Se leggete questo post capite qual'é il problema:
Ok, I finally got to the bottom of what is going on!
When you switch on the iPad and it first negotiates with a cell, it looks for anything faster than 3G and tests to see if there is data, if not it tries 3G and so on until it gets the best possible data connection. However when it connects to a cell after the 1st initialisation, for example when you switch to a new cell, it doesn’t go through this longer negotiation procedure, it just assumes that if there is equipment in the cell for anything faster than 3G it can connect to it.
Some cellular providers are preparing their cells for 4G (or more accurately faster than 3G) but it’s not fully enabled yet. This is confusing the iPad and causing it to lose the data connection. Apple said to me that they are in contact with the cellular providers, their argument is that this is a cell problem and that as more and more 4G capable devices are released there’ll be others with the same problem. However, according to their higher-level tech guys, they are working to see if they can provide a software solution as well.
In the meantime, the only kinda crappy work-around that will actually work is to stop your iPad roaming to a new cell. If you turn off cellular data whilst you move location and then turn it on again, you’ll avoid cell switching and your iPad won’t lock up. This certainly works, unless of course you are somewhere that your iPad hunts between cells even when you are static or if you want to use it whilst moving my car or train. Oh, and if you don’t remember to turn off cellular data before you move to a new location; any of those and you’re stuck with turning off and on again
I do sympathise with Apple a bit, they are leading the way with this technology whilst the other firms learn off their problems. It’s easy to sit back and say “we don’t have a 4G issue” when you don’t actually support 4G at all!
At least Apple are now aware of the issue and are working hard to release some kind of fix. I guess we either wait for it or get a refund. Simples…