As ever there are a few other considerations for using a Range Extender, such as placement. The ideal solution is to position the extender approximately in the middle of your routers existing WiFi coverage rather than at the edge, since otherwise you’ll risk boosting an already poor signal and the performance will suffer.
Equally it’s important to make sure that the extender supports the same WiFi spec (e.g. 802.11n, 802.11ac) as your router and likewise try to pick one that supports both the 2.4GHz and 5GHz bands, assuming your router supports both of those (most modern ones do). Just remember that the extended signal will always perform a little worse than the original, which is largely unavoidable but not a huge concern.
As a general rule everybody should have security / encryption enabled on their home WiFi routers (ideally the WPA2 setting), but some people leave it disabled out of a belief that doing so will improve their network performance. In reality this was only really an issue for the very early WiFi hardware with WEP encryption enabled (this is very easy to hack and should generally never be used) or budget routers with first generation WPA (TKIP) enabled, which struggled to handle the extra overhead.
By comparison the impact of enabling WPA2 on modern hardware, even many cheaper devices, is negligible. Indeed I’ve found that using encryption can actually make the connection more stable and less likely to drop connectivity at the edges of coverage. But I must admit to not being entirely sure why that is (it could just be a quirk of the hardware I’ve used).
Pro Tip: Try to ensure that all of your WiFi kit is using and supports the WPA2 (AES) Advanced Encryption Standard. Some settings, such as WPA2-TKIP/AES, might seem stronger for security but they actually only exist for backwards compatibility (less secure) with older devices and it’s not necessary to use that dual setting unless you have older kit in your network (enabling it may also carry a greater performance detriment).
Some routers give the end-user significantly more flexibility to play with the advanced settings of their WiFi, such as by adjusting the options for Beacon Interval, Fragmentation Threshold, RTS Threshold or various other things. Generally speaking you should leave these well alone as most adjustments will often sacrifice something in one area in order to improve it in another and if you get this balance wrong then problems can occur. But if you do want to try then here are a few quick suggestions.
Beacon Interval (milliseconds)
WiFi routers use these “beacon” signals to help keep the network synchronized and many default to 100ms. Setting a lower (e.g. 50 or 75ms) interval might help your WiFi network to hold its connection with other devices, albeit at a cost to some battery life on other devices. By contrast raising the setting above 100ms could save power but the likelihood of connectivity problems may increase.
RTS Threshold (Request To Send)
The RTS Threshold protocol is a tricky one to explain, but it helps to clear the channel before data is sent. A lower setting may help in busy WiFi environments as it should reduce collisions, but set it too low or incorrectly and your network performance may suffer. It’s a tricky balancing act to get right.
Any data packets larger than the size programmed in this field will be fragmented. Setting smaller packets than the default can improve reliability, especially in busy environments, albeit at the cost of performance. Again, we wouldn’t touch this or the RTS threshold unless you’re comfortable with making such tweaks and always make a note of your settings so you can swap them back if it doesn’t work.
Hopefully some of these tips will prove useful to you or at least provide some additional background on how WiFi works. Just remember that WiFi is far from perfect and wired connections will generally always deliver faster speeds with lower latency and more stability.