Conditional access system for each transmitter in single frequency network, and a method thereof

• US 8,031,870 B2
• Filed: 11/04/2005
• Issued: 10/04/2011
• Est. Priority Date: 03/24/2005
• Status: Active Grant

• Current Assignee: KT Corporation
• Original Assignee: KT Corporation
• Inventors: Hong, Chung-Pyo, Park, Won-Jin
• Primary Examiner(s): Barron, Jr., Gilberto
• Assistant Examiner(s): Cribbs, Malcolm
• Application Number:
  US11/909,566
• Publication Number:
  US 20100195828A1
• Time in Patent Office: 2,160 Days
• Field of Search: 380202-204, 380/229, 380239-242, 725/32, 725 34- 36, 725/119, 725126-127
• US Class Current: 380/239
• CPC Class Codes: H04H 20/06 among broadcast stations
• CPC Class Codes: H04H 20/67 Common-wave systems, i.e. using separate transmitters operating on substantially the same frequency
• CPC Class Codes: H04H 60/15 on receiving information
• CPC Class Codes: H04N 21/2265 Server identification by a unique number or address, e.g. serial number network arrangements, protocols or services for addressing or naming H04L61/00
• CPC Class Codes: H04N 21/25875 involving end-user authentication restricting access to computer systems by authenticating users using a predetermined code G06F21/33; arrangements for secret or secure communication including means for verifying the identity or authority of a user of the system H04L9/32; networks authentication protocols H04L63/08; authentication in wireless network security H04W12/06
• CPC Class Codes: H04N 21/41407 embedded in a portable device, e.g. video client on a mobile phone, PDA, laptop constructional details of equipment or arrangements specially adapted for portable computer application G06F1/1626; arrangements specially adapted for mobile receivers in broadcast systems H04H20/57
• CPC Class Codes: H04N 21/42684 Client identification by a unique number or address, e.g. serial number, MAC address, socket ID network arrangements, protocols or services for addressing or naming H04L61/00
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/6112 involving terrestrial transmission, e.g. DVB-T
• CPC Class Codes: H04N 21/6143 involving transmission via a satellite
• CPC Class Codes: H04N 21/6181 involving transmission via a mobile phone network arrangements for providing broadcast or conference services to substation in data switching networks in combination with wireless systems H04L12/189; wireless uplink channel access H04W74/004
• CPC Class Codes: H04N 21/63345 by transmitting keys key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

The conditional access system in a single frequency network in a digital broadcasting system includes a main broadcasting system transmitting encoded broadcasting signals including a data stream and transmitter identification information (TII) through a main broadcasting network; a repeating system amplifying and transmitting encoded broadcasting signals of the main broadcasting network, or modulating and amplifying a stream input by the main broadcasting system through a cable, and repeating broadcasting signals of the main broadcasting system through a repeating network; a subscriber station decoding the encoded signals of the main broadcasting network included in the broadcasting signals received through the main broadcasting network or the repeating network, TII, and an encoding key according to a decoding method; and a decoding key provider receiving a decoding key from the main broadcasting or repeating system, authenticating a user, and transmitting the decoding key to a charged subscriber station through a mobile communication network.

Claims

1. A conditional access system for a transmitter in a single frequency network for terrestrial and satellite digital broadcasting, the conditional access system comprising:

a main broadcasting system configured to transmit encoded signals including a data stream and a main broadcasting system transmitter identification information (TII) value through a main broadcasting network;

a repeating system configured to;

amplify and transmit the encoded signals of the main broadcasting network, or modulate and amplify a stream input by the main broadcasting system through a private line,

allocate a repeating system TII value to be different from the main broadcasting system TII value, and

repeat the broadcasting signals, including the encoded signals of the main broadcasting network, through a repeating network, wherein the repeating system extracts the main broadcasting system TII value and inserts the repeating system TII value in the broadcasting signals when repeating the broadcasting signals;

a subscriber station configured to decode the encoded signals of the main broadcasting network included in the broadcasting signals received through the main broadcasting network or the repeating network, transmitter identification information (TII), and an encoding key; and

a decoding key provider configured to authenticate a user and transmit a decoding key to a charged subscriber station through a mobile communication network, wherein;

the charged subscriber station is in the repeating network coverage, and

the charged subscriber station is configured to store the decoding key transmitted from the decoding key provider and decode the broadcasting signals using the decoding key corresponding to the repeating system TII value.

