WLAN Design & Implementation
ผศ.ดร. อนันต์ ผลเพิม่
Asst.Prof. Anan Phonphoem, Ph.D.
anan@cpe.ku.ac.th
http://www.cpe.ku.ac.th/~anan
Intelligent Wireless Network Group (IWING Lab)
http://iwing.cpe.ku.ac.th
Computer Engineering Department
Kasetsart University, Bangkok, Thailand
KMITNB Jan 29, 2004
Outline
 WLAN
Technology
 Conceptual Review
– WLAN Configuration
– Management
 Planning
 Design & Implementation Phase
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IWING LAB; Computer Engineering Department; Kasetsart University
Wireless System Path
Source: Mobile Communications International
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Wireless Classification
WWAN
GSM/ GPRS / CDMA
WMAN
IEEE802.16
WLAN
IEEE802.11
HyperLan
WPAN
Bluetooth
WAN
WAN-MAN
PAN
MAN
MAN-LAN
LAN-PAN
Pico-Cell
Personal Operating Space
~50km
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~2km
0km
~10m
Courtesy of IEEE 802.15, Jan. 2001
IWING LAB; Computer Engineering Department; Kasetsart University
History and present of IEEE
802.11
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IEEE 802.11 Family
Standards Band (GHz) Raw Throughput
802.11
2.4
2Mbps (Legacy)
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802.11a
802.11b
802.11g
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2.4
2.4
54Mbps
11Mbps
54Mbps
802.11n
??
100 Mbps
IWING LAB; Computer Engineering Department; Kasetsart University
IEEE 802.11 Family
Standards Descriptions
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802.11c
Improves interoperability
802.11d
Multiple Regulatory Domains (Improve Roaming; New
country)
802.11e
Quality of Service (QoS); prioritizing voice or video
802.11f
Inter-Access Point Protocol (IAPP)
802.11h
Supports measuring and managing the 5-GHz radio
signals in 802.11a
802.11i
Enhanced Security (repairs WEP weakness)
802.11j
Extensions for Japan
802.11k
Passing specific radio frequency health and
management data to higher-level management apps.
IWING LAB; Computer Engineering Department; Kasetsart University
History: 802.11 Legacy
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1997: First standard
– Standard name: IEEE 802.11-1997
– Updated:
IEEE 802.11-1999
– Starting Point for “Standard-based WLAN”
For 2 Mbps: (fallback to 1 Mbps – Noisy): Direct
sequence Spread Spectrum (DSSS) modulation
For 1-2 Mbps Frequency Hopping Spread Spectrum
(FHSS)
Both operate in ISM band 2.4 GHz
FHSS, DSSS, and infrared medium
IWING LAB; Computer Engineering Department; Kasetsart University
802.11b
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802.11b-1999
Range 50 – 100 m. (depends on obstacles)
Omnidirectial antenna
Indoor / Outdoor / Point-to-point (high-gain external
antennas)
Max throughput of 11 Mbit/s (5.5, 2,1 Mbps)
Attenuation: Metal, Thick walls, Water, etc.
ISM Band 2.4 GHz; DSSS; CSMA/CA
14 overlapping ch. (Different ch.for different countries)
– 3 simultaneously ch. (such as 1, 6, and 11)
Proprietary speed extension "802.11b+" (22, 33 and
44 Mbit/s)
IWING LAB; Computer Engineering Department; Kasetsart University
802.11a
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2001 (802.11a-1999)
Max throughput of 54 Mbps (Normally around 20
Mbps)
ISM Band 5 GHz (FCC may open more spectrum)
12 nonoverlapping channels,
– 8 dedicated to indoor
– 4 to point to point
Not widely deployed (US. / Japan)
– 802.11b popularity
– Less range / More attenuation
– Lack of roll back compatibility (now support
a,b,and g)
– In Europe considering HiperLan2
IWING LAB; Computer Engineering Department; Kasetsart University
802.11g
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3rd quarter 2003
ISM Band 2.4 GHz
Max throughput of 54 Mbps (Net 24.7 Mbps)
Fully backwards compatible with 802.11b
Dual-band / Tri-mode
– supporting a, b, and g
– A single wireless card / Access point
IWING LAB; Computer Engineering Department; Kasetsart University
802.11 Wi-Fi
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Specification defined by IEEE (not Compatibity
guarantee)
A special group, Wi-Fi Alliance
– Group of maufacturer
– Test compatibility
– Guarantees interoperability (by issue Wi-Fi
Trademark)
– Start with 802.11b  Dual band/Tri mode (a, b, or g)
– Security standard Wi-Fi Protected Access (WPA)
IWING LAB; Computer Engineering Department; Kasetsart University
Wireless Hot Spot
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Public places
– Top-rated hotels and restaurants
– Colleges / Universities
In-building antenna systems to support
various wireless technologies (Wi-Fi/cellular)
Wireless friendly environmental hot spot
– KUWiN (Kasetsart University Wireless
Network http://kuwin.ku.ac.th)
http://www.wi-fihotspotlist.com/
IWING LAB; Computer Engineering Department; Kasetsart University
WLAN Review
WLAN Category
 Wireless
LANs (WLAN)
– Radio Waves
– Infrared Light
– Carrier currents (“no new wire”)
 Wireless Point-to-Point Networks
 Wireless WANs
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IWING LAB; Computer Engineering Department; Kasetsart University
Radio Based Wireless LANs
 Advantages
– No
line of sights
– Propagate through obstacles
 Disadvantages
– Interference
– Security
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IWING LAB; Computer Engineering Department; Kasetsart University
WLAN Goal
 Compliment
wired LANs (or replace
in the near future?)
