Method and system for selective call routing for transcoder free operation

1. A method for selective call routing, said method comprising:

a switching system receiving a request to originate a call from a first mobile station to a directory number corresponding to a second mobile station, said switching system being connected to a circuit-switched network;

said switching system sending a query to a directory number translation system, said query including said directory number;

said switching system receiving a response from said directory number translation system; and

if said response includes a transcoder-free indication, said switching system forwarding said call to a first gateway, said first gateway being connected to a packet-switched network.

2. The method of claim 1 , further comprising:

said first gateway routing said call through said packet-switched network to a second gateway, said second mobile station operating in a wireless coverage area served by said second gateway.

3. The method of claim 2 , further comprising:

alerting said second mobile station of said call; and

said second mobile station answering said call to establish a transcoder-free communication path between said first mobile station and said second mobile station.

4. The method of claim 3 , further comprising:

said first mobile station and said second mobile station exchanging media in a compressed digital format, via said transcoder-free communication path, without said media being transcoded.

5. The method of claim 4 , wherein said compressed digital format is an Enhanced Variable Rate Coder (EVRC) format.

6. The method of claim 1 , wherein said switching system is a mobile switching center (MSC).

7. The method of claim 6 , wherein said first mobile station is operating in a wireless coverage area provided by a base transceiver station (BTS), and said BTS is communicatively coupled to said MSC via a first base station controller (BSC).

8. The method of claim 7 , wherein said first gateway is communicatively coupled to a second BSC, further comprising:

forwarding said call from said first BSC to said second BSC.

9. The method of claim 1 , further comprising:

said directory number translation system receiving said query; and

in response to said query, said directory number translation system determining whether said call can be transcoder-free; and

if said call can be transcoder-free, said directory number translation system including said transcoder-free indication in said response.

10. The method of claim 9 , wherein said directory number translation system determining whether said call can be transcoder-free comprises:

said directory number translation system determining where said second mobile station is operating.

11. The method of claim 10 , wherein said directory number translation system determines where said second mobile station is operating by querying a home location register (HLR).

12. The method of claim 9 , further comprising:

in response to said query, said directory number translation system determining a routing address based on said directory number; and

said directory number translation system including said routing address in said response.

13. The method of claim 12 , wherein said switching system forwarding said call to a first gateway comprises:

said switching system forwarding said routing address to said first gateway.

14. The method of claim 1 , further comprising:

if said response does not include said transcoder-free indication, said switching system routing said call through said circuit-switched network.

15. A method for selective call routing, said method comprising:

a call connection system sending a query to an information center, said query including a dialed directory number for a call;

said call connection system receiving a response from said information center; and

said call connection system selecting a first communication path for said call if said response includes a transcoder-free indication, said call connection system selecting a second communication path for said call if said response does not include said transcoder-free indication.

16. The method of claim 15 , wherein said first communication path is transcoder-free and said second communication is not transcoder-free.

17. The method of claim 15 , wherein said first communication path includes a packet-switched network and said second communication path includes a circuit-switched network.

18. The method of claim 15 , wherein said call connection system includes a mobile switching center (MSC).

19. The method of claim 15 , wherein said call connection system includes a media gateway and a media gateway controller.

20. A system for selective call routing, said system comprising:

a call connection system for connecting calls to and from at least one mobile station, wherein said call connection system includes a media gateway and a media gateway controller; and

an information center communicatively coupled to said call connection system, wherein said information center determines whether a call from said at least one mobile station to a dialed directory number can be transcoder-free.

21. The system of claim 20 , wherein said call connection system includes a mobile switching center (MSC).

22. The system of claim 20 , wherein said call connection system sends a query to said information center with said dialed directory number in response to a request from said at least one mobile station to originate a call to said dialed directory number.

23. The system of claim 22 , wherein said information center sends said call connection system a response to said query, said response including a routing address.

24. The system of claim 23 , wherein said response includes a transcoder-free indication if said information center determines that said call can be transcoder-free.