Analog/digital system for television services

• US 5,920,626 A
• Filed: 12/20/1996
• Issued: 07/06/1999
• Est. Priority Date: 12/20/1996
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Scientific-Atlanta Incorporated (Cisco Systems, Inc.)
• Inventors: Wall, William E., Ross, Douglas L., Durden, Gregory S.
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US08/770,515
• Time in Patent Office: 928 Days
• Field of Search: 380/10, 380/19, 380/20, 380/49, 380/50, 380/59, 380/15, 380/9, 380/23, 380/25, 348/6, 348/7, 348/8, 348/9, 348/10, 348/11, 348/12, 455/3.1, 455/3.2, 455/4.1, 455/4.2, 455/5.1, 455/6.1, 455/6.2, 455/6.3
• US Class Current: 380/210
• CPC Class Codes: H04N 21/21 Server components or server architectures
• CPC Class Codes: H04N 21/23 Processing of content or additional data; Elementary server operations; Server middleware
• CPC Class Codes: H04N 7/162 Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing
• CPC Class Codes: H04N 7/169 Systems operating in the time domain of the television signal
• CPC Class Codes: H04N 7/20 Adaptations for transmission via a GHz frequency band, e.g. via satellite

Abstract

A combined IRD scrambler/modulator is provided in a headend. A service provider transmits a digital program signal in a digital data stream to a headend which distributes analog program signal to at least one subscriber. The headend receives an encoded digital program signal in the digital data stream from the service provider and decrypts the digital program signal therefrom. The digital program signal includes an audio and a video portion. The video portion of the signal is scrambled by a scrambler. The digital audio portion of the digital program signal and scrambled video portion of the digital program signal are converted to an analog program signal and transmitted to one or more subscribers.

Claims

1. A headend apparatus for receiving a digital data stream including services from a service provider and transmitting the services to at least one subscriber, said apparatus comprising:

a demodulator, located in a headend, for receiving and demodulating the digital data stream;

a decoder, integrated and combined with said demodulator, including,

a decryptor for decrypting a digital signal in the digital data stream,

a video/audio decoder for recovering a video portion and an audio portion from the decrypted digital signal,

an encoder including a scrambler for scrambling at least a portion of the video portion of the decrypted digital signal, and

a digital to analog converter for converting the decrypted digital signal including the scrambled portion to an analog signal including the scrambled portion; and

a transmitter, integrated and combined with said demodulator and said decoder, for transmitting the analog signal to said at least one subscriber.

2. The headend apparatus according to claim 1, wherein said decoder further comprises a scrambling control circuit for generating scrambling control information and providing the scrambling control information to said scrambler.

3. The headend apparatus according to claim 2, wherein said scrambling control circuit generates sync control information and data to be inserted in a vertical blanking interval of the video portion of the decrypted digital signal, the sync control information and data being provided to said scrambler.

4. The headend apparatus according to claim 2, wherein said scrambling control circuit generates sync control information, and said encoder further includes a sync generator for generating a sync signal based on the sync control information.

5. The headend apparatus according to claim 2, further comprising a secure element for providing decryption information to said decryptor and for providing encryption information to said scrambling control circuit.

6. The apparatus according to claim 5, wherein the encryption information includes subscriber authorization data.

7. The headend apparatus according to claim 1, wherein said transmitter transmits the analog signal over SMATV.

8. The headend apparatus according to claim 1, wherein said transmitter transmits the analog signal over cable.

9. The headend apparatus according to claim 1, wherein said transmitter transmits the analog signal over MMDS.

10. The headend apparatus according to claim 1, wherein said transmitter transmits the analog signal over satellite.

11. A service distribution system comprising:

a service provider for providing program information in a digital program signal and transmitting the digital program signal in a digital data stream;

a headend for receiving the digital data stream, said headend including a combined integrated receiver decoder and scrambler/modulator for receiving and decoding the digital program signal from the digital data stream, the digital program signal including an audio portion and a video portion, said combined integrated receiver decoder and scrambler/modulator scrambling a portion of at least the video portion of the digital program signal and then converting the digital program signal to an analog program signal, the analog program signal including the scrambled portion, and transmitting the analog program signal; and

at least one subscriber station for receiving the analog program signal.

