50
Lecture Computer Networks Introduction, Motivation Prof. Dr. Hans Peter Großmann mit M. Rabel sowie H. Hutschenreiter und T. Nau | Sommersemester 2012 | Institut für Organisation und Management von Informationssystemen

Lecture Computer Networks · 2012-06-04 · Lecture Computer Networks ... Page 14 Computer Networks | Introduction, Motivation ... – 1 m ... 10 m PAN (Personal Area Network) –

Embed Size (px)

Citation preview

Lecture Computer Networks

Introduction, MotivationProf. Dr. Hans Peter Großmann mit M. Rabel sowieH. Hutschenreiter und T. Nau | Sommersemester 2012 |Institut für Organisation und Management von Informationssystemen

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 2

Content

• Introduction– History

• Motivation: Real-World Network Implementations– Data/Computer Network

• Uni Ulm Campus Network

– Uni Ulm Campus PBX System

– Networking in Automation• Pumped Storage Hydro Power Plant

• Engine synchronization

– In-Car Networks

– Data Exchange between Mobile Systems • Example: VANET

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 3

Computer Development

1940

1950

1960

1970

Z1 Computer: First computer

Mainframes, Batch-Processing

Timesharing, Multi-user

Minicomputer

1980 Personal Computer (PC), LANs

1990Client/Server Architecture

2000 Grid Computing

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 4

Z1 Computer

Konrad Zuse and the rebuilt Z1 in the Deutsches Technikmuseum Berlin in 1989http://irb.cs.tu-berlin.de/~zuse/Konrad_Zuse/en/Rechner_Z1.html

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 5

Mainframes (Batch Processing)

1950

• Batch environment

• no direct communication

• CPU is busy with one process at a time

• Punched cards and magnetic tapes for source codes

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 6

Time Sharing

1960

• Time Sharing

• Slow Point-to-Point network

• “Star” Network

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 7

Distributed Processing

1970

• Distributed Processing

• Computer-Computer-Communication

• Fast “Bus/Ring”- Networks

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 8

Network

Server 1

Server 2

PC

Client/Server Architecture

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 9

Telecommunication Evolution

Up to the 80s, the architecture of telecommunication networks and computer networks were developed independently

1900

1980

1990

telephone, analogue

ISDN, digital speech & data

ATM, integration of computer networks and telecommunication networks

IP-Networks2000

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 10

Media Development (analog/digital)

Video on Demand, DAB, electronic journals, Interactive CD, DVB, digital

1500

1900

1940

1996

Print media (book, newspaper), analog

radio, analog

TV, analog

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 11

CD-ROM

Video/TV

Print

Dig

ital C

odin

g

Media Transmission

text

images

audio

video

Raw material Digital representation

• Digital coded data is required for an efficient transmission of different transport media

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 12

Convergence

1960 1980 1998

Computer (networks)

Telecommunication Networks

Media

digital

digital

digital

analog

analog

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 13

Aspects of Networking

• Why communication networks?– voice communication– data transfer– ...

• For what purpose?– exchange of messages– exchange of data– long distance telephony / video conferencing– monitoring/control (sensor-/actor-networks)– ...

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 14

Aspects of Networking II

• Expansion– 0.01 m ... 1 m processorboards, (multi-)prozessorsystems– 1 m ... 10 m PAN (Personal Area Network)– 10 m … 1 km LAN (Local Area Network), Field-Bus-Systems – some 10 km MAN (Metropolitan Area Network)– 100 km ... 1000 km WAN (Wide Area Network)– global connected networks

• Different needs for different applications– (native) Computer Networks– Connecting Computer Clusters– Field- Bus-Systems– Ad-hoc Networks– ...

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 15

Real-World Example: Data/Computer Network

• Uni Ulm Campus Network

Status as of the year 2000

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 16

Anwendungsbeipiel Daten-/Rechnernetzwerk

• Campusnetz Uni Ulm

Stand 2000

G r ü n e r H o f

A n i n s t i t u t e ,B W K , R K U

M i c h e l s b e r g , S a f r a n b e r g ,

H o c h s t r ä ß , W i b l i n g e n , e t c .

Z e n t r a l v e r t e i l e r

Z e n t r a l v e r t e i l e r

V e r w a l t u n g U R Z

U n i O s t , U R Z

S c i e n c e P a r k 1O 2 7

B a u s t u f e n B , C , K l i n i k e n O E , B W K

U n i W e s t , T F Z

A u s s e n a n b i n d u n g

. 2 4 0

. 2 4 0

. 2 4 0

S C P 1 &M a t h . O 2 7

. 1 5

. 6 6

. 6 7

. 8 5. 1 6 6

. 2 4 012

9.1

43

.87

.8/2

9

. 2 4 0

T F Z . 3 3

R K UB u r r i I n s t .

