What is Density?
In Webster’s Dictionary, Density is described as…Nope! Not going there!
Density in WiFi is all about having too many devices trying to connect and associate with the WiFi Access Point or Wireless Network. If you’ve ever tried to connect to the same WiFi Access Point only to be repeatedly denied, it’s likely a result of too many devices trying to connect to a single channel AP. In fact the North American average is 2.9 mobile devices per user and that number is growing daily – putting more strain on wireless networks everywhere.
Density is an evolving issue and, with the advent of devices and other WiFi enabled service and products like; Video-over-WiFi, WiFi Calling and the ever-streaming Netflix (37% of all internet traffic in North America). Which tees us up the next issue – Capacity.
Capacity Caps WiFi Performance
We all want better WiFi. Users demand it, Businesses Need it and it’s Mission Critical in so many aspects of living with technology today. With multitudes of services, software and content accessed via WiFi, it’s placing an increasing strain on WiFi networks that is hitting the capable limits of WiFi and essentially breaking it. It’s actually a pretty simple equation – when your phone or tablet transmits or receives data from the wireless router or access point it uses up something called a timeslot.
The more data demand on the WiFi access point, the more timeslots are used. When data demand hits critical mass, all of the timeslots are used and data packets are lost in transmitting and receiving. Packet Loss impacts WiFi even further with increasing “Retries” where the AP attempts to resend the lost data. The result is too much data demand on an access point breaks WiFi. Simple. Sure, there’s software applications like Airtime Fairness and antenna tech like MU-MIMO that were designed to try to solve some of the capacity issues but are truly stop gaps to the fundamental issues of single channel WiFi.
The Evolving Issue of Interference
How do you solve WiFi interference? The short answer is – nope. You don’t solve it – you mitigate it.
The massive acceptance of WiFi as the preferred way to connect wirelessly has also created a “self-fulfilling prophecy” – More WiFi creates More Interference. The technology’s popularity is also creating massive issues for users in high density locations. Let’s break it down…
There’s two types of WiFi interference – CCI & ACI. The first is co-channel interference and it happens almost everywhere. When two WiFi radios are broadcasting on the same channel, the signals collide and, as a result, users see a dramatic impact on their WiFi performance.
The second type of interference, ACI, happens almost everywhere but a little bit tougher for the average user to understand and diagnose. To be basic, if there’s three WiFi radios transmitting and receiving in close proximity and they are on separate channels; 1, 6, 11. When broadcasting (which is pretty much a constant), these channels all have something called side lobes – basically they broadcast in a cone (see image). These cones or side lobes cross over one another and create the dreaded ACI that plague WiFi networks everywhere.