2. The conditional access system of claim 1, wherein the main broadcasting system encodes a multimedia program or contents, and transmits a decoding key for decoding the broadcasting signals according to a predetermined encoding method.

3. The conditional access system of claim 1, wherein the main broadcasting system and the repeating system respectively transmit transmitter identification information (TII) for identifying by the subscriber station whether the transmitted broadcasting signal is a main broadcasting network signal or a repeating network signal.

4. The conditional access system of claim 1, wherein the main broadcasting system is configured to periodically modify the main broadcasting system TII value, and apply a modified TII value to an encoding process.

5. The conditional access system of claim 1, wherein the main broadcasting system sets the main broadcasting system TII value and applies the main broadcasting system TII value so as to protect a corresponding encoding key.

6. The conditional access system of claim 1, wherein the main broadcasting system enables conditional access for respective transmitters by using transmitter identification information (TII) as a key value of a transmission stream, the TII being used for receiving different values from the respective transmitters in the single frequency network.

7. The conditional access system of claim 1, wherein the main broadcasting system generates the encoding key for encoding transmission data by applying an encoding algorithm and a key generation algorithm and encodes the transmission data according to the corresponding encoding key, and the subscriber station finds a key value from a key table according to received TII and decodes the key value.

8. The conditional access system of claim 1, wherein the subscriber station receives TII of the main broadcasting system from the main broadcasting system and receives TII of the repeating system from the repeating system so as to decode the encoded broadcasting signals, and when the subscriber station is the charged subscriber station, the charged subscriber station receives the decoding key through a corresponding mobile communication network to decode the encoded broadcasting signals.

9. The conditional access system of claim 8, wherein when the subscriber station is an uncharged subscriber station, a data stream is descrambled and decoded by using transmitter identification information (TII) and an encoding key in the main broadcasting network, and receiving of the broadcasting signals are controlled in the repeating network.

10. The conditional access system of claim 1, wherein the subscriber station installs a mobile communication module, transmits a proper encoded key and a decoding key for descrambling to each subscriber station through the mobile communication, and a predetermined subscriber station having received the decoding key searches the key table stored in the subscriber station to find a corresponding key value and decodes the received data.

11. The conditional access system of claim 1, wherein the subscriber station installs a programmed function and a table for identifying the received TII value, decoding the received key to extract a corresponding encoding key, and descrambling the received data by using the extracted encoding key.

12. The conditional access system of claim 1, wherein the subscriber station is controlled to generate the same value by applying a predetermined function of G since the scrambled data of the main broadcasting network and the repeating network must be solved with the same keyword as they have the same pattern according to the matching result of the key table for the TII of the main broadcasting network and the TII of the repeating network.

13. The conditional access system of claim 1, wherein when the subscriber station is a terminal for an exclusive use, a key table is received through a PC and an entitlement management message (EMM) to match a value of repeating network TII with a value of the key table, find a descrambling key value, and perform a descramble process, and when the subscriber station is a wireless communication combined terminal, a key table is received through a wireless communication network and a decoding key is received through the wireless communication network to match the decoding key with a value of the key table and find a key value for a scrambling process.

14. The conditional access system of claim 1, wherein the subscriber station has a key table for a charged service in advance, and uses TII or a decoding key to find a matched value from the corresponding key table and descramble the value.

15. The conditional access system of claim 1, wherein the subscriber station has a TII key table for a main broadcasting network, a TII key table for a repeating network, and a TII key table for a charged mobile communication subscriber.

