Introduction to WLANanan/myhomepage/wp-content/...2017/10/01  · Introduction to WLAN Wireless LANs...

Introduction to WLAN

Wireless LANs

รศ. ดร. อนันต์ ผลเพิม่Assoc. Prof. Anan Phonphoem, Ph.D.

anan.p@ku.ac.th

Intelligent Wireless Network Group (IWING Lab)

http://iwing.cpe.ku.ac.th

Computer Engineering Department

Kasetsart University, Bangkok, Thailand

2

Outline

• WLAN Classification

• WLAN Architecture

• Other WLAN Architectures

WLAN Classification

3

Wireless LANs

ACTACT10M100M

1 2 3 4

13 14 15 16

5 6 7 8

17 18 19 20

9 10 11 12

21 22 23 24

UPLINK

1 2 3 4 5 6 7 8 9 101112

131415161718192021222324COLCOL

PWR

SWITCH

ACTACT10M100M

1 2 3 4

13 14 15 16

5 6 7 8

17 18 19 20

9 10 11 12

21 22 23 24

UPLINK

1 2 3 4 5 6 7 8 9 101112

131415161718192021222324COLCOL

PWR

SWITCH

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TCP/IP Protocol Suite(Internet Model)

Applications User service and interface5

Data Link2 Provide framesNode-to-node (same network segment)

Physical (mechanical and electrical spec)1Transmission bit streams

NetworkPacket end-to-end (across network)

3 Move packets from source to destination

Transport Process delivery + Error (TCP/UDP)4Reliable end-to-end (whole message)

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WLAN

TCP/IP & WLAN

Applications5

Transport4

Network3

Data Link2

Physical1

MAC, QoS, Security, Power mang.

Modulation, Frequency

6

Outline

• WLAN Classification

• Radio Waves

• Infrared Light

• Carrier currents (“no new wire”)

• Powerline

• Phoneline

• Network Architecture

Infrared Light

7

Electromagnetic Spectrum

Power,

Voice

Radio communication

Radio, microwave, satellite

Infrared

Light

Ultra-

Violet

Light

X, gamma,

Cosmic rays

0 3,000 Hz 300 GHz

Radio basedWLAN

InfraredWLAN

Carrier CurrentNetwork

Visible light

430-750 THz

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Infrared Light Based WLAN

• Invisible to the naked eye

• Infrared Light LAN operate @ 820 nm.

• Least attenuation by air

• Advantages over Radio Waves:

• More Secure

• Less susceptible to common noises (e.g.oven)

• Better performance High data rate

• Disadvantage:

• Limited Coverage

9

Components

• Adapter Card (NIC)

• Protocol for accessing shared medium

• Transducer

• Similar to radio antenna

• Transmits & receive infrared light signal

http://www.electronics-lab.com/blog/?tag=wireless

LED (light emitting diodes)

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Point-to-point Infrared LAN

Token-Ring

Optical WLANInternet from the Ceiling Light

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Fraunhofer Heinrich Hertz Institute

http://www.hhi.fraunhofer.de/en/project-of-the-month/visible-light-communication/

• Visible Light Communication or VLC• Infrared LEDS• Five meters• Up to 800 Mbit/s (in the lab)

Li-Fi

• Light Fidelity

• Operate on Visible Light

• Use common household LED to enable data transfer

• ~70 Mbps

• Speeds of up to 224 gigabits per second

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Li-Fi

13https://i.ytimg.com/vi/DsJ4YtaUQPU/hqdefault.jpg

14

Outline

• WLAN Classification

• Radio Waves

• Infrared Light

• Carrier currents (“no new wire”)

• Powerline

• Phoneline

• WLAN Architecture

• Other WLAN Architectures

• Carrier currents (“no new wire”)

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Home Network

Office

Living Room Bed Room 2

Bed Room 1Kitchen

ResidentialGateway

Modified from

“Multimedia friendly home wireless LANs”Aura GanzAnan PhonphoemKitti Wongthavarawat

Telematics and Informatics, 2001, Volume 18, Issues 2–3

RadioPowerlinePhoneline

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Home Network

http://media.memoryexpress.com/Assets/Products/MX50120/dl_dhp601av_3.jpg

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Powerline Network

• Carrier-current network

• Wiring from the distribution transformer

• many houses share the same media

• Start with the low speed for control application

60 Hz 10 KHz - 10 MHz

Power PowerlineCommunications

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Powerline Network

• X-10

• CEBus

• LONworks

• Echelon

• HomePlug

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Powerline Network Device

Netgear Wireless Range Extender Kit

85Mbps Ethernet HomePlug 1.0 Turbo

Piggy6• 6-way extension lead• 3 Ethernet ports switch• HomePlug 200Mbps

http://www.solwise.co.uk/net-powerline.htm

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Phoneline Network

• Existing phone wiring

• Similar to powerline communication

• Implement frequency division multiplex

Voice

POTS xDSL Phoneline

communications

20Hz - 3.4KHz 25KHz - 1.1MHz 5.5 - 30 MHz

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Phoneline Network Device

2Wire USB PC Port Phone Line 10Mbps USB Adapter

HomePNA PCI Network Interface CardFrequency Range: 5.5 - 9.5 MHz

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Common Characteristics

•Shared broadcast media

•Harsh channel condition

•attenuation, noise, and interference

•Changing channel condition

•Dynamic network topology

23

Outline

• WLAN Classification

• Radio Waves

• Infrared Light

• Carrier currents (“no new wire”)

