Can I access the main radio in a smart phone from an app?

[neela77777]

I am looking to write an app that accesses the main cell radio in a smart phone -- to transmit on allowed frequencies. Do you know if an app can gain access to the radio, to use it as needed? Thank you.

 

[ManiacJoe]

Are you talking about something like phone to phone, without the towers, something like a walkie-talkie?

 

[neela77777]

yes.

 

[ManiacJoe]

Some handsets used to do that. "Push to talk" was the feature.
I would expect that the feature would require its own radio frequencies so that it did not interfere with the normal phone-to-tower communication.

 

[neela77777]

I think the current PTT apps like Zello use the internet to carry the signal around. I am just wondering if I could use the RF antenna on the phone itself to directly communicate with another phone, say, a half-a-mile or a mile away. Is the RF antenna even accessible to an app running on IOS or Android? I think using the correct frequency and avoiding the frequency used by the phone service provider is a matter of detail.