JP2009206944A - Data transmitting apparatus, data transmitting method, data receiving apparatus, data receiving method and data transfer system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform a transmission in a priority optimized for charges. <P>SOLUTION: A data transmitting apparatus transmits multimedia data over a network in which a band reservation is available and a network utilization charge is different in accordance with the priority of a band-reserved session. The data transmitting apparatus determines one or more sessions (transmission sessions) for transmitting encoded data of the multimedia data via a transmission data distribution section on the basis of a designated network utilization charge U and a ratio of data distribution to the respective transmission sessions (ST1, ST2). In accordance with the data distribution ratio of the transmission sessions, the data transmitting apparatus distributes to each of the sessions the encoded data of the multimedia data generated by an encoder, and divides the data into RTP packets, and transmits them to a receiving side (ST3-ST5). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a data transmission device, a data transmission method, a data reception device, a data reception method, and a data transmission system. More specifically, the present invention is capable of reserving bandwidth and transmitting multimedia data via networks having different network usage charges according to the priority of the reserved bandwidth session. By establishing a session and distributing and transmitting encoded data of multimedia data to be transmitted to each session according to the specified network usage fee, it is optimized for the fee simply by specifying the network usage fee. This is related to a data transmission device or the like in which transmission is performed with a high priority and the user's effort is reduced.

  Conventionally, multimedia data is encoded using a hierarchical encoding scheme, for example, JPEG2000 SVC (Scalable Video Codec), and priority in network transmission according to the importance of the data, for example, DS Field in IEEE 2474, IEEE 802.3p. It has been done to add the priority in the transmission.

  Patent Document 1 describes that a signal to be transmitted is separated into a first traffic signal and a second traffic signal, and a lower priority is given to the first traffic signal than to the second traffic signal. Has been.

  In recent years, a movement toward the construction of a next generation network (NGN) that replaces a conventional circuit-switched telephone line network with a network based on IP (Internet Protocol) technology has become active (for example, Patent Document 2).

The NGN is an IP network that has a bandwidth compensation function and a security function in the network itself, and integrates a telephone service, a video communication service, a data communication service, and the like using a session initiation protocol (SIP). . In this NGN, there is a mechanism in which a certain bandwidth is reserved in advance for specific communication.
Special Table 2000-503176 JP 2007-159142 A

  As described above, priority is given to network transmission according to the importance of data, and transmission is performed. However, transmission considering the network usage fee for each transmission priority in the network is not performed, and the importance in the network is determined only by the importance of the data.

  Therefore, for example, when the user wants to reduce the network usage fee even if the priority in the network is dropped to some extent, or the user wants to flow a lot of data to a session with a low priority in the network because the packet loss rate in the network is low However, transmission was performed with a predetermined priority.

  An object of the present invention is to enable transmission with a priority optimized for a fee.

The concept of this invention is
A data transmission device that transmits bandwidth data through a network that allows bandwidth reservation and has different network usage charges according to the priority of the bandwidth reserved session,
N session transmitters for establishing n sessions (n is an integer of 2 or more) having different priorities;
An encoder that encodes multimedia data to be transmitted to generate encoded data, a network usage fee designation unit that designates a network usage fee,
Transmission data distribution for distributing the encoded data generated by the encoder as transmission data of one or more sessions selected from the n sessions according to the network usage fee specified by the network usage fee specifying unit And a data transmission apparatus comprising:

  In the present invention, multimedia data to be transmitted is encoded by an encoder to obtain encoded data. The encoded data is distributed as transmission data of one or a plurality of sessions selected from the n sessions according to the designated network usage fee, and transmitted by the corresponding session transmission unit.

  As a result, only by specifying the network usage fee, transmission is performed with the priority optimized for the fee, and the user's effort is reduced. In addition, when only a single priority session is used, the network usage fee can only be specified at a non-consecutive stage, but in this invention, the encoded data is distributed to sessions with a plurality of priorities. Thus, continuous charge designation can be performed, and usage charges can be reduced according to the user's wishes.

  On the data receiving apparatus side, n sessions (n is an integer of 2 or more) having different priorities are established, and the encoded data received in the n sessions is decoded to receive the received multimedia. Data is generated.

