METHOD OF TRANSMITTING AND RECEIVING MULTICAST DATA

• US 20080181161A1
• Filed: 07/18/2007
• Published: 07/31/2008
• Est. Priority Date: 01/25/2007
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lim, Sun Ju, GI KIM, Yang
• Granted Patent: US 8,059,572 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04W 72/30 Resource management for broadcast services

Abstract

The present invention relates to a wireless mobile communication system, and more particularly, to a method of transmitting data to mobile terminals in the wireless mobile communication system capable of transmitting multicast data.

In order to solve the aforementioned problems in the prior art, a method of transmitting data to mobile terminals in a mobile terminal communicating with a network through which multicast data are transmitted. The method of the present invention comprises the steps of transmitting a requesting frame to the network for requesting the multicast data when the start of a multicast service is recognized through an upper layer of the mobile terminal; receiving a response frame from the network in response to the request frame; and receiving the multicast data from the network.

Claims

1. A method of transmitting and receiving multicast data in a network in which a multicast service is provided from a specific network entity and then transmitted to at least one mobile terminal, the method comprising the steps of:

receiving a query message containing information on the multicast service from the network entity;

if a request frame for requesting multicast data is received from the at least one mobile terminal, transmitting to the network entity a report message for allowing the mobile terminal to join the multicast service;

receiving multicast data corresponding to the multicast service from the network entity and transmitting the received multicast data to the at least one terminal;

checking the number of mobile terminals, which have joined the multicast service, based on a group table provided on the network to manage the mobile terminals; and

changing a multicast data transmitting and receiving mode according to the number of terminals which have joined the multicast service.

2. The method as claimed in claim 1, wherein the step of changing a multicast data transmitting and receiving mode comprises the steps of:

comparing the number of joined terminals with a threshold value;

if it is determined that the number of joined terminals is smaller than the threshold value, setting the multicast data transmitting and receiving mode to a wireless communication method using a point-to-point wireless bearer; and

if it is determined that the number of joined terminals is greater than or equal to the threshold value, setting the multicast data transmitting and receiving mode to a wireless communication method using a point-to-multipoint wireless bearer.

3. The method as claimed in claim 2, wherein the threshold value is determined in accordance with the maximum number of channels that can be allocated in a point-to-point manner for each mobile terminal in the network.

4. The method as claimed in claim 3, wherein if the multicast data transmitting and receiving mode is set to the wireless communication method using a point-to-point wireless bearer, the network receives feedback information from the mobile terminal.

5. The method as claimed in claim 4, wherein the feedback information includes at least one or more of channel load, AP channel report, neighbor report, received channel power indicator (RCPI), and received signal to noise indicator (RSNI).

6. The method as claimed in claim 4, wherein the feedback information is real-time transport control protocol (RTCP).

7. The method as claimed in claim 3, wherein the group table includes at least one or more of information on the mobile terminal that requests the multicast service, a multicast MAC address for identifying the multicast service requested by the mobile terminal, information on a group number for identifying at least one mobile terminal, and information on expiration time for allowing information on the mobile terminal to be deleted from the group table when the mobile terminal does not respond to the network.

8. The method as claimed in claim 1, further comprising the steps of:

transmitting to the mobile terminal a request message for confirming whether the mobile terminal exists in the network.

9. The method as claimed in claim 8, wherein the request message is transmitted through any one of a separate action frame, beacon, and multicast data.

10. The method as claimed in any one of claims 1 to 9, wherein the query message and the report message are repeatedly transmitted and received at a predetermined time interval, and information on the mobile terminal, which has joined the multicast service, stored in the group table is updated every time interval.

11. The method as claimed in claim 10, wherein the multicast data transmitting and receiving mode is changed at the predetermined time interval.

12. A method of transmitting and receiving multicast data in a network in which a multicast service is provided from a specific network entity and then transmitted to at least one mobile terminal, the method comprising the steps of:

transmitting to the mobile terminal a request message for confirming whether the mobile terminal exists in the network;

receiving a response message corresponding to the request message from the mobile terminal;

updating a group table provided in the network to manage the mobile terminal according to contents of the response message; and

changing a multicast data transmitting and receiving mode according to the mobile terminal registered in the group table.

13. The method as claimed in claim 12, wherein the response message is any one of a service sustain message for maintaining a joined state to continue receiving the multicast service and a service end message for terminating the joined state to stop receiving the service.

