APPARATUS FOR COLLISION MITIGATION OF MULTICAST TRANSMISSIONS IN WIRELESS NETWORKS

• US 20110096711A1
• Filed: 06/30/2008
• Published: 04/28/2011
• Est. Priority Date: 06/23/2008
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Wu, Minquan, Mathur, Saurabh, Perumanam, Ramkumar, Mandrekar, Ishan, Liu, Hang
• Granted Patent: US 8,462,686 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04W 74/008 with additional processing of random access related information at receiving side
• CPC Class Codes: H04W 74/0816 with collision avoidance

Abstract

Message formats and apparatus are described that reserve access to a communication medium in a multicast system. A first message, a multicast request-to-send message, includes a duration field having information representing the reserved time for a communication medium, multicast receiver and transmitter address fields, and bits that specifies a destination that is expected to reply to the multicast digital message. The bits that specify a destination can be extended to a plurality of fields that each contain different destination identifiers. Example destination identifiers include association identifiers or media access control addresses. Alternately, the bits that specify a destination can have a first field containing an offset and a second field indicating destinations with respect to the offset. A second message includes a duration field and multicast receiver and transmitter address fields. The second message is used to cancel a data transmission resulting from a multicast request-to-send message.

Claims

1. An apparatus comprising:

a device for receiving a multicast digital message, the multicast digital message having a format comprising;

a duration field;

a multicast receiver address field;

a multicast transmitter address field; and

bits specifying a destination that is requested to reply to the multicast digital message.

2. The apparatus of claim 1, wherein the multicast digital message comprises a multicast request-to-send message to reserve time in a communication medium to receive multicast data.

3. The apparatus of claim 1, wherein the bits specifying a destination comprise one of:

a plurality of fields each specifying a single destination; and

a first field having an offset and a second field indicating destinations with respect to the offset.

4. The apparatus of claim 3, wherein the plurality of fields each include a destination identifier comprising one of an association identifier and a media access control address.

5. The apparatus of claim 1, further comprising a frame control field, wherein the frame control field comprises a frame type identification, and the duration field comprises information representing a reservation time for a communication medium.

6. (canceled)

7. (canceled)

8. An apparatus comprising:

a device for receiving a multicast digital message, the digital message having a format comprising;

a duration field;

a multicast receiver address field; and

a multicast transmitter address field;

wherein the multicast digital message acts to cancel a previously received multicast request-to-send message, the previously received multicast request-to-send message comprising a field specifying a destination that is expected to respond to the multicast request-to-send message by transmitting a multicast clear-to-send message.

9. (canceled)

10. (canceled)

11. (canceled)

12. (canceled)

13. (canceled)

14. (canceled)

15. (canceled)

16. (canceled)

17. A computer program storage device containing computer instructions which, when executed, enable processing of a multicast digital message, the digital message having a format comprising:

a duration field;

a multicast receiver address field;

a multicast transmitter address field; and

bits specifying a destination that is requested to reply to the message.

18. The storage device of claim 17, wherein the message comprises a multicast request-to-send message to reserve time in a communication medium to receive multicast data.

19. The storage device of claim 17, wherein the bits specifying a destination comprise one of:

a plurality of fields each specifying a single destination; and

a first field having an offset and a second field indicating destinations with respect to the offset.

20. The storage device of claim 19, wherein the plurality of fields each include a destination identifier comprising one of an association identifier and a media access control address.

21. The storage device of claim 17, further comprising a frame control field, wherein the frame control field comprises a frame type identification, and the duration field comprises information representing a reservation time for a communication medium.

22. A computer program storage device containing computer instructions which, when executed, enable processing of a multicast digital message, the digital message having a format comprising:

a duration field comprising information representing a remaining time that a communication medium is reserved;

a multicast receiver address field; and

,

a multicast transmitter address field;

wherein the digital message acts to cancel a previously received multicast request-to-send message, the previously received multicast request-to-send message comprising a field specifying a destination that is expected to respond to the multicast request-to-send message by transmitting a multicast clear-to-send message.