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Wireless Data. Outline. History Technology overview Cellular communications 1G : AMPS; 2G : GSM; 2.5G : GPRS, EDGE; 3G : UMTS Satellite systems Wireless LAN 802.11, Bluetooth Mobility support WAP Wireless applications. History. Local Area Networks (LANS)

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Outline l.jpg
Outline

  • History

  • Technology overview

  • Cellular communications

    • 1G: AMPS; 2G: GSM; 2.5G: GPRS, EDGE; 3G: UMTS

  • Satellite systems

  • Wireless LAN

    • 802.11, Bluetooth

  • Mobility support

    • WAP

  • Wireless applications


History l.jpg
History

  • Local Area Networks (LANS)

    • LAN is a fast (~Mb/s), geographically limited (~km) digital communications network which is owned and operated by the user organization.

    • History of LANs

      • Packet radio networks (Aloha and Slotted Aloha in Hawaii

      • Ethernet

        • The first LAN was an early version Ethernet in 1976, ~ 3 Mb/s

        • Digital-Intel-Xerox “DIX specification in 1979, 10 Mb/.s

        • Ethernet 2 in 1982



Aloha net l.jpg
Aloha Net

  • One of the first functioning wireless networks in the USA, conceived and implemented at the University of Hawaii campus at Manoa.

  • Its purpose was to link the University mainframe computer to client computers located on outer islands at University campuses. Put in place in the early 1970s, it was dubed the Aloha Net. Key punch cards were fed through a reader, and sent over the commercial phone lines


Aloha system l.jpg
Aloha System

  • First random access system (1971).

  • Allowed 7 campuses on 4 islands to access main computer with terrestrial microwave.

  • Each station has an FM transmitter/receiver.

  • No direct communication between stations.

  • 407.35 MHz for inbound traffic. Employs random access.

  • 413.475 MHz for outbound traffic. 9600 bps transmission speed.


The pure aloha protocol l.jpg
The Pure ALOHA Protocol:

  • Each station is coupled to a single broadcast channel.

  • Station transmits whenever it has a packet to send.

  • If there isn't a collision, receiver sends an ack over a separate channel.

  • If there is a collision, no ack is sent and transmitter times out. Time-out interval is at least as long as 2-way propagation time.

  • Station retransmits after random amount of time.


Slotted aloha l.jpg
Slotted ALOHA:

  • Packets have equal length of L bits. Packet time is TRANSP = L/R seconds, where R is the transmission rate of the channel.

  • Time is divided into fixed-length slots of length TRANSP. Clocks in stations are synchronized.

  • A station can begin transmission only at the beginning of a slot.

  • The efficiency of slotted ALOHA is the fraction of slots containing successful transmissions when there are many stations and each station has many packets to send.

  • The maximum efficiency of slotted ALOHA is 1/e = .37. This gives

    • 37% successes

    • 37% empty slots

    • 26% collisions

  • Throughput in bits/sec is R * efficiency.


Invention of ethernet l.jpg
Invention of Ethernet

  • “In late 1972, Metcalfe and his Xerox PARC colleagues developed the first experimental Ethernet system to interconnect the Xerox Alto, a personal workstation with a graphical user interface.

  • The experimental Ethernet was used to link Altos to one another, and to servers and laser printers.

  • The signal clock for the experimental Ethernet interface was derived from the Alto's system clock, which resulted in a data transmission rate on the experimental Ethernet of 2.94 Mbps.


Invention of ethernet10 l.jpg
Invention of Ethernet

  • Metcalfe's first experimental network was called the Alto Aloha Network. In 1973 Metcalfe changed the name to "Ethernet," to make it clear that the system could support any computer--not just Altos--and to point out that his new network mechanisms had evolved well beyond the Aloha system.

  • He chose to base the name on the word "ether" as a way of describing an essential feature of the system: the physical medium (i.e., a cable) carries bits to all stations, much the same way that the old "luminiferous ether" was once thought to propagate electromagnetic waves through space. Thus, Ethernet was born.”


