Transmission of text/multimedia messages over bearer connections

1. A method of transmitting text/multimedia messages over a bearer interface of a mobile network, the method comprising:

receiving a text/multimedia message in a first network element of the mobile network;

communicating with a second network element of the mobile network using a signaling interface to select a bearer connection on a non-voice circuit-mode bearer interface to use for routing the text/multimedia message to the second network element; and

routing the text/multimedia message to the second network element using the selected bearer connection on the non-voice circuit-mode bearer interface;

wherein if the non-voice circuit-mode bearer interface is not available or not supported then the method further includes:

communicating with the second network element using the signaling interface to select a bearer connection on a voice bearer interface to use for routing the text/multimedia message to the second network element; and

routing the text/multimedia message to the second network element using the selected bearer connection on the voice bearer interface.

2. The method of claim 1 wherein the non-voice circuit-mode bearer interface comprises an Interoperability Specification (IOS) A5 interface.

3. The method of claim 2 further comprising:

formatting the text/multimedia message according to Intersystem Link Protocol (ISLP).

4. The method of claim 1 wherein the voice bearer interface comprises an Interoperability Specification (IOS) A2 interface.

5. The method of claim 4 further comprising:

formatting the text/multimedia message according to 64/56 kbps Pulse Code Modulation (PCM).

6. The method of claim 1 wherein the signaling interface comprises an Interoperability Specification (IOS) A1 interface.

7. A base station system, comprising:

a signaling processor operable to receive a text/multimedia message, to transmit a signaling message request to an Mobile Switching Center (MSC) using a signaling interface to select a bearer connection on a non-voice circuit-mode bearer interface to use for routing the text/multimedia message to the MSC, and to receive a signaling message response from the MSC over the signaling interface indicating a selected bearer connection on the non-voice circuit-mode bearer interface to use for routing the text/multimedia message; and

a bearer processor operable to route the text/multimedia message to the MSC over the selected bearer connection on the non-voice circuit-mode bearer interface;

wherein if the non-voice circuit-mode bearer interface is not available or not supported, then:

the signaling processor is further operable to receive the signaling message response from the MSC over the signaling interface indicating a selected bearer connection on a voice bearer interface to use for routing the text/multimedia message; and

the bearer processor is further operable to route the text/multimedia message to the MSC over the selected bearer connection on the voice bearer interface.

8. The base station system of claim 7 wherein the non-voice circuit-mode bearer interface comprises an Interoperability Specification (IOS) A5 interface.

9. The base station system of claim 8 wherein the bearer processor is further operable to:

format the text/multimedia message according to Intersystem Link Protocol (ISLP).

10. The base station system of claim 7 wherein the voice bearer interface comprises an Interoperability Specification (IOS) A2 interface.

11. The base station system of claim 10 wherein the bearer processor is further operable to:

format the text/multimedia message according to 64/56 kbps Pulse Code Modulation (PCM).

12. The base station system of claim 7 wherein the signaling interface comprises an Interoperability Specification (IOS) A1 interface.

13. A mobile switching center, comprising:

a signaling processor operable to receive a text/multimedia message, to select a bearer connection on a non-voice circuit-mode bearer interface to use for routing the text/multimedia message to a base station system, and to transmit a signaling message to the base station system over the signaling interface indicating the selected bearer connection on the non-voice circuit-mode bearer interface to use for routing the text/multimedia message; and

a bearer processor operable to route the text/multimedia message to the base station system over the selected bearer connection on the non-voice circuit-mode bearer interface;

wherein if a non-voice circuit-mode bearer interface is not available or not supported, then:

the signaling processor is further operable to select a bearer connection on a voice bearer interface for routing the text/multimedia message, and to transmit a signaling message to the base station system over the signaling interface indicating a selected bearer connection on the voice bearer interface to use for routing the text/multimedia message; and

the bearer processor is further operable to route the text/multimedia message to the base station system over the selected bearer connection on the voice bearer interface.

14. The mobile switching center of claim 13 wherein the non-voice circuit-mode bearer interface comprises an Interoperability Specification (IOS) A5 interface.

15. The mobile switching center of claim 14 wherein the bearer processor is further operable to:

format the text/multimedia message according to Intersystem Link Protocol (ISLP).

16. The mobile switching center of claim 13 wherein the voice bearer interface comprises an Interoperability Specification (IOS) A2 interface.

17. The mobile switching center of claim 13 wherein the signaling interface comprises an Interoperability Specification (IOS) A1 interface.