16. The conditional access system of claim 15, wherein when the subscriber station is a terminal for exclusive use of an uncharged service, a TII key table for a main broadcasting network is installed;

when the subscriber station is a terminal for exclusive use of a charged service without a communication module, a TII key table for a main broadcasting network and a TII key table for a repeating network for a charged service are additionally installed;

when the subscriber station has a wireless communication module and it is a unsubscribed terminal combined with an uncharged service, a TII key table for a main broadcasting network is installed; and

a charged service combined terminal having a wireless communication module and having registered to a charged service has a TII key table for a main broadcasting network and a TII key table for a charged communication subscriber.

17. The conditional access system of claim 1, wherein when the subscriber station is a terminal for exclusive use without a communication module, a TII key table for a repeating network is received through a PC or an EMM so as to subscribe to a charged service, and when the subscriber station is a wireless communication combined terminal and is subscribed to a charged service, a TII key table for a charged communication subscriber is received through the corresponding wireless communication network.

18. The conditional access system of claim 1, wherein the subscriber station receives a corresponding key table at the initial subscription stage, and the key table is periodically updated with a new key table value so as to prevent hacking and manage subscribers'"'"' cancellation.

19. The conditional access system of claim 1, wherein when the subscriber station is a terminal for exclusive use, the subscriber station receives a TII key table for a repeating network that is periodically modified so as to manage subscribers, and when the subscriber terminates subscription after registration, the subscriber station does not receive a TII key table for a repeating network to consecutively prevent the data received through the repeating network from being decoded.

20. The conditional access system of claim 1, wherein in the case of a wireless communication subscriber, when the subscriber is subscribed to a TII key table for a modified charged communication subscriber, the subscriber station consecutively and automatically receives signals, and when the subscriber is not subscribed to the wireless communication, the subscriber is controlled to no longer receive the TII key table for a charged communication subscriber.

21. The conditional access system of claim 1, wherein the subscriber station is encoded by using the terminal'"'"'s proper number, and controls the transmitter identification information (TII) to be decoded by the corresponding terminal, thereby preventing hacking.

22. The conditional access system of claim 1, wherein the subscriber station periodically modifies the main broadcasting network TII value and the repeating network TII value so as to prevent TII hacking.

23. The conditional access system of claim 1, wherein the decoding key provider periodically transmits a key through a mobile communication network or the Internet so that the subscriber station may decode the received key and extract the corresponding encoding key.

24. A conditional access subscriber station for a transmitter in a single frequency network for terrestrial and satellite digital broadcasting, the conditional access subscriber station comprising:

an OFDM demodulator configured to select a channel when encoded broadcast signals are received through an antenna, and convert the encoded broadcast signals into OFDM signals;

a transmitter identification information (TII) extractor configured to extract a TII signal and an encoded key from the OFDM signals;

a key table configured to search for a key value according to stored TII values;

a DAB de-ensembler configured to divide the OFDM signals into DAB data and MPEG2 TS data signals;

a network identification (NIS) decoder configured to combine three keys, namely a main broadcasting station TII key, repeater station TII key, and a decoding key, for decoding the encoded broadcasting signals according to the TII values by using the key table or an ID of a subscriber station, and decode the MPEG2 TS data signals output by the DAB de-ensembler; and

a multimedia processing module for processing the decoded MPEG2 TS data or DAB data to be displayable,

wherein the subscriber station of a charged subscriber identifies whether the encoded broadcast signals are from a main broadcasting network or a repeating network by using the TII values, decodes the encoded broadcast signals by using a main broadcasting station TII value when the encoded broadcast signals are from the main broadcasting network, and decodes the broadcast signals by using the decoding key received through a mobile communication network when the encoded broadcast signals are from the repeating network.

25. The conditional access subscriber station of claim 24, wherein the subscriber station decodes the key table by using a terminal ID which is a proper number of the corresponding terminal since the key table is encoded.