Invention of ethernet11 l.jpg
Invention of Ethernet

  • The diagram ... was drawn by Dr. Robert M. Metcalfe in 1976 to present Ethernet ... to the National Computer Conference in June of that year. On the drawing are the original terms for describing Ethernet.


Ethernet topologies and protocols l.jpg
Ethernet Topologies and Protocols

  • Traditional Ethernet employs a bus topology, meaning that all devices or hosts on the network use the same shared communication line. Each device possesses an Ethernet address, also known as MAC address. Sending devices use Ethernet addresses to specify the intended recipient of messages.


Ethernet topologies and protocols13 l.jpg
Ethernet Topologies and Protocols

  • Data sent over the Ethernet exists in the forms of frames. An Ethernet frame contains a header, a data section, and a footer having a combined length of no more than 1518 bytes. The Ethernet header contains the addresses of both the intended recipient and the sender.


Ethernet topologies and protocols14 l.jpg
Ethernet Topologies and Protocols

  • Data sent over the Ethernet is automatically broadcast to all devices on the network. By comparing their Ethernet address against the address in the frame header, each Ethernet device tests each frame to determine if it was intended for them and reads or discards the frame as appropriate. Network adapters incorporate this function into their hardware.


Ethernet topologies and protocols15 l.jpg
Ethernet Topologies and Protocols

  • There are four major types of media in use today: Thickwire, thin coax, unshielded twisted pair (UTP), and fiber optic.Ethernet media are used in two basic topologies called "bus" and "star". The topology defines how a node (which is any device such as a computer, printer, or hub) is connected to the network.A bus topology consists of nodes connected together by a single long cable. Each node "taps" into the bus and directly communicates with all other nodes on the bus. The major advantage of this topology is the easy expansion, by adding extra "taps", and the lack a hub. The major disadvantage is that any break in the cable will cause all nodes on the cable to loose connection to the network.A star topology links exactly two nodes together on the network. A hub is used to collection point where many of the connections come together. The major advantage is any single break only disables one host. The major disadvantage is the added cost of a hub.





Ethernet packet format l.jpg
Ethernet Packet Format

preamble

start

frame

source

adrs

dest

adrs

length

data

payload

padding

CRC



Why wireless l.jpg
Why Wireless?

  • Human freedom

    • Portability v. Mobility

  • Objective: “anything, anytime, anywhere”

  • Mobility

    • Size, weight, power

    • Functionality

    • Content

  • Infrastructure required

  • Cost

    • Capital, operational


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The m-Commerce “Revolution”

1. High mobile phone penetration: 4 per PC worldwide

2. Convergence of the Internet and the mobile phone

3. Transition to 3rd Generation

4. Personalization, location- & context-sensitive applications and services


Wireless subscribers worldwide l.jpg

(in millions)

1800

1600

1400

1200

Rest of World

1000

Asia Pacific

North America

800

European Union

600

400

200

0

Year

1995

2000

2005

2010

Wireless Subscribers Worldwide

SOURCE: UMTS FORUM


Electromagnetic spectrum l.jpg

4G CELLULAR

56-100 GHz

3G CELLULAR

1.5-5.2 GHz

1G, 2G CELLULAR

0.4-1.5GHz

Electromagnetic Spectrum

HARMFUL RADIATION

LIGHT

RADIO

SOUND

VHF = VERY HIGH FREQUENCY

UHF = ULTRA HIGH FREQUENCY

SHF = SUPER HIGH FREQUENCY

EHF = EXTRA HIGH FREQUENCY

SOURCE: JSC.MIL


Wireless telephony l.jpg
Wireless Telephony

WIRELESS

AIR LINK

WIRED

PUBLIC SWITCHED

TELEPHONE NETWORK

SOURCE: IEC.ORG


Cell clusters l.jpg

ACTUAL COVERAGE

AREA OF CELL 3

ACTUAL COVERAGE

AREA OF CELL 1

Cell Clusters

CELL 1 OVERLAPS 6 OTHERS

DIFFERENT FREQUENCIES

MUST BE USED IN ADJACENT

CELLS

SEVEN DIFFERENT SETS OF

FREQUENCIES REQUIRED

SOURCE: IEC.ORG


Space division multiple access sdma l.jpg
Space Division Multiple Access (SDMA)

