[HOW TO] Diagnose Wireless Issues

_Dragon_

So what do you do when you have interference with your wifi and it affects your speed so much you can't use your phone or ipad, can you buy a adapter so you can use ethernet?

mickevh

Unless your client device offers such as an ethernet adapter, then a Wi-Fi Access Point is the Wi-Fi-to-ethernet bridge.

If you suspect interference, one first needs to prove it - it's no use "just assuming." That might need some tools that cost quite a lot of money and the surveys can be very time consuming to complete which is probably not worth the effort and expense for most SOHO users.

You could try using changing radio channels and see if that avoids the interference source - though the dynamic nature of the RF environment Wi-Fi uses may mean that doesn't work for long, if at all.

You could try deploying additional AP's closer to the locale where you use your clients. Such is generally the most effective solution. Even then it's not guaranteed; Wi-Fi is inherently unreliable and fickle, not least because no-one "owns" the transmission medium (the radio airwaves) and they are available for anyone to do pretty much anything they like with so long as they remain within permitted maximum transmission power. Essentially, eveyone just has to "play nice" together, though of course just because they should, doesn't mean they do. Ultimately, you may just have to be a bit "zen" about it.

psychopomp1

If you router & clients support them (many 3rd party routers do), try the higher powered (~ 1 watt) 5ghz DFS channels - they are numbered around 120. These are perfectly legal channels in Blighty, however they are also radar channels so your router will automatically kick you off these if it detects any conflict - so probably not a good idea to use them if you live near an airport/airfield.

_Dragon_

I'm in a flat above a business I'm pretty sure the interference I'm getting is from their equipment, it doesn't happen all the time,  It's a pain because they have now decided to open up later and now work some weekends, When the interference happens my speed drops right down something they have definitely blocks out the signal. I don't think it's because everyone is on the same channel when it comes to Ap's

Maybe I should be thinking about getting a 5ghz router  but the thing is does mobile phones and ipads work on 5ghz.

I am in the process of hard wiring everything I can it just leaves the mobile phones/ipad.

psychopomp1

Most new-ish smartphones and most (if not all) ipads support the 5ghz band.

mickevh

This is exactly the symptoms one would expect if they are using the same radio channels as you. Wi-Fi is fundamentally a "only one thing at a time can transmit" technology. There more things in the area, the more data they transmit, the more contention there is for some "air time."

Some people make the error of thinking that the only thing that matters with regard to air time contention is stuff that's Associated with your AP - but that's not the case, the air time contention rules are based on what can hear what, not what's in session with which AP.

I live in flats, whilst my router and my neighbours may not be able to "hear" each other, when we are both sat on our respective sofa's either side of our party wall, both our client device can hear each other very well and have to play nice together, which means if we're both busy fiddling, it hits both of our "speeds." The only mitigation available is to try and use different non-interfering radio channels.

The 5GHz radio penetrates "stuff" (walls, doors, air,) less well which in such situations can be actually beneficially as we are less likely to hear each other. Contrary to popular belief, "more power from the router" is not the universal cure all for Wi-Fi interference - not least because it does nothing about transmissions from the clients to the AP's.

It's simplest to think of it in terms of sound: If you are getting bleed through from the neighbours conversation (and remember the "only thing at a time can talk" rule) then one party in my conversation shouting louder will cause the neighbours to shout louder in response then we get onto a huge arms race. The better solution is for us all to talk less loudly and move closer together in our respective properties. Same for Wi-Fi - more AP's closer to the client and/or better radio channel planning and management is the solution.

Channel interference is particularly bad in the 2.4GHz waveband because the radio transmissions penetrate further and there's very few channels to choose from (than 5GHz) hence the suggestion to try 5GHz.

Their  products of the last few years do - Apple publish some data on what wavebands, protocols, speeds, etc. their kit supports.

_Dragon_

Thanks, I actually think it's something electrical interfering using the 2.4ghz band rather than something they are using through wifi, first I thought it was a microwave but it can't be as it happens alot and it goes on for ages. Sometimes you hear a rumbling sound which makes me think its a appliance of some sort.

Biggest mistake I made was saying yes to this flat, The agency said it will be nice as they shut at 5pm and don't work weekends, that was right but six months later it all changed. they became loud and now work late and even weekends.

mickevh

It's not unknown, esp. in the 2.4GHz band - video sender, baby monitors, car alarms, (my favourite,) etc. use the same frequency band.

The Wi-Fi rules about air time contention take this into account. Wi-Fi is "listen before talk" protocol and the standards lay down criteria about how "quiet" other transmissions need to be before they can be disregarded, (there's almost always some level of background "noise" - again think of it in terms of sound,) - IIRC that threshold is a bit higher for non-Wi-Fi devices than Wi-Fi ones.

@psychopomp1 - DFS, ah what fun - one of my jobs was in central London and our AP's used to go nuts whenever Heathrow was on westerly ops. and the planes were being vectored over us!