26. A conditional access method for a transmitter by a charged subscriber in a single frequency network for terrestrial and satellite digital broadcasting, the conditional access method comprising:

a) a charged subscriber receiving broadcasting signals including a data stream and transmitter identification information (TII);

b) searching a TII key table to find a corresponding key value depending on the cases of a receiver for exclusive use and a wireless communication combined receiver;

c) applying;

main broadcasting network TII or repeating network TII, and

an encoding key value so as to descramble the data stream;

d) checking whether the data stream can be descrambled and decoded;

e) the charged subscriber receiving a decoding key through a mobile communication network when the data stream cannot be descrambled and decoded; and

f) decoding the data stream and receiving broadcasting signals when the data stream can be decoded,

wherein the charged subscriber decodes the data stream using the decoding key corresponding to repeating network TII;

wherein f) further comprises scrambling and decoding, with the charged subscriber, the data stream by using the TII and the encoding key in the main broadcasting network, and identifying, with the charged subscriber, the main broadcasting network and the repeating network by using the TII to identify the network received by the current terminal by using the TII in the repeating network and descrambling and decoding the data stream by using the decoding key received through the mobile communication network.

27. The conditional access method of claim 26, wherein receiving the broadcasting signals in a) includes receiving encoded signals in the main broadcasting system, and descrambling and decoding the encoded signals by the main broadcasting system TII or the decoding key.

28. A conditional access method for a transmitter by an uncharged subscriber in a single frequency network for terrestrial and satellite digital broadcasting, the conditional access method comprising:

a) an uncharged subscriber receiving broadcasting signals including a data stream and transmitter identification information (TII);

b) using the TII as a key value so as to descramble the data stream;

c) checking whether the data stream can be descrambled and decoded;

d) decoding the data stream and receiving the broadcasting signals when the data stream can be decoded; and

e) conditionally controlling receiving of the broadcasting signals when the uncharged subscriber'"'"'s terminal is handed off from the main broadcasting network to the repeating network,

wherein e) further comprises periodically modifying, with an encoding server in the main broadcasting system, the TII of the main broadcasting system which is used by the uncharged subscriber to identify whether the broadcasting signals are from the main broadcasting network and decoding the broadcasting signals, and applying the TII as modified to scrambling of the data stream, and hence the uncharged subscriber is controlled to conditionally receive the broadcasting signals.

29. The conditional access method of claim 28, wherein receiving the broadcasting signals in a) comprises receiving encoded broadcasting signals in the main broadcasting system to be descrambled and decoded through the TII of the main broadcasting system or the decoding key.

30. The conditional access method of claim 28, wherein conditionally controlling receiving in e) comprises descrambling and decoding, with the uncharged subscriber, the data stream by using the TII and the encoding key in the main broadcasting network, and receiving of the broadcasting signals is conditionally controlled in the repeating network.

31. The conditional access method of claim 28, wherein the step e) comprises:

e-1) increasing a value of a counter installed in the uncharged subscriber station;

e-2) checking whether the value of the counter corresponds to a period value established by the main broadcasting system; and

e-3) resetting the counter when the counter corresponds to the period value established by the main broadcasting system.

32. The conditional access method of claim 31, wherein resetting the counter in e-3) comprises resetting the value of the counter of the uncharged subscriber station, the uncharged subscriber'"'"'s terminal does not use the main broadcasting system TII in the repeating network, and the broadcasting signals are conditionally received.

33. A conditional access system for a transmitter in a single frequency network for terrestrial and satellite digital broadcasting, the conditional access system comprising:

a main broadcasting system configured to encode broadcasting signals including a data stream and transmitter identification information (TII) through a main broadcasting network;

a repeating system configured to;

amplify and transmit encoded broadcasting signals of the main broadcasting network, or modulate and amplify a stream input by the main broadcasting system through a private line,

allocate a repeating system TII value to be different from the main broadcasting system TII value, and

repeat broadcasting signals of the main broadcasting system through a repeating network; and

a decoding key provider configured to authenticate a user and transmit the decoding key to a charged subscriber station through a mobile communication network,

wherein the decoding key corresponds to the repeating system TII value,

wherein the repeating system extracts the main broadcasting system TII included in the broadcasting signals of the main broadcasting system and inserts the repeating system TII value, which is different from the main broadcasting system TII value when repeating the broadcasting signals of the main broadcasting system.