JP2004228678A - Streaming distribution control apparatus, streaming distribution control method, and streaming distribution control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a streaming distribution control apparatus, a streaming distribution control method, and a streaming distribution control program by which a streaming restart time is shortened at the time of hand-over. <P>SOLUTION: When a mobile terminal 60 hands over to other network 50B and a reception section 84 of the streaming distribution control apparatus 80 disclosed herein receives a care of address, a detection section 86 detects a bandwidth D3 related to a network prefix part D2 of the network 50B after hand-over from a database 83 of a storage section 82. Then a communication control section 88 adjusts a data quantity of streaming data received by the mobile terminal 60 on the basis of the detected bandwidth. Since a data amount of the streaming data is adjusted without performing negotiation with respect to the QoS (quality of service) at hand-over of the mobile terminal 60, the restart time of streaming distribution can be reduced more than that of a streaming distribution control apparatus of prior arts. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a streaming distribution control device that controls streaming distribution, a streaming distribution control method, and a streaming distribution control program.
[0002]
[Prior art]
Conventionally, as a technique in such a field, there is a technique disclosed in Patent Document 1 below. The streaming distribution control device described in this publication, by cooperating two software modules (an application agent (AA) and a stream agent (SA)) generated for each stream, a stream between its own terminal and a partner terminal. And QoS (communication service quality) adjustment control. QoS control is performed based on a control standard (control policy). The control standard includes (a) a QoS adjustment method, (b) an upper limit, a lower limit, and an average of the adjustable QoS. , (C) stepwise adjustment / non-adjustment of QoS control, (d) communication stream priority, and (e) a plurality of parameter sets and user satisfaction with each set. .
[0003]
[Patent Document 1]
JP-A-11-275145
[0004]
[Problems to be solved by the invention]
When a mobile terminal such as a notebook computer switches the network (handover), the IP address of the mobile terminal changes with the handover. Therefore, when a packet is delivered to the IP address before the handover, there is a problem that the mobile terminal after the handover cannot receive the packet. In recent years, Mobile-IP technology has been proposed as a means for solving such a problem.
[0005]
This Mobile-IP technology (hereinafter referred to as “mobile IP”) is a technology that gives a permanent IP home address to a mobile terminal and transfers a packet addressed to the IP home address even if the mobile terminal performs handover. It is a technology for correctly delivering to The mobile IP includes a "home agent (HA)" which is a router connected to a home network of a mobile terminal, and a "foreign agent (FA)" which is a router connected to a network (external network) other than the home network. Are used. The mobile terminal to which the IP home address is assigned transmits a care-of address indicating its current network location to the HA at the timing of handover to the external network to which the FA is connected, and sends the IP home address to the care-of address. The HA sends a packet addressed to the address (addressed to the mobile terminal). If this mobile IP is applied to the above-mentioned streaming distribution control device, it becomes possible for the mobile terminal to receive streaming data transmitted from the streaming server without an instantaneous interruption even at the time of handover of the mobile terminal. .
[0006]
However, the above-mentioned conventional streaming distribution control device has the following problems. In other words, each time the environment (communication band or CPU usage) of the own terminal changes, negotiation is performed between the AA of the own terminal and the AA of the partner terminal, and the AA derives a new QoS. In IP, negotiation about QoS is performed every time a mobile terminal performs handover. Until the negotiation is completed, the streaming distribution temporarily stopped at the time of the handover of the mobile terminal is not restarted, and the streaming restart time is extended by the negotiation time.
[0007]
The present invention has been made in order to solve the above-described problems, and has as its object to provide a streaming distribution control device, a streaming distribution control method, and a streaming distribution control program in which streaming resumption time during handover is reduced. And
[0008]
[Means for Solving the Problems]
The streaming distribution control device according to the present invention includes: a storage unit in which identification information of a plurality of networks to which a mobile terminal can be connected and bandwidths of those networks are stored in association with each other; Receiving means for receiving a handover signal including identification information of the network after the handover transmitted from the mobile terminal at the time of handover, and associating the receiving means with the identification information included in the handover signal when the receiving means receives the handover signal; Detection means for detecting the bandwidth stored in the storage means, and communication control means for adjusting the amount of streaming data received by the mobile terminal from the streaming server based on the bandwidth detected by the detection means. Prepare.
