VoIP and native carrier call integration

1. A method, comprising:

receiving, at a switch in a mobile operator network, an incoming call for a mobile device;

querying a convergence gateway from soft switch via an application programming interface (API) at the convergence gateway to determine a current call state of the mobile device;

delivering the incoming call via the soft switch over IP as a VoIP call to a VoIP calling software application on the mobile device if the mobile device is not currently engaged on a VoIP call; and

delivering the incoming call as a second VoIP call via the VoIP calling software application, if the mobile device is currently engaged on a VoIP call.

2. The method of claim 1 , further comprising providing call waiting, call hold, call swap, or call joining at the mobile device using the VoIP calling software application.

3. The method of claim 1 , further comprising delivering a second incoming call via a mobile operator network as a native call to the mobile device, and providing call waiting, call hold, call swap, or call joining at the mobile device using operator network-assisted native call functions.

4. The method of claim 1 , further comprising performing evaluation of the incoming call using a number portability database to determine whether the incoming call is able to be rerouted to a soft switch; and routing the incoming call to the soft switch.

5. The method of claim 1 , wherein the convergence gateway is situated in an operator network as a gateway between a plurality of base stations and a network switching subsystem in a 2G, 3G, or 4G LTE network.

6. The method of claim 1 , wherein the API is enabled to be accessed by the VoIP calling software application on the mobile device for handling VoIP calls and for determining a current call state of the mobile device.

7. The method of claim 1 , wherein the API is enabled to be accessed by an operator core network for handling native calls and for determining a current call state of the mobile device.

8. A non-transitory computer-readable medium comprising instructions which, when executed on a processor at a gateway, cause the gateway to perform steps comprising:

receiving a request to deliver an incoming call;

determining whether a mobile device is currently engaged on a Voice over IP (VoIP) call using a VoIP application on the mobile device;

delivering the incoming call via a mobile switching station in a mobile operator network as a native telephone call to the mobile device, if the mobile device is not currently engaged on a VoIP call;

delivering the incoming call as a second VoIP call via the VoIP application, if the mobile device is currently engaged on a VoIP call; and

enabling an application programming interface (API) to be accessed by the VoIP calling software application on the mobile device for handling VoIP calls and for determining a current call state of the mobile device.

9. The non-transitory computer-readable medium of claim 8 , the steps further comprising providing call waiting, call hold, call swap, or call joining at the mobile device using the VoIP calling software application.

10. The non-transitory computer-readable medium of claim 8 , the steps further comprising delivering a second incoming call via a mobile operator network as a native call to the mobile device, and providing call waiting, call hold, call swap, or call joining at the mobile device using operator network-assisted native call functions.

11. The non-transitory computer-readable medium of claim 8 , the steps further comprising performing evaluation of the incoming call using a number portability database to determine whether the incoming call is able to be rerouted to a soft switch; and routing the incoming call to the soft switch.

12. The non-transitory computer-readable medium of claim 8 , wherein the gateway is situated in an operator network as a gateway between a plurality of base stations and a network switching subsystem in a 2G, 3G, or 4G LTE network.

13. The non-transitory computer-readable medium of claim 8 , the steps further comprising enabling an application programming interface (API) to be accessed by an operator core network for handling native calls and for determining a current call state of the mobile device.