D R K & I L MZ S W

F A W

R e k t o r a m t &D e k a n a t

S e m i n a r f ü r P ä d . &B i b l i o . O E 1 &

T B A & B a u a m t

B W K

K l i n i kN e t z

. 8 9 | . 1 0 8 | . 1 0 9 | . 1 1 0

V e r w a l t u n g. 9 0 | . 9 1 | . 9 5

G r ü n h o f g a s s e

T B AP r ü f . A m t &S t u d . S e k r .

W o h n h . H e i l m e y e r s t . . 2 2 0

T S N e t z . . 2 0 0

. 1

U R Z - G S 1. 2 4 1 . 2 4 0

U R Z - G W 2. 1

. 1.1

. 2 4 1 . 9 9

.24

0.9

9

N 2 5 - G W 4. 2 4 1 . 1 0 2

P e e r i n gp e e r - g a t e

1 2 9 . 1 4 3 . 8 7 . 1 1

T e s i o nS w i t c h

B e l W üu l 1 . b e l w u e . d e

12

9.1

43

.87

.9

S c h u l e n , B k u p .

D a i m l e r C h r y s l e r

N 2 6 - S W 1. 2 4 0 . 1 1 1

10

.1

3.1

3.2

1 0 . 2

2 . 1

O 2 5 - G W 1. 1 0

N 2 6 - G W 3. 4 | . 1 4 | . 6 3

.24

0.8

9

N 2 5 - G W 2

.89

|.108

|.1

09|.1

10

.24

0.1

02

. 7

. 4 5. 2 0 3 | . 2 0 4

U R Z - V - G W 1

.90

|.91|

.95

. 9 6 . 9 9

. 9 2

. 9 4

G H - V - S W 1. 9 1 . 9 8

H O - G W 1

.9|.

