Card tricks: why Apple put a microSIM into the iPad

Amidst the roll call of familiar technology in this morning’s iPad announcement Apple threw a curve ball – the tablet would rely on a ‘microSIM card’ for its connection to 3G mobile phone networks rather than the conventional SIM card.

Coming on the heels of the announcement that the 3G iPad would be sold unlocked and rely on pre-paid mobile broadband rather than a contract mention of what Jobs called “the new GSM microSIM card” went almost unnoticed at first.

But it seems to be a clever maneuver to ensure that at least in the early days iPad buyers will be able to buy their prepaid broadband only from Apple-approved carriers – on the basis that those carriers will be the first to offer microSIM cards.

Also known as 3FF cards (for ‘3rd Form Factor’ as the microSIM follows the original credit card-sized SIM and today’s thumbnail-sized wafer) microSIMs are around half the size of the current SIM card.

Regular SIM meet Micro SIM.

It’s hard to argue that the iPad lacks the physical space for a regular SIM card. After all Apple managed to squeeze one into the iPhone – surely there’s room for one in an device that’s almost three times as large?

It’s more likely that the decision to use a microSIM is intended to ensure that iPad owners can’t take their unlocked iPad then grab the best prepaid mobile broadband deal and slide that carrier’s SIM card into their tablet.

This may seen odd when all four Australian carriers sell the iPhone and are thus likely to do the same for the iPad – but the US is just one country where Apple has signed an exclusivity deal with a single carrier in the form of AT&T.

So while the iPad itself is unlocked early buyers are still locked into AT&T and specifically to AT&T’s Apple-approved data plans which will be tied to the microSIM cards.

UPDATE: here’s an interesting diagram showing the Micro SIM (3FF) format overlaid on a regular SIM card format — potentially useful to cut large size SIM cards down to size. Available in PDF format here.