 Two main reasons
– Increase user mobility &
productivity
– Increase installation flexibility in
difficult cabling situations
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IWING LAB; Computer Engineering Department; Kasetsart University
WLAN Questions
 Throughput
?
 Scalability
?
 Performance ?
 Best technologies ?
 Application support ?
– client-server / Network programs
– Quality-of-service
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IWING LAB; Computer Engineering Department; Kasetsart University
Data rates and Range
Source: Proxim
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IWING LAB; Computer Engineering Department; Kasetsart University
WLAN Configurations
 Independent
WLAN
 Infrastructure WLAN
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IWING LAB; Computer Engineering Department; Kasetsart University
Independent WLAN
Ad Hoc
 Simplest
 Rapid deployment
 Peer-to-peer
 No administration
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IWING LAB; Computer Engineering Department; Kasetsart University
Independent WLAN
Single Cell
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Multiple Cells
IWING LAB; Computer Engineering Department; Kasetsart University
Independent WLAN
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Can extended
range by using an
Access Point (acting
as a repeater)
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Infrastructure WLAN
Need an Access Point
 Connect to the wired
LAN
 Need Infrastructure
 Need administration
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IWING LAB; Computer Engineering Department; Kasetsart University
Infrastructure WLAN
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IWING LAB; Computer Engineering Department; Kasetsart University
Infrastructure WLAN
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IWING LAB; Computer Engineering Department; Kasetsart University
SOHO Infrastructure WLAN
Hub/Switch
Access Point
Server
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Computer
Printer
IWING LAB; Computer Engineering Department; Kasetsart University
(Large) Infrastructure WLAN
Internet
LAN
Hub/Switch
Router
Hub/Switch
LAN
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IWING LAB; Computer Engineering Department; Kasetsart University
Simple WLAN Management
Internet
LAN
Hub/Switch
Router
Hub/Switch
LAN
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IWING LAB; Computer Engineering Department; Kasetsart University
VLAN Switch Management
Internet
LAN
VLAN Switch
Router
VLAN Switch
LAN
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IWING LAB; Computer Engineering Department; Kasetsart University
AP with VLAN Capability
Internet
LAN
Hub/Switch
Router
Hub/Switch
LAN
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IWING LAB; Computer Engineering Department; Kasetsart University
Mobile IP
Internet
Router
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LAN
IWING LAB; Computer Engineering Department; Kasetsart University
Mobile IP
Internet
Router
Home
Agent
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LAN
Foreign
Agent
IWING LAB; Computer Engineering Department; Kasetsart University
WLAN Planning
Design Requirements
To Keep in mind
– Availability
– Scalability
– Manageability
– Interoperability
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Planning
 Set
Project Management Principles
 Planning a project
 Executing the project
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IWING LAB; Computer Engineering Department; Kasetsart University
Set Project Management Principles
 Clear
goal / activities /
communications
 Reduction of risks
 On time / within budget
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IWING LAB; Computer Engineering Department; Kasetsart University
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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IWING LAB; Computer Engineering Department; Kasetsart University
Planning a project
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Define the project scope
Develop a work plan / schedule
Identify resources (team/materials)
Develop a budget
(labor/HW/SW/management)
Define project operations (role/standard)
Evaluation risks (cause of risks  adjust)
IWING LAB; Computer Engineering Department; Kasetsart University
Executing the project
Kick-off meeting (review project plan)
 Status check
 Technical meeting
 Progress report
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IWING LAB; Computer Engineering Department; Kasetsart University
Define WLAN requirements
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User profile &
interface
Functional
(expected)
Application
Information Flow
Performance
(Reliability/Availabilit
y/BW/Delay)
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System Interface
Environmental
Department support
Regulation (RF)
Mobility
Security
Budget
Schedule
IWING LAB; Computer Engineering Department; Kasetsart University
Design & Implementation
Phase
Implementing a WLAN
Design
DesignaaWLAN
WLAN
 Prepare for operational support
 Installation
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IWING LAB; Computer Engineering Department; Kasetsart University
Design & Implementation Cycle
Source: Cisco Networking Academy
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IWING LAB; Computer Engineering Department; Kasetsart University
Design Phase
 Define
network elements
 Select products
 Site survey
 Verify the design
 Document the design
 Procure components
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IWING LAB; Computer Engineering Department; Kasetsart University
