Should WiFi routers be set to a channel or choose automatically


This question is about scenarios where many other independent routers are nearby, like in apartment buildings etc.

There are many articles online (like this one on lifewire) showing how to manually find a channel / frequency for routers to use, and getting a list of networks with channel numbers is simple (iwlist *interface* scan | grep \(Channel).

However, does it make sense to choose the channel manually if most other routers are set to choose automatically?
Or will it make things worse after a short while, when other routers change channels?

Best Answer

It really depends on a couple of things:

  1. Is it s really nice router? If so, it will probably do proper channel selection based on local usage/interference, and may even recheck when it restarts, in which case you probably want it set to auto-selection. If it's a cheap router though, 'Auto' is almost always one of a couple predefined channels (for example, in the 2.4GHz band in the US, 'Auto' usually means channel 1 or channel 8, or on rare occasion channel 6 or 11), and in that case check the next point.
  2. How much interference are you actually seeing? Ideally, grab a Wi-Fi signal analyzer app for your phone, and see what channels are being actively used in your area. If your router is auto-selecting a channel that's in active use by just one other AP and that other AP has a weaker signal in the entire area you want covered, you're probably fine. If on the other hand you see multiple other AP's on that channel or another AP has a stronger signal than your router does in an area you need covered, you should probably look at manually specifying a channel instead of just letting the router choose one.
  3. As a special case, if you're using WoWLAN (Wake on Wireless LAN) on your network, you almost certainly want to go to the trouble of specifying a channel manually regardless, as WoWLAN will stop working if your router changes the channel while a device is offline, and any interference can cause issues with WoWLAN.

Also, just a general tip when choosing a channel manually, try to find one that is as far from any other used channels as possible. With a few special exceptions like channel 14 in the 2.4GHz band most channels partially overlap at least one other channel, so being as far from other channels that are in-use as possible will help reduce interference.