WLAN Design

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WLAN Design Implementation

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• Asst.Prof. Anan Phonphoem, Ph.D.
• anan_at_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
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Outline

• WLAN Technology
• Conceptual Review
• WLAN Configuration
• Management
• Planning
• Design Implementation Phase

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Wireless System Path
Source Mobile Communications International
4
Wireless Classification
WWAN GSM/ GPRS / CDMA
WPAN Bluetooth
WLAN IEEE802.11 HyperLan
WMAN IEEE802.16
WAN
WAN-MAN
PAN
MAN
MAN-LAN
LAN-PAN
Pico-Cell
Personal Operating Space
0km
50km
2km
10m
Courtesy of IEEE 802.15, Jan. 2001
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History and present of IEEE 802.11
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IEEE 802.11 Family
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IEEE 802.11 Family
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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/

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WLAN Review
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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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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 WLAN
• Infrastructure WLAN

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Independent WLAN

• Ad Hoc
• Simplest
• Rapid deployment
• Peer-to-peer
• No administration

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Independent WLAN
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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 Point
• Connect to the wired LAN
• Need Infrastructure
• Need administration

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Infrastructure WLAN
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Infrastructure WLAN
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SOHO Infrastructure WLAN
Server
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(Large) Infrastructure WLAN
Internet
Router
Hub/Switch
Hub/Switch
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Simple WLAN Management
Internet
Router
Hub/Switch
Hub/Switch
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VLAN Switch Management
Internet
Router
VLAN Switch
VLAN Switch
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AP with VLAN Capability
Internet
Router
Hub/Switch
Hub/Switch
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Mobile IP
Internet
Router
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Mobile IP
Internet
Router
Home Agent
Foreign Agent
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WLAN Planning
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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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Set Project Management Principles

• Clear goal / activities / communications
• Reduction of risks
• On time / within budget

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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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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 check
• Technical meeting
• Progress 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

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Design Implementation Phase
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Implementing a WLAN

• Design a WLAN
• Prepare 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 elements
• Select products
• Site survey
• Verify the design
• Document the design
• Procure 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

• Functionality
• Availability
• Support
• Price
• Standard compliance

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Site Survey

• Determine coverage area (Cell)
• Determine number of cells needed
• Determine 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
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Conducting Site Survey

• Preparation Phase
• Execution Phase
• Post survey Phase

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Preparation Phase

• Contact the authorized person
• Blueprint / Floor plan
• Access point / notebook / wireless card
• Power cord extension / Walkie-Talkie

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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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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
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Example
Computer Room
WC
Lecture Room 1
Elv1
Control Room
Elv2
Lecture Room 2
Common room
Lab
WC
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Signal Status
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Example
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Example
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Design Phase

• Define network elements
• Select products
• Site survey
• Verify the design
• Document the design
• Procure components

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Implementing a WLAN

• Design a WLAN
• Prepare for operational support
• Training / Helpdesk
• Admin / network monitoring
• Installation

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Implementing a WLAN

• Design a WLAN
• Prepare for operational support
• Installation
• Storage
• HW Installation / power outlet
• network connection point / wiring
• testing

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Summary

• Clear Design Goals
• Get support from all levels
• Well plan
• Awareness Design
• Caution about the implementation
• Documentation

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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)