[0009]
In this streaming distribution control device, when the mobile terminal performs handover to another network and the receiving unit receives the handover signal, the detecting unit detects the bandwidth associated with the identification information of the network after the handover from the storage unit. . Then, the communication control means adjusts the amount of streaming data received by the mobile terminal based on the detected bandwidth. That is, when the mobile terminal performs handover to a certain network, the communication control means adjusts the data amount of the streaming data received by the mobile terminal to a data amount suitable for the network. Therefore, at the time of handover of the mobile terminal, the data amount of the streaming data is adjusted without performing the negotiation on the QoS. Therefore, compared with the conventional streaming distribution control device that adjusts the data amount after the negotiation on the QoS is performed. Delivery restart time is reduced.
[0010]
Further, it is preferable that the communication control unit adjusts the data amount of the streaming data transferred by the router that transfers the streaming data from the streaming server to the mobile terminal via the network. In this case, streaming distribution control can be performed using a conventional mobile terminal and streaming server.
[0011]
Also, the streaming server stores a plurality of pieces of streaming data having different data amounts for the same content streaming data, and the communication control means converts the streaming data received by the mobile terminal from the streaming server into the same streaming data as the streaming data. It is preferable that the amount of streaming data received by the mobile terminal be adjusted by changing the streaming data of the content to streaming data having a different data amount. In this case, since the amount of streaming data transmitted from the streaming server is changed by the communication control means, the amount of streaming data received by the mobile terminal is naturally changed.
[0012]
Also, in the case where the streaming data is distributed on condition that the session IDs of the transmitting node and the receiving node match, the communication control means changes the streaming data to a different data amount and the streaming data is transmitted from the streaming server to the router. When the streaming distribution is performed with the new session ID, the communication control means matches the streaming server with the router with the new session ID, matches the router with the mobile terminal with the conventional session ID, and sets the streaming control. Preferably, the data is delivered from the streaming server to the mobile terminal. In this case, by matching the streaming server and the router with the new session ID, the streaming data is transmitted from the transmitting node as the streaming server to the receiving node as the router. Also, by matching the router and the mobile terminal with the conventional session ID, streaming data is transmitted from the transmitting node as the router to the receiving node as the mobile terminal. At this time, since the session ID of the mobile terminal is not changed before and after the streaming data is changed, the conventional general mobile terminal can be used without preparing a special mobile terminal capable of separately changing the session ID. The terminal can change the data amount of the streaming data described above.
[0013]
Also, in the case where the streaming data is distributed from the streaming server to the mobile terminal on condition that the session IDs of the streaming server and the mobile terminal match, the communication control means may change to the streaming data having a different data amount. When the streaming distribution from the streaming server to the router is performed using a new session ID, the communication control means preferably changes the session ID used between the router and the mobile terminal to the new session ID. In this case, even when the streaming distribution is performed on condition that the session IDs match, the communication control unit can adjust the amount of streaming data received by the mobile terminal.
[0014]
Further, when the mobile terminal performs handover to a network with a smaller bandwidth, the communication control means compresses the data amount of the streaming data transmitted from the streaming server to reduce the data amount of the streaming data received by the mobile terminal. Adjustment is preferred. In this case, for example, even when the streaming server prepares only one type of streaming data, the mobile terminal can receive the streaming data according to the bandwidth of the network after the handover.
[0015]
In a streaming distribution control method according to the present invention, identification information of a plurality of networks to which a mobile terminal can be connected and bandwidths of the networks are stored in a storage unit in association with each other. Receiving a handover signal transmitted from the mobile terminal when the handover to another network is performed, the handover signal including identification information of the network after the handover is included, and the detecting unit detects that the receiving unit has received the handover signal. Detecting the bandwidth stored in the storage means in association with the identification information included in the handover signal, and the communication control means determines whether or not the mobile terminal is a streaming server based on the bandwidth detected by the detection means. Adjusting the amount of streaming data received from the Obtain.