12. The service distribution system according to claim 11, wherein said combined integrated receiver decoder and scrambler/modulator includes:

a demodulator for demodulating the digital data stream;

a decoder including,

a decryptor for decrypting the digital program signal in the digital data stream,

a video/audio decoder for recovering the video portion and the audio portion from the decrypted digital program signal.

an encoder including a scrambler for scrambling a portion of at least the video portion of the decrypted digital program signal, and

a digital to analog converter for converting the decrypted digital program signal including a scrambled portion to the analog program signal including a scrambled portion, and

a transmitter for transmitting the analog program signal to said at least one subscriber.

13. The service distribution system according to claim 12, wherein said service provider includes conditional address control for adding subscriber authorization data to the program information in the digital program signal, wherein said at least one subscriber receives the analog program signal in accordance with the subscriber authorization data therein.

14. The service distribution system according to claim 13, wherein said decoder further comprises a scrambling control circuit for generating scrambling control information and providing the scrambling control information to said scrambler.

15. The service distribution system according to claim 14, wherein the scrambling control circuit generates sync control information and data to be inserted in a vertical blanking interval of the video portion of the decrypted digital program signal, the sync control information and data being provided to said scrambler.

16. The service distribution system according to claim 12, wherein said combined integrated receiver decoder and scrambler/modulator further comprises a secure element for providing decryption information to said decryptor and for providing encryption information to said scrambling control circuit.

17. The service distribution system according to claim 16, wherein the encryption information includes subscriber authorization data.

18. The service distribution system according to claim 11, wherein said headend transmits the analog program signal to said at least one subscriber station over SMATV.

19. The service distribution system according to claim 11, wherein said headend transmits the analog program signal to said at least one subscriber station over cable.

20. The service distribution system according to claim 11, wherein said headend transmits the analog program signal to said at least one subscriber station over MMDS.

21. The service distribution system according to claim 11, wherein said headend transmits the analog program signal to said at least one subscriber station over satellite.

22. A method for transmitting program information from a service provider to at least one subscriber comprising the steps of:

transmitting program information in a digital program signal from a service provider to a headend, the digital program signal being transmitted as part of a digital data stream;

receiving and decoding the digital program signal from the digital data stream, the digital program signal including an audio portion and a video portion;

scrambling at least a portion of the video portion;

converting, after said scrambling, the digital program signal to an analog program signal, the analog program signal including the scrambled portion; and

transmitting the analog program signal to at least one subscriber station.

23. The method according to claim 22, further comprising the step of generating scrambling control information from encryption information and using the scrambling control information to scramble the video portion of the digital program signal.

24. The method according to claim 22, further comprising the step of generating sync data and data to be inserted in a vertical blanking interval of the video portion of the digital program signal.

25. The method according to claim 22, wherein the encryption information includes subscriber authorization data.

26. The method according to claim 22, further comprising the step of adding subscriber authorization data to the program information in the digital program signal at the service provider, wherein said at least one subscriber receives the analog program signal in accordance with the subscriber authorization data.

27. In a combined receiver/decoder and scrambler/modulator located in a headend of a distribution system, a method for facilitating distribution of services from a service provider to at least one subscriber, said method comprising the steps of:

demodulating a digital data stream;

decrypting a digital signal in the digital data stream;

recovering a video portion and an audio portion from the decrypted digital signal;

scrambling at least a portion of the video portion of the decrypted digital signal;

converting, after said scrambling, the decrypted digital signal to an analog signal, the analog signal including the scrambled portion; and

transmitting the analog signal to said at least one subscriber,

wherein the demodulating, decrypting, recovering scrambling and converting steps are performed in the combined receiver/decoder and scrambler/modulator.

28. The method according to claim 27, wherein said step of transmitting includes transmitting the analog signal over SMATV.

29. The method according to claim 27, wherein said step of transmitting includes transmitting the analog signal over cable.

30. The method according to claim 27, wherein said step of transmitting includes transmitting the analog signal over MMDS.

31. The method according to claim 27, wherein said step of transmitting includes transmitting the analog signal over satellite.