JP5573167B2 - Content sharing system, content sharing method and program - Google Patents

Description

  The present invention relates to a content sharing system, a content sharing method, and a program capable of sharing content data between users in a group in real time using group communication.

  One of the rich media communication tools that handle information on various media such as text, still images, audio, and videos. Real-time sharing of content within a group by transferring data such as photos between terminals during a group call. There is content sharing technology.

  In normal group communication, content data is transmitted from the terminal to the server, and the content data is duplicated by the server and distributed to other terminals in the group. If the communication speed from the transmission terminal to the reception terminal is not sufficient, there is a problem that the time from when the content data is transmitted from the transmission terminal until it reaches the reception terminal increases and the quality of communication deteriorates.

  As a technique for solving this problem, a technique of compressing content data by a server is known, and a technique related to this is disclosed in Patent Document 1. In Patent Document 1, the available bandwidth to the connection destination is determined when distributing the video data, and the reduction rate of the video data is determined from the comparison result between the bit rate of the video data and the available bandwidth. It is disclosed that video data is reduced (compressed) and transmitted according to a reduction rate.

JP 2000-138918 A

However, when the related technology disclosed in Patent Document 1 is adopted as a real-time content sharing technology during a group call, a function for measuring the communication speed to the receiving terminal is sent to the transmitting terminal of the content transmission source and based on this measurement result. In the group call, since data from one transmitting terminal is sent to a plurality of receiving terminals via a relay server, a one-to-many communication is performed. The transmitting terminal must measure the communication speed for each receiving terminal and send the content compressed with a different reduction rate for each receiving terminal, which increases the load on the transmitting terminal with limited resources. there were.
In addition, since content data is individually transmitted from the transmitting terminal to each receiving terminal, a large load is applied to the line from the transmitting terminal to the relay server, and the time taken for the content to reach the receiving terminal There is a problem that the voice communication may be hindered and the progress of the voice call may be hindered.

  The present invention solves the above-mentioned problems of the related art, and at the time of a group call, the time from when the transmitting terminal transmits content data until the receiving terminal completes reception is always within the time limit, It is an object of the present invention to provide a content sharing system, a content distribution method, and a program that can maintain communication quality in content sharing.

  In order to solve the above problems, a content sharing system according to the present invention includes a transmission terminal and a reception terminal that transmit and receive content data, and a relay server that relays content data between the two terminals. A communication bandwidth measuring means for measuring an available bandwidth to a relay server that is a data transmission destination, and an inquiry means for sending inquiry information including the measured available bandwidth and the data amount of the content data to the relay server; A data compression unit that compresses the content data at a data reduction rate notified from the relay server in response to the inquiry information, and a data transmission unit that transmits the compressed content data to the relay server, Server communication in which the relay server measures the available bandwidth to the transfer destination of the content data A data reduction rate in the transmission terminal based on the area measurement means and the information included in the inquiry information when the inquiry information is received from the transmission terminal and the available bandwidth measured by the server communication bandwidth measurement means And a reduction rate determining means for respectively determining a data reduction rate in the relay server, a reduction rate notifying means for notifying the transmission terminal of the determined data reduction rate at the transmitting terminal, and sent from the transmitting terminal Data compression means for compressing content data at the determined data reduction rate; and data transfer means for transferring the compressed content data to the receiving terminal, wherein the reduction rate determination means includes the content data Each data is set so that the transmission completion time when transmitting from the transmitting terminal to the receiving terminal is within a preset time limit. To further comprising a function of determining the reduction rate.

  The content sharing method of the present invention is a content sharing system comprising a transmission terminal and a reception terminal that transmit and receive content data, and a relay server that relays the content data between the two terminals. The available bandwidth to the relay server that is the data transmission destination is measured, inquiry information including the measured available bandwidth and the data amount of the content data is transmitted to the relay server, and the inquiry information is received. The relay server measures the usable bandwidth to the transfer destination of the content data, and transmits the content data from the transmitting terminal to the receiving terminal based on the measured usable bandwidth and the information included in the inquiry information The transmission terminal and the relay server so that the transmission completion time is within a preset time limit. The relay server determines the data reduction rate of the content data in each of the buses, the relay server notifies the transmission terminal of the determined data reduction rate of the transmission terminal, and receives the notification of the data reduction rate The transmission terminal compresses the content data at the data reduction rate, the transmission terminal transmits the compressed content data to the relay server, and the relay server that receives the content data at the determined data reduction rate The content data is compressed, and the compressed content data is transferred to the receiving terminal.

  In addition, the content sharing program of the present invention can be used as a transfer destination of the content data in a computer that controls the operation of a relay server that relays the content data between a transmission terminal that transmits and receives content data and a reception terminal. When receiving inquiry information including a function of measuring a bandwidth, a data amount of the content data from the transmission terminal, and an available bandwidth from the transmission terminal to the relay server, the information included in the inquiry information is measured. The content in each of the transmission terminal and the relay server so that the transmission completion time is within a preset time limit when the content data is transmitted from the transmission terminal to the reception terminal based on the available bandwidth A function for determining the data reduction rate of data and the determined transmission terminal A function of notifying the transmitting terminal of the data reduction rate to be transmitted, a function of compressing the content data sent in response to the notification at the data reduction rate in the relay server, and the receiving terminal of the compressed content data And executing a function to output to.

  Since the present invention is configured as described above, this enables compression of content data based on the measurement result of the communication band at the transmission terminal and the relay server, so that the communication band from the transmission terminal to the reception terminal is not sufficient. However, it is possible to adjust the data volume of the transmitted content and keep the time required for content transmission between the terminals within the time limit without concentrating the load on the transmitting terminal, and the quality of experience as a real-time content sharing service ( QoE: Quality of Experience can be improved.