88

I S D Nf r e e w a y

O 2 7 - G W 1

. 6 8 | . 7 0

.24

0.9

6

. 7 1 | . 7 2

. 7 3 | . 7 4. 1 2 | . 7 5 | . 2 0 7

. 7 7 | . 2 0 9. 6 9 | . 7 6

N 2 6 - G W 4. 2 4 0 . 1 0 6

.5|.1

11

N 2 6 - A S 1. 2 0 0 . 2 3 8

I N - U L M

M 2 3 - S T 2

2.2

. 1 1 | . 5 5 | . 6 0

. 5 5

. 4 3

. 4 3

. 4 1

. 6 4. 1 1 | . 5 5 | . 6 0

. 1 1 | . 5 5 | . 6 0

U R Z - G W 1. 2 4 0 . 1 0 4

. 2 0 0

. 6

O 2 6 - G W 1.24

0.9

7

. 4 2 .46|

.47

s e v e r i n

H I C O MT e l e f o n a n l a g e

S C P - 2 2 - S W 1. 1 5 . 9 8

S C P - 2 0 - S W 2. 8 5 . 9 7

S C P - 2 0 - S W 1

S C P - 1 8 - S W 1. 6 6 . 9 8

. 8 5 . 9 8

o r i o n

l y r a

w e g a

d e v - n u l l

U R Z - S W 81 3 4 . 6 0 . 1 . 2 4 4

U R Z - C X 2

U R Z - S W 1

U R Z - S W 3

U R Z - C X 4

U R Z - C X 3

U R Z - C X 1

U R Z - S W 4. 2 4 0

D F NW i N S h u t t l e

D F Nu n i - u l m 1 . w i n - i p . d f n . d e

B e l W üu l 2 . b e l w u e . d e

F & L F Wt o r

1 2 9 . 1 4 3 . 8 7 . 1 0

. 2 4 0 . 1 0 8

F W B a c k u pu l m - i n

1 2 9 . 1 4 3 . 8 7 . 1 0

. 2 4 0 . 1 0 9

U 2 - 4 1 - G W 1. 2 | . 2 5 | . 2 7 | . 2 9 | . 1 2 0 | . 2 0 2 . 2 4 0 . 4 1

U 2 - 4 3 - G W 1. 2 4 | . 2 6 | . 2 8 | . 3 0 | . 1 2 1 . 2 4 0 . 4 3

U 2 - 4 5 - G W 1. 2 0 | . 2 1 | . 1 2 2 . 2 4 0 . 4 5. 2 2. 2 3

U 2 - 4 7 - G W 1. 3 7 | . 3 8. 3 1 - . 3 6 | . 1 2 3 . 2 4 0 . 4 7

M 2 3 - G W 1. 1 6 | . 5 0 | . 8 0. 1 9 3

. 2 4 0 . 9 2

M 2 4 - G W 1. 2 4 0 . 9 1. 1 7

. 4 8

. 6 2

M 2 5 - G W 1. 2 4 0 . 9 0. 4 9

. 6 5

. 8 4

N 2 4 - G W 1. 2 4 0 . 9 0

. 1 8

. 4 4

. 6 1

. 1 9 6

Z I K - F W .50

.3

O 2 7 - 2 - S W 1. 1 6 6 . 9 8

N 2 6 - G W 2. 1 5 | . 6 6 | . 6 7 | . 8 5 | . 1 6 6. 2 4 0 . 1 0 5

N 2 6 - G W 1 .24

0.9

8

.10

0.9

9.9

8.9

7.8

2

M I C H - S W 1.10

9.9

7

K F G - S W 1.110

.98

V - F W. 9 6 . 9 8

. 2 4 3 . 2

.24

0

. 9 | . 8 8

W o h n h . F r a u e n s t e i g e . 1 0 9

W o h n h . S p r o l l . 1 0 5W o h n h . W u r m . 1 0 6

W i b l i n g e n F & LW i b l i n g e n V e r w .

P a r k s t r a s s e . 8 9B i o m e t r i e . 1 0 9

B i b l i o . M i c h . . 1 0 9V i l l a F l e i n e r . 1 0 9

B i b l i o . S a f r a n b g . 1 0 9

V i l l a E b e r h . . 1 0 8P s y c h . I I I . 1 0 8

H e r z c h i r u r g i e . 1 0 8

H O - S W 1 .9.9

8

F H - U l m

F H - B i b e r a c hH a y i n g e n

G e i s l i n g e n

M u l t i C h a n n e l

u l m a t h o m e. 8 . 2 5 4 . 8 . 2 5 3

8 x

S2

M

T e s i o n

. 8 . 2 5 4

N 2 6 - C X 1

. 3 | . 1 3 | . 7 9 | . 8 3. 1 0

. 2 1 7

. 3 | . 8 3

. 1 3 | . 7 9. 2 4 1 . 9 5

c a s t o r

t i n g e r. 2 4 0

U R Z - G S 2. 2 4 1 . 2 4 1

11

2

U R Z - S W 91 3 4 . 6 0 . 1 . 2 4 6p o 2 5

S u b n e t z 8 u n d u l m a t h o m e h ä n g e nv o r ü b e r g e h e n d a n N 2 5 - g w 2

g a , O k t . 9 9

T e l e k o m

. 2 4 5 . 1

. 2 4 3 . 1

R e s e r v . f . S e k r e t a r i a t

N 2 5 - G S 1. 2 4 1 . 2 3 9

N 2 6 - G S 1. 2 4 1 . 2 3 8

G l a s f a s e rA U I / T h i c k w i r eT h i n w i r eT w i s t e d P a i rS o n s t i g e

A T M S w i t c h

B r i d g e / S w i t c h

E n d g e r ä t

H u b / R e p e a t e r

R o u t e rG i g a b i t E t h .F a s t E t h .

A T M

E t h e r n e t

F D D I

S o n s t i g e

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 17

Real-World Example: Data/Computer Network

• Uni Ulm Campus Network

Status as of september 2007

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 18

Anwendungsbeipiel Daten-/Rechnernetzwerk

• Campusnetz Uni Ulm

Stand 2007

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 19

Anwendungsbeipiel Daten-/Rechnernetzwerk

• Campusnetz Uni Ulm

Stand 2007

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 20

Real-World Example: Data/Computer Network

• Uni Ulm Campus PBX (Private Branch Exchange) System

Status as of the year 2008

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 21

Anwendungsbeipiel Daten-/Rechnernetzwerk

• TK-Anlagenverbund Uni Ulm

Stand 2008

Lecture Computer NetworksIntroduction, Motivation II

Prof. Dr. H. P. Großmann and B. Wiegel andA. Schmeiser and M. Rabel | Wintersemester 2010 / 2011 |Institute for Information Resource Management

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 23

Content

• Introduction– History

• Motivation: Real-World Network Implementations– Data/Computer Network

• Uni Ulm Campus Network

– Uni Ulm Campus PBX System

– Networking in Automation• Pumped Storage Hydro Power Plant

• Engine synchronization

– In-Car Networks

– Data Exchange between Mobile Systems • Example: VANET

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 24

Application: Pumped Storage Hydro Power Plant

Energy must be produced according to the current consumption:

