Method and Apparatus for Using the Video Blanking Period for the Maintenance of a Modem that is Used for Wireless Transmission of Video

• US 20070171304A1
• Filed: 01/04/2007
• Published: 07/26/2007
• Est. Priority Date: 01/06/2006
• Status: Active Grant

• Current Assignee: Amimon Limited (Vitec Group PLC)
• Original Assignee: Amimon Limited (Vitec Group PLC)
• Inventors: Elnathan, Nathan, Freundlich, Shay, Feder, Meir, Reznic, Zvi
• Granted Patent: US 8,365,238 B2
• Time in Patent Office: Days
• US Class Current: 348/473
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04N 17/00 Diagnosis, testing or measuring for television systems or their details
• CPC Class Codes: H04N 7/083 with signal insertion during the vertical and the horizontal blanking interval , e.g. MAC data signals
• CPC Class Codes: H04N 7/088 the inserted signal being digital

Abstract

The vertical blanking period is an idle period in video transmission that was originally intended for allowing the trace back of an electron beam to its point of origin. When sending the video signal over a wireless channel, the wireless channel may remain free of transmission of data during this period. However, in wireless transmission of a video signal in general, and in the transmission of an essentially uncompressed video signal in particular, there is a need to use all the bandwidth available, especially when transmitting a high-definition video signal. Therefore, a method is taught for using the vertical blanking period of a video signal for modem maintenance.

Claims

1. A method for maintenance of a modem that sends a video signal over a wireless channel, wherein the maintenance is performed during blanking periods, comprising the steps of:

checking for a vertical blanking period in a video frame of said video signal;

performing modem maintenance activities during the vertical blanking period; and

repeating the steps of the method for each subsequent video frame as required for modem maintenance.

2. The method of claim 1, said blanking periods comprising:

a vertical blanking period and a horizontal blanking period.

3. The method of claim 2, said vertical blanking period and said horizontal blanking period comprising a portion of time when no video signal is transmitted.

4. The method of claim 1, the step of performing modem maintenance comprising any of:

performing at least one modem maintenance activity; and

performing at least a portion of a modem maintenance activity.

5. The method of claim 1, the step of performing modem maintenance comprising at least:

transmitting a plurality of preambles, wherein each preamble comprises at least data for performing the modem maintenance activities.

6. The method of claim 5, said data for performing the modem maintenance activities comprising any of control signals, auxiliary signals, synchronization signals, and management signals.

7. The method of claim 5, the modem maintenance activities comprising any of signal detection, synchronization, automatic gain control, transmitter power control, dynamic frequency selection, high-bandwidth digital content protection key resolution, identification of channels used by other transmitters, and channel estimation.

8. The method of claim 1, further comprising the step of:

transmitting uplink data during the vertical blanking period.

9. The method of claim 8, the uplink data comprising extended display identification data.

10. The method of claim 8, the uplink data comprising data transmitted from a video display unit (VDU) to a video source unit (VSU).

11. The method of claim 6, further comprising the step of:

transmitting audio signals during the vertical blanking period.

12. The method of claim 11, further comprising the step of:

keeping the wireless channel free of any signal transmission during a portion of the vertical blanking period.

13. A video frame structure used for transmission of video data over a wireless channel, comprising:

a first portion of a vertical blanking period during which a plurality of preambles are transmitted; and

a video data portion during which a video signal is transmitted.

14. The video structure of claim 13, further comprising a second portion of the vertical blanking period during which uplink data are transmitted.

15. The video frame structure of claim 13, the plurality of preambles comprising data for performing modem maintenance activities.

16. The video frame structure of claim 15, the modem maintenance activities comprising of signal detection, synchronization, automatic gain control, transmitter power control, dynamic frequency selection, high-bandwidth digital content protection key resolution, and identification of channels used by other transmitters.

17. The video frame structure of claim 13, the uplink data comprising data transmitted from a video display unit (VDU) to a video source unit (VSU).

18. The video frame structure of claim 16, wherein the wireless channel is kept free of any signal transmission during a portion of the second vertical blanking period.

19. A method for enabling a modem that sends a video signal over a wireless channel to establish the wireless channel for each video frame, comprising the steps of:

transmitting a plurality of preambles during a vertical blanking period;

establishing a wireless channel using data encapsulated in the preambles; and

sending a video data over the wireless channel.

20. The method of claim 19, said data encapsulated in the preambles comprising any of control signals, auxiliary signals, synchronization signals, and management signals.

21. The method of claim 19, the step of establishing said wireless channel comprising the step of performing at least modem maintenance activities.

22. The method of claim 21, the modem maintenance activities comprising any of signal detection, synchronization, automatic gain control, transmitter power control, dynamic frequency selection, high-bandwidth digital content protection key resolution, and identification of channels used by other transmitters.