Interoperability between different types of wireless networks for push to talk group calls

• US 20080200162A1
• Filed: 02/20/2007
• Published: 08/21/2008
• Est. Priority Date: 02/20/2007
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Chu, Thomas P., Salisbury, Charles, Perzentka, Ping Z., Kadel, Bryan, Chowdhury, Sharmin
• Granted Patent: US 7,974,650 B2
• Time in Patent Office: Days
• US Class Current: 455/422.1
• CPC Class Codes: H04L 12/1836 with heterogeneous network architecture
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04W 4/10 Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 76/45 for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services

Abstract

An exemplary gateway apparatus provides push-to-talk (PTT) communications between users in one network with users in another network where the networks utilize different communication protocols. It includes two protocol modules that interface with the two networks, respectively. The protocol modules are capable of receiving and transmitting messages compatible with the communication protocols used by the associated networks. An interoperability module, connected between the two modules, converts PTT control messages received from one of the networks into PTT control messages compatible with and transmitted to the other network. The PTT control messages received from the one network have a protocol that differs from the protocol of the PTT control messages transmitted to the other network.

Claims

1. A method for providing push-to-talk (PTT) communications between users in first network with users in a second network where the first and second networks utilize different communication protocols, the method comprising the steps of:

utilizing first and second protocol modules of a gateway to interface with the first and second networks, respectively, the first and second protocol modules capable of receiving and transmitting messages compatible with the communication protocols used by the respective first and second networks;

converting, by the gateway, PTT control messages received from one of the first and second networks into PTT control messages compatible with and transmitted to the other of the first and second networks where the PTT control messages received from the one of the first and second networks have a protocol that differs from the protocol of the PTT. control messages transmitted to the other of the first and second networks.

2. The method of claim 1 wherein the converting step is implemented by an interoperability module connected between the first and second protocol modules.

3. The method of claim 1 further comprising the steps of:

determining at the gateway node which one of the first and second networks includes a home server hosting a PTT group call for each talk group, where the home server for a PTT group call can reside in either of the first and second networks;

each of the first and second protocol modules having two selectable interface functions where one interface function supports communications when the associated network includes the home server and the other interface function supports communications when the associated network does not include the home server;

selecting the one interface function for use by the first protocol module and the other interface function for use by the second protocol module based on the determining step determining that the home server is contained in the first network.

4. The method of claim 1 wherein the first protocol module provides a communication interface with an Open Mobile Alliance Push to Talk over Cellular standard and the second protocol module provides a communication interface with an Intra-RF Sub-Systems Interface standard.

5. The method of claim 3 wherein the first protocol module provides a communication interface with an Open Mobile Alliance (OMA) Push to Talk over Cellular (PoC) standard and the second protocol module provides a communication interface with an Intra-RF Sub-Systems Interface standard, the first protocol module having selectable interfaces that function as a PoC controlling server and end user device, the second protocol module having selectable interfaces that function as a radio frequency sub-system (RFSS) home server and an RFSS serving server.

6. The method of claim 4 wherein the first protocol module supports transmission of an audio stream from a user in the first network where the user is not a floor owner thereby providing a losing audio forwarding function.

7. The method of claim 4 wherein the first protocol module supports transmission of audio from a user in the first network where the user speaks before the user'"'"'s handset receives a floor grant from a server thereby providing an early audio detection and forwarding function.

8. The method of claim 1 wherein the first and second networks use different first and second audio codec conversion protocols, respectively, the method further comprising converting by the gateway audio information received with one of the first and second audio codec conversion protocols from a corresponding one of the first and second networks into audio information with the other of the first and second audio codec conversion protocols for transmitting the latter to the other of the first and second networks.

9. The method of claim 1 wherein a predetermined call group includes members in the first and second networks, the method further comprising the first protocol module of the gateway functioning as a PTT server for the members in the first network and determining the identity of a first member in the first network that is a winner within the first network of the right transmit information to other members of a call group, the second protocol module of the gateway receiving from a global PTT server in the second network an identity of a second member in the second network that is a winner within the second network of the right transmit information to other members of the call group, determining by the gateway the one of the first and second members that will be a global winner giving the one member the current right to transmit information to all of the members of the call group in both the first and second networks.

10. A gateway apparatus that provides push-to-talk (PTT) communications between users in first network with users in a second network where the first and second networks utilize different communication protocols, the gateway apparatus comprising:

first and second protocol modules interface with the first and second networks, respectively, the first and second protocol modules capable of receiving and transmitting messages compatible with the communication protocols used by the respective first and second networks;

an interoperability module, connected between the first and second modules, converts PTT control messages received from one of the first and second networks into PTT control messages compatible with and transmitted to the other of the first and second networks, where the PTT control messages received from the one of the first and second networks have a protocol that differs from the protocol of the PTT control messages transmitted to the other of the first and second networks.

11. The gateway apparatus of claim 10 further comprising:

means for determining which one of the first and second networks includes a home server hosting a PTT group call, where the home server for a PTT group call can reside in either of the first and second networks;

each of the first and second protocol modules having two selectable interface functions where one interface function supports communications when the associated network includes the home server and the other interface function supports communications when the associated network does not include the home server;

means for selecting the one interface function for use by the first protocol module and the other interface function for use by the second protocol module based on the determination made by the determining means that the home server is contained in the first network.

12. The gateway apparatus of claim 10 wherein the first protocol module provides a communication interface with an Open Mobile Alliance Push to Talk over Cellular standard and the second protocol module provides a communication interface with an Intra-RF Sub-Systems Interface standard.

13. The gateway apparatus of claim 11 wherein the first protocol module provides a communication interface with an Open Mobile Alliance (OMA) Push to Talk over Cellular (PoC) standard and the second protocol module provides a communication interface with an Intra-RF Sub-Systems Interface standard, the first protocol module having selectable interfaces that function as a PoC controlling server and end user device, the second protocol module having selectable interfaces that function as a radio frequency sub-system (RFSS) home server and an RFSS serving server.

14. The gateway apparatus of claim 12 wherein the first protocol module supports transmission of an audio stream from a user in the first network where the user is not a floor owner thereby providing a losing audio function.

15. The gateway apparatus of claim 12 wherein the first protocol module supports transmission of audio from a user in the first network where the user speaks before the user'"'"'s handset receives a floor grant from a server thereby providing an early audio function.

16. The gateway apparatus of claim 10 wherein the first and second networks use different first and second audio codec conversion protocols, respectively, the gateway apparatus further comprising means for converting audio information received with one of the first and second audio codec conversion protocols from a corresponding one of the first and second networks into audio information with the other of the first and second audio codec conversion protocols before transmitting the latter to the other of the first and second networks.

17. The gateway apparatus of claim 10 wherein a predetermined call group includes members in the first and second networks, the gateway apparatus wherein the first protocol module serves as a PTT server for the members in the first network and determines the identity of a first member in the first network that is a winner within the first network of the right transmit information to other members of a call group, the second protocol module receiving from a global PTT server in the second network an identity of a second member in the second network that is a winner within the second network of the right transmit information to other members of the call group, further comprising means for determining the one of the first and second members that will be a global winner giving the one member the current right to transmit information to all of the members of the call group in both the first and second networks.