METHOD FOR TRANSMISSION OF MBMS CONTROL INFORMATION IN A RADIO ACCESS NETWORK

• US 20110070905A1
• Filed: 09/27/2007
• Published: 03/24/2011
• Est. Priority Date: 10/03/2006
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Vukajlovic, Vera, Kazmi, Muhammad, Baldemair, Robert
• Granted Patent: US 8,547,892 B2
• Time in Patent Office: Days
• US Class Current: 455/507
• CPC Class Codes: H04W 28/20 Negotiating bandwidth
• CPC Class Codes: H04W 72/30 Resource management for broadcast services

Abstract

The present invention relates to multimedia broadcast and multicast services, MBMS, in a cell wherein variable transmission bandwidth is employed. In particular the invention relates to transmission of MBMS control information relating to broadcast and multicast services. According to the method and arrangement of the invention the manner in which the transmission of MBMS control information is performed and/or the content of the MBMS control information is determined based on the amount and the portion of the cell bandwidth that is used for MBMS transmission.

Claims

1. A method in a radio network node for transmission of multimedia broadcast and multicast service (MBMS) control information, in connection to a MBMS service, in a radio access network comprising a radio base station serving a cell wherein variable transmission bandwidth is employed and the cell has a defined maximum transmission bandwidth, said defined maximum transmission bandwidth comprising a full bandwidth, and a defined minimum bandwidth portion of the full bandwidth, the method comprising:

a) dynamically activating transmission of MBMS control information based on an amount and portion of a cell bandwidth that is used for MBMS transmission;

b) modifying content of the MBMS control information based on the amount and the portion of the cell bandwidth that is used for MBMS transmission;

or

c) a combination of a) and b).

2. The method according to claim 1, further comprising:

determining the bandwidth requirement for a MBMS transmission;

positioning the MBMS transmission in the available bandwidth;

determining if more or less than one minimum bandwidth portion is used for the MBMS service; and

if one minimum bandwidth portion or less is used for the MBMS service the MBMS control information is sent in, and only in, the minimum bandwidth portion used for the MBMS service, and if more than one minimum bandwidth portion is used for the MBMS service MBMS control information is sent in more bandwidth portions than the minimum bandwidth portion carrying the major part of the MBMS service.

3. The method according to claim 2, wherein if more than one minimum bandwidth portion is used for the MBMS service the MBMS control information is duplicated in all the minimum bandwidth portions.

4. The method according to claim 2, wherein if more than one minimum bandwidth portion is used for the MBMS service full MBMS control information is provided in the minimum bandwidth portion carrying the greater part of the MBMS transmission and reduced MBMS control information is provided in other minimum bandwidth portion or portions, and the reduced MBMS control information comprises information about where the full MBMS information is positioned in the full bandwidth.

5. The method according to claim 4, wherein the full and reduced MBMS control information are transmitted alternately in respective bandwidth portions at different times.

6. The method according to claim 2, wherein if more than one minimum bandwidth portion is used for the MBMS service first MBMS control information is provided in a first minimum bandwidth portion and comprises full control information for that bandwidth portion, and second MBMS control information is provided in a second minimum bandwidth portion and comprises full control information for that bandwidth portion, and wherein the first MBMS control information comprises an indication of the second control information and the second control information comprises an indication of the first MBMS control information.

7. The method according to claim 6, wherein the first and second MBMS control information are transmitted alternately in respective bandwidth portions at different times.

8. The method according to claim 2, wherein if more than one minimum bandwidth portion is used for the MBMS service the same MBMS control information is transmitted in all bandwidth portions but alternately in different bandwidth portions at different times.

9. The method according to claim 1, wherein unicast, single cell MBMS and multi-cell MBMS services are offered in the same cell.

10. The method according to claim 9, wherein MBMS services are multiplexed in time domain or in frequency domain or combinations thereof.

11. The method according to claim 1, wherein only multi-cell MBMS services are offered in a cell.

12. The method according to claim 1, wherein the minimum bandwidth portion represents the minimum bandwidth requirement of user equipment supported in the cell.

13. The method according to claim 1, wherein the MBMS control information comprises MBMS control channel or MBMS notification or combination thereof.

14. The method according to claim 13, wherein the MBMS notification indicates the modification of MBMS control channel specific to its portion of the cell bandwidth.