1 is a functional block diagram illustrating a schematic configuration of a content sharing system according to a first embodiment of the present invention. It is a sequence diagram which shows the whole operation | movement of the content sharing system of embodiment disclosed in FIG. It is a schematic block diagram which shows the specific example of embodiment disclosed in FIG. It is a sequence diagram which shows the whole operation | movement of the content sharing system of 2nd Embodiment which concerns on this invention. It is a functional block diagram which shows schematic structure of the content sharing system of 3rd Embodiment which concerns on this invention. It is a sequence diagram which shows the whole operation | movement of the content sharing system of embodiment disclosed in FIG.

  Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a functional block diagram showing the configuration of the content sharing system according to the first embodiment of the present invention. As shown in FIG. 1, the content sharing system according to the first embodiment includes a plurality of user terminals 1A to 1D and a relay server 2 connected to the user terminals 1A to 1D through a line.

  In the content sharing system of the first embodiment, the user terminals 1A to 1D are configured to perform group communication via the relay server 2, and the user terminals 1A to 1D are configured to share content between the user terminals 1A to 1D. In this configuration, the content transmitted from one of the IDs is copied by the relay server 2 and distributed to other user terminals.

  Here, FIG. 1 shows a case where the four user terminals 1A to 1D are made into one group, but the number is not limited to four, and may be plural. The user terminals 1A to 1D and the relay server 2 may be configured to be connected via a communication network such as the Internet (not shown).

  The user terminals 1A to 1D have common components, for example, mobile phones. In FIG. 1, only the configuration related to content transmission in the internal configuration of the user terminal 1A is shown. The configuration related to reception is omitted. Hereinafter, the present embodiment will be described for the case where the user terminal 1A transmits content data.

  The user terminal 1A (hereinafter referred to as a transmission terminal) includes an information processing unit 10, a content storage unit 11 that stores content data, and a communication unit 16 that communicates with the relay server 2. The information processing unit 10 includes: The communication bandwidth measuring means 12 for measuring the available bandwidth to the relay server 2 that is the destination of the content data, and the inquiry information including the measured available bandwidth and the data amount of the content data are sent to the relay server 2 Inquiry means 13, data compression means 14 for compressing content data at a data reduction rate notified from relay server 2 corresponding to the inquiry information, and data transmission means for transmitting the compressed content data to relay server 2 15. The bandwidth that can be used for the relay server 2 is a bandwidth that can be used for data transmission to the relay server 2, and “band” here refers to a data transfer rate.

  The relay server 2 includes an information processing unit 20 and a communication unit 26 that communicates with the user terminals 1A to 1D. The information processing unit 20 is a user terminal 1B to 1D (hereinafter referred to as reception) that is a transfer destination of content data. Communication bandwidth measuring means 21 for measuring each available bandwidth to the terminal), information included in the inquiry information when the inquiry information is received from the transmission terminal, and available bandwidth measured by the communication bandwidth measuring means 21 Based on the above, the data reduction rate in the transmission terminal and the data reduction in the relay server 2 so that the transmission completion time is within a preset time limit when content data related to the inquiry information is transmitted from the transmission terminal to the reception terminal Reduction rate determining means 22 for determining the rate, reduction rate notifying means 23 for notifying the transmitting terminal of the data reduction rate at the determined transmission terminal, Correspondingly, the data compression unit 24 compresses the content data sent from the transmission terminal at the data reduction rate in the relay server determined by the reduction rate determination unit 22, and transfers the compressed content data to each receiving terminal. Data transfer means 25.

  The communication bandwidth measuring means 12 in the transmitting terminal (user terminal 1A) measures the available bandwidth available for data transmission to the relay server 2 and the available bandwidth measurement result in response to the request from the inquiry means 13. It has a function to answer. Here, the communication band measuring means 12 may be configured to measure and respond to the available bandwidth when receiving a request from the inquiry means 13, or to measure and record the available bandwidth periodically in advance. In addition, a configuration in which the latest measurement result when the request is received from the inquiry unit 13 may be used. In addition, the available bandwidth measuring method in the communication bandwidth measuring means 12 may be, for example, the well-known technique “pathchirp”. “Pathchirp” is a technique for continuously transmitting measurement packets and measuring the available bandwidth based on the arrival status on the receiving side.

  The inquiry unit 13 obtains a communication band usable for data transmission to the relay server 2 from the communication band measurement unit 12 when content to be shared by the group is designated by the user via an input unit (not shown). The content storage unit 11 is searched to acquire the data amount of the content specified by the user, and has a function of transmitting inquiry information including the available bandwidth and the data amount of the specified content to the relay server 2. The relay server 2 can be inquired about the data reduction rate for the content data for completing the sharing of the content between the terminals within the time limit.

  The inquiry unit 13 has a function of sending the data reduction rate notified from the relay server 2 corresponding to the inquiry information to the data compression unit 14 together with the user-specified content data identification information.

  The data compression means 14 has a function of reading content data specified by the user from the content storage unit 11 and performing data compression processing according to the data reduction rate notified from the relay server 2. For example, when the content data is still image data, the compression rate adjustment of JPEG (Joint Photographic Experts Group) may be adopted as the data compression processing method. Thereby, the content data can be compressed to a size suitable for completing the sharing of the content between the user terminals within the time limit.

  The content transmission unit 15 has a function of inputting the compressed content data output from the data compression unit 14 and transmitting the content data to the relay server 2.

