Talk:Network compatibility of devices/@comment-172.6.34.78-20150704062927

We are in U.S. and traveling to Germany for 3 weeks. We are trying to decide the best options for both cellular and data needs. Our three phones are actually different... 1. iPhone 4 - Model A1332 with GSM 2. iPhone 5 - Model A1428 LTE without UMTS 1700 3. iPhone 5 - Model A1428 LTE with UMTS 1700 All three phones are AT&T phones that have been UNLOCKED.

I've been looking at the Vodafone SIM card to include both Cell calls and Data needs. But, I have several questions...

1. If I place a combo (cell & data) Vodafone SIM card in my phone (it's my understanding that Vodafone is the best choice for LTE coverage in Germany)  will the Vodafone SIM card be compatible with my UNLOCKED AT&T cell phones?

2. If I place a combo Vodafone SIM Card in my phone, will I be able to use the phone as a mobile hotspot and tether other WIFI enabled devices to my iPhone?

3. If I'm able to do the above, am I also able to make VoIP calls on my iPhone?

4. If I'm NOT able to use a combo Vodafone SIM card in my iPhone that allows me to tether other devices to it and still be able to use it to make phone calls, am I able to simply put a straight DATA SIM card in the iPhone and ONLY use it as a mobile hotspot in order to tether other devices to it?

5. Are there any other carriers that would allow me to do the above?

6. If I can't do any of the above, can I just get a MiFi mobile hotspot, that is GSM compatible, insert an Aldi or Vonafone SIM DATA card and then access the internet/data from my iPhone via wifi to the MiFi mobile hotspot (while using a separate Cell plan/Sim card for calling on the iPhone?