[0016]
In this streaming distribution control method, when the mobile terminal performs handover to another network and the receiving means receives the handover signal, the detecting means detects the bandwidth associated with the identification information of the network after the handover from the storage means. . Then, the communication control means adjusts the amount of streaming data received by the mobile terminal based on the detected bandwidth. That is, when the mobile terminal hands over to a certain network, the communication control means adjusts the data amount of the streaming data received by the mobile terminal to a data amount suitable for the network. Therefore, at the time of handover of the mobile terminal, the amount of streaming data is adjusted without negotiating the QoS. Therefore, compared with the conventional streaming distribution control method in which the amount of data is adjusted after negotiating the QoS, Delivery restart time is reduced.
[0017]
The streaming distribution control program according to the present invention includes identification information of a network after handover, which is transmitted from a mobile terminal when a mobile terminal capable of connecting a computer to a plurality of networks hands over to another network. The receiving means for receiving the handover signal, and when the receiving means receives the handover signal, the identification information of the plurality of networks and the bandwidths of the networks are stored in association with each other and are included in the handover signal. Detecting means for detecting a bandwidth associated with the identification information, and functioning as communication control means for adjusting a data amount of streaming data received by the mobile terminal from the streaming server based on the bandwidth detected by the detecting means. Features.
[0018]
By executing the communication control program using a computer, the mobile terminal performs handover to another network, and when the receiving means receives the handover signal, the detecting means uses the bandwidth associated with the identification information of the network after the handover. Is detected from the storage means. Then, the communication control unit adjusts the amount of streaming data received by the mobile terminal based on the detected bandwidth. That is, when the mobile terminal performs handover to a certain network, the communication control means adjusts the data amount of the streaming data received by the mobile terminal to a data amount suitable for the network. Therefore, at the time of handover of the mobile terminal, the data amount of the streaming data is adjusted without performing the negotiation on the QoS. Is shortened.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a streaming distribution control device, a streaming distribution control method, and a streaming distribution control program according to the present invention will be described in detail with reference to the accompanying drawings. Note that the same or equivalent elements are denoted by the same reference numerals, and a description thereof will be omitted if the description is duplicated.
[0020]
As shown in FIG. 1, the streaming distribution system 10 includes three foreign agents (FAs) connected to the Internet (public IP network) NW. ₁ , FA ₂ , FA ₃ ) 20A, 20B, and 20C, a home agent (HA) 30, and a streaming server 40.
[0021]
The three foreign agents 20A, 20B, 20C are a kind of router, and three external networks 50A, 50B, 50C having different bandwidths are connected to the Internet NW via the foreign agents 20A, 20B, 20C. The three external networks 50A, 50B, and 50C have different data transfer capacities. The external network 50A is a broadband network (for example, bandwidth: 2 Mbps), the external network 50B is a narrowband network (for example, bandwidth: 64 Kbps), and the external network. The network 50C is an intermediate band network (for example, a bandwidth: 384 Kbps).
[0022]
Each of the external networks 50A, 50B, 50C has a radio base station (BS ₁ , BS ₂ , BS ₃ ) 70A, 70B, 70C are connected. The mobile terminal 60 is a mobile IP-compatible notebook personal computer, and when switching between the wireless base stations 70A, 70B, and 70C and performing handover between the external networks 50A, 50B, and 50C, the care-of address (handover signal) to the home agent 30. ). The care-of address is an IP address assigned to the foreign agent 20A, 20B, 20C acquired by the mobile terminal 60 from the foreign agent 20A, 20B, 20C. Each of the care-of addresses is referred to by referring to a network prefix part of the IP address. The networks 50A, 50B, 50C are distinguished from each other.
[0023]
The home agent 30 is a kind of router like the foreign agents 20A, 20B, and 20C, receives a packet transmitted to an IP home address unique to the mobile terminal 60, and connects to the external networks 50A, 50B, and 50C. It transfers to the mobile terminal 60 which was done. When transferring, the home agent 30 uses the care-of address received from the mobile terminal 60. In addition, a streaming distribution control device 80 described later is functionally coupled to the home agent 30 so that data communication is possible with each other.
[0024]
According to the mobile IP in cooperation with the foreign agent 20A, 20B, 20C and the home agent 30 connected to the Internet NW, when the mobile terminal 60 performs a handover between the external networks 50A, 50B, 50C, the external network 50A , 50B, and 50C, obtains a care-of address from the foreign agents 20A, 20B, and 20C, notifies the home agent 30 of the care-of address, and causes the home agent 30 to transfer data addressed to the IP home address. 60 can receive the data via foreign agents 20A, 20B, 20C.