14. The method as claimed in claim 13, wherein the response message contains category, action, multicast MAC address and cause parameters;

and if the response message is the service sustain message or service end message, the cause parameter is set to a code corresponding to the service sustain message or service end message.

15. A method of transmitting and receiving multicast data in a network in which a multicast service is provided from a specific network entity and then transmitted to at least one mobile terminal, the method comprising the steps of:

receiving from the mobile terminal, a transition message provided when the mobile terminal moves between networks; and

updating a group table provided in the network to manage the mobile terminal according to contents of the transition message.

16. The method as claimed in claim 15, wherein the transition message includes a multicast MAC address for identifying the multicast service provided to the moving mobile terminal.

17. A method of transmitting and receiving multicast data in a network in which a multicast service is provided from a specific network entity and then transmitted to at least one mobile terminal, the method comprising the steps of:

receiving from the mobile terminal an association request message transmitted to the network by the mobile terminal; and

updating a group table provided in the network to manage the mobile terminal according to contents of the association request message.

18. The method as claimed in claim 17, wherein the association request message contains a multicast MAC address element including information on a service currently used by the mobile terminal.

19. The method as claimed in claim 17 or 18, further comprising the step of informing a previous network that the mobile terminal has joined a new network.

20. The method as claimed in claim 19, wherein the informing step is performed through a transfer mode using an ADD-notify packet or a MOVE-notify packet.

21. The method as claimed in claim 20, wherein the ADD-notify packet or the MOVE-notify packet contains a multicast MAC address element.

22. A method of transmitting and receiving multicast data in a mobile terminal that receives a multicast service from a specific network entity through an AP, the method comprising the steps of:

transmitting a service activation request frame to the AP to receive the multicast service;

receiving a service activation response frame from the AP; and

receiving data from the AP according to a multicast data transmitting and receiving mode set by the AP,

wherein the multicast data transmitting and receiving mode is determined according to the number of mobile terminals registered in a group table of the AP through the service activation request frame.

23. The method as claimed in claim 22, wherein the service activation request frame contains a multicast MAC address for identifying the multicast service requested by the mobile terminal and information on expiration time for allowing information on the mobile terminal to be deleted from the group table when the mobile terminal does not respond to a network.

24. The method as claimed in claim 22, wherein the multicast data transmitting and receiving mode is set either to a wireless communication method using a point-to-multipoint wireless bearer when the number of mobile terminals registered in the group table is greater than or equal to a threshold value or to a wireless communication method using a point-to-point wireless bearer when the number of mobile terminals registered in the group table is smaller than the threshold value.

25. The method as claimed in claim 24, wherein the mobile terminal transmits feedback information containing any one or more of channel load, AP channel report, neighboring report, received channel power indicator (RCPI), and received signal to noise indicator (RSNI) to the AP, when the multicast data transmitting and receiving mode is set to a wireless communication method using a point-to-point wireless bearer.

26. The method as claimed in any one of claims 22 to 25, further comprising the steps of:

receiving from the AP a request message for confirming whether the mobile terminal exists in the network; and

transmitting a response message in response to the request message.

27. A method of transmitting and receiving multicast data in a mobile terminal that receives a multicast service from a specific network entity through an AP, the method comprising the steps of:

receiving from the AP a request message for confirming whether the mobile terminal exists in a network; and

transmitting a response message for updating a group table provided in the network, in response to the request message.

28. The method as claimed in claim 27, wherein the response message contains category, action, multicast MAC address and cause parameters, and wherein the mobile terminal assigns a service sustain code to the cause parameter when the response message is a service sustain message, and assigns a service end code to the cause parameter when the response message is a service end message, and then transmits the response message to the AP.

29. A method of transmitting and receiving multicast data in a mobile terminal that receives a multicast service from a specific network entity through an AP, the method comprising the step of:

transmitting a transition message for updating a group table provided in a network to manage the mobile terminal when the mobile terminal moves between networks,

wherein the transition message contains a multicast MAC address for identifying the multicast service provided to the moving mobile terminal.

30. A method of transmitting and receiving multicast data in a mobile terminal that receives a multicast service from a specific network entity through an AP, the method comprising the step of:

transmitting an association request message to receive the multicast service when the mobile terminal moves between networks,

wherein a group table provided in the network is updated to manage the mobile terminal according to the association request message.

31. The method as claimed in claim 30, wherein the association request message contains a multicast MAC address element including information on a service currently used by the mobile terminal.