Content distribution system

• US 20040174824A1
• Filed: 09/25/2003
• Published: 09/09/2004
• Est. Priority Date: 09/27/2002
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Futa, Yuichi, Matsuzaki, Natsume, Ohta, Yuusaku, Yamauchi, Hiroki
• Granted Patent: US 7,349,396 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 41/0893 Assignment of logical groups to network elements
• CPC Class Codes: H04L 41/509 wherein the managed service relates to media content delivery, e.g. audio, video or TV
• CPC Class Codes: H04L 43/50 Testing arrangements
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 63/0492 by using a location-limited connection, e.g. near-field communication or limited proximity of entities
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 40/20 based on geographic position or location
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: H04W 76/10 Connection setup

Abstract

A content distribution system in which content transmission/reception is suppressed when there is a high risk of contents being stolen by a third party during communication. A content server acquires a communication distance indicating how far the content server is from a terminal in data communication. The content server conducts content transmission/reception when the communication distance is less than or equal to a predetermined value, and suppresses content transmission/reception when the communication distance exceeds the predetermined value.

Claims

1. A communication device, comprising:

an acquiring unit operable to acquire a communication distance indicating how far the communication device is from another communication device in data communication;

a distance judging unit operable to judge whether the acquired communication distance is less than or equal to a predetermined value; and

a communication unit operable, when judged in the affirmative, to conduct content transmission/reception with the other communication device.

2. The communication device of claim 1, wherein

the communication unit conducts data communication with the other communication device prior to conducting the content transmission/reception, and

the communication distance indicates how many relay devices data transmitted by the other communication device passed through before reaching the communication device.

3. The communication device of claim 2, wherein

the communication distance indicates how many routers, as the relay devices, the data passed through from the other communication device to the communication device.

4. The communication device of claim 3, wherein

the communication unit conducts the data communication in a packet format that includes a time-to-live whose value decreases by “

1”

for every router passed through, and

the acquiring unit uses the time-to-live in acquiring the communication distance.

5. The communication device of claim 4, further comprising:

a key sharing unit operable to share key information with the other communication device.

6. The communication device of claim 5, further comprising:

an encryption unit operable, using the shared key information, to encrypt contents and decrypt encrypted contents, wherein

the communication unit transmits/receives encrypted contents.

7. The communication device of claim 6, wherein

each packet received from the other communication device includes first identification information that uniquely identifies a router to which the other communication device is connected, and

the communication device further comprises:

a router-information acquiring unit operable to acquire second identification information that uniquely identifies a router to which the communication device is connected;

an ID judging unit operable to judge whether the first identification information matches the second identification information; and

a suppressing unit operable, if judged in the negative, to suppress the content transmission/reception by the communication unit.

8. The communication device of claim 7, wherein

a data size of each packet transmitted/received by the communication unit is equal to a maximum transmission unit of a network to which the communication unit is connected, and

transmission/reception of partial packets is prohibited.

9. The communication device of claim 8, wherein

the time-to-live included in each packet received from the other communication device is set to a predetermined value at the time of transmission, and

the acquiring unit reads a value of the time-to-live from the received packet, and acquires the communication distance based on the difference between the read value and the predetermined value of the time-to-live.

10. The communication device of claim 9, wherein

the predetermined value of the time-to-live is “

1”

.

11. The communication device of claim 10, wherein

at least part of each packet received/transmitted by the communication unit is encrypted, and

the encryption unit outputs each received packet to the acquiring unit after decrypting the encrypted part of the packet, and outputs each packet for transmission to the communication unit after encrypting at least part of the packet.

12. The communication device of claim 1, wherein

the communication distance indicates a distance between the communication device and the other communication device.

13. The communication device of claim 1, wherein

the communication distance indicates a time period required in data communication between the communication device and the other communication device.

14. A content distribution system in which a content is transmitted from a transmission device to a reception device, the transmission device including:

an acquiring unit operable to acquire a communication distance indicating how far the communication device is from another communication device in data communication;

a distance judging unit operable to judge whether the acquired communication distance is less than or equal to a predetermined value; and

a transmission unit operable, when judged in the affirmative, to transmit the content to the reception device, and

the reception device operable to receive the content transmitted by the transmission device.

15. A content distribution method used by a communication device, comprising the steps of:

acquiring a communication distance indicating how far the communication device is from another communication device in data communication;

judging whether the acquired communication distance is less than or equal to a predetermined value; and

conducting content transmission/reception with the other communication device when judged in the affirmative.

16. A content distribution computer program used by a communication device, comprising the steps of:

acquiring a communication distance indicating how far the communication device is from another communication device in data communication;

judging whether the acquired communication distance is less than or equal to a predetermined value; and

conducting content transmission/reception with the other communication device when judged in the affirmative.

17. An LSI for executing a content distribution computer program used by a communication device, the program comprising the steps of:

acquiring a communication distance indicating how far the communication device is from another communication device in data communication;

judging whether the acquired communication distance is less than or equal to a predetermined value; and

conducting content transmission/reception with the other communication device when judged in the affirmative.