Ok, this has nothing to do with either the Raspberry Pi or any Android device but I think it may be helpful. At least it is for me.
I own a car with a rather expensive and somewhat “feature rich” hands-free equipment. It is capable of using the normal hands-free profile (HFP) or, and that is my preferred connection method, something called “rSAP” (remote SIM Access Profile). This means that the phone transfers the SIM credentials to the car’s system and this is then acting as a mobile phone with my SIM-card inserted (when, in fact, my SIM card stays in the mobile phone). The advantage of using this profile/technology is that the car uses its own outside antenna thus having less electromagnetic signals inside the car and a much better reception of signals.
As I came to understand the rSAP technology is not much used outside Germany/Europe. In fact, from discussions with friends from the US I came to the conclusion that rSAP is fairly unknown there. Continue reading