  Here, the inquiry unit 13 and the data compression unit 14 in the user terminals 1A to 1D of the present embodiment are configured to search for user-specified content data from the content data stored in the content storage unit 11, but the present invention is not limited thereto. Instead, the user-specified content data may be stored in advance in the content storage unit 11 or may be input to the inquiry unit 13 via the input unit.

  Next, the communication bandwidth measuring means 21 in the relay server 2 individually measures the available bandwidth available for data transmission to the user terminals 1B to 1D (receiving terminals) set as the content data transfer destinations. And a function of answering a measurement result of each available bandwidth in response to a request from the reduction rate determining means 22. The communication band measuring means 12 may be configured to measure and reply to the available bandwidth when receiving a request from the inquiry means 13, or to measure and record the available bandwidth periodically in advance. The latest measurement result may be answered when a request is received from the inquiry means 13. In addition, the available bandwidth measurement method in the communication bandwidth measuring means 21 may be “pathchirp” as in the communication bandwidth measuring means 12 described above, for example.

  When receiving the inquiry information from the transmitting terminal, the reduction rate determining unit 22 acquires a communication band that can be used for data transmission from the communication band measuring unit 12 to each receiving terminal, and each acquired usable band and Based on the information included in the inquiry information, the transmission completion time until transmission of the content data indicated in the inquiry information from the transmission terminal to the reception terminal is completed is within a preset time limit. A function of calculating a data reduction rate for the content data at the transmission terminal and the relay server 2 is provided. Here, the calculated data reduction rate may be “0%”. Further, the data reduction rate at the relay server 2 is calculated as a different data reduction rate for each receiving terminal. Thereby, in order to complete the content transmission between the user terminals 1A to 1D within the time limit, whether or not the content data needs to be compressed at the transmission terminal or the relay server 2, and the data reduction in each case of the compression Rate can be determined.

  This reduction rate determination means 22 maximizes the objective function with the data amount of content data received at the receiving terminal as a variable, while satisfying a predetermined constraint condition as the data reduction rate at the transmitting terminal and the relay server 2. To calculate.

  The constraint condition is that the estimated time from when the transmission terminal starts to transmit the content data until the relay server 2 relays the content data and the reception terminal completes reception is within a predetermined time limit, The data reduction rate between the transmission terminal and the relay server 2 is set to a predetermined upper limit value or less.

  As the objective function, for example, there is a total amount of content data received by the user terminals 1B, 1C, and 1D. By maximizing the total amount of received content data, the content data quality can be maintained within the range that can be transmitted within the time limit.

  The reduction rate notification unit 23 has a function of notifying the transmission terminal of the data reduction rate in the transmission terminal determined by the reduction rate determination unit 22.

  The data compression means 24 inputs the content data from the transmitting terminal, duplicates it for sending to each receiving terminal, and individually performs data compression processing on each content data at a data deletion rate determined for each transfer destination. It has a function. The content transfer means 25 has a function of transferring the compressed content data to each receiving terminal.

  With such a configuration, the content sharing system according to the first embodiment transmits transmission content data to and from the transmission terminal and the relay in accordance with the communication band from the transmission terminal to the relay server 2 and the communication band from the relay server 2 to the reception terminal. Since the data is compressed and transferred by the server 2, the quality of the content data received by the user terminals 1B to 1D can be maintained as much as possible while sharing the content data within the time limit.

  Next, the overall operation of the content sharing system according to the first embodiment will be described. Here, the following description of the operation is an embodiment of the content sharing method of the present invention.

  FIG. 2 is a sequence diagram showing the operation of the content sharing system according to the first embodiment. As shown in FIG. 2, in the content sharing system of the first embodiment, first, in the transmission terminal (user terminal 1A), the inquiry unit 13 inputs identification information of content data to be shared designated by the user. When the content storage unit 11 is searched by inputting through the unit, or the content data to be shared is input from the input unit (step S1 in FIG. 2), use of data transmission to the relay server 2 to the communication band measuring unit 12 A possible bandwidth is requested and acquired (step S2 in FIG. 2). Here, the communication band measuring unit 12 may measure the available band in response to a request from the inquiry unit 13, or may periodically measure the communication band in advance and reply with the latest measurement result.

  The inquiry means 13 transmits inquiry information including the available bandwidth to the relay server 2 and the data amount of the shared content data to the relay server 2 in order to inquire about the data reduction rate for the content data at the time of transmission (step of FIG. 2). S3).

  In the relay server 2, the reduction rate determination unit 22 receives the inquiry information and requests the communication band measurement unit 21 for an available bandwidth for data transmission from the relay server 2 to each of the user terminals 1B, 1C, and 1D. (Step S4 in FIG. 2). Here, the communication bandwidth measuring unit 21 may measure the available bandwidth in response to a request, or may measure the available bandwidth periodically in advance and reply with the latest measurement result.

  Subsequently, the reduction rate determining unit 22 shares the transmission terminal and the relay server 2 based on the available bandwidth measured by the communication band measuring unit 21, the information included in the inquiry information, and the preset time limit. The data reduction rate for the content data is determined (step S5 in FIG. 2), and the data reduction rate at the transmission terminal is notified to the transmission terminal (step S6 in FIG. 2).

