Computerized device and method for analyzing signals in a multimedia over coax alliance (MOCA) network and similar TDM / encrypted networks

• US 8,146,125 B2
• Filed: 07/01/2009
• Issued: 03/27/2012
• Est. Priority Date: 07/01/2009
• Status: Active Grant

• Current Assignee: Spirent Communications Incorporated
• Original Assignee: Spirent Communications Incorporated
• Inventors: Dailey, David, Grinkemeyer, Douglas
• Primary Examiner(s): SHEPARD, JUSTIN E
• Application Number:
  US12/496,545
• Publication Number:
  US 20110001833A1
• Time in Patent Office: 1,000 Days
• Field of Search: 725/120
• US Class Current: 725/107
• CPC Class Codes: H04H 20/12 Arrangements for observation, testing or troubleshooting
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/205 jitter monitoring
• CPC Class Codes: H04N 17/004 for digital television systems

Abstract

The present invention relates to testing signals on a coaxial home network that carries a digital video signal. It has direct application to testing so-called Multimedia over Coax Alliance (MoCA) standards-compliant networks and applies to similar networks. In one mode, a computerized device joins the MoCA network and relays signals intended for a set-top-box to the STB. In another mode, the computerized device joins the MoCA network instead of the STB and tests signal strength, attenuation and similar physical layer characteristics.

Claims

1. A method of testing MoCA signals routed to a set-top-box and evaluating performance of the set-top-box, including:

coupling a computerized device to a physical medium, in position between a set-top-box (abbreviated “

STB”

) and a signal source;

the computerized device joining at a physical layer a first MoCA network to which the signal source belongs by emulating at the first physical layer a STB;

the computerized device creating at a physical layer a second MoCA network coupled to the STB by acting as a network controller at the second physical layer;

the computerized device bridging both command and content packets between the first and second MoCA networks, thereby connecting the STB and the signal source;

the computerized device analyzing packets received from the first MoCA network that comprise a video signal to evaluate a quality of the video signal; and

the computerized device reporting the quality of the video signal while bridging the video signal to the STB, whereby a user can view output of the STB on a TV or monitor.

2. The method of claim 1, wherein analyzing the packets received further includes calculating a mean opinion score (abbreviated “

MOS”

) from at least an analysis of packet headers.

3. The method of claim 1, wherein analyzing the packets received further includes calculating a mean opinion score (abbreviated “

MOS”

) from at least an analysis of packet loss and classification of types of lost packets without decryption of encrypted video signals.

4. The method of claim 1, wherein analyzing the packets received further includes calculating a media delivery index (abbreviated “

MDI”

) from analysis at least of packet loss and classification of types of lost packets.

5. The method of claim 1, wherein analyzing the packets received further includes calculating a media delivery index (abbreviated “

MDI”

) from measurement of at least a delay factor and a media loss rate without decryption of encrypted video signals.

6. The method of claim 1, further including using MoCA radio frequency D channels for both the first and second MoCA networks.

7. A method of testing MoCA networks and signals exchanged between a set-top-box and a router and between the set-top-box and additional MoCA enabled devices, including:

coupling a computerized device to a physical medium, in position between a set-top-box (abbreviated “

STB”

) and a signal source;

the computerized device joining at a physical layer a first MoCA network to which the signal source belongs by emulating at the first physical layer a STB;

the computerized device creating at a physical layer a second MoCA network coupled to the STB by acting as a network controller at the second physical layer;

the computerized device bridging packets from the STB to at least one remote MoCA device, the bridged packets including requests for and a streamed video signal;

the computerized device measuring signal bandwidth of packets bridged between first and second networks and calculating dropped and errored packet statistics;

the computerized device analyzing packets received from the first MoCA network that comprise a video signal to evaluate a quality of the video signal; and

the computerized device reporting at least the measured signal bandwidth and a quality of a video signal received from the remote MoCA enabled device.

8. The method of claim 7, wherein at least some of the bridged packets are dumped to computer readable storage media for analysis by a packet analyzer.

9. The method of claim 7, wherein the analyzing for the router and the remote MoCA enabled device are performed on an encrypted signal received without decrypting the encrypted signal.

10. The method of claim 7, wherein analyzing the signal bandwidth to evaluate the quality further includes evaluating a unicast signal at a location of the STB.

11. The method of claim 7, further including analyzing the signal bandwidth to evaluate the quality further includes evaluating a multicast signal at multiple locations, repeating at least the coupling step at the multiple locations.

12. A device used to test MoCA signals routed to a set-top-box and evaluating performance of the set-top-box, including:

first and second MoCA signal processors, in communication with each other, with an effective extent of RF isolation between each other;

a first coaxial port coupled to the first MoCA signal processor and a second coaxial port coupled the second MoCA signal processor;

a display viewable by a user;

logic running on hardware, the hardware coupled to the first and second MoCA signal processors and to the display, the logic adapted to

bridge control and content packets exchanged between first and second MoCA enabled devices that communicate through the first and second coaxial ports, including emulating at a first physical layer the second MoCA enabled device to the first MoCA enabled device and emulating at a second physical layer the first MoCA enabled device to the second MoCA enabled device,

analyze packets received from the first MoCA enabled device that comprise a video signal to evaluate a quality of the video signal, and

report on the display a summary of the quality of the video signal while bridging the video signal packets to the second MoCA enabled device, whereby a user the second MoCA enabled device can view video on a TV or monitor while the quality of the video signal is reported.

13. The device of claim 12, further including second logic running on the hardware, the second logic adapted to calculate a mean opinion score (abbreviated “

MOS”

) from at least an analysis of packet headers.

14. The device of claim 12, further including second logic running on the hardware, the second logic adapted to calculate a mean opinion score (abbreviated “

MOS”

) from at least an analysis of packet loss and classification of types of lost packets without decryption of encrypted video signals.

15. The device of claim 12, further including second logic running on the hardware, the second logic adapted to calculate a media delivery index (abbreviated “

MDI”

) from at least an analysis of packet loss and classification of types of lost packets without decryption of encrypted video signals.

16. A device used to test MoCA signals routed to a set-top-box and evaluating performance of the set-top-box, including:

a first MoCA signal processor;

a first coaxial port coupled to the first MoCA signal processor;

a display viewable by a user;

logic running on hardware, the hardware coupled to the first MoCA signal processor and to the display, the logic adapted to

emulate a properly functioning STB,

analyze signal bandwidth and the packets received from via the first coaxial port to evaluate a quality of packet exchange, and

report on the display a summary of the signal bandwidth and the quality of the packet exchange.

17. The device of claim 16, further including second logic running on the hardware, the second logic adapted to cause the remote MoCA device to send packets comprising a video signal and to calculate a mean opinion score (abbreviated “

MOS”

) from at least an analysis of packet headers.

18. The device of claim 16, further including second logic running on the hardware, the second logic adapted to cause the remote MoCA device to send packets comprising a video signal and to calculate a mean opinion score (abbreviated “

MOS”

) from at least an analysis of packet loss and classification of types of lost packets without decryption of encrypted video signals.

19. The device of claim 16, further including second logic running on the hardware, the second logic adapted to cause the remote MoCA device to send packets comprising a video signal and to calculate a media delivery index (abbreviated “

MDI”

) from at least an analysis of packet headers.

20. The device of claim 16, further including second logic running on the hardware, the second logic adapted to cause the remote MoCA device to send packets comprising a video signal and to calculate a media delivery index (abbreviated “

MDI”

) from at least an analysis of packet loss and classification of types of lost packets without decryption of encrypted video signals.