• Base Load Power Plants– Nuclear– Lignite (Brown Coal)– Run-of-the-river Hydro

• Mid-Load Power Plants– Black Coal (Anthrazite)

• Peak Load Power Plants– Natural Gas– Pumped Storage Hydro

• Feed-in Electricity– Combined Heat and Power– Renewable Energy Sources:

Wind, Solar

Source: http://de.wikipedia.org; Kraftwerksmanagement

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 25

Principle of a Pumped Storage Hydro Power Plant I

Turbine Operating Mode Pump Operating Mode

0 bis 150 MW -150 MW

Source: Hamburgische Electricitäts-Werke AG, 40 Jahre Pumpspeicherwerk Geesthacht

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 26

Principle of a Pumped Storage Hydro Power Plant II

Hydraulic Short-Circuiting using the example ofKopswerk II, Montafon, Austria

Source: Vorarlberger Illwerke AG; http://www.kopswerk2.at/

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 27

At any time (also during change over of operating mode) another mode can be addressed

Overview Operating Modes and their Change Over

Source: Voith Hydro, Heidenheim

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 28

Underground Hydroelectric Power Station with 3 Units

Source: Vorarlberger Illwerke AG; http://www.kopswerk2.at/

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 29

• Maschinery Cavern:– Length: ca. 88 m– Width: max. ca. 30.5 m– Hight: max. ca. 60.5 m

• Total Hight of aMaschine Unit:approx. 38 m

• Nominal Speed: 500 rpm

• Nominal Power perTurbine: 150 MW

• Input Power per Pump:150 MW

• Head: approx. 800 m

Section of Machinery Cavern

Source: Vorarlberger Illwerke AG; http://www.kopswerk2.at/

TailwaterHeadwater

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 30

CAM Model

MMI – Men Machine InterfacePLC – Programmable Logic Controller

••• •••••• •••

AS-Interface

PROFIBUS, CAN

Ethernet, TCP/IP

Factory LevelMain Control Level

Process LevelFieldbus Level

Sensor/Actuator LevelCAN

IEEE 1394, IP over 1394Gateway

Sen

sor

Sen

sor

Act

uato

r

Act

uato

r

Sen

sor

Sen

sor

Act

uato

r

Act

uato

r

Ga

tew

ay

Gat

eway

PLC

MMI

PLC

MMI

Main ControlPC Firewall Firewall Main ControlPC

Internet

PLC

PLCPLC

Latency Time Data Size

Seconds

10 ... 100 ms

1 ... 10 ms

kBytes

1 ... 100 Bytes

Bits ... Bytes

Minutes MBytes

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 31

Plant Control System

• General Power Plant Control System• Machine Control System• Visualization of the Control System Processes• Remote Control via Connection to the Illwerke Control Center

Source: Vorarlberger Illwerke AG; http://www.kopswerk2.at/

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 32

Machine Control System

• Control and Protection of each Unit

• Consists per Unit of„Islands of Hardware“ for:

– Automatic (decentralized PLC)– Mechanical Protection (centralized PLC)– Mechanical Emergency Protection

(relay control)

• Decentralized Peripheral Devices:Sensors (e.g. Pressure, Flow,Temperature) are wired on each floorto the corresponding field control cabinet

• At the Power Plant:– 176 Control Cabinets– 4.800 Cables; Total Length ca. 217 km– Overall approx. 8,500 Data Points

Source: Vorarlberger Illwerke AG; http://www.kopswerk2.at/

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 33

Time Response of a Distributed System

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 34

Content

• Introduction– History

• Motivation: Real-World Network Implementations– Data/Computer Network

• Uni Ulm Campus Network

– Uni Ulm Campus PBX System

– Networking in Automation• Pumped Storage Hydro Power Plant

• Engine synchronization

– In-Car Networks

– Data Exchange between Mobile Systems • Example: VANET

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 35

Application: In-Car Networks

• Conventional Wiring System till the 1980s– Power Supply (Battery, Generator)– Starter– Ignition System– Lighting– Driver Assistance

and ComfortElectronics

• Rising FunctionalRange demandsmore Cabeling

Source: Bosch; Autoelektrik Autoelektronik am Ottomotor

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 36

Complex Features in Modern Vehicles

• Power Train– Engine Management System,

Exhaust After-treatment– Automatic Transmission

• Road Safety– Electronic Stability Program (ESP)– Adaptive Headlights, Cornering Lights– Adaptive Cruise Control (ACC)– Night Vision

• Comfort Electronics– Automatic Air Conditioning, Auxiliary Heating– Electric Window Lifts, Electric Sunroof– Electric Seat/Mirror Adjustment

