Method and system for setting up a call in a mobile communication system supporting PTT service

• US 20060246933A1
• Filed: 04/20/2006
• Published: 11/02/2006
• Est. Priority Date: 04/20/2005
• Status: Abandoned Application

• Current Assignee: University of Louisiana At Monroe (Louisiana Board of Regents), Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Yoon, Bo-Young, Kim, Kyu-Yeon, Na, Ho-Taek
• Application Number:
  US11/407,072
• Publication Number:
  US 20060246933A1
• Time in Patent Office: Days
• US Class Current: 455/518
• 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

A method and system for providing a Push-To-Talk (PTT) service in association with a Radio Access Network (RAN) and an Internet Protocol (IP) network are provided. Each of access terminals (ATs) supporting the PTT service is allocated a multicast IP during session setup, and joins in a chat room for a group for the PTT service using a multicast protocol message. Each of access networks (ANs) allocates a shared channel to the RAN to process a group call between ATs in the group if the AT is an AT in the group. A PTT system performs session setup with the AT, allocates information including a multicast IP allocated to the group of the AT during the session setup, and after the session setup, provides the PTT service between the ATs in the group using a routing protocol for the multicast IP in the IP network. Each router configures a multicast tree of the group, and upon receiving transmission data from the AT, transmits the data to the ATs in the group according to the multicast tree.

Claims

1. A method for setting up a call in a mobile communication system supporting a Push-To-Talk (PTT) service in association with a radio access network (RAN) and an Internet Protocol (IP) network, the method comprising the steps of:

(a) if an access terminal (AT) in a group logs on, performing session setup with a server providing the PTT service using a multicast protocol; and

(b) after the session setup, performing a group call between ATs in the group using a shared channel in the RAN between an access network (AN) and the AT.

2. The method of claim 1, wherein the step (a) comprises the steps of:

if the AT logs on the server, analyzing subscriber information of the AT and transmitting group information and setup information including a multicast IP of the group to the AT; and

receiving, by the AT, the multicast IP allocated thereto, and joining in a chat room for the group.

3. The method of claim 2, wherein the chat room joining step comprises the steps of:

configuring a multicast tree using a multicast routing protocol in the IP network;

transmitting, by the AT, a PTT request message for joining in the chat room to the server;

upon receiving the PTT request message, adding, by the server, the AT to the chat room and transmitting a PTT response message to the AT along with session setup information; and

upon receiving the PTT response message, setting up, by the AT, session media using the PTT response message.

4. The method of claim 3, wherein the multicast routing protocol is a Core Based Multicast protocol.

5. The method of claim 4, wherein the Core Based Multicast protocol is an Internet Group Management Protocol (IGMP).

6. The method of claim 2, further comprising the step of allocating a security session key to the AT to guarantee security of the group.

7. The method of claim 1, wherein the step of performing a group call comprises the steps of:

(b1) if a specific AT in the group obtains a floor, receiving a traffic channel allocated from the access network (AN);

(b2) after obtaining the floor, transmitting data to a rendezvous point (RP) router that manages a multicast routing protocol; and

(b3) transmitting, by the RP router, the received data to all ATs having a multicast IP of the group.

8. The method of claim 7, wherein a floor obtaining step comprises the steps of:

transmitting, by the AT, a floor request message to the server;

transmitting, by the server, a floor grant message to the RP router; and

transmitting, by the RP router, the floor grant message to all ATs having the multicast IP of the group.

9. The method of claim 8, wherein the step (b2) comprises the steps of:

transmitting, by the AT, the data to the RP router;

upon receiving the data, transmitting, by the RP router, the received data to all ATs having the same multicast IP; and

transmitting the data to all ATs in the group over the shared channel.

10. The method of claim 8, wherein the floor request message is transmitted using a short data burst (SDB).

11. A system for providing a Push-To-Talk (PTT) service in association with a Radio Access Network (RAN) and an Internet Protocol (IP) network, comprising:

a plurality of access terminals (ATs) supporting the PTT service, for receiving a multicast IP allocated thereto during session setup, and joining in a chat room for a group for the PTT service using a multicast protocol message;

a plurality of access networks (ANs) for allocating a shared channel to the RAN to process a group call between ATs in the group if the AT is an AT in the group;

a plurality of PTT systems for performing session setup with the AT, allocating information including a multicast IP allocated to the group of the AT during the session setup, and after the session setup, providing the PTT service between the ATs in the group using a routing protocol for the multicast IP in the IP network; and

a plurality of routers for configuring a multicast tree of the group, and upon receiving transmission data from the AT, transmitting the data to the ATs in the group according to the multicast tree.

12. The system of claim 11, wherein the PTT system comprises:

a PTT server for managing a session of the ATs in the group, and upon receiving data transmitted by a calling AT in the group, transmitting the data to the routers to provide a group call between the ATs in the group; and

a group list management server (GLMS) for managing a multicast IP pool and a security session key allocated to the group.

13. The system of claim 11, wherein the routing protocol is a Core Based Multicast protocol.

14. The system of claim 13, wherein the Core Based Multicast protocol is an Internet Group Management Protocol (IGMP).