MANY CELLS CAN SHARE

SAME FREQUENCIES IF

SEPARATED IN SPACE

PATTERN CAN BE

REPLICATED OVER

THE ENTIRE EARTH

200 FREQUENCIES

IN ONE CELL

TOTAL NUMBER OFFREQUENCIES = 1400

WORLDWIDE


Cell handover l.jpg
Cell Handover

AS PHONE MOVES FROM CELL “A” TO CELL “B”:

• CELL “A” MUST HAND THE CALL OVER TO “B”

• PHONE MUST CHANGE FREQUENCIES

• CELL “A” MUST STOP TRANSMITTING

Minimum

performance

contour

A

x

y

B

z

Handover threshold

contour

SOURCE: R. C. LEVINE, SMU


Cell sizes l.jpg

MACROCELL: $1M

FAST-MOVINGSUBSCRIBERS

PICOCELLS

MICROCELL: $250K

SLOW-MOVINGSUBSCRIBERS

Cell Sizes

GSM:

100m - 50 km

250 km/hr


Multiple access l.jpg
Multiple Access

Code Division

Time Division

Frequency Division

SOURCE: WASHINGTON UNIV.


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Cellular Generations

  • First

    • Analog, circuit-switched (AMPS)

  • Second

    • Digital, circuit-switched (GSM, Palm) 10 Kbps

  • Advanced second

    • Digital, circuit switched, Internet-enabled (WAP) 10 Kbps

  • 2.5

    • Digital, packet-switched, TDMA (GPRS, EDGE)40-400 Kbps

  • Third

    • Digital, packet-switched, wideband CDMA (UMTS)0.4 – 2 Mbps

  • Fourth

    • Data rate 100 Mbps; achieves “telepresence”


Gsm architecture l.jpg

CELL TRANSMITTER

& RECEIVER

INTERFACE TO LANDTELEPHONE NETWORKS

HIERARCHY

OF CELLS

STOLEN, BROKEN

CELLPHONE LIST

LIST OF

ROAMINGVISITORS

PHONE

ENCRYPTION,

AUTHENTICATION

LIST OF SUBSCRIBERS

IN THIS AREA

SIM:

IDENTIFIES A

SUBSCRIBER

GSM Architecture

DATA RATE: 9.6 Kbps

SOURCE: UWC


Gsm frame structure l.jpg
GSM Frame Structure

SOURCE: DANIEL ROLF


From gsm to umts l.jpg

WCDMA

8 PSK

GMSK

GMSK

TECHNOLOGY

From GSM to UMTS

PACKET

SWITCHED

HSCSD = High Speed Circuit Switched Data

GPRS = General Packet Radio System

EDGE = Enhanced Data Rates for GSM Evolution

UMTS = UniversalMobile TelecommSystem

kbit/s

2000

UMTS

BUILT ON TOP

OF GSM

384

EDGE

170

VoIP

GPRS

64

HSCSD

43.2

1999

2000

2001

2002

2003

CIRCUIT

SWITCHED

SOURCE: HPY


Slide35 l.jpg
UMTS

  • Universal Mobile Telecommunications System

  • Data at 2 megabits (> T1) but only indoors

  • Outdoors same as EDGE (384 Kbps)

  • Arthur Andersen says no wireless app needs more than 300 Kbps. WRONG!

  • Based on WCDMA (wideband CDMA)

  • Huge spectrum license costs

    • UK 40B€; German 50B€

  • GSM to EDGE costs 7% of GSM investment

  • GSM to UMTS costs 200-300% of GSM investment

SOURCE: WAPLAND


Slide36 l.jpg
UMTS

  • ITU open standard: IMT-2000

  • Includes satellites

  • Different countries use different air interfaces

  • UMTS Subscriber Identity Module (USIM)

    • operating system software for any UMTS device

    • graphic files, electronic signature data, personal files, fingerprints and biometric data.