• Powerline

• Phoneline

• WLAN Architecture

• Other WLAN Architectures

Radio Waves

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ISM Bands

• Industrial, Scientific, and Medical frequency band

• Can operate without FCC licenses

• Tx output power 1 watt

• Eliminate cost and time consuming for licenses

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ISM Bands Radio Spectrum

• Cheaper• Few area• Longer Tx Range

• High BW, high data rate• Less susceptible to noise• Less Tx Length

• Worldwide

26MHz

902MHz

928MHz

902 MHz

83.5 MHz

2.40GHz

2.4835GHz

2.4 GHz

125 MHz

5.725GHz

5.850GHz

5.7 GHz

26

Radio Based Wireless LANs

• Advantages

• No line of sights

• Propagate through obstacles

• Disadvantages

• Interference

• Security

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Components:

Wireless Access Point

28

Components:

WLAN Network Interface Card

For Notebook Computer

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Components:

WLAN Network Interface Card

USB Type USB Type: with external antenna

ChargerBuy

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Components:

WLAN Network Interface Card

Built-in

31

Components:

WLAN NIC for Desktop

PCMCIA Adapter

D-Link DWA-556 Xtreme N Wireless PCI

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Components:

Antenna

• Micro-strip Antenna

• Omni/directional

• Indoor/Outdoor

http://free-download-update.blogspot.com/2008/01/14dbi-18dbi-and-205dbi-pcb-panel-wifi.html

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Directional Antenna

34

Indoor Directional Antenna

Source: www.techworks.com

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Outdoor 2.4 GHz Band Antennas

24-dBi Directional Antennawith Up/Down Converter on Mast

6-dBi Omni-Directional Antennawith Up/Down Converter on Mast

Source: Wi-Lan Technology (UC Wireless)

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Other Components

• WLAN Bridge

• WLAN Router

• VLAN Switch

37

Selecting Products

• Functionality

• Availability

• Support

• Price

• Standard compliance

38

Outline

• WLAN Classification

• WLAN Architecture

• WLAN Topology

• WLAN Design and Implementation

• Other WLAN Architectures

WLAN Topology

39

WLAN Topology

• Physical: Single Cell & Multiple Cells

• Logical: Ad-hoc & Infrastructure

• Connectivity: Standalone & Wired Network Interface

• MAC: Distributed & Centralized

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Physical:Single Cell VS. Multiple Cells

AP AP AP

Multiple CellsSingle Cell

41

Logical:Ad-hoc VS. Infrastructure

Infrastructure

AP

Ah-hoc

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Connectivity:Standalone VS. Wired Network Interface

Standalone

AP

Wired Network Interface

43

MAC:Distributed VS. Centralized

Distributed Centralized

44

Outline

• WLAN Classification

• WLAN Architecture

• WLAN Topology

• WLAN Design and Implementation

• Other WLAN Architectures

WLAN Design and Implementation

45

WLAN Design and Implementation

• Define network elements

• Select products

• Site survey

• Verify the design

• Document the design

• Procure components

• Installation

• Testing

46

Cost of Ownership

• Infrastructure costs

• Client device costs

• Monthly costs (Power & Internet Access)

• Management costs

• Training

• Downtime costs

• Support costs (Troubleshoot + repair)

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Infrastructure WLAN

• Need an Access Point

• Connect to the wired LAN

• Need Infrastructure

• Need administration

48

Infrastructure WLAN

49

Infrastructure WLAN

50

Roaming

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SOHO Infrastructure WLAN

Hub/Switch

ComputerServer

Access Point

Printer

52

(Large) Infrastructure WLAN

Router

Internet

Hub/Switch

LAN

Hub/Switch

LAN

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Communication Path (End-to-End)

Applications

Transport

IP

802.11

Physical

Router

Hub/Switch/Bridge Hub/Switch/Bridge

802.3

Physical

IP

802.3

Physical

802.3

Physical

802.3

MAC

Physical

802.11

MAC

Physical

Relay

Applications

Transport

IP

802.11

Physical

802.3

MAC

Physical

802.11

MAC

Physical

Relay

54

Simple WLAN Management

Router

Internet

Hub/Switch

LAN

Hub/Switch

LAN

55

VLAN Switch Management

Router

Internet

VLAN Switch VLAN Switch

LAN

LAN

56

AP with VLAN Capability

Router

Internet

Hub/Switch

LAN

Hub/Switch

LAN

57

Outline

• WLAN Classification

• WLAN Architecture

• Other WLAN ArchitecturesOther WLAN Architectures

Other WLAN Architectures

• Wireless Mesh Network

• Wireless Ad hoc Network

• Wi-Fi Direct, Wi-Fi P2P(Printer)

• Wireless Sensor Network

• Wireless Video Sensor Network (WVSN)

• Mobile Ad-hoc Network (MANET)

• Vehicular Ad-hoc Network (VANET)

• Delay-Tolerant Networking (DTN)

• Femtocell

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Wireless Video Sensor Network (WVSN)

59

DeerNet http://spie.org/x14634.xml?highlight=x2410

Vehicular Ad-hoc Network (VANET)

60http://www.car-2-car.org/

Delay-Tolerant Networking (DTN)

61http://protogenist.wordpress.com/2012/07/18/dtn-network-model-evolution/

Delay-Tolerant Networking (DTN)

62http://protogenist.wordpress.com/2012/07/18/dtn-network-model-evolution/

Femtocell

• Provide indoor coverage (Macrocell cannot)

• Offload traffic from Macrocell (improve Macrocell capacity)

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FAP: Femtocell Access Point (UMTS/HSPA/GSM/EDGE/LTE)

http://www.smallcellforum.org/aboutsmallcells-small-cells-consumer-faqs

Macrocell