  Here, the reduction rate determination means 22 calculates each data reduction rate so as to maximize the objective function within preset constraint conditions. This restriction condition is that transmission completion times from when a transmission terminal (user terminal 1A) starts to transmit content data until each reception terminal (user terminals 1B, 1C, 1D) completes reception are within a predetermined time limit. And making the data reduction rate at the transmitting terminal and the relay server 2 be equal to or less than a predetermined upper limit value. As an example of the objective function, there is a total amount of content data received by each receiving terminal, and each data reduction rate is calculated so that this total is maximized. Also, the data reduction rate at the relay server 2 is calculated differently for each receiving terminal, and when it is not necessary to reduce the content data, the value of the data deletion rate is calculated as “0%”.

  Subsequently, in the transmission terminal, the inquiry unit 13 receives the data reduction rate and outputs it to the data compression unit 14. The data compression unit 14 compresses the shared content data according to the notified data reduction rate and outputs the compressed data to the content transmission unit 15 (step S7 in FIG. 2). At this time, if the value of the data reduction rate is “0%”, the shared content data is output as it is. Then, the content transmission means 15 transmits the compressed content data to the relay server 2 (step S8 in FIG. 2).

  When the data compression unit 24 inputs the received content data in the relay server 2, the data amount of the content data for each receiving terminal (user terminals 1B, 1C, 1D) according to the data reduction rate notified from the reduction rate determination unit 22 Is compressed and output to the content transfer means 25 (step S9 in FIG. 2). Also at this time, if the value of the data reduction rate is “0%”, the shared content data is output as it is. Subsequently, the content transfer means 25 transfers the compressed content data to the corresponding receiving terminal (step S10 in FIG. 2). Specifically, content data compression processing and content data transmission processing are repeated for each receiving terminal (user terminals 1B, 1C, 1D). Then, content data is received at the receiving terminal, and content sharing is completed.

  By operating in this way, the content sharing system according to the first embodiment is configured to be a transmission terminal or a relay server according to the communication band from the transmission terminal to the relay server 2 and the communication band from the relay server 2 to the reception terminal. Since the content data is compressed according to the determination result and distributed according to the determination result, the quality of the content data received at each receiving terminal is maintained while sharing the content data within the time limit. Can do.

  Here, regarding the information processing unit 10 in the user terminals 1A to 1D described above, that is, the communication band measuring means 12, the inquiry means 13, the data compression means 14, and the content transmission means 15, the function contents are programmed and stored in the computer. The content storage unit 11 may be configured by an auxiliary storage device.

  The information processing unit 20 in the relay server 2, that is, the communication bandwidth measuring unit 21, the reduction rate determining unit 22, the reduction rate notifying unit 23, the data compressing unit 24, and the content transferring unit 25 are programmed with their function contents programmed. The computer may be configured to execute.

  Next, a specific example of the first embodiment will be described.

  In this specific example, the user terminals 1A to 1D are mobile phones, the information processing unit 10 is realized by a central processing unit and a memory, and the content storage unit 11 is realized by an SD card. In the relay server 2, the information processing unit 20 is realized by a central processing unit and a memory. Both the information processing units 10 and 20 function by the computer program recorded in the memory being executed by the central processing unit. User terminals 1A to 1D, which are mobile phones, are connected via a wireless network, and the relay server 2 is connected to a core network that connects the wireless networks. This connection configuration is shown in FIG.

  In this specific example, it is assumed that the user terminals 1A to 1D are used for the users A to D, respectively, and the user A's mobile phone when the user A is talking with the user B, the user C, and the user D. The case where the photograph preserve | saved on the telephone (user terminal 1A) is shared with user B, C, D is demonstrated.

  When the user A selects the photo data having the data amount “1 Mbyte” in the JPEG format, the mobile phone of the user A (user terminal 1A) measures an available bandwidth for data transmission to the relay server 2. If the measurement result is “1 Mbps (megabits per second)”, the user terminal 1A notifies the relay server 2 of inquiry information including the data amount “1 Mbyte” and the measurement result “1 Mbps”. The relay server 2 that has received the inquiry information measures the available bandwidth from the relay server 2 to each of the mobile phones (user terminals 1B, 1C, 1D) of the users B, C, D.

  When the measurement results are “1 Mbps for user terminal 1B”, “2 Mbps for user terminal 1C”, and “200 Kbps for user terminal 1D”, the content sharing time limit is 16 seconds and the maximum reduction rate Is set to 90%, the estimated time to completion of content data transmission when compressed at the maximum reduction rate in the relay server 2 is 1 byte = 8 bits (1 Mbyte × 8 ÷ 1 Mbps) + ((100% −90%) × 1 Mbyte × 8 ÷ 200 Kbps) = 8 seconds + 4 seconds = 12 seconds.

  Since this value is within the time limit, data compression at the user terminal 1A is unnecessary, and the data reduction rate “0%” is notified to the user terminal 1A. The relay server 2 calculates the data reduction rate of the content data transmitted to each of the user terminals 1B, 1C, 1D. From the above calculation, the transmission time from the user terminal 1A to the relay server 2 is “8 seconds”, and the remaining time from the relay server 2 to the user terminals 1B, 1C, 1D is “8 seconds” (time limit 16 seconds-8 seconds). ), The amount of data transmitted from the relay server 2 to the user terminals 1B, 1C, and 1D in 8 seconds is estimated, and compared with the original amount of photographic data, each data reduction rate is as follows: Calculate.