SOURCE: WAPLAND


General packet radio service gprs l.jpg
General Packet Radio Service (GPRS)

  • General Packet Radio Service (GPRS) is a new service designed for digital cellular networks (GSM-Global System for Mobile Communications, DCS, PCS).

  • It utilises a packet radio principle and can be used for carrying end user’s packet data protocol (such as IP and X.25) information from/to a GPRS terminals to/from other GPRS terminals and/or external packet data networks.

  • GPRS is standardised in ETSI (European Telecommunications Standards Institute).


General packet radio service gprs38 l.jpg
General Packet Radio Service (GPRS)

  • GPRS uses a packet-mode technique to transfer high-speed and low-speed data and signalling in an efficient manner over GSM radio networks. GPRS optimises the use of network resources and radio resources. Strict separation between the radio subsystem and network subsystem is maintained, allowing the network subsystem to be reused with other radio access technologies. GPRS does not mandate changes to an installed MSC base.


General packet radio service gprs39 l.jpg
General Packet Radio Service (GPRS)

  • GPRS is designed to support from intermittent and bursty data transfers through to occasional transmission of large volumes of data. Four different quality of service levels are supported. GPRS is designed for fast reservation to begin transmission of packets, typically 0,5 to 1 second. Charging will typically be based on the amount of data transferred.


General packet radio service gprs40 l.jpg
General Packet Radio Service (GPRS)

  • GPRS introduces the following two new major network elements:

    • SGSN—Sends data to and receives data from mobile stations, and maintains information about thelocation of a mobile station (MS). The SGSN communicates between the MS and the GGSN. SGSN

    • GGSN—A wireless gateway that allows mobile cell phone users to access the public data network

    • (PDN) or specified private IP networks. The GGSN function is implemented on the Cisco Systems’ router.



General packet radio service gprs42 l.jpg
General Packet Radio Service (GPRS)

  • User sessions are connected from a mobile station to a Base Transceiver Station (BTS), to a Base Station Controller (BSC). The combined functions of the BTS and BSC are referred to as the Base Station Subsystem (BSS). From there, the SGSN provides access to the GGSN, which serves as the gateway to the data network.


Satellite systems l.jpg

GEO

MEO

LEO

Satellite Systems

GEO (22,300 mi., equatorial)

high bandwidth, power, latency

MEO

high bandwidth, power, latency

LEO (400 mi.)

low power, latency

more satellites

small footprint

V-SAT (Very Small Aperture)

private WAN

SOURCE: WASHINGTON UNIV.


Gps satellite constellation l.jpg
GPS Satellite Constellation

  • Global Positioning System

  • Operated by USAF

  • 25 satellites

  • 6 orbital planes at a height of 20,200 km

  • Positioned so a minimum of 5 satellites are visible at all times

  • Receiver measures distance to satellite

SOURCE: NAVSTAR


Automatic vehicle location avl l.jpg
Automatic Vehicle Location (AVL)

  • Benefits of AVL

  • Fast dispatch

  • Customer service

  • Safety, security

  • Digital messaging

  • Dynamic route optimization

  • Driver complicance

  • Sample AVL Users

  • Chicago 911

  • Inkombank, Moscow

  • Taxi companies

SOURCE: TRIMBLE NAVIGATION


Gps and auto insurance l.jpg
GPS and Auto Insurance

  • Need to rate drivers accurately

    • age, residence and driving record not enough

    • driving after midnight is 10 TIMES as risky as at 8:00 a.m.

    • commuting is the safest kind of driving

    • parking in high-crime neighborhoods increases payout

  • Progressive Insurance (Mayfield, Ohio)

  • “Autograph” policy: car is outfitted with GPS, cellular modem, microprocessor + 256KB memory

  • When ignition is turned on, car records location every six minutes

  • Once a month, uploaded to Progressive by cellphone


Gps and auto insurance47 l.jpg
GPS and Auto Insurance

  • Customer is billed retrospectively every month

  • 25-50% savings in premiums

  • Increases Progressive’s share but also gives them the right share (safe drivers)


