Bezzicni Multimediski Mrezi-predavanja 1

7/28/2019 Bezzicni Multimediski Mrezi-predavanja 1

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Wireless Multimedia Networks

. -

Prof. Dr. Toni Janevski

email: [email protected]


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Wireless MultimediaIntroduction


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Wireless Multimedia Networks , Prof. Dr. Toni Janevski

Goal of Wireless and Mobile Networking

People and their machines should be ableto access information and communicate

with each other easily and securely, in any

medium or combination of media voice,data, image, video, or multimedia any

time, anywhere, in a timely, cost-effective

way.

Dr. G. H. Heilmeier, Oct 1992


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Heilmeier's Catechism What are you trying to do? Articulate your objectives

using absolutely no jargon.

How is it done today, and what are the limits of currentpractice?

What's new in your approach and why do you think it willbe successful?

Who cares? If you're successful, what difference will itmake?

What are the risks and the payoffs?

How much will it cost? How long will it take?

What are the midterm and final "exams" to check forsuccess?


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Technology Trends

Development and deployment of wirelesstechnology and infrastructure

in-room, in-building, on-campus, in-the-field,

MAN, WAN

Miniaturization of computing machinery

. . . -> PCs -> laptop -> PDAs ->embedded computers/sensors


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At Home

WiFi

WiFi

WiFi

cellular

bluetooth

UWB

satellite WiFi 802.11g


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At Home

Source: http://teacher.scholastic.com/activities/science/wireless_interactives.htm


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At Home: Last-Mile Many users still dont

have broadband reasons: out of service

area; some considerexpensive

Broadband speed is stilllimited DSL: 1-8 Mbps

download, and 100-800Kbps upload

Cable modem: depends

on your neighbors Insufficient for several

applications (e.g., high-quality video streaming)


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On the Move

Source: http://www.ece.uah.edu/~jovanov/whrms/


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On the Move: Context-Aware

Source: http://www.cs.cmu.edu/~aura/docdir/sensay_iswc.pdf


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On the Road


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Example: Vehicle Infrastructure

Integration (VII) Establishing a vehicle-to-vehicle

and vehicle-to-roadside

communications system safety: e.g., intersection collision

avoidance/violation warning/turnconflict warning, curve warning

mobility: e.g., crash data,

weather/road surface data,construction zones, emergencyvehicle signal pre-emption

commercial benefits

Implementation: a network of220,000 IEEE 802.11a and 802.11pwireless hot spots

More info: http://www.its.dot.gov/vii/index.htm


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Collision Avoidance atIntersections

Two millionaccidents at

intersections

per year in US

Source: http://www.fhwa.dot.gov/tfhrc/safety/pubs/its/ruralitsandrd/tb-intercollision.pdf


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Collision Avoidance : V2V Networks

stalled vehiclewarning

bland spots


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Disaster Recovery

9/11, Tsunami, Hurricane Katrina,South Asian earthquake

Wireless communication andmobile computing capability

can make a differencebetween life and death ! rapid deployment

efficient resource and energy usage

flexible: unicast, broadcast, multicast, anycast resilient: survive in unfavorable and untrusted environments

http://www.att.com/ndr/


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Habitat Monitoring: Example on Great Duck Island

Patch

Network

Transit Network

Basestation

Gateway

A 15-minute human visit leads to 20%offspring mortality


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Wireless and Mobile Networking

Driven by technology and vision

wireless communication technology

global infrastructuredevice miniaturization

The field is moving fast


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Why is the FieldChallenging?


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Challenge 1: Unreliable and

Unpredictable Wireless Links

Asymmetry vs. PowerReception v. DistanceStandard Deviation v.

Reception rate

What Robert Poor (Ember)

calls The good, the bad and

the ugly

Wireless links are not reliable: they may vary over

time and space


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Challenge 2: Open Wireless Medium

Wireless interference

Hidden terminals and

Exposed terminal

Wireless security

eavesdropping, denial of service,

S1

S2

R1

R1

S1 R1 S2

R1 S1 S2 R2


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Challenge 3: Mobility

Mobility causes poor-quality wireless links

Mobility causes intermittent connection

under intermittent connected networks,

traditional routing, TCP, applications all break

Mobility changes context, e.g., location


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Challenge 4: Limited Resources Limited bandwidth

Limited battery power

Limited processing, display and storage

Sensors,

embedded

controllers

Mobile phones

voice, data simple graphical displays

GSM

PDA

data

simpler graphical displays

802.11

Laptop

fully functional

standard applications battery; 802.11

PPerformanceerformance/Weight/Power Consumption/Weight/Power Consumption


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Challenge 5: Changing Regulation and

Multiple Communication Standardscellular phones satellites wireless

LAN

cordless

phones

1992:GSM

1994:

DCS 1800

2001:

IMT-2000

1987:

CT1+

1982:

Inmarsat-

A

1992:Inmarsat-B

Inmarsat-M

1998:

Iridium

1989:

CT 2

1991:

DECT 199x:proprietary

1997:

IEEE 802.11

1999:

