iOS 9 allows us to do phone calls on iPad even when an iPhone is connected to a GSM network and not to a WiFi network, as was necessary in the past, but the functionality goes further than that.
If in iOS 8 the Continuity function required connecting an iPhone or an iPad tablet to the same Wi-Fi network to allow receiving or initiating phone calls on the tablet, or sending text messages, in iOS 9 things are completely different.
In iOS 9 mobile carriers can allow users to make phone calls from the iPad even when the iPhone is connected directly to a GSM data network and not to the same WiFi network as the iPad tablet, but support must be offered by each carrier in part.
Going further than that, the Apple company allows the initiation or acceptance of phone calls from the iPad even when the iPhone terminal is closed, so that if you run out of battery for the terminal, you will still be able to use it for calls.
iOS 9 – now you can make phone calls via iPad or Mac without an active iPhone
The existence of this possibility in iOS 9 reveals the fact that the Continuity function requires a direct collaboration between Apple and the mobile operators, who make the connection between an iCloud account and a phone number.
Basically, in the telephone operator's servers, a phone number is directly linked to an iCloud account, so any call received on it will be transferred directly to an iPad tablet, even if the iPhone on which the function was activated was closed.
Considering that this function of iOS 9 requires a close collaboration between Apple and mobile phone operators, you can imagine that it is still very far from being offered in Romania, so don't get your hopes up.
In the same vein, the WiFi Calling function is not offered in Romania for the same reasons and this will not change soon.
