Occasionally we come across disgruntled ADSL customers who wildly blame their ISP (internet service provider) for slow internet speeds... but then, once on site, we find it's just a WiFi (Wireless Network, or WLAN) issue.
Here are the most common causes of Wireless Network problems we see on the field, and how we recommend you mitigate or even overcome speed issues.
Static / Fixed WLAN Channel Setting
Every wireless router / AP (access point) has an option to choose between a range of frequency channels or a default "auto" setting. We highly recommend users keep this setting on "auto" at all times, to prevent channel interference.
Simply put, if you select a static/fixed WLAN channel/frequency for your Wireless LAN, there is a chance that one of your neighbours uses the same channel for their WiFi too. This will cause interference on both your network, and your neighbours network, as they fight for supremacy in the battle of signal to noise. Each network will think it's data is the signal, and the other network's data is the noise. They will continue to blast out error correction packets and never see eye to eye; both networks will run slow and may even experience network dropouts.
The "auto" setting overcomes these issues by scanning the local airwaves and selecting the quietest channel to use. That way, there's minimal interference to maximise your WLAN bandwidth.
As each WLAN channel has a slight frequency overlap, it is rare to have a case where there is no interference, not to mention atmospheric and other environmental interference.
Auto Channel is set, still get interference from Neighbours' Networks
If you live in a big apartment complex (such as Wolli Creek or Zetland in Sydney NSW) then you may have an issue where you are helplessly surrounded by 20 or more Wireless Networks (i.e. from your close neighbours; upstairs, downstairs, next door, even in the building across from you!).
Typical (cheaper) wireless routers / APs (access points) run in the 2.4GHz spectrum and have only 14 channels that are spaced rather close together (only 5MHz apart, 22MHz wide), which is great for most suburban areas, but for dense residential complexes this can mean perhaps three of four networks are sharing the same channel at any one time, fighting for signal strength in the sea of noise from neighbouring wireless networks.
There are three options here; you could:
resort to using a wired ethernet connection - by connecting your laptop/PC directly to the router/AP with a network cable / patch lead - and just don't use the wireless network (which is undeniably inconvenient these days); or
buy an external antenna for your router, to boost the signal an extra 3dB-6dB which would stabilise your own network, but could totally wipe out your neighbours' networks; or
upgrade your router/AP to a 5GHz / Dual Band product so you can take advantage of the extra channels that the 5GHz spectrum has to offer.
In this case we would recommend you use a 5GHz router/AP for your mobile devices, plus use a wired ethernet connection between your media devices such as your TV and Gaming Consoles. This will maximise your internet speed where you need it most (online gaming, streaming online media) and help increase your wireless network speeds when using your mobile devices to check emails, post FaceBook selfies and view your Instagram feed.