  “User terminal 1B: 8 seconds × 1 Mbps = 1 Mbyte—no compression required, data reduction rate 0%”, “User terminal 1C: 8 seconds × 2 Mbps = 2 Mbyte> 1 Mbyte—no compression required, data reduction rate 0%”, “User terminal 1D: 8 seconds × 200 Kbps = 0.2 Mbyte <1 Mbyte... Compression required, data reduction rate is 0.2 Mbyte / 1 Mbyte = 20%”

  Then, since the compression processing at the user terminal 1A is unnecessary, the photo data is transmitted to the relay server 2 as it is. When the relay server 2 receives the photo data, the relay server 2 transmits data to the user terminals 1B, 1C, and 1D. Since data compression processing is not required for the user terminals 1B and 1C, the photo data is transmitted as it is. Regarding the transmission to the user terminal 1D, since the data reduction rate “20%” is calculated, the data amount of the photo data is compressed to “0.2 Mbyte” by adjusting the compression rate of JPEG, and then transmitted. The user terminals 1B, 1C, and 1D receive the photo data and share the photo data.

  As described above, in the content sharing system according to the first embodiment, both the user terminals 1 </ b> A to 1 </ b> D and the relay server 2 measure the communication bandwidth measuring units 12 and 21 that measure the available bandwidth to the transmission partner, and the transmitted content. Data compression means 14 and 24 for compressing data, and the relay server 2 includes a transmission terminal which is a terminal for transmitting content data and a reduction rate determination means 22 for determining a data reduction rate at the relay server 2, and this reduction The rate determination means 22 determines the content in the transmission terminal and the relay server based on the available bandwidth between the transmission terminal and the relay server 2 and between the relay server 2 and the reception terminal, the amount of content data, and the time limit for content sharing. Determine the data reduction rate for each data.

  Therefore, according to the content sharing system of the first embodiment, even when the communication band from the transmission terminal to the reception terminal is not sufficient, content sharing is possible without interfering with the group call between the user terminals 1B, 1C, and 1D. The data transmission time can be kept within the time limit, and the quality of experience in content sharing can be improved.

  In addition, since the data compression processing for content data is shared and adjusted between the transmission terminal and the relay server 2 in accordance with the available bandwidth from the transmission terminal to the reception terminal, the data compression processing amount of the transmission terminal can be minimized. The load on the user terminals 1A to 1D can be suppressed.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described.

  In the content sharing system of the second embodiment, after the reduction rate determination means 22 in the relay server 2 receives content data from the user terminals 1A to 1D, the data reduction rate in the relay server 2 is set to the remaining time limit again. Unlike the first embodiment described above, the other configurations are the same as those of the first embodiment in that a function for calculating based on the above is provided.

  FIG. 4 is a sequence diagram illustrating the overall operation of the system sharing system according to the second embodiment. Here, a case where the user terminal 1A transmits content data will be described.

  As shown in FIG. 4, in the system sharing system of the second embodiment, first, in the transmission terminal (user terminal 1A), the inquiry unit 13 receives the identification information of the shared content data designated by the user via the input unit. When input is performed to search the content storage unit 11 or shared content data is input from the input unit (step S1 in FIG. 4), the measurement result of the available bandwidth related to data transmission to the relay server 2 to the communication bandwidth measuring means 12 Is requested and acquired (step S2 in FIG. 4).

  Subsequently, the inquiry means 13 transmits inquiry information including the available bandwidth to the relay server 2 and the data amount of the shared content data to the relay server 2 in order to inquire about the data reduction rate for the content data at the time of transmission (see FIG. 4 step S3).

  In the relay server 2, when the reduction rate determination means 22 receives the inquiry information, the communication band measurement means 21 can use the data transmission from the relay server 2 to the receiving terminals (user terminals 1 B, 1 C, 1 D). A bandwidth measurement result is requested (step S4 in FIG. 4). Subsequently, the reduction rate determination means 22 calculates a data reduction rate for the shared content data at the transmission terminal and the relay server 2 (step S5 in FIG. 4), and notifies the transmission terminal of the data reduction rate at the transmission terminal. (Step S6 in FIG. 4).

  In the transmitting terminal, the inquiry means 13 receives the data reduction rate and outputs it to the data compression means 14. The data compression unit 14 compresses the shared content data according to the notified data reduction rate and outputs the compressed data to the content transmission unit 15 (step S7 in FIG. 4). At this time, if the value of the data reduction rate is “0%”, the shared content data is output as it is. Then, the content transmission means 15 transmits the compressed content data to the relay server 2 (step S8 in FIG. 4).

  When the relay server 2 receives the content data, the reduction rate determination means 22 calculates the data reduction rate at the relay server 2 (step S11 in FIG. 4). The data reduction rate calculation procedure at this time is based on the remaining time obtained by subtracting the time required for the communication with the relay server 2 from the user terminal 1A and the data amount of the content data. The bandwidth required for transmission is calculated, and when the available bandwidth to the receiving terminal is larger than the required bandwidth, the data reduction rate is set to “0%”. The data reduction rate is calculated accordingly.

  As the available bandwidth to the receiving terminals (user terminals 1B, 1C, 1D) used at this time, the latest value measured by the communication bandwidth measuring means 21 may be used, or the value obtained at the time of the inquiry in step S4. It may be used.

  Subsequently, the data compression unit 24 individually compresses the content data for each receiving terminal (user terminals 1B, 1C, 1D) in accordance with the data reduction rate notified from the reduction rate determination unit 22, and sends the content data to the content transfer unit 25. Output (step S9 in FIG. 4). Then, the content transfer means 25 transfers the compressed content data to the corresponding receiving terminal (step S10 in FIG. 4). Specifically, content data compression processing and content data transmission processing are repeated for each receiving terminal (user terminals 1B, 1C, 1D). Then, content data is received at the receiving terminal, and content sharing is completed.