802.11b, Bluetooth

1988:

Inmarsat-

C

analogue

digital

1991:

D-AMPS

1991:

CDMA

1981:

NMT 450

1986:

NMT 900

1980:

CT0

1984:CT1

1983:

AMPS

1993:

PDC

2000:GPRS

2000:IEEE 802.11a

Fourth

Generation

(Internet based)


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Wireless and Mobile

Towards Wireless IP


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The Wireless WorldSpeeds and Distances for Major Alternatives

1G

WWAN

WMAN

WLAN

WPAN

10 kbps 100 kbps 1 Mbps 10 Mbps 100 Mbps 1 Gbps

802.15.4

Zigbee802.15.1

Bluetooth

IEEE

802.15.3a UWB

WiMedia

IEEE 802.11b, a, g Wi-Fi

IEEE 802.16a

WiMAX (fixed),

802.16e (mobile)

2G 2.5G 3G 4G

IEEE802.11n

802.20

Mobile-Fi

Wireless

Wide-Area

Networks

Wireless

Metropolitan-

Area

Networks

Wireless

Local-Area

Networks

Wireless

Personal-

AreaNetworks

Legacy Current Emerging Future

8

02.2

1Inter-

NetworkHa

ndoffs

NFC


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Wireless Technology Evolution to 3.9G

CDMA

(IS-95A) GSM

CDMA

(IS-95B)

cdma

2000

1xEV-DO

Rev 0/A/B

UMB

802.20

2G

2.5G

3G

3.5G

3.9G

GPRS

E-GPRS

EDGE

HSDPA

FDD/TDD

TDMA

IS-136

WCDMA

FDD/TDD

TD-SCDMA

LCR-TDD

HSUPA

FDD/TDD

HSPA+LTE

E-UTRA

IEEE

802.16

Fixed

WiMAX

802.16d

Mobile

WiMAX

802.16e

WiBRO

IEEE

802.11

802.11g

802.11a

802.11g

802.11n

CDMA GSM/UMTS IEEE Cellular IEEE LAN


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Towards an All-IP Mobile Network

Evolution towards an all-IP mobile network

BSC

Internet

BTS

BTS

GSM/GPRS

core network

3G core

networkRNC

Node B

Node B

2G(+)

3G

FutureG

Al l-IP core

network

RAN

RAN

IP connectiv ity

BSS

Source:

Toni Janevski, Traffic Analysis and Design of Wireless IP Networks, Artech House Inc, Boston, USA, 2003.


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All-IP Wireless Network Concept

All-IP mobile network concept

All-IP

core

network

Service

creation

Contentservers

Application

servers

User

terminals

All-IP

RAN

2G / 2G+

3G

WirelessLAN

Broadband

RAN

Network

operator

Telephony

operator

Applicationprovider

Content

provider

Portal

Trustedprovider

Scenario for operators in wirelessand mobile networks beyond 3G

Source:

Toni Janevski, Traffic Analysis and Design of Wireless IP Networks, Artech House Inc, Boston, USA, 2003.


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Wireless and Mobile Overview Wireless networks today:

Cellular Mobile Networks (2G, 2G+, 3G, HSPA)

Wireless Metropolitan Area Networks (e.g.,WiMAX)

Wireless LANs (e.g., IEEE 802.11 family)

Wireless Personal Networks (e.g., Bluetooth) Trends: 4G mobile, Ad-hoc networks

Common adopted technology: IP Trend: toward all-IP wireless networks

Common characteristic: heterogeneity


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Key Players in Wireless Battle Driving forces for wireless technologies development

and spectrum allocation are:

Governments Spectrum management is powerful tool

Military and Police need communications

Industry and Operators

Level of technology development Market triggers development and changes

Academia

Research and Development (R&D)

Users or Citizens The ones who pay for the commercial service

Citizens pay taxes, which may be used for R&D, for military andpolice communications, or for free communications services

Wireless

Standards


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Spectrum Management Models

RegulatorsEconomists Engineers

Command & ControlCommand & Control

- Gov. knows best

- first come, first served

- Beauty Contests

- Low flexibil ity- Pro Government

Property RightsProperty Rights

(a.k.a. the MARKET )

- Market knows best

- Auctions/2ndary trading

- High f lexibility

- Pro Big Business

LicenceLicence--freefree

(a.k.a. the COMMONS)

Nobody knows best

- No Legal Protection

- Technical Protection

- High f lexibility

- Pro- Innovation

Avoid

Interference!

Maximize

Value!

Source: Frame and Perspectives of Radio Spectrum Policy in the European Union for Future Wireless

Networks and Services, R.Niepold, European Commission, Paris, April 2004.


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Need for Speed

bps

2.5G

3G

4G

2G

3.5G

100

1.000

10.000

100.000

1.000.000

10.000.000

100.000.000

1.000.000.000

10.000.000.000

1960 1970 1980 1990 2000 2010

Source:

http://www.ccs.neu.edu/home/rraj/G250Projects/NachiketMehta.ppt

More bits/sec per Hertz

are required because

spectrum is scarce


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What Next ?

