Wireless cards aka WiFi cards card are devices used for communicating with other wireless devices such as access points or routers. They use radio waves to revive and send data in the same way as mobile phones but on a much smaller scale. Mobile phone companies use a certain frequency range (vast) to communicate with the mobile network whilst wireless network cards use a much smaller range of frequency which is also shared with other radio devices such as microwaves, cordless phones, household appliances, radios and Bluetooth devices. This effectively leaves wireless card competing against other devices for the already smaller frequency space which leads to interference and as a result poor network performance, drop outs, lower download speeds.

It is important to remember that different wireless cards are different to each other so you may find that you have another wireless device that operates perfectly in the same spot as another wireless device, quite simply because they use a ever so slightly different frequency.

Other factors that can affect wireless cards in a custom built PC is software, mainly firewalls and antivirus programs on the PC itself or even on the network device that the card is trying to talk to such as the routers software. 

In English?

Imagine you are meeting a friend in a bar, it’s his birthday, you arrive and your birthday friend is already there. Imagine your birthday fiend is the router and you are a wireless card. 

At the beginning of the evening you are talking to your friend on a 1 on 1 basis, it is easy to have a conversation, you can hear them clearly and they can hear you. As more friends, who are also wireless cards, arrive they also want to chat to the birthday friend and congratulate them for surviving another year, meaning your friend’s time is then divided between all of the friends so when you wish to talk about something different you effectively now have to politely wait until the current conversation is over. Talk at the same time as another friend to the birthday boy/girl as another friend, then they will probably be unable to understand and process what both of you are saying at the same time. 

Add in the rest of the public, who again are also wireless cards, microwaves, household appliances etc who are also taking to their own birthday friend and the noise level increases making it harder for you and your friends to hear your birthday friend. The general public, for this explanation, are your neighbours. 

Your little network is the same, more devices mean more interference on what is already quite a small frequency range which will lead to problems.

What can be done about it?

1 – Check your wireless card - The first thing to do is to check if there is an issue with your wireless card in the first place which is a quick and easy test. Get your wireless card to look for a wireless network – If it picks up a SSID (the network name) then the wireless card is working correctly. It does not have to be your SSID (as you may have a router/access point problem), it could be a SSID from over the road or next door neighbour, but the important thing is to “see” a wireless network out there. Depending on how many SSID’s you pick up will also give you a good indication of how many other wireless devices are out there. These found devices and the associated devices that connect to said devices will be causing interference with your own network.

2 – Change your wireless channel – The wireless channel is basically the set frequency range that a router or access point operates in. Moving to a new channel is usually the easiest thing to do. 

There are loads of free programs out there, “Netstumbler” is a well used one; http://www.netstumbler.com/downloads/ download it, install it and run it on your PC, it should automatically start scanning to find what is around. If you can, run it close to your router/access point to get a better picture of what is close to the router/access point as the issues you are having are not to do with your wireless card. Find the least populated channel and change your router to said channel. You may have to try several channels until you find the best channel. 

Your router/access point supplier should be able to help you change your wireless channel or alternatively simply read its instructions.

3 – Further work – Chances are changing your channel has solved or at least reduced your issues however the next easiest thing to try is to ensure you do not have any software on the custom built PC that will cause problems. This includes but not limited to, firewalls, antivirus, virus’s – Uninstall/delete the lot and if that still does not help, backup and reinstall the operating system with only the wireless card driver and try to replicate the issues. 

4 – Finally – It is time to start eliminating the interfering devices. It probably won’t be practical to start knocking on local peoples doors asking them to switch off their wireless devices even if your neighbours microwave is the root of your issues, but you can eliminate your own. Switch them all off and unplug them, if the issue is resolved then you know it’s something you own casing the problem – get rid of it or change it. This also includes turning off your mobile phone.

My Wireless card is not working at all

So the wireless card does not pick up a SSID – Try the following;

- Reinstall the driver.

- Reinstall the operating system followed by the driver (get the latest from the wireless card manufacturer’s website).

- Is the wireless card even plugged in?

- Replace it/try another card.

Final Straw

Probably the best test out of them all is to pick up the PC, monitor, keyboard & mouse – even if it is a gaming desktop or small form factor mini PC and take it to another address such as a friends or family and try to connect to their network. Whilst not the most practical test is does offer a brilliant diagnosis to prove that the problems being experienced are because of another device in the systems home proximity. Does it solve, reduce or change the problem? If it does then you know where the issue lies.