Defining Network Elements
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Identify the network elements
– SW (Application / Communication)
– OS
– LAN /WAN (media / backbone)
– Wireless connection (media / data rate)
– Addressing
– Network management
Determining requirements
– Choose standard (mature) technologies
IWING LAB; Computer Engineering Department; Kasetsart University
Selecting Products
 Functionality
 Availability
 Support
 Price
 Standard
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compliance
IWING LAB; Computer Engineering Department; Kasetsart University
Site Survey
 Determine
coverage area (Cell)
 Determine number of cells needed
 Determine the Access Point
location
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IWING LAB; Computer Engineering Department; Kasetsart University
Environmental Consideration
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Environment characteristics
– Completed Open (empty floor, no desk)
– Semi-Open (partitioning area)
– Closed (Blocked room, high wall)
Barriers
– RF penetration
– Attenuations
IWING LAB; Computer Engineering Department; Kasetsart University
RF Barriers
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RF Barrier
Attenuation
Air
minimum
Wood
Low
Partitions
Plaster
Low
Office partitions
Synthetic Material
Low
Office patitions
Glass
Low
Windows
Water
Medium
Damp wood, aquarium
Bricks
Medium
Walls
Marble
Medium
Walls
Paper
High
Paper rolls
Concrete
High
Floors / Walls
Very High
Desk / partitions / elevator
Metal
Example
IWING LAB; Computer Engineering Department; Kasetsart University
Conducting Site Survey
 Preparation
Phase
 Execution Phase
 Post survey Phase
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IWING LAB; Computer Engineering Department; Kasetsart University
Preparation Phase
Contact the authorized person
 Blueprint / Floor plan
 Access point / notebook / wireless card
 Power cord extension / Walkie-Talkie
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IWING LAB; Computer Engineering Department; Kasetsart University
Execution Phase
Verify the blueprint
 Mark permanent user locations
 Mark permanent roaming area
 Identify obstacles / interference sources
 Identify preliminary of AP
 Test and Record signal strength of
selected locations
 Adjust AP location
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IWING LAB; Computer Engineering Department; Kasetsart University
Post Survey Phase
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Documentation
– Summarize the updated floor plan
– Summarize locations of AP
– Summarize / Draw the coverage area
– Note on restrictions and sugestions
IWING LAB; Computer Engineering Department; Kasetsart University
Example
Lecture
Room 1
Computer
Room
WC
Elv1 Control
Elv2 Room
Lecture
Room 2
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Lab
WC
Common
room
IWING LAB; Computer Engineering Department; Kasetsart University
Example
1
3
4
Computer
B
Room
Lecture
Room 1
A
WC
5
2
11
Elv1 Control
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Elv2 Room
6
D
C
Lecture
Room 2
8
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Lab
9
10
WC
Common
room
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IWING LAB; Computer Engineering Department; Kasetsart University
Signal Status
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IWING LAB; Computer Engineering Department; Kasetsart University
Example
AP Pos Com. Quality
A
Note
1
2
6
B
1
2
3
4
5
C
6
7
8
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9
10
IWING LAB; Computer Engineering Department; Kasetsart University
Example
AP Pos Com. Quality
A
B
C
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1
Poor
2
V.good
6
Fair
1
Poor
2
Poor
3
Good
4
V.good
5
Poor
6
Poor
7
Poor
8
Poor
9
Good
10
Note
Near microwave oven
IWING LAB; Computer Engineering Department; Kasetsart University
V.Good
Design Phase
 Define
network elements
 Select products
 Site survey
 Verify the design
 Document the design
 Procure components
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IWING LAB; Computer Engineering Department; Kasetsart University
Implementing a WLAN
 Design
a WLAN
 Prepare for operational support
– Training / Helpdesk
– Admin / network monitoring
 Installation
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IWING LAB; Computer Engineering Department; Kasetsart University
Implementing a WLAN
 Design
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a WLAN
 Prepare for operational support
 Installation
– Storage
– HW Installation / power outlet
– network connection point / wiring
– testing
IWING LAB; Computer Engineering Department; Kasetsart University
Summary
 Clear
Design Goals
 Get support from all levels
 Well plan
 Awareness Design
 Caution about the implementation
 Documentation
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IWING LAB; Computer Engineering Department; Kasetsart University
References
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WLAN course material, Anan Phonphoem, Computer
Engineering, Kasetsart University, 2001
Guide to Designing and Implementing Wireless LANs, Mark
Ciampa, Course Technology – Thomsom Learning, 2001, ISBN
0-619-03494-7
Wireless LANs: Implementing Interoperable Networks, Jim
Geier, MTP, 1999, ISBN 1-57870-081-7
Principles of Wireless Networks, Kaveh Pahlavan & Prashant
Krishnamurthy, Prentice Hall, 2002, ISBN 0-13-093003-2
IEEE 802.11 Standard (www.ieee.org)
Wireless LAN Association (www.wlana.org)
Wireless LAN Alliance (www.wlana.com)
IWING LAB; Computer Engineering Department; Kasetsart University