WLAN Design & Implementation ผศ. ดร. อนันต์ ผลเพิ่ม Asst.Prof....

WLAN Design & Implementation

ผศ.ดร. อนั�นัต์ ผลเพิ่��ม Asst.Prof. Anan Phonphoem, Ph.D.anan@cpe.ku.ac.thhttp://www.cpe.ku.ac.th/~anan

Intelligent Wireless Network Group (IWING Lab) http://iwing.cpe.ku.ac.thComputer Engineering DepartmentKasetsart University, Bangkok, Thailand

KMITNB Jan 29, 2004

IWING LAB; Computer Engineering Department; Kasetsart University2

Outline

WLAN TechnologyConceptual Review

– WLAN Configuration– Management

PlanningDesign & Implementation Phase

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Wireless System Path

Source: Mobile Communications International

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Wireless Classification

WAN

WAN-MAN

MAN

Pico-Cell

MAN-LAN

PAN

LAN-PAN

0km~50km ~2km ~10m

Personal Operating Space

Courtesy of IEEE 802.15, Jan. 2001

WPANBluetooth

WLANIEEE802.11HyperLan

WWANGSM/ GPRS /

CDMA

WMANIEEE802.16

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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)

802.11a 5 54Mbps

802.11b 2.4 11Mbps

802.11g 2.4 54Mbps

802.11n ?? 100 Mbps

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IEEE 802.11 Family

Standards Descriptions

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.

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History: 802.11 Legacy

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

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802.11b 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)

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802.11a

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

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802.11g

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

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802.11 Wi-Fi

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)

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Wireless Hot Spot

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/

WLAN Review

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WLAN Category

Wireless LANs (WLAN)– Radio Waves– Infrared Light– Carrier currents (“no new wire”)

Wireless Point-to-Point NetworksWireless WANs

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Radio Based Wireless LANs

Advantages– No line of sights– Propagate through obstacles

Disadvantages– Interference– Security

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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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WLAN Questions

Throughput ? Scalability ? Performance ? Best technologies ?Application support ?

– client-server / Network programs– Quality-of-service

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Data rates and Range

Source: Proxim

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WLAN Configurations

Independent WLANInfrastructure WLAN

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Independent WLAN

Ad HocSimplestRapid deploymentPeer-to-peerNo administration

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Independent WLAN

Single Cell Multiple Cells

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Independent WLAN

Can extended range by using an Access Point (acting as a repeater)

2d

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Infrastructure WLAN

Need an Access PointConnect to the wired

LANNeed InfrastructureNeed administration

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Infrastructure WLAN

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Infrastructure WLAN

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SOHO Infrastructure WLAN

Hub/Switch

ComputerServer

Access Point

Printer

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(Large) Infrastructure WLAN

Router

Internet

Hub/Switch

LAN

Hub/Switch

LAN

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Simple WLAN Management

Router

Internet

Hub/Switch

LAN

Hub/Switch

LAN

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VLAN Switch Management

Router

Internet

VLAN Switch VLAN Switch

LAN

LAN

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AP with VLAN Capability

Router

Internet

Hub/Switch

LAN

Hub/Switch

LAN

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Mobile IP

Router

Internet

LAN

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Mobile IP

Router

Internet

LAN

Home Agent

Foreign Agent

WLAN Planning

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Design Requirements

To Keep in mind– Availability– Scalability– Manageability– Interoperability

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Planning

Set Project Management PrinciplesPlanning a projectExecuting the project

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Set Project Management Principles

Clear goal / activities / communications

Reduction of risksOn time / within budget

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Cost of Ownership

Infrastructure costsClient device costsMonthly costs (Power & Internet Access)Management costs

– Training– Downtime costs– Support costs (Troubleshoot + repair)

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Planning a project

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)

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Executing the project

Kick-off meeting (review project plan)Status checkTechnical meetingProgress report

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Define WLAN requirements

User profile & interface

Functional (expected)

Application Information Flow Performance

(Reliability/Availability/BW/Delay)

System Interface Environmental Department support Regulation (RF) Mobility Security Budget Schedule

Design & Implementation Phase

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Implementing a WLAN

Design a WLANPrepare for operational support Installation

Design a WLAN

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Design & Implementation Cycle

Source: Cisco Networking Academy

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Design Phase

Define network elementsSelect productsSite surveyVerify the designDocument the designProcure components

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Defining Network Elements

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

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Selecting Products

FunctionalityAvailabilitySupportPriceStandard compliance

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Site Survey

Determine coverage area (Cell)Determine number of cells neededDetermine the Access Point

location

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Environmental Consideration

Environment characteristics– Completed Open (empty floor, no desk)– Semi-Open (partitioning area)– Closed (Blocked room, high wall)

Barriers– RF penetration– Attenuations

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RF Barriers

RF Barrier Attenuation Example

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

Metal Very High Desk / partitions / elevator

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Conducting Site Survey

Preparation PhaseExecution PhasePost survey Phase

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Preparation Phase

Contact the authorized person Blueprint / Floor planAccess point / notebook / wireless cardPower cord extension / Walkie-Talkie

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Execution Phase

Verify the blueprintMark permanent user locationsMark permanent roaming area Identify obstacles / interference sources Identify preliminary of APTest and Record signal strength of

selected locationsAdjust AP location

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Post Survey Phase

Documentation– Summarize the updated floor plan– Summarize locations of AP– Summarize / Draw the coverage area– Note on restrictions and sugestions

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Example

WC

WC

Lecture Room 1

Lecture Room 2

ComputerRoom

Lab

ControlRoom

Elv1

Elv2

Commonroom

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Example

WC

WC

Lecture Room 1

Lecture Room 2

ComputerRoom

Lab

ControlRoom

Elv1

Elv2

Commonroom

A

B

C

D

1

2

34

5

6

8 9

10

11

12

7

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Signal Status

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Example

AP Pos Com. Quality Note

A 1

2

6

B 1

2

3

4

5

C 6

7

8

9

10

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Example

AP Pos Com. Quality Note

A 1 Poor

2 V.good

6 Fair

B 1 Poor

2 Poor

3 Good

4 V.good

5 Poor

C 6 Poor

7 Poor Near microwave oven

8 Poor

9 Good

10 V.Good

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Design Phase

Define network elementsSelect productsSite surveyVerify the designDocument the designProcure components

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Implementing a WLAN

Design a WLANPrepare for operational support

– Training / Helpdesk– Admin / network monitoring

Installation

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Implementing a WLAN

Design a WLANPrepare for operational supportInstallation

– Storage– HW Installation / power outlet– network connection point / wiring– testing

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Summary

Clear Design GoalsGet support from all levelsWell planAwareness DesignCaution about the implementationDocumentation

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References

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)