s6 Wireless Networks

7/28/2019 s6 Wireless Networks

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2EI-1010 Wireless Data Networks


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Satellite Data Communications

SolarPanels

Transmitterand TransmitAntenna

OriginatingGroundStation

DestinationGroundStation

Receiverand

ReceiveAntenna


4/324EI-1010 Wireless Data Networks

Satellite Characteristics

Wide area coverage of the earths surface

Long transmission delays

Broadcast transmission

Large channel bandwidth

Transmission costs independent of distance



Common Frequency Bands

Satellite BandsSatellite Bands

ISM band Interference2.4 (2.483-2.500)1.6 (1.610-1.625)L/S

High Equipment cost30 (27.5-30.5)20 (17.7-21.7)Ka

Attenuation due to rain14 (14.0-14.5)11 (11.7-12.2)Kn

Ground links Interference6 (5.925-6.425)4 (3.7-4.2)C

IssuesDown-Link (GHz)Up-Link (GHz)Band

Other Common BandsOther Common Bands

300 MHz-1GHzUHF

30-300 MHz TV (Ch 7) 175 MHz (0.175 GHz) FM 100 MHz (0.1 GHz)VHF

1000 KHz (0.0001 GHz)AM



Satellite Orbits

LEO - Low Earth Orbit

MEO - Medium Earth Orbit

GEO - Geosynchronous Earth Orbit



LEO Satellite Characteristics

LEO - Low Earth Orbit

Lifespan 5-8 years

Number required for coverage 48-66

Speed 27000 Km/hr

Distance 800 Km

Orbit rate 90 min to 2 hours

Openline to ground station - 20 min

C, Ku, and Ka Bands

Global and data messaging

Cheaper, less powerful, smaller footprint



MEO Satellite Characteristics

MEO - Medium Earth Orbit

Lifespan 10-12 years

Number for coverage = 20

Speed 19000 Km/hr

Distance 2000 Km

Orbit rate 90 min to 2 hours Openline to ground station = 2 - 4 Hrs

C, Ku, and Ka Bands

64 Mbps broadband data Primarily voice communications - Iridium,

Globalstar, ICO, Odyssey satellite by Teleglobe



GEO Satellite Characteristics

GEO - Geosynchronous Earth Orbit

Lifespan 12 - 17 years

Majority of satellites (180)

Distance 36000 Km

Speed = earth rotation = 11000 Km/hr - fixed

Footprint = 1/3 of earth

250 milliseconds

C-Band, Ku-Band

Fixed Communication (Television, VSAT)

Canadian Anik satellites from Telesat Canada


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Satellite Components

X-Wing Reflector

Spacecraft Control Process

Inertial Reference Unit

Momentum Wheel

490N Liquid Apogee Motor

22N ThrusterNickel-Hydrogen Battery Cells

Solar Wing

Sensor Suite

Ku-Band Transponders

L-Band Antenna ArrayKa-Band Beacon Horn

Solar Wing Drive

Mirrored Radiator Panel

L-Band Transponders


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Satellite Network

SolarPanels

Transmitterand Transmit

Antenna

OriginatingGroundStation

DestinationGroundStation

ReceiverandReceiveAntenna


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Satellite Advantages

Can reach a large geographical area

High bandwidth

Cheaper over long distances


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Satellite Disadvantages

High initial cost

Susceptible to noise and interference

Propagation delay


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Satellite Transmission Applications

Television distribution

a network provides programming from a central

location

direct broadcast satellite (DBS)

Long-distance telephone transmission

high-usage international trunks

Private business networks


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2000 - Internet via Satellite

DirecPC - Hughes Network

Today 100 000 customers in US

$500 dish + $20/month

Upstream56Kbps

Downstream400KbpsKu-band

Telephone

Network

Upstream56Kbps

Internet


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2003 - Internet via Satellite

Hughes, iSky, Astrolink, Gilat

Predict 1.2 Million customers by 2003

$dish (free) + monthly charge

Bi-directionalDownstream

226MbpsUpstream 20Mbps

Ka-band

Internet

High SpeedUplinkTera bps


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Bluetooth Concept

Special Interest Group consisting of 1400 members

founded by Ericsson, IBM, Intel, Nokia and Toshiba.

Set a standard for low cost short range radiotechnology between devices, i.e. palmpilot, PC, cell,

VCR, watch, printer, fax, joystick, etc

It is estimated that by 2005 the Bluetooth wirelesstechnology will be a built-in feature in more than 670

million products with Bluetooth wireless technology

(according to market researchers Cahners In-Stat

Group).


