METHOD AND DEVICE FOR LOW LATENCY GROUP-ADDRESSED STREAMING

• US 20170244769A1
• Filed: 02/23/2017
• Published: 08/24/2017
• Est. Priority Date: 02/23/2016
• Status: Active Grant

• Current Assignee: Sennheiser Electronic GmbH & Company KG
• Original Assignee: Sennheiser Electronic GmbH & Company KG
• Inventors: Cauduro Dias de Paiva, Rafael, Fischer, Daniel
• Granted Patent: US 10,375,134 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method of low latency group-addressed audio/video streaming in an IEEE 802.11 wireless network is provided. A data stream from at least one access point is transmitted to a plurality of wireless receiving stations as multicast traffic. The data stream comprises beacon frames at beacon intervals. Data packets of the data stream from the at least one access point are transmitted to a plurality of wireless receiving stations as multicast traffic as soon as available for transmission. The transmission of data packets that were transmitted during a previous beacon interval is repeated during a subsequent beacon interval as multicast traffic.

Claims

1. A method for low latency group-addressed streaming in an IEEE 802.11 wireless network, executed by an access point device, comprising the steps of:

transmitting a data stream from the access point device to a plurality of wireless receiving stations as multicast traffic,

wherein the data stream comprises beacon frames at beacon intervals;

detecting that at least one of the wireless receiving stations is in power save mode or sleep mode; and

upon said detecting;

transmitting data packets of the data stream from the access point to the plurality of wireless receiving stations as multicast traffic as soon as the data packets are available for transmission and during a first beacon interval, and

repeating transmission of the data packets that were transmitted during the first beacon interval during a subsequent second beacon interval and after a beacon frame of the second beacon interval as multicast traffic.

2. The method according to claim 1, wherein the beacon frame of the subsequent second beacon interval comprises a Delivery Traffic Information Map (DTIM) message.

3. The method according to claim 1, wherein transmission of additional data packets comprised in one or more further beacon intervals as multicast traffic is also repeated during the second beacon interval and after said beacon frame, the one or more further beacon intervals being after the first beacon interval and before the second beacon interval.

4. The method according to claim 3, wherein the data packets whose transmission is repeated during the second beacon interval are grouped into a block of repeated data, and the block of repeated data is transmitted after said beacon frame of the second beacon interval and before the first data packet that has not been transmitted in any earlier beacon interval.

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

buffering those data packets of the data stream that were transmitted during the first beacon interval in the access point such that they can be transmitted during the second beacon interval and after the next beacon frame comprising a Delivery Traffic Information Map.

6. The method according to claim 1, wherein the plurality of wireless receiving stations comprises a first and a second set of receiving station,

wherein receiving stations of the first set of receiving stations are not in a power saving mode,

wherein receiving stations of the second set of receiving stations are in a power saving mode,

wherein data packets of the data stream are transmitted to the first set of wireless receiving stations as multicast traffic as soon as they arrive in the access point and before the access point transmits any beacon frame, and

wherein those data packets of the data stream that were transmitted during the first beacon interval are transmitted to the second set of wireless receiving stations as multicast traffic during the second beacon interval after the second beacon frame, and wherein the second set of wireless receiving stations awakes after the second beacon frame so that it is able to receive the re-transmitted data packets.

7. The method according to claim 1, wherein the access point is a simple client station which is capable of sending data directly to other stations through the network.

8. A device for low latency group-addressed streaming, the device being operable as an access point in an IEEE 802.11 wireless network, the network further comprising a plurality of wireless receiving stations, the device comprising:

a transmitter unit adapted to wirelessly transmit a data stream to the plurality of wireless receiving stations as multicast traffic, the data stream comprising beacon frames at beacon intervals; and

a detector unit adapted to detect that at least one of the wireless receiving stations is in power save mode or sleep mode,

wherein the transmitter unit is further adapted to transmit data packets of the data stream to the plurality of wireless receiving stations as multicast traffic as soon as the data packets are available for transmission and during a first beacon interval, and

wherein the transmitter unit is further adapted to repeat the transmission of said data packets during a subsequent second beacon interval and after transmission of a beacon frame as multicast traffic if the detector unit detected that at least one of the wireless receiving stations is in power save mode or sleep mode.

9. The device according to claim 8, wherein the beacon frame of the second beacon interval comprises a Delivery Traffic Information Map (DTIM) message.

10. The device according to claim 9, wherein at least one further beacon interval exists after the first beacon interval and before the second beacon interval,

wherein none of the beacon frames of said at least one further beacon interval comprises a Delivery Traffic Information Map message,

wherein the transmitter unit is further adapted to transmit further data packets of the data stream to the plurality of wireless receiving stations as multicast traffic as soon as the further data packets are available for transmission and during said at least one further beacon interval, and

wherein the transmission unit is further adapted to repeat the transmission of the further data packets as multicast traffic during said second beacon interval and after transmission of the beacon frame of said second beacon interval.

11. The device according to claim 10, wherein the data packets whose transmission is repeated during the second beacon interval are grouped into a block of repeated data, and

wherein the block of repeated data is transmitted after said beacon frame of the second beacon interval and before the first data packet that has not been transmitted in an earlier beacon interval.

12. The device according to claim 8, further comprising:

a packet buffering unit adapted to buffer data packets at least until said repeated transmission of the buffered data packets.

13. An IEEE 802.11 wireless network, comprising:

at least one device according to claim 8.