GSM vs UMTS SIM Differences

[3GScottishUser]

I have taken a picture of two 02 SIMS so that they can be compared.

The attached image shows an 02 GSM SIM placed next to an 02 3G UMTS one.

Sorry that the image is not totally clear but I'm sure you can see the difference.

[Ben]

Cool, thanks! Though it does look like you took that picture while whizzing along inside a tumble dryer

Never thought to put SIM pics up!

Originally Posted by 3GScottishUser

Sorry that the image is not totally clear but I'm sure you can see the difference.

Yep, they've been made by different manufacturers.

The actual SIMs are not really substantially physically different, so far as I am aware, but the authentication information stored on them definitely is.

Cheers,
Jez

I recently got a Samsung Z500 on O2, and a new SIM card. When I tried by old 2.5G sim in the Samsung I got a sim card error message. However, I have been able to use the 3g sim card very happily in 2.5g handsets. So I take it 3g sim cards are backwards compatable.

Well... I hate i put a pin to a balloon, but my O2 sim (2G) is identicle to the UMTS one. I wonder if it is some sort of software on the chip which makes the difference?

[miffed]

Well when I put my wifes 2.5g (PAYG) sim into my moto a925 I got instant 3G - so while there may be differences in the sims , whether or not that makes a blind bit of difference in the real world is another matter

Why ? - thats what we have to ask ourselves - My Voda example prooves the was no NEED to change the sim format , I think the whole "USIM's for 3G devices and SIM's for 2G and never the twain shall meet" was , yet again , Twoddle put about by an insecure H3G to discourage people from unlocking their phones on discovery of their poor service

Remember all the stories ? "put a USIM in your 2G phone and you'll fry it man !!!! " and everything short of "if you try to use a 2G sim in a 3G handset planes will fall out of the sky " when in reality , all that would happen is H3G would lose a few quid

So how many "fried phones" have we heard about ? none !

This is yet another example of how Three are unable to compete on an even playing field , so choose to use deceit ! booo !

Rant over