15. A method in a user equipment in a cellular radio communication network, said user equipment is operating with a bandwidth, hereinafter referred to as the minimum bandwidth portion, that is smaller than the full bandwidth offered by a cell in which the user equipment is operating in, the user equipment adapted for reception of multimedia broadcast and multicast service transmissions in a variable bandwidth scenario, comprising MBMS control information, the method comprising:

reading the MBMS control information sent in the minimum bandwidth portion where the user equipment is currently tuned for receiving MBMS service;

identifying MBMS services or identities of MBMS services offered in a minimum bandwidth portion or portions where the user equipment is not currently tuned; and

performing frequency reconfiguration or retuning its frequency to the identified other minimum bandwidth portion or portions to receive the corresponding MBMS control information and MBMS service.

16. The method according to claim 15, wherein the user equipment in the reading step reads reduced MBMS control information and performs the frequency reconfiguration or retuning to read full MBMS control information.

17. A radio network node adapted for performing multimedia broadcast and multicast services in a cell wherein variable transmission bandwidth is employed and the cell has a defined maximum transmission bandwidth, hereinafter referred to as the full bandwidth, and a defined minimum bandwidth portion of the full bandwidth, the multimedia broadcast and multicast services comprising transmission of MBMS control information, the radio network node comprising:

a radio communication module adapted for communication with one or more user equipment;

an MBMS module adapted to provide multimedia broadcast services in the cell that the radio network node serves;

a MBMS control information module adapted to handle the control information associated with an MBMS service and to dynamically activate MBMS control information based on bandwidth and position information of a MBMS transmission; and

a MBMS bandwidth determining module in connection with the MBMS control information module, adapted to determine the bandwidth needed for the MBMS transmission and the capabilities of the user equipment which are to receive the MBMS transmission and to position the MBMS transmission in the available bandwidth and to provide the MBMS control information module with the required bandwidth and position information.

18. The radio network node according to claim 17, wherein the MBMS control information module is adapted to determine if more or less than one minimum bandwidth portion is used for an MBMS service;

and if one minimum bandwidth portion or less is used for the MBMS service arrange the MBMS control information to be sent is sent in the minimum bandwidth portion used for the MBMS service, and if more than one minimum bandwidth portion is used for the MBMS service arrange the MBMS control information to be sent in both the minimum bandwidth portions.

19. The radio network node according to claim 18, wherein the MBMS control information module is adapted to arrange the MBMS control information to be duplicated in the minimum bandwidth portions.

20. The radio network node according to claim 18, wherein the MBMS control information module is adapted to provide full MBMS control information in the minimum bandwidth portion carrying the greater part of the MBMS transmission and reduced MBMS control information in other minimum bandwidth portion or portions, and wherein the reduced MBMS control information comprises information about there the full MBMS information is positioned in the full bandwidth.

21. The radio network node according to claim 18, wherein the MBMS control information module is adapted to provide first MBMS control information to be provided in a first minimum bandwidth portion and comprising full control information for that bandwidth portion, and second MBMS control information in a second minimum bandwidth portion and comprising full control information for that bandwidth portion, and wherein the first MBMS control information comprises an indication of the second control information and the second control information comprises an indication of the first MBMS control information.

22. The radio network node according to claim 21, wherein MBMS module is adapted to transmit the first and second MBMS control information in respective bandwidth portions at different times.

23. The radio network node according to claim 17, wherein the MBMS module is adapted to provide both unicast, single cell MBMS and multi-cell MBMS services.

24. The radio network node according to claim 17, wherein the MBMS module is adapted to multiplex the MBMS services in time domain or in frequency domain or combinations thereof.

25. A user equipment for operating with a bandwidth, the bandwidth comprising a minimum bandwidth portion, that is smaller than a full bandwidth offered by a cell in which the user equipment operates, the user equipment comprises comprising:

a radio communication module for reception of multimedia broadcast and multicast service transmissions in a variable bandwidth scenario;

an MBMS receiving module in connection with the radio communication module wherein the MBMS receiving module

reads MBMS control information in a minimum bandwidth portion to which the user equipment is currently tuned,

identifies MBMS services or identities of MBMS services offered in the current minimum bandwidth portion or another portion, and

instructs the radio communication module to perform frequency reconfiguration or retune its reception to another minimum bandwidth portion if identified that relevant MBMS control information or services are present in another minimum bandwidth portion than the current minimum bandwidth portion.