Method and apparatus for restoring port status in a cable television tap

• US 6,463,588 B1
• Filed: 10/08/1998
• Issued: 10/08/2002
• Est. Priority Date: 10/08/1998
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Scientific-Atlanta Incorporated (Cisco Systems, Inc.)
• Inventors: Su, Sou-Pen, Seol, Jaegyoo, Jenkins, Joel P.
• Primary Examiner(s): Faile, Andrew
• Assistant Examiner(s): BUI, KIEU OANH T
• Application Number:
  US09/168,709
• Time in Patent Office: 1,461 Days
• Field of Search: 725/115, 725/118, 725/127, 348/192, 348/193
• US Class Current: 725/127
• CPC Class Codes: H04L 12/28 characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks] wireless communication networks H04W ; arrangements for dividing the transmission path H04W40/00
• CPC Class Codes: H04N 7/17354 in an intermediate station common to a plurality of user terminals

Abstract

A communication system (100) includes a tap (120) that has an input port (202) for receiving a signal and output ports (225) coupled to the input port (202) for providing the signal to subscriber equipment (125). Each of the output ports (225) has a programmed status comprising either an enabled status or a disabled status. After the statuses have been programmed and the output ports (225) have been set, a controller (210) coupled to the output ports (225) periodically restores the programmed status of the output ports (225) after programmed period of time, thereby automatically resetting inadvertent status changes.

Claims

1. A tap for use in a communication system, the tap comprising:

an input port for receiving a signal;

ports coupled to the input port for providing the signal to subscriber equipment, the ports each having a programmed status comprising an enabled status or a disabled status;

a memory for storing the programmed status of each of the ports;

programming means coupled to the memory for storing the programmed status of each of the ports in the memory; and

a controller coupled to the ports for periodically restoring the programmed status of the ports after a period of time, wherein the controller restores the programmed status based on information stored in the memory,

wherein the memory stores a programmed time value indicative of the period of time after which the controller is to restore the programmed status.

2. The tap of claim 1, further comprising:

a clock for providing time values, wherein the controller references the clock to determine when to restore the programmed status of the ports.

3. The tap of claim 1, wherein each of the ports is associated with a port address, and wherein the programming means comprises:

the input port for receiving a programming command for programming the port status.

4. The tap of claim 3, wherein the programming command comprises:

a programming code that identifies received information as the programming command;

at least one port address associated with at least one port; and

status information indicative of the programmed status,

wherein, in response to reception of the programming command, the controller writes the programmed status into the memory and sets the at least one port associated with the at least one port address in accordance with the programmed status.

5. The tap of claim 4, wherein, in response to reception of the programming command, the controller enables an addressed port in response to the status information indicating the enabled status, and the controller disables an addressed port in response to the status information indicating the disabled status.

6. A communication system for providing signals, the communication system comprising:

a transmitter for transmitting the signals;

a tap coupled to the transmitter for splitting off a portion of the signals; and

receiving equipment coupled to the tap for receiving the portion of the signals, wherein the tap comprises;

an input port for receiving the signals from the transmitter;

first and second output ports coupled to the input port for providing the portion of the signals to the receiving equipment, the first and second output ports each having a programmed status comprising an enabled status or a disabled status;

a memory for storing the programmed status of each of the first and second output ports;

programming means coupled to the memory for storing the programmed status of each of the first and second output ports in the memory; and

a controller coupled to the first and second output ports for periodically restoring the programmed status of the first and second output ports after a period of time, wherein the controller restores the programmed status based on information stored in the memory, and

wherein the memory of the tap stores a programmed time value indicative of the period of time after which the controller is to restore the programmed statuses.

7. The communication system of claim 6, wherein the transmitter comprises headend equipment.

8. The communication system of claim 6, wherein the receiving equipment comprises subscriber equipment.

9. The communication system of claim 6, wherein the communication system comprises a cable television system.

10. The communication system of claim 6, wherein the tap further comprises:

a clock for providing time values, wherein the controller references the clock to determine when to restore the programmed statuses of the first and second output ports.

11. The communication system of claim 6, wherein the first and second output ports of the tap are respectively associated with first and second port addresses, and wherein the programming means comprises:

the input port for receiving a programming command for programming the port status.

12. The communication system of claim 11, wherein the programming command comprises:

a programming code that identifies received information as the programming command;

at least one of the first and the second port addresses to indicate an addressed port; and

status information indicative of the programmed status for the addressed port,

wherein, in response to reception of the programming command, the controller writes the programmed status of the addressed port into the memory and sets the addressed port in accordance with the programmed status.

13. A method in a tap for use in a communication, the tap comprising output ports, each of which is associated with a programmed status, and a controller for setting statuses of the output ports in accordance with the programmed statuses, the method comprising the steps of:

receiving at least one programming command indicative of the programmed statuses;

storing the programmed statuses in a memory of the tap;

setting the statuses of the output ports in accordance with the at least one programming command;

determining that a programmed period of time has expired, wherein the determining step comprises the steps of;

receiving a current time value from a clock included in the tap;

referencing a stored programmed time value, indicative of the programmed period of time, and a stored restore time value, indicative of a previous time at which the controller previously restored the programmed statuses of the output ports; and

restoring the programmed statuses of the output ports in response to determining that the difference between the current time value and the restore time value is greater than or equal to the programmed time value; and

restoring each output port to its programmed status in response thereto.

14. The method of claim 13, wherein the restoring step occurs regardless of whether the programmed statuses of the output ports have been reprogrammed.

15. The method of claim 13, wherein the determining and restoring steps occur regardless of whether further programming commands have been received.

16. The method of claim 13, wherein the restoring step comprises the step of sending control signals to the ports indicative of the programmed statuses.