  In the second embodiment, since the data reduction rate in the relay server 2 is calculated after the content data is received by the relay server 2, even when the available bandwidth from the transmitting terminal to the relay server 2 fluctuates, Corresponding to the fluctuation, high-quality content data can be transmitted to each receiving terminal within the time limit.

[Third Embodiment]
Next, a third embodiment according to the present invention will be described.

  FIG. 5 is a functional block diagram showing the configuration of the content sharing system of the third embodiment. As shown in FIG. 5, the content sharing system of the third embodiment is provided with a plurality of relay servers 2A, 2B, and 2C, and each of the relay servers 2A, 2B, and 2C has a user terminal 1A, 1B, and 1C and a user. This is different from the first embodiment described above in that the terminals 1D and 1E and the user terminals 1F and 1G are connected.

  The user terminals 1A to 1G of the third embodiment have common components and have the same configuration as the user terminals 1A to 1D of the first embodiment described above.

  The relay servers 2A, 2B, 2C in the third embodiment transfer their contents to other relay servers when the reduction rate determination means 22A, 22B, 22C receives inquiry information from a transmitting terminal that communicates directly. A function for requesting the measurement result of the available bandwidth to the destination, the usable bandwidth to the content transfer destination from another relay server returned in response to this request, and the available bandwidth to the content transfer destination measured in advance And a function for determining a data reduction rate at each of the relay terminals 2A, 2B, and 2C based on the inquiry information from the transmission terminal, and a communication bandwidth measuring means for a bandwidth measurement result request from another relay server 21A, 21B, 21C a function of returning the measurement result of the available bandwidth to the content transfer destination, and data notified from other relay servers in response to this reply Unlike the relay server 2 of the first embodiment described above in that it has a function of sending the reduction rate to the data compression means 24A, 24B, 24C, the other configurations are the same as those of the relay of the first embodiment described above. Same as server 2.

  Next, the overall operation of the content sharing system according to the third embodiment will be described. Here, a case where the user terminal 1A transmits content data will be described.

  FIG. 6 is a sequence diagram showing the overall operation of the content sharing system of the third embodiment. As shown in FIG. 6, in the content sharing system of the third embodiment, first, in the transmission terminal (user terminal 1A), the inquiry unit 13 uses the input unit to input the identification information of the content data to be shared designated by the user. When the content storage unit 11 is searched by inputting the content data or the content data to be shared is input from the input unit (step S1 in FIG. 6), the communication band measuring unit 12 can be used for data transmission to the relay server 2A. A bandwidth measurement result is requested and acquired (step S2 in FIG. 6). Subsequently, the inquiry unit 13 transmits inquiry information including the available bandwidth to the relay server 2 and the data amount of the shared content data to the relay server 2 (step S3 in FIG. 6).

  In the relay server 2A, when the inquiry information is received, the reduction rate determination unit 22A requests the measurement result of the available bandwidth to the content transfer destination from the relay servers 2B and 2C (step S12 in FIG. 6).

  When the relay server 2B (or 2C) receives a request from the relay server 2A, the reduction rate determination means 22B (or 22C) transfers the user terminals 1D and 1E to which the communication band measurement means 21B (or 21C) is transferred. (Or the measurement result of the available bandwidth to the user terminals 1F and 1G) is requested (step S13 in FIG. 6). The reduction rate determination means 22B (or 22C) sends the minimum bandwidth among the responses from the communication bandwidth measurement means 21B (or 21C) to the relay server 2A (step S14 in FIG. 6).

  In the relay server 2A, the reduction rate determination unit 22A sends the measurement result of the available bandwidth related to data transmission from the relay server 2A to the user terminals 1B and 1C of the receiving terminal or the relay servers 2B and 2C to the communication band measuring unit 21A. A request is made (step S4 in FIG. 6). Subsequently, the reduction rate determining means 22A determines the data reduction rate for the content data to be shared at the transmitting terminal and the relay servers 2A, 2B, and 2C (step S5 in FIG. 6).

  When determining the data reduction rate, the transmission completion time is calculated based on each available bandwidth when content data is transmitted without compressing the data amount from the transmitting terminal to each receiving terminal, and this transmission completion time is limited. If data compression is required compared to the time, whether or not sharing can be completed within the time limit by compressing the data amount to the maximum reduction rate at the relay servers 2A, 2B, 2C at the connection position close to the receiving terminal. judge. If sharing can be completed, the data reduction rate is calculated to meet the time limit. If sharing within the time limit is impossible, it is determined whether sharing can be completed within the time limit by compressing data at the relay server 2A or the transmission terminal that communicates directly with the transmission terminal. If sharing can be completed, the data reduction rate is calculated to meet the time limit.

  Then, the data reduction rate at the transmission terminal is notified to the transmission terminal (step S6 in FIG. 6), and the data reduction rate at the relay servers 2B and 2C is notified to the relay servers 2B and 2C (step S15 in FIG. 6). ).

  Subsequently, in the transmission terminal, the inquiry unit 13 receives the data reduction rate and outputs it to the data compression unit 14. The data compression unit 14 compresses the shared content data according to the notified data reduction rate and outputs the compressed data to the content transmission unit 15 (step S7 in FIG. 6). At this time, if the value of the data reduction rate is “0%”, the shared content data is output as it is. Then, the content transmission means 15 transmits the compressed content data to the relay server 2A (step S8 in FIG. 6).