Location aware applications l.jpg
Location-Aware Applications

  • Vehicle tracking

  • Firemen in buildings, vital signs, oxygen remaining

  • Asset tracking

  • Baggage

  • Shoppers assistance

  • Robots

  • Corporate visitors


Automatic identification and data capture aidc l.jpg
Automatic Identificationand Data Capture (AIDC)

  • Problem: how to obtain data from physical objects

    • Examples: product ID, price, serial number

  • Bar code two-dimensional

  • Magnetic stripe card

  • Smart card

  • Radio Frequency Identification (RFID)

  • Real-Time Locating Systems (RTLS)

TAG

RFID CIRCUIT

WAND READER


Aidc applications l.jpg
AIDC Applications

  • Highway toll collection

  • Freight containers

  • Animal identification

  • Theft detection

  • Inventory, asset management

  • Traffic control

  • Gas station billing

SOURCE: TSS


Java ring l.jpg
Java Ring

  • Java-enabled iButton

  • Communicates by contact at 142 Kbps

  • 64 KB ROM and 134 KB RAM

  • Stores 30 digital certificates with 1024-bit keys

  • Uses: authentication, epayment, access

  • Cost: $15-30 in unit quantity

SOURCE: IBUTTON.COM


Wireless lan l.jpg
Wireless LAN

  • Idea: just a LAN, but without wires

  • Not as easy since signals are of limited range

  • Uses unlicensed frequencies, low power

  • 2.4 GHz

    • IEEE 802.11 (wireless ethernet)

    • 802.11a standard (new)

      • Capable of 54 mb/s

    • 802.11b standard - most common form

      • Capable of 11 mb/s

  • 5.2 GHz

    • OFDM (orthogonal FDMA) modem technology (30 Mbps) IEEE 802.11

  • Bluetooth


Wireless lan components l.jpg
Wireless LAN Components

Extended

Range

Antenna

WaveLAN ISA

(Industry Standard

Architecture) Card

WavePOINT II

Transmitter

Ethernet

Converter

11 Mbps WaveLAN

PCMCIA Card

SOURCE: LUCENT


Wireless lan configurations l.jpg
Wireless LAN Configurations

CLIENT AND ACCESS POINT

WIRELESS PEER-TO-PEER

BRIDGING WITH

DIRECTIONAL ANTENNAS

MULTIPLE ACCESS POINTS + ROAMING

UP TO 17 KM !

SOURCE: PROXIM.COM


Bluetooth l.jpg
Bluetooth

A standard permitting for wireless connection of:

  • Personal computers

  • Printers

  • Mobile phones

  • Handsfree headsets

  • LCD projectors

  • Modems

  • Wireless LAN devices

  • Notebooks

  • Desktop PCs

  • PDAs


What is bluetooth l.jpg
What is Bluetooth?

  • A short-range wireless technology

  • Designed for several needs

    • Interconnecting a computer and peripherals

      • Clear the snake’s nest behind the desk!

    • Interconnecting various handheld devices

      • Laptop computer, cell phone, palmtop

      • Preplanning of network is impractical

    • Any short-range application where low cost is essential

      • Goal: $5 parts cost

    • Intended to be embedded in other devices

  • What it is not

    • Another wireless LAN


Bluetooth characteristics l.jpg
Bluetooth Characteristics

  • Operates in the 2.4 GHz Industrial-Scientific-Medical (ISM) (unlicensed)! band. Packet switched. 1 milliwatt. Low cost.

  • 10m to 100m range

  • Uses Frequency Hop (FH) spread spectrum, which divides the frequency band into a number of hop channels. During connection, devices hop from one channel to another 1600 times per second

  • Bandwidth 1-2 megabits/second

  • Supports up to 8 devices in a piconet (two or more Bluetooth units sharing a channel).

  • Built-in security.

  • Non line-of-sight transmission through walls and briefcases.

  • Easy integration of TCP/IP for networking.




Where did the name come from l.jpg
Where Did the Name Come From?

