I've been running an experiment for several weeks in an effort to reduce my electronic footprint and increase my privacy/anonymity in my country (Australia). I'm not a tin-foil mad-hatter, I just don't agree with the ways in which Governments and corporations are mishandling and abusing the privacy of citizens. As part of my experiment, I wanted to reduce my trackability by replacing my Android smartphone with an anonymously purchased Nokia dumbphone.
I still need access to my existing phone number, though, so I thought there might be a way to leave my Android phone at my residential address and have incoming phone calls transferred to the new phone. AFAIK, call forwarding/call diverting isn't suitable for my experiment because it's handled by the telco, not the phone, and I don't want to create an identifiable relationship between my personal phone and the new private phone.
I researched developing an Android app that would transfer incoming calls, but I've read apps can't get the low-level access required for the voice channel. I initially imagined it to function like a network router... except without packet headers and more magic. A viable alternative is forwarding the incoming call over VoIP but I have no experience with VoIP, SIP, infrastructure, etc.
I'd enjoy your non-/technical feedback and suggestions