Aero2 is one of the less popular carriers in Poland, mainly because they do not advertise their services. Aero2 has won a frequency tender in which they have been granted 2600 MHz band for LTE, but the company has to provide a free mobile Internet access service until 2014. This free service is called “BDI” – more info about it is only available in polish here. The service itself is nothing fancy, with download speed limited to 512 kbit and PDP context re-set every 30 minutes. Still, as a free service (there is no catches – you only have to pay 20 PLN deposit fee for the SIM card), it is a very good choice for tablet owners.
Unfortunately, not every terminal is compatible with the service. Aero2 is only offering a data plan, without voice telepfony or text messaging. They limit the services at SIM card level, by disabling TS 11 and TS 21 services (see this 3GPP spec to see what the TS and BS services are), and allowing only the BS 70 service (packet data). iPad 2 can use the bearer service, but it does not show signal strength, and very often it goes into “Searching…” or “No service” mode. The weird part is, PDP context is still available even then (PDP context is the logical connection between user’s terminal and an IP network – such as the Internet or internal company network). I have reported this bug to Apple.
EDIT: Apple bug reports are under NDA, so unfortunately I can’t post the Apple Engineering team response.
