wi-fi planning - the 7 secrets
TRANSCRIPT
The 7 Secrets
Wi-Fi Planning
Agenda
1. Who’s on the line?
2. Why are we here?
3. The 7 secrets of Wi-Fi Planning
+ hands-on demos
Jussi@JussiKiviniemi
11 years at Ekahau
Mikko@ekaMikko
9 years at Ekahau
Ekahau <3 CWNP
• CWNP = Wi-Fi knowledge = power
• Ekahau = Wi-Fi tools
Ekahau <3 CWNP
• Tools + power = superpowers?
(or power tools?)
Ekahau <3 CWNP
CWNP and Ekahau have been
working together for 10 or so
years.
Various CWNP courses feature
Ekahau products.
Ekahau Wi-Fi Tools
Site Survey & Planning
Mobile SurveyTroubleshooting
Spectrum AnalyzerFight interference
Ekahau Site Survey Prow/ 3D Wi-Fi Planner
These guys and 500,000+ others use our stuff.
“The simplest and most effective way to design, evaluate and document Wi-Fi.”
- Blake Krone / Experienced wireless consultant
“This tool rocks! For years, our field teams and our partners have been using Ekahau Wi-Fi Tools.”
- William Aguilar / Extreme Networks
“Absolutely the best live surveying tool around”
- Bruce Alexander / Cisco Systems
“First class products and continuous development and innovation”
- Ian Morris / MLR Networks
“Using <competing product> is like pulling your nails out.”
- Justin Cetko, WLAN Consultant / Skyline Networks
“Happy to say it’s the best survey/planning tool I’ve worked with.”
- Tom Berry / Meru Networks
“Great investment, exceptional software. Extremely accurate planning.”
- Ben Cabrera / Stater Bros. Markets
“Quickest to use, superior accuracy. Customer support has the friendliest bunch of folks.
- Jim Florwick / Cisco Systems
If you only have 5 minutes today
1. Talk to people2. Map is your friend3. The world is not 2D4. Coverage is easy…5. … but channel overlap is harder…6. … and capacity is … like … ultra-complex7. Don’t always plan.
The Goal of Wi-Fi Planning
Determine
1. the minimum number of APs and
2. optimal AP configurations
to best satisfy the users’ requirements
Troubleshoot Validate
PlanMonitor
Requirements
Simulation
Site survey
Spectrum analysis
Spectrum analysis
Continuous
Packet analysis
Periodic surveys
Life Cycle of a Wi-Fi Network
Methods
Various ways to design Wi-Fi networks:
1. Best guess
2. Square feet/meter
3. Map-based ROM
4. Map based accurate
Today, we’ll focus mostly on #4.
Rough Order of Magnitude (ROM)
If you are very low on time, you could just
cut some corners and take a best guess.
Here’s how.
#1: Talk to people
What exactly is required from the network?
Secret #1: Talk to people
• Areas to cover and NOT to cover• Required coverage• Required capacity• Where APs can’t be placed• Budgetary constraints• Vendor constraints• Deliverables• Schedule
#2: This works for Indiana Jones. Not for you.
Secret #2: Use high quality maps
• Sucky maps may be OK for site surveys…• … but not for planning
Secret #2: Use high quality maps
+ white background + 1:1 Proportions + meter/feet scale + overall easy to read
Secret #2: Use high quality maps
Secret #2: Use high quality maps
#3 is for 3D.
Secret #3: Everything is 3D.
Signals travel through floors.
Secret #3: Everything is 3D.
• APs work differently at different heights• High ceilings = directional antennas
Secret #3: Everything is 3D.
• Shelves, racks are not all the way to ceiling• But they attenuate the signals.• So do cubicles.
Secret #3: Everything is 3D.
• What about outdoor planning?
Secret #4: Coverage design
• This is the easiest part of the puzzle…• … but only a small part of it
Secret #4: Coverage design
• Pay attention to highly attenuating walls and areas• Consider also 2nd AP coverage (overlap)• Consider floor-to-floor bleed• Consider the 3D aspects
Secret #5: Overlap
Just one Wi-Fi device can talk at a time.
Secret #5: Overlap
Adding APs often makes capacity worse, not better.
3 usable channels on 2.4GHz.
Where to put the next AP?
Channel 1
Channel 6
Channel 11
Channel 1
Co-Channel interference:More than one AP audible per frequency
Adjacent channel interference
Channel 1
Channel 2
Adjacent channel interference:APs on overlapping channels
Secret #6 – Capacity.
There’s only so much load one AP can take.• ~ 200 associations per radio• ~50-300MBps throughput per radio• ~10 voice calls per radio
Secret #6 – Capacity.
There’s only so much total airtime per channel.
Again, adding APs may not help at all.
Using retro devices ain’t cool, man
Not go
od
Secret #6 – Capacity.
There’s only so much total airtime per channel.
Again, adding APs may not help at all.
“Capacity planning sucks,because it’s complex”
Capacity calculations 101
How many users? x How many devices per user? + How many other devices?---= Devices and their types
x Which applications are run on the devices?===================== Total capacity required
- Areas to cover - Types of end user devices - Types of access points - Channels/bands used - Single / multiple floors - Wall materials
What else affects capacity?
Secret #7 – When NOT to plan?
If it’s quicker / cheaper to do it on-site,perhaps better just go there?
Secret #7 – When NOT to plan?
Challenging environments:• Mountains / hills• Stadiums• Oil refineries• Hugely complex manufacturing plants
Any questions?Now would be a good time to ask.
ekahau.com/wifidesign