Elastic Wi-Fi. It’s probably not a term you’ve heard before in relation to wireless and Wi-Fi. I’m going to run through some principles I’ve learnt over a few years in the business to help you improve Wi-Fi performance, but first, I’ll digress...
You can't have it all with Wi-Fi: You have to Compromise
Many years ago I learnt to fly. Its kind of similar in complexity to the workload if you were driving two or three cars at once. The plane isn’t glued to the ground, but operates in 3 dimensions (or planes, if you can excuse the pun).
You kick in a bit of rudder to affect a yaw and start dropping a wing in the turn. You can compensate with a bit of aileron to put you in a straight turn – there’s even a little ball in the dashboard so you can check you’re not skidding around a turn.
For every action, there is a secondary action wireless is the same. You can stretch an elastic band across your fingers and pull it in all directions.. just not all at once. Let's delve into some Wi-Fi principles and see if you can spot what I mean.
1. Less Access Points = Higher Transmit Power
You turn your access points on and if you have a half decent network, you have Radio Resource Management (RRM) in operation. The role of RRM is to help balance RF power and ensure coverage is consistent.
Without enough APs, RRM will power up the access points to their maximum, because the AP density is low.
This is where it gets really misleading. The Post Install RF Survey is going to look ok when you look at the survey results, but clients won’t roam properly and low power devices will drop out. Why does that happen, when you have enough apparent coverage? Just having RF coverage isn't the best or only measure of a good Wi-Fi network, as it turns out.
With less APs, you will only achieve a data-only grade Wi-Fi and it probably won’t allow low power clients to roam very well.
Lesson: Spend your budget how you will – but get the best advice on what you’ll get for it
2. Too many Access Points = Higher Channel Utilisation
At the opposite end of the spectrum is the whack-a-mole theory on RF design. Just like the game of whack-a-mole, wherever there's a coverage hole, you add an AP.
You have APs everywhere you look and assume that with so many APs, it can’t fail to work properly.
Unfortunately, this isn’t true either!
If you skimp on a proper RF survey in favour of adding as many APs as you can, you’ll end up with loads of beacons in the air from all those APs and a high channel utilisation. That doesn't sound too good right?
Instead of giving you the gold plated Wi-Fi network you expected, you ended up with too many APs, costing more than you needed to spend, and a network that’s like a stretched elastic band!
There's also the concept of different channels, which perform differently to consider.
Lesson: Get a proper RF survey that takes into account the services and clients you actually want to support. It will be cheaper than all those extra APs.
3. High Transmit Power = Poor Cell Distribution
So you didn’t put enough APs in, but you’ll fix it by just turning the power up.
A real rookie mistake this one - I’ve seen this one too many times.
You will now get big cells from each AP, which overlap each other and cause you no end of grief with clients not roaming, high co-channel and generally a poor user experience.
Lesson: You can’t get blood out of a stone! Not enough APs is just that – it's not enough and turning up the power will only help you if you only have high powered clients.
4. Cutting Edge Features = Bugs
Sorry, but it seems to be a fact of life with cutting edge technology, especially WI-FI.
New code is crafted and put into production too quickly and you get burnt. I am sure a lot of people relate to this one.
You get a major new version of code, a new AP type and decide to try some of those fancy new features. . and you’re in a world of hurt.
Next thing you’re looking at complex, time consuming bugs, air sniffs and extended periods before you get the network properly operational.
Its been said many times that you need to be careful not to get cut if you’re on the bleeding edge.
Lesson: Test anything new on a friendly, small, contained site. Get the feedback that everything works as expected – don’t bet the farm on something new just working.
5. Cheap Price = Poor Wi-Fi Design
My personal favourite: you’ve accepted a low ball offer on the cheapest RF survey – it’s a race to the bottom to see who can offer the lowest price. No two Wi-Fi designs are the same. They rely on the ability to use the tools, as well as skill and judgement.
It’s a commodity right? Everyone will do the same job? They’re all trained the same, have the same oversight, experience and double checks on the output?
Don’t kid yourself.
The cheapest price will involve some corner cutting – and that corner cutting is going to cost an awful lot more to remediate down the track once you have to revise, add more APs and move the existing ones around.
Lesson: Don’t mix up cheapest price versus best value. The cheapest quote probably won’t deliver you the best outcome. Do your homework – if they’re not asking you how you intend to use the network, they probably are going to do a cookie cutter with the most inexperienced person and deliver you something that’s an approximation of what you actually wanted.
The 5 Principles of Elastic Wi-Fi: Summary
Engineers are people and they are all different – the best qualified command higher prices, so bear that in mind when you select the vendor of choice.
There's so many gotchas in the delivery of Wi-Fi that are so often overlooked and leave many customers with a substandard Wi-Fi network, which drops out and offers poor performance.
We have customers that have spend good money to buy a network which we then help them remediate to the network they thought they were buying in the first place - only it's now cost a lot more.
We do a lot of network reviews if you're interested to have this done on your network, drop us a line - details below.