USB crowned as high speed SIM standard

ETSI has finally agreed a standard for high-speed access to the SIM used in GSM mobile phones, after several years of prevarication and filibustering the winner is...USB.

SIM chips in phones currently communicate with a handset over a serial connection at a speed of 9600bps, which is fine for exchanging cryptographic keys or saving an SMS message to a SIM with a 16KB capacity, but Orange (in France) are already deploying SIMs with a capacity of 128MB, making faster communications essential.

The problem has been that there were two competing standards - one based on MMC (Multimedia Memory Card) and the other on USB (Universal Serial Bus). MMC is easier and cheaper to implement, while USB is more robust and leaves a spare connection on the SIM for other things (such as an NFC antenna connection), and ETSI (the European Telecommunications Standards Institute) has been deadlocked between the options.

Recently, it looked as though MMC would win, and that is the technology which Orange has deployed in anticipation of the standard, but at the last moment SanDisk (manufacturers of various removable memory cards, but not SIMs) stated they owned patents on MMC and would not be happy if it was adopted as a SIM standard. That, combined with the recent merger of the two largest SIM manufacturers, was enough to swing it for USB in the second round of voting: as reported by Card Technology.

It is worth taking a moment to understand the motivations of the different parties involved here:

SanDisk has nothing to gain from high-capacity SIMs, just the reverse as people might be less inclined to use their memory chips, so its effective blocking of MMC could easily be seen as a deliberate attempt to delay any standard being deployed.

The handset manufacturers, who tried to push their own standard at the last minute, also have nothing to gain here as they would much prefer users to store their data on the phone.

So it is only the network operators can gain from using a high-capacity SIM, and they have shown little interest in doing so.

The application deployed by Orange is clever enough: allowing the user to carry the whole user interface with them when they change handsets, including graphics, ring tones and menus, but that requires customised software on the handset too, which is not widely available.

The primary problem seems to be that high-capacity SIMs now exist, and a high-speed interface is needed to use them, so a standard is a good thing. But unless the network operators can think of a compelling application they are not going to force the handset manufacturers to implement the standard - and you can be sure no one is going to support USB on a SIM without being forced to do so. ®