How to receive calls from SIM remotely?

Question

Telephony

Hello.
How to leave the SIM card at home and receive calls according to the algorithm: SIM > Ethernet > Smartphone ?
In theory, I thought about buying a cheap Android smartphone and redirecting any call to a mobile application on iOS (I even thought about a bot for Telegram).
But how difficult is it to implement? Are there ready-made solutions?
PS The operator has no way to make forwarding. And I need an external solution, like a mobile application.

Answer 1

At home, a server computer (was a Raspberry Pi). It includes Huawei E161.
Asterisk works with the chan_dongle module.
Asterisk receives the call and redirects it to another mobile number + a SIP account is called in parallel. If the softphone on iOS is running, the call is accepted there. If it is not started, it is accepted in the classical way.
When a call comes in, the first thing that is sent to the telegram bot is the number of the caller.

Answer 2

The SIM card does not take part in receiving calls, it only serves to identify the client device in the telephone network, therefore your scheme from the question does not make sense (and, moreover, "Ethernet" in it).
You can, for example, set up call forwarding from a mobile number to a number linked to Skype or SIP. This does not even require a switched on phone with the original SIM card - this is done by the operator.

Answer 3

1. We leave, for example, on MTS with a phone number
   
2. We use MTS-connect for calls
   

Answer 4

You need a GSM gateway+Asterisk