A tale of two Sids – and an embarrassing confession…

By | August 22, 2016
This content is 8 years old. Please, read this page keeping its age in mind. Thank you.

Do you remember the advert that used to be on TV? “Don’t forget to tell Sid?” I think it was for shares in British Gas or something like that.

Well, I’m going to tell your about two Sids. Or to be more accurate, two “SSID”s.

First of all, an embarrassing confession. The first thing I like to do when I write something like this is say what the letters SSID stand for. It’s not that it actually matters or that I expect people to try to remember it. It’s just people tend to be curious. (My favourite tech abbreviation is TWAIN which stands for Technology Without An Impressive Name.)

And with SSID, I didn’t actually know. Hadn’t a clue. I knew what they are, but not what the letters stood for. But by the magic of the internet, I found out: It’s Service Set Identifier. I’ll probably forget that by tomorrow and you might want to as well… what’s more important is what a SSID is and what it does.

Most people nowadays tend to connect to the internet via wifi – wirelessly, rather than by plugging your computer into the wall. It doesn’t matter whether it’s a laptop or tablet. Even a smartphone might be using wifi when you’re at home. And even desktop PCs can use wifi instead of being plugged into the phone socket.

And you might have seen the list you tablet or computer has of wifi networks nearby that it could try to connect to. Or the different ones it finds if you try to connect to wifi when you’re in a cafe or hotel.

Some might have sensible names – I might have one called Tim’s wifi. Or if you’re in a cafe it might say “Ace cafe wifi”. Or some will just never have been changed from what it was set at the factory and might say something like “TP-Link 314159” or “Netgear 271828”.

Well, that name is the SSID.

But there’s a reason I’m talking about it. You just might find you have two – I don’t just mean be able to see two in the list but have two that are actually yours. They might have almost the same name – maybe with an A and a B on the end. Or they might have a similar name but one end in 2.4 and one in 5.

So you might see “Tim’s wifi 2.4” and “Tim’s wifi 5”. Or even just “Tim’s wifi” and “Tim’s wifi 5”

The reason is that decent quality model routers (the thing you plug into the wall that actually does the wifi) can often transmit on two frequencies – 2.4 GHz and 5GHz.

In theory, both are equally fast. But in practice, it’s not always true. For a start the 2.4 GHz one tends to work better over longer distances. But on the other hand there tends to be more interference on the 2.4GHz frequency – from other wireless devices and even from things like microwaves. So in some cases if the device is not that far from the router, the 5GHz frequency can in practice be faster.

A lot of the time, the router will be set up to send both frequencies out with the same name or same SSID – so you can’t see them separately.

What happens then? Well, it depends on your laptop, tablet or whatever. Some can’t see 5GHz anyway, so it doesn’t make any difference what’s going on with that, it’ll just find the 2.4GHz one as if the other wasn’t there.

Some will look around and latch on to whichever they find first. This isn’t ideal because it might not be the quicker one, but for most people in most houses it won’t usually make a big difference.

And some will be clever and check for both and use whichever has the better signal. Some will even then keep an eye on it and switch over to the other one if it becomes better.

What if you see both? Well, you can try both to see which works best. But my advice generally is to use the 5GHz one normally if you can unless you’re using your device a long way away from the router (several rooms) in which case use the 2.4GHz. It’s not too hard to switch from one to the other so if the signal starts getting iffy you could switch to the other one. On a PC you tap or click on the little wifi symbol in the bottom right hand corner of the screen and it should give you a list of all the SSIDs it can find or remember.

Phew – that was a bit more technical than most of what I write. But you don’t have to understand it all completely. The thing to remember is that if you’re trying to use wifi and there are two SSIDs listed that look like they’re both the right one except one ends in 2.4, one ends in 5, it probably won’t make too much difference which you use – but if you’re a long way from the router, try the 2.4 one.

Other issues with wifi and your tablet?
The new books I mentioned last Thursday cover various other problems you might have with wifi – when it stops working or goes slow and so on, as well as all sorts of other problems and how to sort them.

There might even be problems you don’t realise you’re having, if you think that’s just how it is!

Anyway, find out a bit more about them (and if you like, order a set to have a look for yourself) here.

2 thoughts on “A tale of two Sids – and an embarrassing confession…

  1. Jack Luxon

    You may be interested in the above link which describes the programme which can be downloaded and used without charge. This enables a user to see all the routers within range of the wi-fi adapter, compare signal strengths and see details of each router which might prompt one to change channel should an adjacent router be using the same. Revision 2 is quite old but I find it more ‘user friendly’ than later versions.

    1. Tim Post author

      Thanks – I’ll have a look at that – it sounds interesting!


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