conducting site surveys for wlan performance and reliability
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- 1. Conducting Site Surveys forWLAN Performance and Reliability Mike Diss SE, EMEA, AirMagnet [email_address] June 16, 2010
2. AirMagnet Overview
- Founded in 2001; based in Sunnyvale, California, USA
- Amassed over 8,500 customers 75 of the Fortune 100
- 25,000+ Product Licenses Sold
- Worldwide support in more than 120 countries
- Global footprint of authorized resellers and distributors
- Recently acquired by Fluke Networks (Worldwide HQ: Everett, WA)
AirMagnet is the leader in wireless LAN security, performance and compliance solutions for wireless LANs. 3. WLAN Lifecycle: Best Practice to Cope with Constant Changes in Wireless
- Pre-Deployment Design and Planning
- Design wireless network tailored to environment, user and application needs
- Operational Management
- Proactively monitor WiFi, RF, Voice performance to identify problems before impact
- Security Management
- Iron-clad protection with visibility and defense from all forms of wireless threats
4. Conducting Site Surveys forWLAN Performance and Reliability 5. History of WLAN Design Goals
- Old Way
- Minimum # of Access Points
- Maximum Power
- 30+ Users per AP
- Bandwidth what Bandwidth
- New Way
- 10 Users per AP
- Minimum Power
- Lots of Access Points
- Network Performance (& Signal Quality) is Paramount
6. Need for Site Surveys
- New Installations
- How many APs needed?
- Where should they be placed?
- How should they be configured?
- Existing Installations
- Were the correct number of APs deployed?
- Were they deployed in the best location?
- Ongoing Network Optimization
- Support for new users
- Support for new technology
- Support for new applications
7. Site Surveying Phases
- Site Survey
- Reporting & Sign-off
- Periodic Site Surveys
8. Phase 1: Preparation Phase
- Preparation checklist Questions to ask
- Do you know all the stakeholders?
- Is wireless access needed for indoors or outdoors or both?
- Are any building blueprints or street maps available?
- Where do you require coverage?
- What type of business is it?
- Is this a new deployment or an add-on to the existing one?
9. Phase 1: Preparation Phase (Continued)
- If adding to an existing wireless network:
- Are you unhappy with it? Are users complaining? Or is your business expanding?
- What equipment have you installed? Where are they installed?
- Think about capacity
- How many users require wireless service and what applications will they use?
- What is the geographical distribution for the users?
- Will they be using applications where they need to roam? What are their throughput requirements?
10. Phase 1: Preparation Phase (Continued)
- Are there any known major non Wi-Fi interfering sources? Do you know their locations?
- Is this a multi-floor deployment?
- What are the security requirements?
- Where are the power and Ethernet drops throughout the facility? Is the customer open to installing new drops?
- What is the anticipated growth for the future?
11. Phase 1: Preparation Phase (for 802.11n)
- Questions to ask for 802.11n networks
- Am I deploying an 802.11n Greenfield network or do I need to support legacy 802.11a/b/g devices?
- Will the 802.11n devices be deployed in the 2.4 GHz or 5 GHz Band? Or do you want the Site Survey product to recommend the choice?
- What type of clients will be connecting to the network?
- Will I deploy 802.11n devices for my Guest Network?
- Do I see coverage overlap from APs that belong to my neighbor? Is that coverage from 802.11n or legacy 802.11a/b/g devices?
12. Phase 2: Site Survey
- Load floor plan maps
- Supported format
- Simple, black and white plans
- Calibrate your floor map scale
- Survey tips and tricks
- Perform a visual inspection of the facility
- Can I get everywhere I need to?
- Figure out where you require coverage and where you dont including areas that obscure results
- Perform survey during normal business hours
- Dont scan unwanted channels
- Exterior survey to discover RF channels being used
13. Phase 2: Site Survey
- Survey tips and tricks
- Make good judgement on the Signal Propagation Assessment value
- Measurement intervals accuracy
- Auto Logging Data Period
- No further than what your Signal Propagation Assessment is set to
- Take readings on both sides of the wall
- Also take readings along the perimeter of the rooms
- Recommendation:Plan your walking path
- Results in more accurate clicking
14. Phase 2: Site Survey
- Survey tips and tricks
- Take readings around the outside of your building
- Place your man where you are headed for and then click when you reach that location
- Dont try and do it all in one go
- Enable you to retract when necessary
- Switch between auto sampling and click only sampling as you walk around
- Auto sampling for straight line walks (i.e. corridors)
- Click only for points within a room
- Size of hashing at click points indicates range of Signal Propagation Assessment
15. Phase 2: Site Survey
- Perform your surveys
- Passive Surveys
- Collect signal data from all APs & Stations in the area
- Active Surveys
- Collect actual performance metrics (data rate, retries, etc)
- Mandatory for 802.11n deployments
- Iperf Surveys
- Collect uplink/downlink performance statistics
16. RF Spectrum Site Survey
- Gather RF Spectrum Data
- Non Wi-Fi devices operate in the same spectrum as Wi-Fi
- Cause interference and severely degrade the overall network performance
- Even more important for time sensitive applications
- Locate interfering devices on floor map
- Preferred method: Collect RF data at the same time as a Wi-Fi Survey
17. Phase 3: Analysis Phase
- Visualize Wi-Fi signal coverage
- Visualize real-world user performance metrics
- Data rates, retries, losses
- Uplink/downlink performance
- Visualize Roaming areas
- Visualize areas that suffer from Channel Interference
18. RF Coverage Analysis
- Visualize Wi-Fi signal coverage at every location
- Locate dead spots in your coverage
- Know coverage for yo