  • Harald Blaatand “Bluetooth” II

    • King of Denmark 940-981

    • Son of Gorm the Old (King of Denmark) and Thyra Danebod (daughter of King Ethelred of England)

  • Noted for unifying Denmark and Sweden

  • This is one of two Runic stones erected in his capitol city of Jelling (central Jutland)

    • This is the front of the stone depicting the chivalry of Harald.

    • The stone’s inscription (“runes”) say:

    • Harald christianized the Danes

    • Harald controlled Denmark and Norway

    • Harald thinks notebooks and cellular phones should seamlessly communicate


Bluetooth devices l.jpg
Bluetooth Devices

ALCATEL

One TouchTM 700

GPRS, WAP

ERICSSON R520

GSM 900/1800/1900

ERICSSON

BLUETOOTH

CELLPHONE

HEADSET

NOKIA 9110 + FUJI

DIGITAL CAMERA

ERICSSON

COMMUNICATOR


Home and office of the future l.jpg

Connected PC

Connected Families

Mobile display pad

Electronic Program guide

Read & set security system

Home Theater control

Display News headlines

Office Laptop

Connect to office LAN

Email

Home Printer access

Surf from anywhere

Share files

Family Car

Trip Navigation downloads

Download News/Entertainment

Grandma’s Brownies

3 cups flour

1 cup grated chocolate

1 cup sugar

1 stick butter

Broadband

Internet Pipe

Ethernet or

HomePNA

Grandma’s

3 cups flour

1 cup grated chocolate

1 cup sugar

1 stick butter

1/2 cup chopped walnuts

minutes.

Main Home PC

HOME

INDEX

Fridge Pad

Family Calendar

Recipe Display

Build shopping lists

Voice messaging

Intercom

Cordless Phone

Remote Speech recognition

Call by name

Build shopping lists

Home PBX

Additional PC(s)

Kids Room PC

Printer access

Internet access

File access

Home and Office of the Future

SOURCE: IEEE


Wireless application support l.jpg
Wireless Application Support

  • WAP (Wireless Application Protocol) and iMode

  • High-level protocols that use cellular transport

  • WAP:

    • Uses WML (Wireless Markup Language)

    • Divides content into “cards” equal to one telephone screen

    • Simplified but incompatible form of HTML

    • To send to a WAP phone, must broadcast WML content


Wap applications l.jpg

Internet

MobileNetwork

WAP Applications

Web Content

Server

Non Mobile

Internet User

WAP Gateway

Mobile

Terminal

iNexware

Database

Server

WAP simulator

SOURCE: DANET


Imode l.jpg
iMode

  • Telephone, pager, email, browser, location tracking, banking, airline tickets, entertainment tickets, games

  • NTT DoCoMo (ドコモ means “anywhere”)

  • Japan is the wireless Internet leader:

SOURCE: EUROTECHNOLOGY JAPAN K.K.


Imode66 l.jpg
iMode

  • Sits on top of packet voice/data transport

  • As of January 2001, > 18 million subscribers

    • 50,000 new ones per day

  • 15% of Japan, 40% of DoCoMo users

  • 1380 “official” sites, 665 application partners

  • 37,000 unofficial sites

  • Fee based on data transmitted

SOURCES: XML.COM, NTT


Imode67 l.jpg
iMode

  • Phonetic text input (better for Japanese)

  • SLOW: 9.6 Kbps, but 3G will raise to 384 K in 2001

  • Uses cHTML (compact HTML)

    • same rendering model as HTML (whole page at a time)

    • low memory footprint (no tables or frames)

  • Java port coming

  • Standby time: 400 min., device weight 2.4 oz. (74g)

SOURCES: XML.COM, NTT


Imode operation l.jpg

BILLING

DB

INTERNET

INFO

PROVIDER

USER

DB

IP

IP

iMode Operation

DoCoMo

Packet

Network

(PDC-P)

iMode

Servers

HTTP

PACKET DATA

SOURCE: SAITO & SHIN


Key takeaways l.jpg
Key Takeaways

  • Mobile growing very rapidly

  • Cell systems need large infrastructure

  • Wireless LAN does not

  • Content preparation is a problem

  • Wireless business models largely unexplored

  • Bandwidth, bandwidth, bandwidth


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