• Infotainment– Radio, TV, CD, DVD, MP3– Navigation– Online Services– …

Source: http://de.wikipedia.org; Abstandsregeltempomat

Source: http://www.mercedes-benz.de; Nachtsichtassistent

Source: http://www.bmw.de; Navigationssystem

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 37

Network Architecture of a S-Class (BR 221)

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 38

Network Architecture of a typical Medium-sized Vehicle

Source: http://www.tomshardware.com/de/bmw-x5-flexray-datenbus-neu,testberichte-1546-5.html

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 39

Automotive Fieldbus Systems

• Historically arised Demands– Driving relevant Features– Safety– Comfort– „Home/Office on Wheels“

• Specialised Networks– Control– Regulation– Automation– Audio/Video

• Embedded Systems Environment– Limited Resources

LIN

FlexRay

CAN

MOST150 Ethernet

Bandwidth[Bit/s]

20k500k

10M

100M

1G

MOST

LIN – Local Interconnect NetworkCAN – Controller Area NetworkMOST – Media Oriented Systems Transport

Latency?

Cyclic or Event-driven Signals?

Jitter?

Redundancy? Safety?

Centralised or distributed Application?

Topology?

Payload Size?

EMC?

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 40

Heterogeneous Network Environment in Vehicles

• Consolidation not possible– Divergent QoS

Requirements– Conservative

DevelopmentApproach

– Cost Pressure

� Complex systemsrequire costly application-specificgateways

LIN – Local Interconnect NetworkCAN – Controller Area NetworkTTP – Time Triggered ProtocolMOST – Media Oriented Systems Transport

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 41

Content

• Introduction– History

• Motivation: Real-World Network Implementations– Data/Computer Network

• Uni Ulm Campus Network

– Uni Ulm Campus PBX System

– Networking in Automation• Pumped Storage Hydro Power Plant

• Engine synchronization

– In-Car Networks

– Data Exchange between Mobile Systems • Example: VANET

42

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 42

Communication between mobile clients - Example: vehicles

– Vehicles are able to exchange information between each other• What information is worth to exchange ?• What applications can be deployed ?• How can information be disseminated ?• What sort of information is related to the different clients ?

– Wireless communication technology • What are the requirements ?• Is it possible to deploy existing technology ?• What are the challenges to overcome?

43

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 43

What information can be exchanged between vehicles ?

– Allgemeiner Ablauf / Organisation– Zeitplan– Themen

44

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 44

Possible Applications - Safety of Life

Safety of Life

– Local warnings in case of the following traffic situations • Accidents • Bad weather (like fog or icy roads)• Obstacles on the road• Slow or non moving vehicles (end of a traffic jam)

– Electronic break lights • Warning messages in case of an emergency break

45

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 45

Possible Applications - Co-operative Driving

Autonomous vehicles– Exchange of driving

maneuvers (overtaking, turn ...)

– co-operative fusion of sensor data• Exchange of

information about objects detected by on-board sensors

46

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 46

Possible Applications - Decentralized Services

– Fast distribution of the local traffic information• Congested roads• Parking information• Traffic light information

47

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 47

Challenges for the technology

Aspect– Reliability– Delay and latency of the messages– Real-time capability

Criteria SAFETY OF LIFE

Co-operative Driving #1

Co-Operative Driving #2

Decentralized Services

Reliability High High High High

Delay Low Delay Low Delay Low Delay No relevance

Real-Time-Capability

No No Yes No

Information destinations

Nodes in a dedicated area

Nodes in a dedicated area

Nodes in a dedicated area

Interested nodes in a dedicated area

48

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 48

Possible technologies - Infrastructure based network for mobile clients (GSM/GPRS/UMTS) ?

UMTS, GSM/GPRS

– support mobility of clients (+)

– already deployed in a wide area (+)

– infrastructure has to be added -> expensive (-)

– high overhead due to centralized structure (-)

– addressing of certain clients difficult (-)

49

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 49

Possible technologies - Ad-Hoc-Network ?

Ad-Hoc Network – Nodes connect to each other spontaneously (+)– Clients have to provide function of the active components (+)– no infrastructure needed (+)

Bluetooth– long inquiry process(--)

IEEE 802.11 (WLAN)– no setup process (+)– not for mobile environments (-)

50

Computer Networks | Introduction, Motivation | Sommersemester 2012Page 50

VANET

Vehicular Ad Hoc Network– Similar to WiFi– Broadcast network only– High node mobility

Challenges / Tasks to get this going ...– Medium Access Control (MAC)– Message Forwarding, Routing, Data Dissemination– Reliability– Prioritization– Resource Allocation