Page 1
Introduction to WLAN
Wireless LANs
รศ. ดร. อนันต์ ผลเพิม่Assoc. Prof. Anan Phonphoem, Ph.D.
[email protected]
Intelligent Wireless Network Group (IWING Lab)
http://iwing.cpe.ku.ac.th
Computer Engineering Department
Kasetsart University, Bangkok, Thailand
Page 2
2
Outline
• WLAN Classification
• WLAN Architecture
• Other WLAN Architectures
WLAN Classification
Page 3
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
Page 4
4
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)
Page 5
5
WLAN
TCP/IP & WLAN
Applications5
Transport4
Network3
Data Link2
Physical1
MAC, QoS, Security, Power mang.
Modulation, Frequency
Page 6
6
Outline
• WLAN Classification
• Radio Waves
• Infrared Light
• Carrier currents (“no new wire”)
• Powerline
• Phoneline
• Network Architecture
Infrared Light
Page 7
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
Page 8
8
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
Page 9
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)
Page 10
10
Point-to-point Infrared LAN
Token-Ring
Page 11
Optical WLANInternet from the Ceiling Light
11
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)
Page 12
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
12
Page 13
Li-Fi
13https://i.ytimg.com/vi/DsJ4YtaUQPU/hqdefault.jpg
Page 14
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”)
Page 15
15
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
Page 16
16
Home Network
http://media.memoryexpress.com/Assets/Products/MX50120/dl_dhp601av_3.jpg
Page 17
17
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
Page 18
18
Powerline Network
• X-10
• CEBus
• LONworks
• Echelon
• HomePlug
Page 19
19
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
Page 20
20
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
Page 21
21
Phoneline Network Device
2Wire USB PC Port Phone Line 10Mbps USB Adapter
HomePNA PCI Network Interface CardFrequency Range: 5.5 - 9.5 MHz
Page 22
22
Common Characteristics
•Shared broadcast media
•Harsh channel condition
•attenuation, noise, and interference
•Changing channel condition
•Dynamic network topology
Page 23
23
Outline
• WLAN Classification
• Radio Waves
• Infrared Light
• Carrier currents (“no new wire”)
• Powerline
• Phoneline
• WLAN Architecture
• Other WLAN Architectures
Radio Waves
Page 24
24
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
Page 25
25
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
Page 26
26
Radio Based Wireless LANs
• Advantages
• No line of sights
• Propagate through obstacles
• Disadvantages
• Interference
• Security
Page 27
27
Components:
Wireless Access Point
Page 28
28
Components:
WLAN Network Interface Card
For Notebook Computer
Page 29
29
Components:
WLAN Network Interface Card
USB Type USB Type: with external antenna
ChargerBuy
Page 30
30
Components:
WLAN Network Interface Card
Built-in
Page 31
31
Components:
WLAN NIC for Desktop
PCMCIA Adapter
D-Link DWA-556 Xtreme N Wireless PCI
Page 32
32
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
Page 33
33
Directional Antenna
Page 34
34
Indoor Directional Antenna
Source: www.techworks.com
Page 35
35
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)
Page 36
36
Other Components
• WLAN Bridge
• WLAN Router
• VLAN Switch
Page 37
37
Selecting Products
• Functionality
• Availability
• Support
• Price
• Standard compliance
Page 38
38
Outline
• WLAN Classification
• WLAN Architecture
• WLAN Topology
• WLAN Design and Implementation
• Other WLAN Architectures
WLAN Topology
Page 39
39
WLAN Topology
• Physical: Single Cell & Multiple Cells
• Logical: Ad-hoc & Infrastructure
• Connectivity: Standalone & Wired Network Interface
• MAC: Distributed & Centralized
Page 40
40
Physical:Single Cell VS. Multiple Cells
AP AP AP
Multiple CellsSingle Cell
Page 41
41
Logical:Ad-hoc VS. Infrastructure
Infrastructure
AP
Ah-hoc
Page 42
42
Connectivity:Standalone VS. Wired Network Interface
Standalone
AP
Wired Network Interface
Page 43
43
MAC:Distributed VS. Centralized
Distributed Centralized
Page 44
44
Outline
• WLAN Classification
• WLAN Architecture
• WLAN Topology
• WLAN Design and Implementation
• Other WLAN Architectures
WLAN Design and Implementation
Page 45
45
WLAN Design and Implementation
• Define network elements
• Select products
• Site survey
• Verify the design
• Document the design
• Procure components
• Installation
• Testing
Page 46
46
Cost of Ownership
• Infrastructure costs
• Client device costs
• Monthly costs (Power & Internet Access)
• Management costs
• Training
• Downtime costs
• Support costs (Troubleshoot + repair)
Page 47
47
Infrastructure WLAN
• Need an Access Point
• Connect to the wired LAN
• Need Infrastructure
• Need administration
Page 48
48
Infrastructure WLAN
Page 49
49
Infrastructure WLAN
Page 51
51
SOHO Infrastructure WLAN
Hub/Switch
ComputerServer
Access Point
Printer
Page 52
52
(Large) Infrastructure WLAN
Router
Internet
Hub/Switch
LAN
Hub/Switch
LAN
Page 53
53
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
Page 54
54
Simple WLAN Management
Router
Internet
Hub/Switch
LAN
Hub/Switch
LAN
Page 55
55
VLAN Switch Management
Router
Internet
VLAN Switch VLAN Switch
LAN
LAN
Page 56
56
AP with VLAN Capability
Router
Internet
Hub/Switch
LAN
Hub/Switch
LAN
Page 57
57
Outline
• WLAN Classification
• WLAN Architecture
• Other WLAN ArchitecturesOther WLAN Architectures
Page 58
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
58
Page 59
Wireless Video Sensor Network (WVSN)
59
DeerNet http://spie.org/x14634.xml?highlight=x2410
Page 60
Vehicular Ad-hoc Network (VANET)
60http://www.car-2-car.org/
Page 61
Delay-Tolerant Networking (DTN)
61http://protogenist.wordpress.com/2012/07/18/dtn-network-model-evolution/
Page 62
Delay-Tolerant Networking (DTN)
62http://protogenist.wordpress.com/2012/07/18/dtn-network-model-evolution/
Page 63
Femtocell
• Provide indoor coverage (Macrocell cannot)
• Offload traffic from Macrocell (improve Macrocell capacity)
63
FAP: Femtocell Access Point (UMTS/HSPA/GSM/EDGE/LTE)
http://www.smallcellforum.org/aboutsmallcells-small-cells-consumer-faqs
Macrocell