices– Combinations of PDAs, mobile phones, and pagers

• Smart phones

• PDAs with add-on modules

• MP3 phone hybrids

• Personal communicators

– Two distinct trends in development• One uses designs for handsets and combines them with PDA

information services.

• The other uses existing PDA designs and adds voice capabilities.


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9.3 Wireless Carriers

• Wireless Carriers: companies providing wireless Internet access to mobile devices– Services

– Pricing

– Network coverage


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9.3.1 Mobile-phone Service Providers

• Service providers offer “complete” solutions– Voice, messaging, e-mail and wireless web options

• Service Plans– Talk time/air time: amount of time user communicates on

phone• Peak hours: usually daytime, most expensive, less hours

offered

• Off-peak hours: other times (usually nights and weekends), less expensive, more hours offered


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9.3.1 Cell-phone Service Providers

• US Operators

• Sprint, Verizon and AT&T lead in coverage area and market share

Service Provider Example Plans (range of minutes)

Extra Minutes Cost (cents/minute)

Prices (dollars/month) Note: service contract usually required.

Sprint PCS 180-2000 0.35-0.40 $29.99-$149.99

Verizon Wireless 150-2000 0.20-0.40 $35-$200

Cingular 100-2000 0.35 $29.99-$149.99

AT&T Wireless 450-2000 0.25-0.35 $59.99-$199.99

VoiceStream Wireless 300-1500 0.25-0.30 $39.99- $139.99

Nextel 400-2000 0.25-0.35 $59.99-$199.99

MCI Worldcom 50-2500 0.30-0.40 $19.99-$199.99

US Cellular 300-1500 0.20-0.30 $30-$100 Fig. 9.4 U.S. Mobile-phone Service Providers and examples of rate plans

available. [***H. Bray, “Busy Signals,” The Boston Globe 12 March 2001: C6***][***<www.sprintpcs.com>, <www.cingular.com>, <www.nextel.com> and <www.verizonwireless.com>***]


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9.3.2 Wireless Internet Service Providers (WISPs)

• GoAmerica and Omnisky are main service providers for PDAs in US

• GoAmerica– Web-browsing and e-mail services

– Go.web allows viewing entire web pages

• Omnisky– E-mail, stock trading, chatting and web-surfing

– Monthly or prepaid plan, no minute restrictions


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9.3.3 SMS and Other Messaging Services

• Short Messaging Service (SMS): GSM networks - more popular outside US– Enhanced Message Service (EMS): small images, sounds,

animations and text

– Multimedia Messaging Service (MMS): text, sounds, images, video and multimedia

– Future: • Advertising

• M-commerce

• Location-based services


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9.3.3 SMS and Other Messaging Services

service provider Text-based messaging service

Price

Sprint PCS Wireless Web Messaging 30 for $1.99/month or 200 for $9.99/month

Verizon Wireless Mobile MessengerSM 0.02 cents per message received, 0.10 cents per message sent

Cingular Interactive messaging 0.10 cents per message

AT&T Wireless 2-way text messaging 0.10 cents per message Fig. 9.5 Messaging services offered from the four U.S. wireless carriers.

[***<www.sprintpcs.com>, <www.cingular.com>, <www.verizonwireless.com> and <www.att.com>***].


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9.3.4 Wireless Web and Other Wireless Services

• Carrier services for convergence devices (voice, text and e-mail)– Packages combine all three or offer each individually

Wireless Web Service Servic e Provider, C ountry

KDDI Web Messaging Service KDDI, Japan

BT Genie British Telcom, UK

Sprint PCS Wireless Web Sprint PCS, United States

i-mode NTT DoCoMo, Japan Fig. 9.6 Largest wireless-Web services (and their providers) in the world.


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9.4 Wireless Networks

• Corporations, businesses and colleges building wireless networks allowing information access anytime from anywhere

• Local Area Networks (LAN) and Wide Area Networks (WAN)– Use wires and cables to connect users to central server

– Many companies and residences turning to wireless solutions for area networks

• Wireless Local Area Networks (WLANs), Wireless Wide Area Networks (WWANs) and Wireless Personal Area Networks (WPANs) – Transmit data through air


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9.4.1 Wireless Local Area Networks (WLANs)

• Wireless Local Area Networks (WLANs)– Inexpensive wireless internet access in heavily populated

areas

– Coverage area size of college campus or office complex

– WLAN methods of communication• Peer-to-peer communications: device communicates directly

with another device

• Access Points: gateways at points in network, allows communication with other servers

– No WLAN unifying standard• 802.11 used in 1997, IEEE introduced 802.11b in 1999

• 802.11a, 802.11e, 802.11g and HiperLAN/2 under development


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• WLANs (cont’d)– WLAN spread-spectrum technologies: spread signals over

frequencies• Direct Sequence Spread Spectrum (DSSS)

– Divides spectrum into 14 channels– Information coded into bits, bits make up chips, 64 chips

sent in burst• Frequency Hopping Spread Spectrum (FHSS)