[0025]
The streaming server 40 is a server that stores streaming data such as video and music and distributes them. As the streaming data, three types of data having different data amounts for the same content, that is, broadband data, narrowband data, and intermediate band data are prepared. Here, the broadband data, the narrowband data, and the intermediate band data are streaming data having a data amount suitable for the external network 50A, the external network 50B, and the external network 50C, respectively. The data amount is adjusted according to the number of frames and the image quality.
[0026]
Next, the streaming distribution control device 80 coupled to the home agent 30 will be described in detail with reference to FIG. The streaming distribution control device 80 mainly includes a CPU (central processing unit), a storage device such as a hard disk and a memory, a data transmission / reception device, and the like as physical components, and a storage unit 82 as a functional component. (Storage means), a reception section 84 (reception means), a detection section 86 (detection means), and a communication control section 88 (communication control means).
[0027]
The storage unit 82 stores a database 83. As shown in FIG. 3, the database 83 includes three items of a network D1, a network prefix D2, and a bandwidth (Kbps) D3, and a plurality of these items are stored in association with each other. . Here, the network D1 is a name of the external networks 50A, 50B, 50C and the like. The network prefix part D2 is a bit string for identifying the external networks 50A, 50B, and 50C among the bit strings of the IP address, and is information unique to each network. The bandwidth D3 is a value indicating the data transfer capability of the external networks 50A, 50B, 50C. The larger this value is, the higher the network has a higher data transfer capability.
[0028]
The receiving unit 84 receives the care-of address from the mobile terminal 60 via the home agent 30. Based on the identification information of the external networks 50A, 50B, and 50C included in the care-of address received by the reception unit 84, the detection unit 86 detects a numerical value of the bandwidth associated with the identification information from the storage unit. More specifically, the detection unit 86 detects the value of the bandwidth stored in the storage unit 82 in association with the network prefix unit based on the network prefix unit (identification information) of the care-of address.
[0029]
The communication control unit 88 adjusts the amount of streaming data that the mobile terminal 60 receives from the home agent 30 based on the bandwidth detected by the detection unit 86. That is, the communication control unit 88 requests the streaming server 40 via the home agent 30 to transmit streaming data (for example, narrowband data) suitable for the detected bandwidth (for example, 64 Kbps), and The streaming data transferred from 30 to the mobile terminal 60 is changed.
[0030]
Among the protocols used for streaming distribution, there is a protocol for distributing streaming data by matching the session IDs in both the transmitting node and the receiving node. In streaming distribution under such a protocol, if the streaming data is changed to another one as described above, a new session ID is shared between the streaming server 40 and the home agent 30. In order to share the new session ID between the home agent 30 and the mobile terminal 60, a special mobile terminal 60 having a session ID switching function is required.
[0031]
Therefore, even in a conventional general mobile terminal, the communication control unit 88 converts the session ID so that no trouble occurs when the streaming data is changed to another one. Specifically, the communication control unit 88 converts a session ID newly shared between the streaming server 40 and the home agent 30 into a session ID of the past, thereby establishing a session between the home agent 30 and the mobile terminal 60. To maintain. That is, the communication control unit 88 matches the streaming server 40 with the home agent 30 using the new session ID, and matches the home agent 30 with the mobile terminal 60 using the conventional (existing) session ID. By doing so, the session ID of the mobile terminal 60 is not changed before and after the streaming data is changed, so that a special mobile terminal capable of separately changing the session ID is not prepared, The change of the data amount of the streaming data described above is realized in a certain general mobile terminal.
[0032]
Also, among the protocols used for streaming distribution, there is a protocol that uses a unique session ID between the mobile terminal 60 and the streaming server 40. In such a case, since the streaming distribution is started only when the session IDs of the mobile terminal 60 and the streaming server 40 match, if the streaming data is changed to another one as described above, the mobile terminal 60 Cannot receive streaming data properly. Therefore, in this case, the communication control unit 88 notifies the mobile terminal 60 of the session ID newly shared between the streaming server 40 and the home agent 30 to solve this problem. That is, even when the streaming distribution is performed on condition that the session IDs match, the communication control unit 88 adjusts the amount of streaming data received by the mobile terminal 60.
