Content transmission device and content reproduction device

• US 20070032975A1
• Filed: 02/14/2005
• Published: 02/08/2007
• Est. Priority Date: 03/31/2004
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Kuwabara, Takashi, Mori, Toshiaki, Kaihotsu, Yuji, Tamamoto, Akihiro, Nakakita, Manabu
• Granted Patent: US 8,352,989 B2
• Time in Patent Office: Days
• US Class Current: 702/86
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

The present invention realizes streaming reproduction in an environment in which a communication speed changes due to a change in the position of a moving body such as a vehicle.

A content reproduction device 10 includes: a plurality of communication units (a cellular phone 101 and a wireless LAN communication unit 104), each receiving a content transmitted in segments from a content transmission device over a communication path; a content reconstruction unit 113 that has a buffer 1130 in which each segmented data of the content received by each of the communication units is temporarily accumulated, and that reconstructs each segmented data accumulated in the buffer 1130 into the content; a reproduction unit 114 that reproduces, at a predetermined bit rate, the content reconstructed by the content reconstruction unit 113; and a communication control unit 110 that: calculates, for every predetermined time, target transmission speeds to be assigned for content reception performed by the respective communication units, based on free space in the buffer 1130 and the bit rate; and transmits a first request signal indicating the calculated target transmission speeds to the content transmission device via one of the communication units.

Claims

1. A content reproduction device that performs streaming reproduction of a content, said device comprising:

a plurality of communication units, each being operable to receive a content transmitted in segments from a content transmission device over a communication path;

a content reconstruction unit having a buffer in which each segmented data of the content received by each of said communication units is temporarily accumulated, and operable to reconstruct each segmented data accumulated in said buffer into the content;

a reproduction unit operable to extract the content from said buffer at a predetermined bit rate and to reproduce the content at the predetermined bit rate, the content having been reconstructed by said content reconstruction unit; and

a communication control unit operable to;

calculate, for every predetermined time, target transmission speeds to be assigned for content reception performed by said respective communication units, based on free space in said buffer and the bit rate; and

transmit a first request signal indicating the calculated target transmission speeds to the content transmission device via one of said communication units.

2. The content reproduction device according to claim 1,

wherein the first request signal indicates addresses for said respective communication units.

3. The content reproduction device according to claim 1,

wherein the first request signal is a content obtainment command indicating addresses for said respective communication units.

4. The content reproduction device according to claim 1, further comprising

a communication fee storage unit which stores, in advance, communication fees of said respective communication units,

wherein said communication control unit is operable to determine the target transmission speeds of said respective communication units based on the communication fees.

5. The content reproduction device according to claim 1, further comprising:

a present position detection unit operable to detect a present position;

a traveling route obtainment unit operable to obtain a traveling route starting from the present position detected by said present position detection unit; and

a reception state storage unit which stores, in advance, data reception speeds of said respective communication units at each position on the traveling route obtained by said traveling route obtainment unit,

wherein said communication control unit is operable to determine the target transmission speeds of said respective communication units based on free space in said buffer and the data reception speeds of said respective communication units at a position indicated by information on a planned transit position after the present position, the data reception speeds being stored in said reception state storage unit.

6. The content reproduction device according to claim 5, further comprising

a reception speed measurement unit operable to measure data reception speeds of said respective communication units,

wherein said communication control unit is operable to:

calculate modified target transmission speeds, each being calculated based on a difference between the target transmission speed assigned for the content reception of each of said communication units and each of the data reception speeds measured by said reception speed measurement unit; and

transmit a second request signal indicating the calculated target transmission speeds to the content transmission device via one of said communication units.

7. A content transmission device that transmits a content over a communication path, said device comprising:

a content accumulation unit operable to accumulate a content;

a communication unit operable to communicate, over the communication path, with a content reproduction device that includes a plurality of communication units with different addresses; and

a content segmentation unit operable to;

determine amounts of content data to be transmitted based on target transmission speeds of the respective addresses every time a first request signal indicating target transmission speeds of the respective addresses is received, the amounts of content data to be transmitted being determined for the respective addresses;

segment the content accumulated in said content accumulation unit; and

transmit each segmented data of the content addressed to each of the addresses via said communication unit.

8. A content reproduction method for performing streaming reproduction of a content, said method comprising:

a plurality of communication steps, in each of which a content transmitted in segments from a content transmission device over a communication path is received;

a content reconstruction step of temporarily accumulating, in a buffer, each segmented data of the content received in each of said communication steps, and reconstructing each segmented data accumulated in the buffer into the content;

a reproduction step of extracting the content from the buffer at a predetermined bit rate and reproducing the content at the predetermined bit rate, the content having been reconstructed in said content reconstruction step; and

a communication control step of;

calculating, for every predetermined time, target transmission speeds to be assigned for content reception performed in said respective communication steps, based on free space in the buffer and the bit rate; and

transmitting a first request signal indicating the calculated target transmission speeds to the content transmission device using one of said communication steps.

10. A program for a content reproduction device that performs streaming reproduction of a content, said program causing a computer to execute the steps included in the content reproduction method according to claim 8.

9. A content transmission method for transmitting a content over a communication path, said method comprising:

a communication step of communicating, over the communication path, with a content reproduction device that includes a plurality of communication units with different addresses; and

a content segmentation step of;

determining amounts of content data to be transmitted based on target transmission speeds of the respective addresses every time a first request signal indicating target transmission speeds of the respective addresses is received, the amounts of content data to be transmitted being determined for the respective addresses;

segmenting the content accumulated in a content accumulation unit; and

transmitting each segmented data of the content addressed to each of the addresses using said communication step.

11. A program for a content transmission device that transmits a content over a communication path, said program causing a computer to execute the steps included in the content transmission method according to claim 9.