Method of identifying multiple digital streams within a multplexed signal

• US 20020101991A1
• Filed: 12/04/2000
• Published: 08/01/2002
• Est. Priority Date: 12/13/1999
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Scientific-Atlanta Incorporated (Cisco Systems, Inc.)
• Inventors: Bacon, Kinney, Hammond, Maynard
• Granted Patent: US 7,298,846 B2
• Time in Patent Office: Days
• US Class Current: 380/212
• CPC Class Codes: H04N 21/4181 for conditional access
• CPC Class Codes: H04N 21/434 Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream demultiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4623 Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14

Abstract

In a subscriber television system with a host terminal, the present invention allows the identification of the individual packets from two separate MPEG transport streams that have been multiplexed together for decoding by a single external conditional access or point-of-deployment (POD) module. The decoding of individual packets from two separate MPEG transport streams supports the use of multiple tuner host terminals for such functions as picture-in-picture (PIP) program viewing and the viewing of one program while recording a second program.

Claims

1. In a system with a plurality of packetized data streams, a method of designating a source of at least one packetized data stream within a multiplexed signal including at least a portion of the at least one packetized data stream, the method comprising the steps of:

assigning a unique designator to the source of the at least one packetized data stream;

multiplexing at least the portion of the at least one packetized data stream with at least a portion of a second packetized data stream to create the multiplexed signal; and

transmitting the unique designator in conjunction with the multiplexed signal, wherein transmission of the unique designator indicates the source of the portion of the multiplexed signal as the source of the at least one packetized data stream.

2. The method of claim 1, wherein the packetized data stream is in a format compliant with one of Moving Picture Experts Group type 2 (MPEG-2) standard, Moving Picture Experts Group type 4 (MPEG-4) standard, Asynchronous Transfer Modulation (ATM) standard, and Internet Protocol (IP) standard.

3. The method of claim 1, wherein the step of transmitting the unique designator comprises the steps of:

creating a unique designator signal that includes the unique designator; and

transmitting the unique designator signal in conjunction with the multiplexed signal, wherein the unique designator signal provides the unique designator at the start of the at least one packet of the at least one packetized data stream.

4. The method of claim 1, wherein the step of transmitting the unique designator comprises the steps of:

creating a unique designator signal that includes the unique designator; and

transmitting the unique designator signal in conjunction with the multiplexed signal, wherein the unique designator signal provides the unique designator at the start of the at least one byte of the at least one packetized data stream.

5. In a system with a plurality of packetized data streams, a method of designating to an external conditional access module a source of at least one packetized data stream within a multiplexed signal including at least a portion of the at least one packetized data stream, the method comprising the steps of:

assigning a unique designator to the source of the at least one packetized data stream;

multiplexing at least the portion of the at least one packetized data stream with at least a portion of a second packetized data stream to create the multiplexed signal; and

transmitting the unique designator in conjunction with the multiplexed signal to the external conditional access module, wherein transmission of the unique designator indicates the source of the portion of the multiplexed signal as the source of the at least one packetized data stream.

6. The method of claim 5, wherein the packetized data stream is in a format compliant with one of Moving Picture Experts Group type 2 (MPEG-2) standard, Moving Picture Experts Group type 4 (MPEG-4) standard, Asynchronous Transfer Modulation (ATM) standard, and Internet Protocol (IP) standard.

7. The method of claim 5, wherein the step of transmitting the unique designator comprises the steps of:

creating a unique designator signal that includes the unique designator; and

transmitting the unique designator signal in conjunction with the multiplexed signal to the external conditional access module, wherein the unique designator signal provides the unique designator at the start of the at least one packet of the at least one packetized data stream.

8. The method of claim 5, wherein the external conditional access module decrypts the at least one packet of the at least one packetized data stream based on the source of the at least one packetized data stream indicated by the unique designator.

9. In a host terminal, a method of multiplexing together packets from at least two packetized data streams to enable decryption of the packets by an external conditional access module, the method comprising the steps of:

assigning a unique designator to each originating packetized data stream of the at least two packetized data streams;

multiplexing the packets forming portions of the at least two packetized data streams into a signal;

creating an association for each packet in the signal with the unique designator of the originating packetized data stream from which each packet originated;

transmitting the signal and the associations of the packets to the external conditional access module; and

decrypting, in the external conditional access module, the packets in the signal based on the originating packetized data stream as indicated by the associated unique designator.