[0033]
Next, a streaming distribution control method using the above-described streaming distribution control device 80 will be described with reference to FIG. FIG. 4 is a flowchart showing a procedure in which the streaming distribution control device 80 adjusts the amount of streaming data received by the mobile terminal 60. As shown in FIG. 4, first, when the mobile terminal 60 connected to the external network 50A is handed over to the external network 50B (see the dashed line in FIG. 1), the mobile terminal 60 transmits the care-of address received from the foreign agent 20B. The data is transmitted to the home agent 30 (S10). The receiving unit 84 of the streaming distribution control device 80 receives the care-of address (for example, 129.62.18.26) via the home agent 30 (S12). When the receiving unit 84 receives the care-of address, the detecting unit 86 detects the bandwidth D3 associated with the network prefix unit D2 from the storage unit 82 based on the network prefix unit (129.62.) Of the care-of address. (S14). Based on the bandwidth detected in this way, the communication control unit 88 requests the streaming server 40 via the home agent 30 to transmit streaming data of a data amount suitable for the bandwidth. , The streaming data transferred to the mobile terminal 60 is changed (S16).
[0034]
As described above in detail, when the mobile terminal 60 performs a handover, the streaming distribution control device 80 receives the care-of address transmitted from the mobile terminal 60, and receives the external network 50A, 50B, Detect 50C bandwidth. Then, the streaming data received by the mobile terminal 60 is changed to streaming data having a data amount suitable for the bandwidth. As described above, the streaming distribution control device 80 adjusts the data amount of the streaming data without performing the negotiation on the QoS. In comparison, the restart time of streaming distribution is reduced. Further, since the streaming distribution control device 80 is only functionally coupled to the home agent 30, there is no need to prepare a streaming server or a mobile terminal whose specifications have been changed separately, and these can use a conventional one. .
[0035]
The method of adjusting the amount of streaming data received by the mobile terminal 60 is not limited to the method of requesting the streaming server 40 to transmit streaming data having a different amount of data, or the method of adjusting the amount of streaming data transferred by the home agent 30. There is a method in which the communication control unit 88 of the streaming distribution control device 80 performs compression. That is, when the mobile terminal 60 has handed over to a network with a smaller bandwidth, that is, when the amount of data transferred by the home agent 30 is larger than the data suitable for the bandwidth detected by the detection unit 86, the home The agent 30 performs data amount compression processing on the stream data transferred, such as reducing the number of frames. As described above, when the communication control unit 88 adjusts the data amount of the streaming data received by the mobile terminal 60 by the compression process, the streaming server 40 prepares only one type of broadband data and the home agent 30 By adjusting the compression level, it is possible to cope with various external networks 50A, 50B, 50C and the like to which the mobile terminal 60 connects.
[0036]
In the above description, an example is shown in which the streaming distribution control device 80 is coupled to the home agent 30. However, the streaming distribution control device 80 may be coupled to the streaming server 40. In this case, the home agent 30 that has received the care-of address transmits this care-of address to the streaming distribution control device 80 via the streaming server 40, thereby substantially the same as the streaming distribution control method described above. The effect will be achieved.
[0037]
Next, a streaming distribution control program according to an embodiment of the present invention will be described with reference to FIG. As shown in FIG. 5, the streaming distribution control program 90 includes a main module 92 for controlling the processing, a receiving module 94, a detection module 96, and a communication control module 98. The functions realized by executing the streaming distribution control program 90 using a computer and operating the receiving module 94, the detecting module 96, and the communication control module 98 respectively include the receiving unit 84 and the detecting unit 86 described above. And the respective functions of the communication control unit 88.
[0038]
The present invention is not limited to the above embodiment, and various modifications are possible. For example, the identification information of the external network may be information in a data format such as the network D1 shown in FIG. 3 other than the network prefix part of the care-of address. In addition, the mobile terminal may be a mobile phone or a PDA compatible with Mobile IP other than the notebook personal computer. Furthermore, the number of external networks connected to the public IP network and to which the mobile terminal can perform handover may be appropriately increased or decreased.
[0039]
【The invention's effect】
According to the present invention, there is provided a streaming distribution control device, a streaming distribution control method, and a streaming distribution control program in which the time required for restarting streaming distribution during handover is reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a streaming distribution system according to an embodiment of the present invention.
