ROBUST UNICAST/BROADCAST/MULTICAST COMMUNICATION PROTOCOL

• US 20140119268A1
• Filed: 01/06/2014
• Published: 05/01/2014
• Est. Priority Date: 12/31/2008
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: Chu, Liwen, Vlantis, George A.
• Granted Patent: US 9,538,525 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04L 12/43 with synchronous transmission, e.g. time division multiplex [TDM], slotted rings
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02

Abstract

Methods and apparatus for implementing a robust unicast/broadcast/multicast protocol are provided. In one aspect, a method of avoiding collision of intra-basic service set unicast, broadcast or multicast transmissions notifies stations in the basic service set of a reserved transmit opportunity for a unicast, broadcast or multicast transmission. Transmissions from at least one station in the basic service set are deferred until after the reserved unicast, broadcast or multicast transmit opportunity.

Claims

1. A method of avoiding collision of intra-basic service set unicast,

broadcast or multicast transmissions, the method comprising:

notifying, via a central reservation wireless communication device, stations in the basic service set of a transmit opportunity for a reserved time interval for a unicast, broadcast or multicast transmission; and

deferring transmission from at least one station in the basic service set until after the reserved time interval.

2. The method of claim 1 wherein notifying the stations in the basic service set of the transmit opportunity comprises broadcasting an information element related to the transmit opportunity in at least one beacon or action frame to the stations in the basic service set.

3. The method of claim 2 wherein broadcasting an information element related to the transmit opportunity comprises broadcasting at least one of an active indication to indicate whether or not the transmit opportunity is currently enabled, an activation start time to indicate a time when the transmit opportunity will be enabled if the transmit opportunity is not currently enabled, a transmit opportunity type, a source address, a destination address, a service interval, an offset to the service interval, and a duration of the transmit opportunity.

4. The method of claim 1 wherein notifying the stations in the basic service set of the transmit opportunity comprises broadcasting the transmit opportunity using a delivery traffic indication message (DTIM) beacon to stations in the basic service set.

5. The method of claim 1 wherein deferring transmission from at least one station in the basic service set until after the reserved time interval comprises setting a network allocation vector (NAV) in the at least one station in the basic service set to stop frame transmission during the reserved time interval.

6. An access point of an intra-basic service set, comprising:

a transmitter;

a receiver;

a control circuit coupled to the transmitter and the receiver, the control circuit including logic to reserve a unicast, broadcast or multicast transmit opportunity (TXOP) in the intra-basic service set, the logic to reserve the unicast, broadcast or multicast TXOP arranged to direct the transmitter to transmit an information element having fields, the fields including;

an active indication field configurable to indicate whether or not the TXOP is currently enabled;

an activation start time field configurable to indicate a time when the TXOP will be enabled if the TXOP is not currently enabled;

a TXOP type field;

a source address field;

a destination address field;

a service interval field;

an offset to the service interval field; and

a duration of the TXOP field.

7. The access point of claim 6 wherein the control circuit logic to reserve a unicast, broadcast or multicast transmit opportunity (TXOP) is configured to direct the transmitter to transmit the information element during a beacon broadcast and at a time other than during the beacon broadcast.

8. The access point of claim 6 wherein the control circuit logic to reserve a unicast, broadcast or multicast TXOP is configured to set the service interval field to indicate at least one TXOP time interval is being reserved.

9. The access point of claim 6 wherein the control circuit logic to reserve a unicast, broadcast or multicast TXOP is configured to set the service interval field to indicate one TXOP time interval is being reserved in a first transmission and configured to set the service interval to indicate at least two TXOP time intervals are being reserved in a second transmission.

10. The access point of claim 6 wherein the control circuit logic to reserve a unicast, broadcast or multicast TXOP is configured to set the service interval field based on a specific characteristic of the access point.

11. The access point of claim 6 wherein the control circuit logic to reserve a unicast, broadcast or multicast TXOP is configured to adjust the offset to service interval field based on traffic on a transmission medium, the traffic indicated by information received via the receiver.

12. The access point of claim 6 wherein the control circuit logic to reserve a unicast, broadcast or multicast TXOP is configured to set the active indication field to a first value if and only if the unicast, broadcast or multicast TXOP is currently enabled and configured to set the active indication field to a second value if the unicast, broadcast or multicast TXOP is not currently enabled.

13. The access point of claim 12 wherein the control circuit logic to reserve a unicast, broadcast or multicast TXOP is configured to set the activation start time field when the TXOP will be enabled if the active indication field is set to the second value.

14. The access point of claim 13 wherein the control circuit logic to reserve a unicast, broadcast or multicast TXOP is configured to direct the transmitter to transmit the TXOP information element a plurality of times when active indication field is set to the second value.

15. The access point of claim 6 wherein the control circuit logic to reserve a unicast, broadcast or multicast TXOP is configured to detect an overlapping basic service set using information received via the receiver and configured to set the TXOP type field to a first value or a second value based on the detection.

16. A system including two or more stations and an access point, the two or more stations and the access point formed into an intra-basic service set, the access point configured as a central reservation wireless communication device, the access point, comprising:

a transmitter;

a receiver;

a control circuit coupled to the transmitter and the receiver, the control circuit including logic to reserve a unicast, broadcast or multicast transmit opportunity (TXOP) in the intra-basic service set, the logic configured to direct the transmission of an information element indicating whether or not the TXOP is currently enabled and an activation start time to indicate a time when the TXOP will be enabled if the TXOP is not currently enabled.

17. The system of claim 16 wherein the logic of the control circuit is configured to direct a plurality of transmissions of the information element, at least one transmission during a beacon broadcast and at least one transmission during an action frame.

18. The system of claim 16 wherein the logic of the control circuit is configured to reserve at least two TXOP time intervals.

19. The system of claim 16 wherein the logic of the control circuit is configured to detect traffic on a transmission medium of the intra-basic service set and adjust a service interval offset based on the detected traffic.

20. The system of claim 16 wherein the logic of the control circuit is configured to detect an overlapping basic service set and configured to set a TXOP type field based on the detection.