Method of reliable multicasting

• US 20070064718A1
• Filed: 09/19/2005
• Published: 03/22/2007
• Est. Priority Date: 09/19/2005
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Metke, Anthony, Ekl, Randy
• Granted Patent: US 7,561,599 B2
• Time in Patent Office: Days
• US Class Current: 370/432
• CPC Class Codes: H04L 12/1868 Measures taken after transmission, e.g. acknowledgments
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06

Abstract

Disclosed is a method for reliable multicasting. The method comprises receiving a multicast packet, sending a first acknowledgement for having received the multicast packet, and receiving a second acknowledgement in response to having sent the first acknowledgement.

Claims

1. A method for reliable multicasting, wherein the method comprises:

receiving a multicast packet;

sending a first acknowledgement for having received the multicast packet; and

receiving a second acknowledgement in response to having sent the first acknowledgement.

2. The method of claim 1 wherein the multicast packet adheres to IP multicasting protocols.

3. The method of claim 1 wherein the first acknowledgement is an asynchronous unicast acknowledgement message.

4. The method of claim 1 wherein at least one of the first acknowledgement and the second acknowledgement is an application layer message.

5. The method of claim 1 further comprising sending an indication that reliability is required, prior to the steps of receiving, sending, and receiving.

6. The method of claim 1 wherein the steps of receiving, sending, and receiving, are performed by a station.

7. The method of claim 1 further comprising maintaining knowledge of a relationship between the multicast packet, the first acknowledgement, and the second acknowledgement.

8. The method of claim 1 further comprising receiving a second multicast packet before the step of sending a first acknowledgment;

and

sending a third acknowledgement for having received the second multicast packet.

9. A method for reliable multicasting in a wireless local area network (WLAN), wherein the WLAN adheres to an IEEE 802 protocol, wherein the method comprises:

at a station in the WLAN;

sending an indication to an access point in the WLAN that reliability is required for multicast packets sent by the access point;

receiving a multicast packet from the access point;

sending a first acknowledgement for having received the multicast packet to the access point; and

receiving a second acknowledgement in response to having sent the first acknowledgement from the access point.

10. The method of claim 9 wherein the indication is an enhanced IGMP join message.

11. The method of claim 9 further comprising indicating reliability for a specific multicast group address.

12. The method of claim 9 wherein the first acknowledgement is an asynchronous unicast acknowledgement message.

13. The method of claim 9 wherein at least one of the first acknowledgment and the second acknowledgement specify the multicast packet.

14. The method of claim 9 wherein the second acknowledgement is an atomic acknowledgment message.

15. The method of claim 9 further comprising retransmitting the first acknowledgement upon expiration of a second acknowledgement wait time.

20. The method of claim 15 wherein indicating further comprises at least one of a) receiving an enhanced IGMP message from the station, b) maintaining knowledge of specific multicast group addresses that require reliability, and c) preconfiguring multicast group addresses to require reliability.

16. A method for reliable multicasting in a wireless local area network (WLAN), wherein the WLAN adheres to an IEEE 802 protocol, wherein the method comprises:

at an access point in the WLAN;

indicating that reliability is required for multicast packets sent by the access point;

sending a multicast packet to the station;

receiving a first acknowledgement from the station for the sent multicast packet; and

sending a second acknowledgement to the station in response to having received the first acknowledgement.

17. The method of claim 16 further comprising retransmitting the multicast packet to the station at an expiration of a first acknowledgement wait time.

18. The method of claim 16 further comprising maintaining knowledge of stations in the WLAN that require reliability after the step of receiving of an indication.

19. The method of claim 16 further comprising retransmitting the second acknowledgement to the station upon receipt of a retransmitted first acknowledgement.