FIG. 2 is a system configuration diagram of the streaming distribution control device of FIG. 1;
FIG. 3 is a diagram showing a data configuration of a database of FIG. 2;
FIG. 4 is a flowchart showing a streaming distribution control method according to the embodiment of the present invention.
FIG. 5 is a diagram showing a streaming distribution control program according to the embodiment of the present invention.
[Explanation of symbols]
10: Streaming distribution system, 20A, 20B, 20C: Foreign agent, 30: Home agent, 40: Streaming server, 50A, 50B, 50C: External network, 60: Mobile terminal, 70A, 70B, 70C: Wireless base station, 80 ... a streaming delivery control device, 82 ... a storage unit, 84 ... a reception unit, 86 ... a detection unit, 88 ... a communication control unit, 90 ... a streaming delivery control program, D2 ... a network prefix unit, D3 ... a bandwidth.

Claims (8)

Storage means for storing identification information of a plurality of networks to which a mobile terminal can be connected, and the bandwidth of those networks stored in association with each other;
A receiving unit that receives a handover signal containing identification information of the network after the handover, transmitted from the mobile terminal when the mobile terminal hands over to another network,
When the receiving unit receives the handover signal, a detecting unit that detects the bandwidth stored in the storage unit in association with identification information included in the handover signal,
A communication control unit that adjusts a data amount of streaming data received by the mobile terminal from a streaming server based on the bandwidth detected by the detection unit. 2. The streaming distribution control device according to claim 1, wherein the communication control unit adjusts a data amount of the streaming data transferred by a router that transfers the streaming data from the streaming server to the mobile terminal via the network. 3. The streaming server stores a plurality of pieces of the streaming data having different data amounts for the streaming data of the same content,
The communication control unit changes the streaming data received by the mobile terminal from the streaming server to the streaming data having the same content as the streaming data and the streaming data having a different data amount, thereby changing the mobile terminal. The streaming distribution control device according to claim 1, wherein the streaming distribution control device adjusts a data amount of the streaming data received by the device. Wherein the streaming data is delivered on condition that the session IDs of the transmitting node and the receiving node match,
When the communication control means changes to the streaming data having the different data amount and the streaming delivery from the streaming server to the router is performed with a new session ID,
The communication control means matches the streaming server with the router with the new session ID, matches the router with the mobile terminal with the conventional session ID, and sends the streaming data from the streaming server. The streaming distribution control device according to claim 3, wherein the streaming distribution control device distributes the content to the mobile terminal. Wherein the streaming data is distributed from the streaming server to the mobile terminal on condition that the session IDs of the streaming server and the mobile terminal match,
When the communication control means changes to the streaming data having the different data amount and the streaming delivery from the streaming server to the router is performed with a new session ID,
The streaming distribution control device according to claim 3, wherein the communication control unit changes a session ID used by the router and the mobile terminal to a new session ID. When the mobile terminal has handed over to the smaller bandwidth network,
The streaming distribution according to claim 1, wherein the communication control unit adjusts a data amount of the streaming data received by the mobile terminal by compressing a data amount of the streaming data transmitted from the streaming server. Control device. The identification information of a plurality of networks to which the mobile terminal can be connected and the bandwidths of those networks are stored in the storage unit in association with each other,
Receiving means for receiving a handover signal including identification information of the network after the handover, transmitted from the mobile terminal when the mobile terminal handed over to the other network,
Detecting means for detecting, with the reception means receiving the handover signal, the bandwidth stored in the storage means in association with identification information included in the handover signal;
Adjusting the data amount of streaming data received by the mobile terminal from a streaming server based on the bandwidth detected by the detection means. Computer
A mobile terminal connectable to a plurality of networks, transmitted from the mobile terminal when handed over to another network, receiving means for receiving a handover signal containing identification information of the network after the handover,
When the receiving means receives the handover signal, the identification information of the plurality of networks and the bandwidths of those networks are respectively associated with the identification information included in the handover signal from the storage means stored in association with each other. Detecting means for detecting the bandwidth,
A streaming distribution control program for causing the mobile terminal to function as communication control means for adjusting the amount of streaming data received from a streaming server based on the bandwidth detected by the detection means.

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