Systems and methods for triggering the transmission of recovery video frames to a video-receiving device over a half-duplex air interface

Patent metadata

Field	Value
Publication number	US-9386252-B2
Application number	US-201414564794-A
Country	US
Kind code	B2
Filing date	Dec 9, 2014
Priority date	Dec 9, 2014
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

An embodiment takes the form of a process that includes transmitting video frames to a receiving device during a first transmission period of one or more time slots of a half-duplex air interface, and receiving feedback messaging from the receiving device during a feedback period of one or more time slots of the half-duplex air interface. The process further includes suspending, after the first transmission period, transmission of video frames for a suspension period of one or more time slots of the half-duplex air interface, and after the feedback period and after the suspension period, transmitting one or more recovery frames to the receiving device during a recovery period of one or more time slots of the half-duplex air interface. The one or more recovery frames collectively include inter-coded macroblock data and/or intra-coded macroblock data.

First claim

What is claimed is:

1. A method comprising:
transmitting video frames to a receiving device during a first transmission period of one or more time slots of a half-duplex air interface;
receiving feedback messaging from the receiving device during a feedback period of one or more time slots of the half-duplex air interface;
after the first transmission period, suspending transmission of video frames for a suspension period of one or more time slots of the half-duplex air interface; and
after the feedback period and after the suspension period, transmitting one or more recovery frames to the receiving device during a recovery period of one or more time slots of the half-duplex air interface,
wherein the one or more recovery frames collectively comprise one or both of (i) inter-coded macroblock data referencing data pertaining to a video frame transmitted during the first transmission period and (ii) intra-coded macroblock data.

2. The method of claim 1 , wherein the feedback messaging is asynchronous feedback messaging, wherein the feedback period is unscheduled.

3. The method of claim 2 , wherein the asynchronous feedback messaging comprises one or more pan-tilt-zoom (PTZ) commands.

4. The method of claim 2 , wherein the feedback period occurs during the first transmission period.

5. The method of claim 4 , wherein suspending transmission of video frames for the suspension period comprises suspending transmission of video frames for the suspension period in response to receiving the feedback messaging from the receiving device during the feedback period.

6. The method of claim 2 , wherein the feedback period occurs after the first transmission period.

7. The method of claim 1 , wherein the feedback messaging is synchronous feedback messaging, wherein the feedback period is scheduled to occur after the first transmission period and during the suspension period.

8. The method of claim 7 , wherein the synchronous feedback messaging comprises one or more adaptive bit rate (ABR) feedback messages.

9. The method of claim 7 , wherein the synchronous feedback messaging comprises one or more session keep-alive messages.

10. The method of claim 7 , wherein a schedule of the feedback period is advertised to receiving devices.

11. The method of claim 1 , wherein:
each video frame transmitted during the first transmission period corresponds to encoding a respective frame from a source video stream, and
suspending transmission of video frames for the suspension period comprises skipping encoding one or more frames from the source video stream.

12. The method of claim 1 , wherein the one or more recovery frames collectively comprise inter-coded macroblock data referencing data pertaining to one or more of the video frames transmitted during the first transmission period.

13. The method of claim 12 , further comprising:
storing a last-known good video frame from among the video frames transmitted to the receiving device during the first transmission period,
wherein the reference data pertaining to one or more of the video frames transmitted during the first transmission period comprises reference data pertaining to the last-known good video frame.

14. The method of claim 13 , further comprising transmitting one or more pre-suspension video frames to the receiving device after storing the last-known good video frame but before suspending transmission of video frames for the suspension period.

15. The method of claim 14 , wherein each of the one or more pre-suspension video frames references a respective immediately preceding video frame.

16. The method of claim 14 , wherein each of the one or more pre-suspension video frames references the last-known good video frame.

17. The method of claim 1 , wherein the one or more recovery frames collectively comprise intra-coded macroblock data.

18. The method of claim 17 , wherein the one or more recovery frames consist of a single intra-coded video frame.

19. The method of claim 17 , wherein the one or more recovery frames comprise multiple recovery frames that include respective different intra-macroblock encoded regions.

20. A system comprising:
a video encoder;
a communication interface;
a processor; and
data storage containing instructions executable by the processor for causing the system to carry out a set of functions, the set of functions including:
transmitting video frames to a receiving device during a first transmission period of one or more time slots of a half-duplex air interface;
receiving feedback messaging from the receiving device during a feedback period of one or more time slots of the half-duplex air interface;
after the first transmission period, suspending transmission of video frames for a suspension period of one or more time slots of the half-duplex air interface; and
after the feedback period and after the suspension period, transmitting one or more recovery frames to the receiving device during a recovery period of one or more time slots of the half-duplex air interface,
wherein the one or more recovery frames collectively comprise one or both of (i) inter-coded macroblock data referencing data pertaining to one or more of the video frames transmitted during the first transmission period and (ii) intra-coded macroblock data.

Assignees

• Motorola Solutions Inc
• Motorola Solutions Inc

Inventors

• Bekiares Tyrone D
• Edwards Mark
• Logalbo Robert D
• Tine Steven D

Classifications

• H04L5/16

  Half-duplex systems; Simplex/duplex switching; Transmission of break signals {non-automatically inverting the direction of transmission} · CPC title

• H04N5/38 Primary

  Transmitter circuitry {for the transmission of television signals according to analogue transmission standards} (H04N5/14 takes precedence) · CPC title

• H04N19/176

  the region being a block, e.g. a macroblock · CPC title

• H04L1/1854 Primary

  Scheduling and prioritising arrangements · CPC title

• H04W28/00

  Network traffic management; Network resource management · CPC title