Systems and methods for reliable broadcast and multicast transmission over wireless local area network
View Patent ↗Broadcast and multicast (BM) systems have not been reliable in the wireless local area networks. Higher bandwidth and more reliable BM transmissions are necessitated by video and audio applications. A class of BM reliable frames is transmitted at a higher rate. The access point performs some rudimentary collision avoidance to enhance reliability, and individual stations are given the ability to send feedback to the access point regarding the quality of the transmission.
1. A method for broadcasting a data burst, the method comprising:
marking each of a first number of frames in the data burst to identify each frame of the first number of frames as a reliable broadcast/multicast (RBM) frame, wherein a second number of frames in the data burst are broadcast/multicast (BM) frames not marked to be identified as the RBM frame;
transmitting a message to a station for collision avoidance;
receiving a response to the message from the station;
transmitting each RBM frame in the data burst separated by a short interframe space (SIFS) only after the transmitting of the message and the receiving of the response; and
transmitting each BM frame in the data burst separated by the SIFS before or after the transmitting of the message.
2. The method of claim 1 , wherein the message is a request to send frame and the response is a clear to send frame.
3. The method of claim 1 , wherein the message is a NULL frame and the response is an acknowledgement frame.
4. The method of claim 1 , wherein the message is a data frame and the response is an acknowledgement frame.
5. The method of claim 1 , wherein the transmitting of each RBM frame is at a higher physical layer (PHY) rate than the transmitting of each BM frame.
6. The method of claim 5 , wherein the higher PHY rate is adjusted based on receiving a RBM feedback frame.
7. The method of claim 6 , wherein the RBM feedback frame comprises a packet error rate (PER).
8. The method of claim 6 , wherein the RBM feedback frame comprises a received signal strength indication (RSSI).
9. The method of claim 6 , wherein the RBM feedback frame comprises report a suggested PHY rate.
10. The method of claim 6 , wherein the RBM feedback frame comprises a modulation coding scheme (MCS).
11. The method of claim 1 further comprising:
if the response is not received, waiting a backoff period; and
if the response is not received, retransmitting the message.
12. The method of claim 1 wherein the transmitting each frame occurs after the transmission of a delivery traffic indication map (DTIM) beacon frame.
13. A method for broadcasting a reliable broadcast/multicast (RBM) burst, the method comprising:
marking each frame in the RBM burst to identify each frame as reliable;
transmitting a message to a station for collision avoidance;
receiving a response from the station; and
transmitting each frame in the RBM burst separated by a short interframe space (SIPS) after receiving the response;
wherein the transmitting each frame begins after a set interval after a target beacon transmission time (TBTT), wherein the set interval is equal to an RBM transmit opportunity (TXOP) start interval plus a non-negative multiple of an RMB TXOP service interval.
14. The method of claim 13 , wherein the RBM TXOP service interval and the RBM TXOP start interval are announced in a beacon frame or transmitted in a probe response.
15. An access point configured for broadcasting a data burst, said access point comprising:
a processor;
a wireless network interface device; and
a memory comprising instructions;
said instructions causing the processor to:
mark each of a first number of frames in the data burst to identify each frame of the first number of frames as a reliable broadcast/multicast (RBM) frame, wherein a second number of frames in the data burst are broadcast/multicast (BM) frames not marked to be identified as the RBM frame;
cause the wireless network interface device to transmit a message to a station for collision avoidance;
cause the wireless network interface device to receive a response to the message from the station;
cause the wireless network interface device to transmit each RBM frame in the data burst separated by a short interframe space (SIFS) only after the transmitting of the message and the receiving of the response; and
cause the wireless network interface device to transmit each BM frame in the data burst separated by the SIFS before or after the transmitting of the message.
16. The access point of claim 15 , wherein the message is a request to send frame and the response is a clear to send frame.
17. The access point of claim 15 , wherein the message is a NULL frame or a data frame and the response is an acknowledgement frame.
18. The access point of claim 15 , wherein the instructions cause the processor to transmit through the wireless network interface device each RBM frame on the broadcast or multicast burst at a higher PHY rate than each BM frame.
19. The access point of claim 18 , wherein the higher PHY rate is adjusted based on receiving a reliable broadcast/multicast feedback frame.
20. The access point of claim 19 , wherein the RBM feedback frame comprises a PER, an RSSI, a suggested PHY rate, an MCS, or a combination thereof.
21. The access point of claim 15 , wherein if no response is received, the instructions cause the processor to wait a backoff period and to cause the wireless network interface device to retransmit the message.
22. The access point of claim 15 , wherein the processor causes the wireless network interface device to transmit the first frame of the RBM burst after the transmission of a DTIM beacon frame.
23. An access point configured for broadcasting a reliable broadcast/multicast (RBM) burst, the access point comprising:
a processor;
a wireless network interface device; and
a memory comprising instructions;
said instructions causing the processor to:
mark each frame in the RBM burst to identify each frame as reliable;
cause the wireless network interface device to transmit a message to a station for collision avoidance;
cause the wireless network interface device to receive a response to the message from the station; and
cause the wireless network interface device to transmit each frame in the RBM burst separated by a short interframe space (SIFS) after receiving the response;
wherein said instructions causing the processor to cause the wireless network interface device to begin transmitting each frame of the RBM burst after a set interval after a target beacon transmission time (TBTT), wherein the set interval is equal to an RBM transmit opportunity (TXOP) start interval plus a non-negative multiple of an RMB TXOP service interval.
24. The access point of claim 23 , wherein the RBM TXOP service interval and the RBM TXOP start interval are announced in a beacon frame or transmitted in a probe response.
25. A method for broadcasting a reliable broadcast/multicast (RBM) burst, the method comprising:
marking each frame in the RBM burst to identify each frame as reliable;
transmitting a message to a station for collision avoidance;
receiving a response to the message from the station; and
transmitting each frame in the RBM burst separated by a short interframe space (SIFS) after receiving the response;
wherein the message is a NULL frame and the response is an acknowledgement frame.
26. An access point configured for broadcasting a reliable broadcast/multicast (RBM) burst, the access point comprising:
a processor;
a wireless network interface device; and
a memory comprising instructions;
said instructions causing the processor to:
mark each frame in the RBM burst to identify each frame as reliable;
cause the wireless network interface device to transmit a message to a station for collision avoidance;
cause the wireless network interface device to receive a response to the message from the station; and
cause the wireless network interface device to transmit each frame in the RBM burst separated by a short interframe space (SIFS) after receiving the response;
wherein the message is a NULL frame and the response is an acknowledgement frame.