  In the relay server 2A, when content data is received from the transmission terminal, the data compression unit 24 compresses the content data individually according to the data reduction rate determined for each of the reception terminals (user terminals 1B and 1C) and the relay servers 2B and 2C. Then, the compressed content data is transmitted to the receiving terminals (user terminals 1B and 1C) or the relay servers 2B and 2C (step S16 in FIG. 6). Steps S9 and S15 are executed for each transfer destination. In the user terminals 1B and 1C, content data is received and sharing is completed.

  Subsequently, in the relay server 2B (or 2C), the data compression means 24B (or 24C) compresses the received content data for each transfer destination according to the notified data reduction rate (step S17 in FIG. 6). At this time, since the notified data reduction rate is for the receiving terminal with the smallest available bandwidth, the data reduction rate may be changed according to the available bandwidth for transfer to other receiving terminals. . Then, the content transfer means 25B (or 25C) transfers the compressed content data to the receiving terminal (step S18 in FIG. 6).

  According to the content sharing system of the third embodiment, even in content sharing via a plurality of relay servers 2A to 2C, content data sharing can be completed within the time limit, and content data quality can be achieved. Can be maintained within a certain range.

  The present invention can be applied to a communication tool for sharing rich media between terminals.

  Examples of the configuration necessary for specifying the present invention will be added below.

(Supplementary Note 1) Consists of a transmission terminal and a reception terminal that transmit and receive content data, and a relay server that relays the content data between both terminals,
The transmission terminal measures communication bandwidth measuring means for measuring the available bandwidth to the relay server that is the transmission destination of the content data, and inquiry information including the measured available bandwidth and the data amount of the content data Inquiry means for sending to the relay server, data compression means for compressing the content data at a data reduction rate notified from the relay server in response to the inquiry information, and transmitting the compressed content data to the relay server Data transmission means,
When the relay server receives the inquiry information from the transmission terminal, the server communication bandwidth measuring means for measuring the usable bandwidth to the transfer destination of the content data, and the information included in the inquiry information and the server Reduction rate determining means for determining a data reduction rate at the transmitting terminal and a data reduction rate at the relay server based on the available bandwidth measured by the communication bandwidth measuring means, and the data reduction at the determined transmitting terminal A reduction rate notification means for notifying the transmission terminal of the rate, a data compression means for compressing the content data sent from the transmission terminal at a data reduction rate in the relay server, and the content data after compression as the reception terminal Data transfer means for transferring to
The reduction rate determining means has a function of determining each data reduction rate so that a transmission completion time is within a preset time limit when transmitting the content data from the transmitting terminal to the receiving terminal. A content sharing system characterized by

  (Supplementary note 2) The content sharing system according to supplementary note 1, wherein the reduction rate determining means has a function of setting each data reduction rate to a preset upper limit value or less.

  (Supplementary note 3) In the content sharing system according to supplementary note 2, the reduction rate determination means includes a data amount of the content data received by the receiving terminal within a condition that the transmission completion time is within the time limit. A content sharing system having a function of determining each data reduction rate so as to maximize the data.

  (Supplementary note 4) In the content sharing system according to supplementary note 3, when a plurality of the receiving terminals are provided, the server communication bandwidth measuring unit has a function of measuring an available bandwidth for each transfer destination of the content data, The reduction rate determination unit has a function of determining a data reduction rate in the relay server for each transfer destination, and the data compression unit in the relay server receives content data from the transmission terminal by the number of transfer destinations. A content sharing system comprising a function of copying and compressing each of them at a data reduction rate for each transfer destination.

  (Supplementary Note 5) In the content sharing system according to Supplementary Note 4, the reduction rate determining unit has a function of calculating a data reduction rate in the relay server based on a remaining time limit after receiving the content data. A content sharing system characterized by this.

  (Supplementary note 6) In the content sharing system according to supplementary note 5, the server communication bandwidth measuring unit includes a function of measuring the usable bandwidth after receiving the content data, and the reduction rate determining unit includes the content A content sharing system comprising a function of calculating a data reduction rate in the relay server based on an available bandwidth measured after receiving data.

(Supplementary note 7) In the content sharing system according to supplementary note 6, a plurality of the relay servers are provided, and one of the relay servers that directly communicates with the transmitting terminal is used as the first relay server, and the other relay servers are used as the second relay server. When the relay server of the first relay server receives the inquiry information from the transmission terminal, the reduction rate determination means of the first relay server requests a bandwidth measurement result to the second relay server, and In response to the request, the usable bandwidth from the second relay server to the content transfer destination that is returned from the second relay server, the usable bandwidth from the first relay server to the content transfer destination, and the transmission A function for determining a data reduction rate at the transmission terminal and a data reduction rate at each relay server based on information included in inquiry information from the terminal; Provided,
The reduction rate determination means of the second relay server returns a measurement result of the available bandwidth from the second relay server to the transfer destination in response to a request for the bandwidth measurement result from the first relay server. A content sharing system comprising a function and a function of notifying the data compression means of a data reduction rate notified from the first relay server in response to the reply.

