Transmission performance testing
First Claim
1. An apparatus for testing the performance of a CATV transmission system having a headend, a plurality of RF channels, and a plurality of downstream nodes, said downstream nodes receiving program material encoded in radio frequency (RF) signals from the headend on the plurality of RF channels, the apparatus comprising:
- a control unit operatively coupled to the headend of the CATV transmission system;
a measurement device operatively connected to at least one downstream node to measure predetermined parameters of the CATV transmission system on at least one predetermined RF channel; and
wherein the control unit suppresses generation of an RF carrier signal on the predetermined RF channel during a portion of a vertical retrace interval to facilitate measurement of the predetermined parameters by the measurement device, said suppression of the RF carrier signal during the portion of the vertical retrace interval causing no disruption of the program material on the predetermined RF channel as viewed by a subscriber.
3 Assignments
0 Petitions
Accused Products
Abstract
Performance testing of transmission signals to ensure quality and compliance with governmental regulations by limiting interference with intended signals, such as entertainment signals seen by viewers, while reducing the manpower required for testing and eliminating the need for communication between field units and sources of transmission in order to improve traditional performance testing, for example, in Cable Television (CTV) Systems or CATV (Community Antenna TeleVision) Systems, which testing not only has been time consuming but also has required partial disruption of service, and application of these concepts to other modes of information transmission.
39 Citations
20 Claims
-
1. An apparatus for testing the performance of a CATV transmission system having a headend, a plurality of RF channels, and a plurality of downstream nodes, said downstream nodes receiving program material encoded in radio frequency (RF) signals from the headend on the plurality of RF channels, the apparatus comprising:
-
a control unit operatively coupled to the headend of the CATV transmission system;
a measurement device operatively connected to at least one downstream node to measure predetermined parameters of the CATV transmission system on at least one predetermined RF channel; and
wherein the control unit suppresses generation of an RF carrier signal on the predetermined RF channel during a portion of a vertical retrace interval to facilitate measurement of the predetermined parameters by the measurement device, said suppression of the RF carrier signal during the portion of the vertical retrace interval causing no disruption of the program material on the predetermined RF channel as viewed by a subscriber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. A method for testing the performance of a CATV transmission system having a headend, a plurality of RF channels, and a plurality of downstream nodes, said downstream nodes receiving program material encoded in radio frequency (RF) signals from the headend on the plurality of RF channels, the method comprising the steps of:
-
operatively coupling a control unit to the headend of the CATV transmission system;
operatively connecting a measurement device to at least one downstream node;
suppressing generation of an RF carrier signal by the control unit on a predetermined RF channel during a portion of a vertical retrace interval;
tuning the measuring device to a center frequency of a picture carrier of the predetermined RF channel; and
measuring predetermined parameters of the CATV transmission system by the measuring device on the predetermined RF channel, wherein suppression of the RF carrier signal during the portion of the vertical retrace interval causes no disruption of the program material on the predetermined RE channel as viewed by a subscriber.
-
-
20. An apparatus for testing the performance of a CATV transmission system having a headend, a plurality of RF channels, and a plurality of downstream nodes, said downstream nodes receiving program material encoded in radio frequency (RF) signals from the headend on the plurality of RF channels, the apparatus comprising:
-
a control unit operatively coupled to the headend of the CATV transmission system;
a measurement device operatively connected to at least one downstream node to measure predetermined parameters of the CATV transmission system on at least one predetermined RF channel;
means for suppressing generation of an RF carrier signal on the predetermined RF channel during a portion of a vertical retrace interval;
said means for suppressing generation of the RF carrier signal facilitating measurement of the predetermined parameters by the measurement device; and
said suppression of the RF carrier signal during the portion of the vertical retrace interval causing no disruption of the program material on the predetermined RF channel as viewed by a subscriber.
-
Specification