Mobile device call management with multiple over-the-top calls

A mobile device, comprising:

• one or more communication interfaces;
• and
• a processing unit configured to execute an operating system (OS) call manager and an over-the-top (OTT) calling application (app) and further configured to:
• receive, via the one or more communication interfaces by the OTT calling app, a notification for a first OTT call,
• send, by the OTT calling app, an internal notification to the OS call manager, wherein the internal notification notifies the OS call manager of the first OTT call,
• assign, by the OS call manager, shared device resources of the mobile device to the first OTT call,
• receive, via the one or more communication interfaces by the OTT calling app, a notification for a second OTT call,
• send, via the one or more communication interfaces, from the OTT calling app to an OTT Telephony Application Server (TAS) without notifying the OS call manager of the second OTT call, a request to switch from the first OTT call to the second OTT call,
• identify, by the OTT calling app, the first OTT call as inactive and the second OTT call as active, and
• allocate, by the OTT calling app, the shared device resources assigned to the first OTT call, to the second OTT call.

A non-transitory storage medium storing instructions executable by a mobile device, wherein the instructions comprise instructions to cause the mobile device to:

• execute an operating system (OS) call manager and an over-the-top (OTT) calling application (app);
• receive, by the OTT calling app, a notification for an incoming first OTT call;
• send, by the OTT calling app, an internal notification to the OS call manager, wherein the internal notification notifies the OS call manager of the first OTT call;
• assign, by the OS call manager, shared device resources of the mobile device to the first OTT call;
• receive, by the OTT calling app, a notification for an incoming second OTT call;
• send, from the OTT calling app to an OTT Telephony Application Server (TAS) without notifying the OS call manager of the second OTT call, a request to switch from the first OTT call to a second OTT call;
• identify, by the OTT calling app, the first OTT call as inactive and the second OTT call as active;
• and
• allocate, by the OTT calling app, the shared device resources assigned to the first OTT call, to the second OTT call.