1A to 1G User terminal 2, 2A to 2C Relay server 10 Information processing unit 11 Content storage unit 12 Communication band measurement unit 13 Inquiry unit 14 Data compression unit 15 Content transmission unit 16 Communication unit 20, 20A, 20B Information processing unit 21, 21A , 21B Communication band measurement means 22, 22A, 22B Reduction rate determination means 23, 23A, 23B Reduction rate notification means 24, 24A, 24B Data compression means 25, 26A, 25B Content transfer means 26, 26A, 26B Communication section

Claims (8)

It consists of a transmission terminal and a reception terminal that transmit and receive content data, and a relay server that relays the content data between both terminals,
The transmitting terminal is
Communication bandwidth measuring means for measuring the available bandwidth to the relay server that is the transmission destination of the content data, and an inquiry for sending inquiry information including the measured available bandwidth and the data amount of the content data to the relay server Means, data compression means for compressing the content data at a data reduction rate notified from the relay server in response to the inquiry information, and data transmission means for transmitting the compressed content data to the relay server. Prepared,
The relay server is
The server communication bandwidth measuring means for measuring the available bandwidth to the transfer destination of the content data, the information included in the inquiry information when the inquiry information is received from the transmitting terminal, and the server communication bandwidth measuring means Reduction rate determination means for determining a data reduction rate at the transmission terminal and a data reduction rate at the relay server based on the measured available bandwidth, and the determined data reduction rate at the transmission terminal. A reduction rate notification means for notifying to the data, a data compression means for compressing the content data sent from the transmitting terminal at a data reduction rate in the relay server, and a data transfer for transferring the compressed content data to the receiving terminal Means and
The reduction rate determining means has a function of determining each data reduction rate so that a transmission completion time is within a preset time limit when transmitting the content data from the transmitting terminal to the receiving terminal. A content sharing system characterized by The content sharing system according to claim 1,
The content sharing system, wherein the reduction rate determination means has a function of setting each data reduction rate to a preset upper limit value or less. The content sharing system according to claim 2,
The reduction rate determining means determines each data reduction rate so that the data amount of the content data received by the receiving terminal is maximized within a condition that the transmission completion time is within the time limit. A content sharing system characterized by having a function. The content sharing system according to claim 3,
When a plurality of the receiving terminals are provided,
The server communication band measuring means has a function of measuring an available band for each transfer destination of the content data,
The reduction rate determining means has a function of determining a data reduction rate in the relay server for each transfer destination,
Content sharing, wherein the data compression means in the relay server has a function of copying content data from the transmission terminal as many as the number of transfer destinations and compressing each of them at a data reduction rate for each transfer destination system. The content sharing system according to claim 4,
When a plurality of the relay servers are provided, one of the relay servers that directly communicates with the transmission terminal is a first relay server, and the other relay server is a second relay server,
A function for requesting a bandwidth measurement result to the second relay server when the reduction rate determining means of the first relay server receives the inquiry information from the transmitting terminal; Included in the available bandwidth from the second relay server to the content transfer destination, the available bandwidth from the first relay server to the content transfer destination, and the inquiry information from the transmission terminal. And a function for determining a data reduction rate in the transmitting terminal and a data reduction rate in each relay server based on the information to be transmitted,
The reduction rate determination means of the second relay server returns a measurement result of the available bandwidth from the second relay server to the transfer destination in response to a request for the bandwidth measurement result from the first relay server. A content sharing system comprising a function and a function of notifying the data compression means of a data reduction rate notified from the first relay server in response to the reply. In a relay server that relays the content data between a transmission terminal and a reception terminal that transmit and receive content data,
Communication bandwidth measuring means for measuring an available bandwidth to the transfer destination of the content data, and inquiry information including a data amount of the content data from the transmission terminal and an available bandwidth from the transmission terminal to the relay server. A reduction rate determining means for determining a data reduction rate of the content data in each of the transmission terminal and the relay server based on information included in the inquiry information and the measured available bandwidth to the transfer destination A reduction rate notification means for notifying the transmission terminal of the data reduction rate in the determined transmission terminal, and content data sent from the transmission terminal in response to the notification at the determined data reduction rate Data compression means for compressing, and data transfer means for transferring the compressed content data to the receiving terminal
The reduction rate determining means has a function of determining each data reduction rate so that a transmission completion time is within a preset time limit when transmitting the content data from the transmitting terminal to the receiving terminal. A relay server characterized by that. In a content sharing system comprising a transmission terminal and a reception terminal that transmit and receive content data, and a relay server that relays content data between both terminals,
Measure the available bandwidth to the relay server to which the transmission terminal is the transmission destination of the content data,
Sending inquiry information including the measured available bandwidth and the data amount of the content data to the relay server,
The relay server that has received this inquiry information measures the available bandwidth to the transfer destination of the content data,
Based on the measured available bandwidth and the information included in the inquiry information, the transmission completion time when transmitting the content data from the transmitting terminal to the receiving terminal is within a preset time limit. In addition, the relay server determines a data reduction rate of the content data in each of the transmission terminal and the relay server,
The relay server notifies the transmission terminal of the data reduction rate in the determined transmission terminal,
The transmitting terminal that has received the notification of the data reduction rate compresses the content data with the data reduction rate,
The transmission terminal transmits the compressed content data to the relay server,
The relay server that has received the content data compresses the content data at the determined data reduction rate,
A content sharing method comprising transferring the compressed content data to the receiving terminal. A computer that controls the operation of a relay server that relays the content data between a transmission terminal and a reception terminal that transmit and receive content data;
When receiving inquiry information including a function for measuring an available bandwidth to the transfer destination of the content data, a data amount of the content data from the transmission terminal, and an available bandwidth from the transmission terminal to the relay server Based on the information contained in the inquiry information and the available bandwidth to the measured transfer destination, the transmission completion time when transmitting the content data from the transmitting terminal to the receiving terminal is within a preset time limit. A function for determining the data reduction rate of the content data in each of the transmission terminal and the relay server, a function for notifying the transmission terminal of the determined data reduction rate in the transmission terminal, and this notification A function for compressing content data sent in accordance with the data reduction rate at the relay server, and this compression Content sharing program that wherein the content data to be executed and a function of transmission to the receiving terminal.

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