– Low cost, allows roaming between different frequencies– Signals hop on 78 patterns over bandwidth, minimizes

interference

– Wireless Andrew at Carnegie Mellon University• WLAN covers CMU campus on 802.11b standard• Faster than DSL and many other technologies• Uses DSSS and requires software installation


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• WLANs (cont’d)– WLAN advantages over wired networks

• Allows information access from anywhere

• Easy to move/install

• Flexible and scalable (shaped and configured)

– Starbucks introducing internet access service on WLAN


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Wireless LANs allow users to communicate among buildings on campus.(Courtesy of Patricia Moulder)


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9.4.2 Wireless Wide Area Networks (WWANs)

• Wireless Wide Area Networks (WWANs)– Wireless networks that cover entire cities or states

– Use cellular networks and satellites

– Cellular Digital Packet Data (CDPD) is one of the most widely used forms of WWANs.

• Supports data speeds of 19.2Kbps

• Used by U.S. carriers like Verizon Wireless and AT&T Wireless

– ARDIS (Motorolla) covers 400 largest US metropolitan areas

– Transcomm covers 93% of US businesses


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9.4.3 Wireless Personal Area Networks (WPANs)

• Wireless Personal Area Networks (WPANs)– Short-range connectivity for small areas

– Bluetooth piconets use WPAN

– Coverage area typically less than 30 feet in radius

– IBM believes in using electrical currents through human body as a form of aWPAN


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• Fixed Wireless: mobile devices/computers in fixed location connected without wires– Point-to-point transmission: network transmits from central

base station to one other point

– Point-to-multipoint transmission: from central base to many users

– Multipoint-to-multipoint access (mesh): from multiple base stations to multiple users

• Local Multipoint Distribution Service (LMDS)– Point-to-multipoint, two-way super-high frequency signals

– Low-powered, 3 mile radius, requires clear line of sight


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• Multichannel Multipoint Distribution Service (MMDS)– Multipoint-to-multipoint

– Higher power than LMDS (35-50 miles)

– Does not require clear line of sight

– Uses Orthogonal Frequency Division Multiplexing (OFDM – chapter 10)


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9.5 Radio Frequency, Laser, Infrared and Bluetooth Wireless

Technology• Technologies allowing sharing among wireless

devices– Radio frequency

– Infrared

– Laser

– Bluetooth


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9.5.1 Radio Frequency (RF)

• Radio Frequency (RF): communications through radio signals– Phones, broadcasts and networks

– Regulated by the Federal Communications Commission (FCC)

• Radio Frequency WLAN: networks devices not close together

• RF WLAN standards– HomeRF

• In home and small offices

• Data and voice products networking between printers, PCs, and phones


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• RF WLAN standards– HomeRF

• In home and small offices

• Data and voice products networking between printers, PCs, and phones

• Uses Shared Wireless Access Protocol (SWAP), FHSS technology

– Wireless Fidelity (Wi-Fi)• 802.11b standard

• Airports, restaurants and other areas

• High power consumption and low reliability in high traffic

• Mice and stereo components use radio frequency technology as well


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HomeRF (Courtesy of HomeRF Working Group, Inc. (www.homerf.com))


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9.5.2 Laser and Infrared Technology

• Laser technology: connects buildings– Transceivers (towers) on rooftops communicate through

signal and link networks

• Infrared technology: connects devices– Up to 30 feet and needs clear line of sight

– More cost-efficient than laser technology

– Concern for infrared: slow speeds and new technologies (Bluetooth)


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9.5.3 Bluetooth

• Bluetooth: radio frequencies– 2,200 companies involved in Bluetooth Consortium

– Point-to-multipoint and FHSS packet-switching

– Can connect multiple devices within a 30 foot radius

– Interference problems: on 2.4GHz band with most other WLAN devices

• Bluetooth allows automatic communication as soon as devices enter coverage area


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9.6 Satellite Communications

• Satellite communications is alternative for wireless networks

• Satellite system types– Low Earth Orbit Satellites (LEOs)

• 100-300 miles above surface: transmit signals quickly

• Hundreds placed in ring following earth’s curvature: communicate with each other until in range of destination user

– Medium Earth Orbit Satellites (MEOs)• 6,000 to 12,000 miles above surface

• Require fewer satellite than LEOs

• Used by government and for weather


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9.6 Satellite Communications

• Satellite system types (cont’d)– Geostationary Orbit Satellites

• 22,282 miles above surface

• Replaced less often

• More transmission delays and distortions

• Satellites provide voice, data, and location-based services

• Iridium– Motorolla satellite network for voice, data, fax and location

– Used 66 LEO satellites, bankrupt in 1999 and bought in 2001 by Iridium Satellite


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9.7 Future of Wireless Communication

• Wireless service moving toward 3G technologies– Battle over technologies and standards

– Provider globalization

– Network upgrades to 3G

Documents

2001 Prentice Hall, Inc. All rights reserved. 1 Chapter 9, Wireless Communications Technologies: Part 1 Outline 9.1 Introduction 9.2Hardware 9.2.1Handsets