10. The method of claim 9, wherein the at least two packetized data streams are in a format compliant with one of Moving Picture Experts Group type 2 (MPEG-2) standard, Moving Picture Experts Group type 4 (PEG-4) standard, Asynchronous Transfer Modulation (ATM) standard, and Internet Protocol (IP) standard.

11. In a system with a plurality of Moving Picture Experts Group type 2 (MPEG-2) standard transport streams and a host terminal, a method of designating to an external conditional access module a source of at least one packet of a first MPEG-2 transport stream within a multiplexed signal including the at least one packet of the first MPEG-2 transport stream, the method comprising the steps of:

assigning a unique designator to the source of the first MPEG-2 transport stream;

creating a transport stream source indicator signal that includes the unique designator associated with the at least one packet of the first MPEG-2 transport stream;

multiplexing the at least one packet of the first MPEG-2 transport stream with packets from at least a portion of a second MPEG-2 transport stream to create the multiplexed signal; and

transmitting to the external conditional access module the transport stream source indicator signal in conjunction with the multiplexed signal, wherein transmission of the transport stream source indicator signal, by the unique designator, indicates the source of the at least one packet as the source of the first MPEG-2 transport stream.

12. The method of claim 11, further including the step of decrypting, in the external conditional access module, the at least one packet based on the source of the first MPEG-2 transport stream.

13. The method of claim 12, further including the step of transmitting the decrypted at least one packet from the external conditional access module to the host terminal.

15. The method of claim 14, wherein the data packets and the packetized data stream are in a format compliant with one of Moving Picture Experts Group type 2 (MPEG-2) standard, Moving Picture Experts Group type 4 (MPEG-4) standard, Asynchronous Transfer Modulation (ATM) standard, and Internet Protocol (IP) standard.

16. The method of claim 14, further comprising an encryptor for encrypting the data packets associated with the at least one packetized data stream.

17. The method of claim 16, wherein the encryption provides copy protection for the data packets associated with the at least one packetized data stream.

19. The host terminal of claim 18, wherein the data packets and the packetized data stream are in a format compliant with one of Moving Picture Experts Group type 2 (PEG-2) standard, Moving Picture Experts Group type 4 (MPEG-4) standard, Asynchronous Transfer Modulation (ATM) standard, and Internet Protocol (IP) standard.

20. The host terminal of claim 18, further comprising a demultiplexer for receiving an output signal from the external conditional access module, for de-multiplexing the output signal, and for providing the at least two packetized data streams as separate packetized data streams.

14. A external conditional access module that can decrypt, based on a unique designator that indicates a source of a data packet, data packets from at least one packetized data stream within an incoming multiplexed signal comprised of data packets from more than one packetized data stream, the external conditional access module comprising:

a host terminal interface for receiving the incoming multiplexed signal from a host terminal, for transmitting an outgoing multiplexed signal to the host terminal, and for communicating the unique designator for each data packet in both the incoming multiplexed signal and the outgoing multiplexed signal;

a de-multiplexer for de-multiplexing the incoming multiplexed signal into data packets associated with the at least one packetized data stream based on the unique designator associated with each data packet;

a controller for determining if decryption is allowed for the data packets associated with the least one packetized data stream and for controlling decryption parameters;

at least one decryptor for decrypting, if decryption is allowed, the data packets associated with the at least one packetized data stream using decryption parameters for the at least one packetized data stream; and

a multiplexer for multiplexing the data packets, including those that were decrypted and those for which decryption was not allowed, into the outgoing multiplexed signal.

18. A host terminal that provides a multiplexed signal to an external conditional access module, wherein the multiplexed signal includes data packets from at least two packetized data streams, the host terminal comprising:

at least two tuners, each tuner for receiving one of the at least two packetized data streams; and

a multiplexer for combining data packets from the at least two packetized data streams into the multiplexed signal, for assigning a unique indicator that indicates which tuner received the packetized data stream associated with the data packets, for transmitting the multiplexed signal to the external conditional access module, and for communicating the unique designator associated with each data packet to the external conditional access module.

21. In a system with a plurality of packetized data streams, a method of designating a source of a first packetized data stream with a multiplexed signal including at least a portion of the at least one packetized data stream, the method comprising the steps of:

assigning a unique designator to the source of the at least one packetized data stream;

multiplexing at least the portion of the at least one packetized data stream with at least a portion of a second packetized data stream to create the multiplexed signal; and

transmitting the unique designator in conjunction with the multiplexed signal, wherein transmission of the unique designator indicates the source of the portion of the multiplexed signal as the source of the at least one packetized data stream.