NEGOTIATION OF CONTROL OVER A PTT CALL BETWEEN AN OMA PoC NETWORK AND A P25 NETWORK

• US 20090005100A1
• Filed: 06/27/2007
• Published: 01/01/2009
• Est. Priority Date: 06/27/2007
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Copeland, Aileen T.
• Granted Patent: US 8,050,700 B2
• Time in Patent Office: Days
• US Class Current: 455/518
• CPC Class Codes: H04L 65/4038 with floor control
• CPC Class Codes: H04L 65/4061 Push-to services, e.g. push-to-talk or push-to-video

Abstract

Communication networks and methods are disclosed for negotiating control over a PTT call between an OMA PoC network and a P25 network. If an OMA PoC PTT server receives a request for the PTT call from a calling party, then the PTT server transmits a call initiation message for the PTT call to the P25 network offering control over the PTT call to a PTT server in the P25 network. The P25 PTT server processes the call initiation message to identify the offer for control, assumes control over the PTT call, and determines whether the calling or called party has the floor for initial transmission for the PTT call. The P25 PTT server then transmits a response message to the OMA PoC PTT server indicating which one of the calling or called party has the floor. The party granted the floor may then initiate voice communications for the PTT call.

Claims

1. A communication network, comprising:

an Open Mobile Alliance (OMA) Push-to-Talk over cellular (PoC) network having a first Push-to-Talk (PTT) server adapted to serve a calling party;

a Project 25 (P25) network having a second PTT server adapted to serve a called party;

the first PTT server adapted to receive a request for a PTT call from the calling party to the called party, to generate a call initiation message for the PTT call that includes an offer for control over the PTT call to the second PTT server, and to transmit the call initiation message to the second PTT server; and

the second PTT server adapted to receive the call initiation message for the PTT call, to process the call initiation message to identify the offer for control over the PTT call, to determine whether the calling party or the called party has the floor for initial transmission for the PTT call responsive to identifying the offer, to generate a response message that includes an indication as to which one of the calling party or the called party has the floor for initial transmission, and to transmit the response message to the first PTT server.

2. The communication network of claim 1 further comprising:

a gateway between the first PTT server and the second PTT server adapted to convert the call initiation message from a protocol supported by the first PTT server to a protocol supported by the second PTT server, and to convert the response message from the protocol supported by the second PTT server to the protocol supported by the first PTT server.

3. The communication network of claim 1 wherein:

the call initiation message comprises a SIP INVITE message; and

the offer for control over the PTT call comprises an SDP parameter indicating that the first PTT server offers to act as a participating PTT server rather than a controlling PTT server.

4. The communication network of claim 3 wherein the SDP parameter comprises a “

tb_granted”

parameter indicating that the first PTT server offers to act as a participating PTT server rather than a controlling PTT server.

5. The communication network of claim 1 wherein:

the response message comprises a SIP 200 OK message; and

the indication as to which one of the calling party or the called party has the floor for initial transmission comprises an SDP parameter indicating which one of the calling party or the called party has the floor for initial transmission.

6. The communication network of claim 5 wherein the SDP parameter comprises a “

C-I”

parameter indicating which one of the calling party or the called party has the floor for initial transmission.

7. A method of operating an Open Mobile Alliance (OMA) Push-to-Talk over cellular (PoC) network having a first Push-to-Talk (PTT) server adapted to serve a calling party and a Project 25 (P25) network having a second PTT server adapted to serve a called party, the method comprising:

receiving a request for a PTT call from the calling party to the called party in the first PTT server;

generating a call initiation message for the PTT call in the first PTT server that includes an offer for control over the PTT call to the second PTT server;

transmitting the call initiation message from the first PTT server to the second PTT server;

processing, in the second PTT server, the call initiation message to identify the offer for control over the PTT call;

determining whether the calling party or the called party has the floor for initial transmission for the PTT call responsive to identifying the offer;

generating a response message that includes an indication as to which one of the calling party or the called party has the floor for initial transmission; and

transmitting the response message from the second PTT server to the first PTT server.

8. The method of claim 7 further comprising:

converting the call initiation message from a protocol supported by the first PTT server to a protocol supported by the second PTT server; and

converting the response message from the protocol supported by the second PTT server to the protocol supported by the first PTT server.

9. The method of claim 7 wherein:

the call initiation message comprises a SIP INVITE message; and

the offer for control over the PTT call comprises an SDP parameter indicating that the first PTT server offers to act as a participating PTT server rather than a controlling PTT server.

10. The method of claim 9 wherein the SDP parameter comprises a “

tb_granted”

parameter indicating that the first PTT server offers to act as a participating PTT server rather than a controlling PTT server.

11. The method of claim 7 wherein:

the response message comprises a SIP 200 OK message; and

the indication as to which one of the calling party or the called party has the floor for initial transmission comprises an SDP parameter indicating which one of the calling party or the called party has the floor for initial transmission.

12. The method of claim 11 wherein the SDP parameter comprises a “

C-I”

parameter indicating which one of the calling party or the called party has the floor for initial transmission.

13. A communication network, comprising:

a first Push-to-Talk (PTT) network and a second PTT network having different rules for assigning control over PTT calls;

the first PTT network adapted to receive a request for a PTT call from a calling party to a called party, and to transmit a call initiation message for the PTT call to the second PTT network that includes an offer for control over the PTT call to the second PTT network; and

the second PTT network adapted to receive the call initiation message for the PTT call, to process the call initiation message to identify the offer for control over the PTT call, to determine whether the calling party or the called party has the floor for initial transmission for the PTT call responsive to identifying the offer, and to transmit a response message to the first PTT network that includes an indication as to which one of the calling party or the called party has the floor for initial transmission.

14. The communication network of claim 13 wherein the second PTT network has a pre-defined rule that the PTT network serving the called party for a PTT call has control over the PTT call.

15. The communication network of claim 13 wherein:

the first PTT network comprises an Open Mobile Alliance (OMA) Push-to-Talk over cellular (PoC) network; and

the second PTT network comprises a Project 25 (P25) network.

16. The communication network of claim 13 further comprising:

a gateway between the first PTT network and the second PTT network adapted to convert the call initiation message from a protocol supported by the first PTT network to a protocol supported by the second PTT network, and to convert the response message from the protocol supported by the second PTT network to the protocol supported by the first PTT network.

17. The communication network of claim 13 wherein:

the call initiation message comprises a SIP INVITE message; and

the offer for control over the PTT call comprises an SDP parameter.

18. The communication network of claim 17 wherein the SDP parameter comprises a “

tb_granted”

parameter.

19. The communication network of claim 13 wherein:

the response message comprises a SIP 200 OK message; and

the indication as to which one of the calling party or the called party has the floor for initial transmission comprises an SDP parameter.

20. The communication network of claim 19 wherein the SDP parameter comprises a “

C-I”

parameter.