Wi-Fi trouble on only one of several computers, almost each night

Question

In our home, we have a couple laptops and other devices (ipad, two samsung phones, wii) connected to a Netgear Wi-Fi router. We live in the top flat, with three flats under us, and with flats on both sides. At the time of writing, I can see 10 wi-fi networks, but there are atleast 6-7 more that are occationally in range. Our own network naturally has the strongest signal, with the router placed high up in the living room.

For a while now, one of the laptops has had problems with the wi-fi, but only parts of the day. It will work fine most of the day, and in the evening it will start to go bad until it's almost impossible to connect. At the same time, the phones, the ipad and the other laptop works fine.

The laptop with the problem is an Asus N56DP. while the other laptop is a Lenovo W530. We have had problems with the Asus when running Windows 8, but also when running Lubuntu Linux from a USB-stick (Booting Lubuntu from USB to make sure it's not a windows driver issue).

My suspicion is that the Asus for some reason is being hit by interference from something the neighbours turn on when they get home from work (TV, computer ?), but how can I track it down or more importantly, work around the problem?

It would also help if anyone can shed light on why the Asus has problems while the Lenovo never has an issue, while connected to the same AP?

Additional info

The router was running with auto-select of best channel, and has also been set to use channel 7 which was given as best alternative by the Android App Wifi Analyzer. When in auto-mode, it looked to be selecting channel 11, which is shared with atleast 4 other networks in range. Channel 7 seems to be clear from direct competition with other networks.

I'm unsure if the router actually supports Wireless N, it only allows selecting the modes: "Up to 54 Mbps", "Up to 65 Mbps" or "Up to 150 Mbps" (I've selected the last one).

The router claims to be a Netgear WNR1000v2 according the the admin interface.

Answer 1

It could be a baby monitor, it could be a microwave oven, it could be a 2.4ghz cordless phone... or any combination thereof. It could be the normal wireless usage. You say it happens with that internal wireless card in the Asus as well as a USB wireless card you tried with Linux (unless you were trying to say you were running Linux off a USB stick using the same internal wireless card). So... what can you do?

As Huskehn pointed out, use a program like inSSIDer and get an idea of what is going on with your neighbors and their networks. I know it only addresses one aspect of the problem, but you can't do anything about the other possibilities if you aren't willing to switch over completely to using Wireless N at 5ghz. I assume that's something you can't do, because of the mixture of devices. Thus, get a good look at the wireless broadcasting topology around you.

Being stuck in Wireless G world, you really are looking at some specific and localized channel choices to reduce interference. You may have heard about the whole channel 1/6/11 dealio... where those channels don't overlap with each other. That means that if your nearest neighbor is using channel 2, you could use 7 and not overlap their signal. If your nearest neighbor is using 2, and the next strongest one down is using 3, you could use 8. See where this is going? You look at the inSSIDer information, and arrange it from strongest to weakest signals, then change the channel you use accordingly so it doesn't overlap with the strongest signals near to you. That will reduce the possibility that a neighbor's wireless usage is causing the problem.

You could also try moving the router closer to the one trouble laptop. There is a small possibility that your problem is being caused by the design of the flat... namely walls and furniture in between the router and that Asus. Soft material like wood and drywall will absorb and weaken signal strength, so putting the router in a better position might make enough of a difference.

You might also consider running an Ethernet cable to that one laptop's location. That would eliminate the issue altogether.

You could purchase a range extender. They aren't all that expensive (about the same as a cheap router) and put that between the laptop and the router. Might seem like overkill, but if it was in the same room as the laptop, you'd almost definitely see no connection issues after that.

Now... ALL of this assumes you have actually tried two different wireless cards (the internal, and an external USB wireless NIC) with that laptop. Why? Because the problem could indeed be exactly what Fiasco Labs said.... the wireless card and/or antenna that is in the laptop. If you actually haven't tried a different wireless card with that laptop... then buy or borrow one and see if the problem continues. Don't think of it as throwing money away at the problem, for you will always find a use for it. I've got a Linksys WUSB54GC, Hawking HWUG1, D-Link DWA-130, and the cutest little mini USB N adapter with a removable antenna you ever did see... and those are just the adapters I keep around for testing and whatnot. Having an extra USB wireless is always a good idea.