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Bluetooth Architecture

2.4 GHz ISM Spectrum

1 Mbps transfer rate - 10 meter radius

Targeted at $10 per chip

Host

Interface

SRAM

FLASH

CPU

Link

Manager

CPU

Link

Controller

CPU

RF

Section


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Bluetooth Drivers

Eliminate cables, printer, fax, mouse, keyboard,

stereo, headset, phones, etc

Transfer information between users, PDA businesscards

e-Voucher dispenser, transfer, collect tickets

Ubiquitous cable replacement, same speakers forstereo and PC


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Wireless LANS

Tower Box Workstation Access Point Access Point TokenRing802.5

Workstation

WirelessNetworkInterface Cardbuilt intoLaptop

Ethernet802.3

Laptop

NarrowBand

Transmit and receive on a specific radio frequency

Spread Spectrum (popular)

Frequency Hopping (FHSS)

Direct Sequence (DSSS)

Wideband radio frequency

SecureReliable

10Mbps

200ft

Infrared (IR)

High frequency

Almost LightLine of sight 3ft

Factors

Transmit power

Propagation path

Interaction with other object (reflection)

Air wave congestion (number of users)

Costs

Access Point - $1000 to $2000


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Wireless LANs

Local Area Networks via wireless systems

Spread Spectrum technology

2 Mbps or 11 Mbps

20 meters to 300 meters

915MHz or 2.4GHz or 5.7MHz

IEEE 802.11 specification - Layer 2 communications

Costs

$2000 Access Point, $500 PC cards, $1000 Antenna


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Wireless LAN Issues

DRIVERS

Mobility

RelocationTemporary networks

Difficult wiring areas

POPULAR USES

Point to Point (High rises)

BARRIERS

High prices (relative to

Ethernet/token ring)Low speeds

Safety concerns

LicensingSecurity


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CDPD

Cellular Digital Packet Data

Utilizes unused channels on the cellular network

for data communications

800 MHz - 900 MHz Frequency range

19.2Kbps

Connection based (always connected)

Designed to work with TCP/IP

Ideal for the following environments:

small amounts of data, reliability, mobility,security

C A i i


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CDPD Applications

Wireless Internet Access

Financial Transaction Processing

Retail - Clothing stores, Corner Stores, etc

Point of Sale

Public Safety

Police, Fire, Ambulance

Alarms and Telemetry

Building security

Field Service and Dispatch

Photocopy (Xerox) repair person

Bell Atlantic Mobility (Verizon)


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y ( )

CDPD - Retail Application

WAN

Financial

Institution

CDPD19.2 Kbps

SecureReliable (cellular)

Always connected

Carrier wide availability

$30 - $80 (US) / month

Bell Atlantic Mobility (BAM)


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Bell Atlantic Mobility (BAM)CDPD Pricing (US)

25$25$25$25Activation per unit

$0.10$0.10$0.10$0.10Outside BAM Area perKB

$0.04$0.05$0.08$0.10Above Limit per KB

4,0001,100400150In BAM Area KB limit

$89.95$49.95$29.95$14.95Monthly AccessCharge

DCBAPackage

WAP


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WAP

Wireless Application Protocol

WAP is a standard for wireless data content delivery

such as web pages to PDAs, cell phones, etcEmploys WML - Wireless Markup Language

Supports: CDPD, CDMA, Flex, GSM, and many

other standard wireless communication protocols


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Overview


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Overview

Concept

Wireless data communications everywhere all the

time via laptops and PDAs to the Internet andUniversity LAN for 10000 users.

Technologies

Spread Spectrum - On Campus - 2Mbps - 30m to300m

CDPD - Off Campus (Pittsburgh) - 19.2Kbps - city

wide

N t k


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Network

High-density buildingLow-density building

Accesspoints(LucentWavePointII)

Accesspoints(Lucent

WavePointII)

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CentralNetworkFacility

Optical FiberCable Plant

BuildingDistributionClosets

RemoteClosets

Router (Cicso 7500)

Switch (Cicso 5000)

Hub

(Bay Networks

2813)

Switch (Cicso1924C)

Hub 2813 (Nortel

(Bay)

Carnegie MellonUniversity Network

Spread Spectrum Across Campus


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Spread Spectrum Across Campus

Bell Atlantic Mobility


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yCDPD Coverage in Pittsburgh

Bell Atlantic was involved in

the CDPD standard and has it

deployed across the US withpartners such as ATT, GTE,

Ameritech, Cellular One

Documents

s6 Wireless Networks