1990 2000 2010

GSM

(2G)W-CDMA

(3G)

GPRS/EDGE

(2.5G)

The future path has fracturedinto a number of possibilities

The Wireless Battle is not over!

4G

3G+

3G &

WLAN

3G &

WLAN &

Brdcst

3G+ &

WLAN

3G &

WLAN &

Ad-hoc

3G+ &

WLAN &

Ad-hoc

4G &WLAN

4G &

WLAN &

Brdcst

4G &

WLAN &

Ad-hoc

2.5G &

WLAN

Source: http://www.ccs.neu.edu/home/rraj/G250Projects/NachiketMehta.ppt


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Overall

Future mobile and wireless networks should provide adaptivepersonal communication with direct IP connectivity, allowing migration

of users, devices and services between heterogeneous wirelessnetworks ranging from GSM to wireless LAN and WiMAX andbroadband mobile access networks such as 3G-HSPA, LTE, or LTE-Advanced, supporting different applications and using multimodemobile terminals to exploit different spectrums for different underlyingwireless technologies.

Personalwireless

networks

Wireless LocalArea Networks

Cellular mobilenetworks

High-speed

wirelessnetworks

Unified w ireless IP network

Source of the Figure: Toni Janevski, Traffic Analysis and Design of Wireless IP

Networks, Artech House Inc, Boston, USA, 2003.


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Mobile UsersChallenges


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User challenges vs. research challenges Are we addressing real user needs?

Engineering vs. sports

Guesses

reliability

ease of use

cost

no manual

integration

limited risk

phishing

data loss

no re-entry

no duplication


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Example: Email configuration

Application configuration

for (mobile) devices painful

SMTP port 25 vs. 587

IMAP vs. POP

TLS vs. SSL vs. secure

authentication

Worse for SIP...


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Mobile whys

Not research, but examples of real irritation

Why does each mobile device need its own power supply?

Why do I have to adjust the clock on my camera each time I travel?

Why do I have to know what my IMAP server is and whether it uses

TLS or SSL?

Why do I have to type in my address book?

Why do I have to synchronize my PDA?

Why do I have to manually update software?

Why is connecting a laptop to a projector a gamble? Why do we use USB memory sticks when all laptops have 802.11b?


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Consumer wireless & mobile devices

MSN Direct weather

Car key Garage door opener

Water leak alarm

wireless door bell


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Philosophy transition

One computer/phone,

many usersOne computer/phone,

one user

Many computers/phones,one user

anywhere,any time

any media

right place (device),right time,right media

~ ubiquitous computing

mainframe erahome phoneparty line

PC eracell phone era


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The mobile everywhere challenge

Mobile phone

Mobile Internet access

Interconnected devices

Internetof things


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What do we need? Standards, new technology?

Radio connectivity 802.11a/b/g/n, 802.15.4

better discovery of networks

Location information everywhere

Discovery: devices & services

network-local discovery (multicast DNS)

missing: location-based discovery

Advanced mobility: session, personal, service

Event notification

Data formats

location, sensor events, ...


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Examples of invisible behavior

MP3 player in car automatically picks up new files in home server

A new email with vcard attachment automatically updates my cellphone address book

The display of my laptop appears on the local projector

without cable or configuration

I can call people I just met without exchanging business cards

My car key opens my front door

My cell phone automatically turns itself off during a lecture

My camera knows where the picture was taken (e.g., Nokia N95knows in which country picture or video was taken)


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An interconnected system

any weather service

school closings

opens doors

incoming call

acoustic alerts

updates location

time, location

alert, events

address book


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Beyond User Mobility


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Application-layer mobility Terminal mobility

one terminal, multiple network addresses Personal mobility

one person, multiple terminals

Session mobility one user, multiple terminals in sequence or in parallel

Service mobility

services move with user


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Session mobility Walk into office, switch from

cell phone to desk phone call transfer problem SIP

REFER

related problem: splitsession across end devices

e.g., wall display + deskphone + PC for collaborativeapplication

assume devices (or stand-ins)are SIP-enabled

third-party call control


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How to find services? Two complementary developments: smaller devices carried on user instead of stationary

devices

devices that can be time-shared

large plasma displays projector

hi-res cameras

echo-canceling speaker systems

wide-area network access

Need to discover services in local environment

SLP (Service Location Protocol) allows querying forservices find all color displays with at least XGA resolution

slp://example.com/SrvRqst?public?type=printer

SLP in multicast mode

SLP in DA (Directory Agents) mode, besides UA (User

Agents) and SA (Service Agents) Need to discover services before getting to environment

is there a camera in the meeting room?

SLP extension: find remote DA via DNS


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Internet

Correspondent

Node (CN)

SIP UA

SLP UA

SIP SM

Local Devices

SLP SA SLP UA

SIP SM SIP UA

SLP DA

Mobile Node (MN)

SLP

SIP

RTP

SIP UA

Transcoder

Session mobility

Documents

Bezzicni Multimediski Mrezi-predavanja 1