  In the present invention, for example, the encoder hierarchically encodes multimedia data to be transmitted, and the transmission data distribution unit distributes the hierarchical data having higher importance among the encoded data as transmission data of a session having higher priority. May be. In this case, when the multimedia data is video data, for example, image quality scalable, resolution scalable, or frame rate scalable is used as a hierarchical structure in hierarchical encoding. As a result, hierarchical data having a high degree of importance is transmitted in a session having a high priority, so that it is possible to optimize charges while ensuring QoS.

  Further, in the present invention, the transmission data distribution unit includes the encoding generated by the encoder in accordance with the network usage fee specified by the network usage fee specifying unit and the network status (for example, packet loss rate, transmission delay, etc.). The data may be distributed as transmission data of one or more sessions selected from n sessions. Thus, by considering the network status, in a network environment that does not require high priority, it is possible to allocate a large amount of data to a low priority session and reduce the network usage fee. In addition, by allocating a large amount of data to the low priority session in this way, it is possible to reduce the amount of data for the high priority session and the reserved bandwidth, and to efficiently use the network bandwidth.

  According to the present invention, when a bandwidth reservation is possible and multimedia data is transmitted via a network having different network usage charges according to the priority of the reserved bandwidth session, a plurality of sessions having different priorities are transmitted. The encoded data of multimedia data to be transmitted is distributed to each session according to the specified network usage fee, and is optimized for the fee simply by specifying the network usage fee. Transmission is performed with a high priority, so that the user's trouble can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration example of a data transmission system 100 as an embodiment. The data transmission system 100 includes a data transmission device 110 and a data reception device 120. These data transmission device 110 and data reception device 120 are connected via an NGN network 130. Here, the NGN network 130 constitutes a network in which bandwidth reservation is possible and the network usage fee varies depending on the priority of the session for which bandwidth reservation has been made.

  The data transmission device 110 will be described. The data transmission apparatus 110 includes an encoder 111, n (n is an integer of 2 or more) session processing units 112-1-112-n, and n RTP (Realtime Transport Protocol) session transmission units 113-1 to 113-. n, a network usage charge designation unit 114, and a transmission data distribution unit 115.

  The encoder 111 encodes video data VD as multimedia data to be transmitted to generate encoded data. The encoder 111 performs hierarchical encoding on the video data VD. The encoder 111 uses, for example, JPEG2000, SVC (Scalable Video Codec) as a hierarchical encoding method, and performs hierarchical encoding on image quality (SNR), resolution, frame rate, and the like.

  The session processing units 112-1 to 112-n convert the data distributed as transmission data among the encoded data generated by the encoder 111 into RTP packets.

  FIG. 2 shows the configuration of the RTP packet. The RTP header includes a version number (v), padding (P), an extension bit indicating the presence or absence of an extension header, the number of transmission sources (Counter), marker information (markerbit), a payload type (Payload type), a sequence number, and a time stamp (TIMESTAMP), synchronization source (source) identifier (SSRC), and contributing source (source) identifier (CSRC) fields are provided.

  On the data receiving side, the processing time is controlled when the RTP packet is expanded based on the time stamp added to the RTP header, thereby enabling real-time image or audio reproduction control. For example, in an RTP packet storing encoded data of moving image data, a common time stamp is set for a plurality of RTP packets belonging to one video frame. An identification flag indicating the presence is stored in the RTP header.

  The RTP session transmission units 113-1 to 113-n each establish a session via the NGN network 130. The RTP session transmission units 113-1 to 113-n transmit the RTP packets generated by the session processing units 112-1 to 112-n through the established session. Here, the sessions established by the RTP session transmitters 113-1 to 113-n have different priorities. That is, the RTP session transmission units 113-1 to 113-n add priority in the DS Field, IEEE 802.3p in RFC 2474, and perform priority transmission.

  Further, the usage fee for the NGN network 130 is set higher as the priority is higher. For example, when the priority of the session established by the RTP session transmission units 113-1 to 113-n is P1 to Pn, and the network usage area per unit transmission rate (1 bps) of each session is K1 to Kn, P1> When P2>...> Pn, K1> K2>.

  The network usage fee designation unit 114 is a part for the user to designate a network usage fee. The user can designate the network usage fee as the fee U by inputting the fee U into the network usage fee designation unit 114. The network usage fee U specified by the network usage fee specifying unit 114 is a user's desired fee when the encoded data generated by the encoder 111 described above is transmitted via the NGN network 130.

  Based on the network usage fee U specified by the network usage fee specifying unit 114, the transmission data distribution unit 115 uses one or a plurality of sessions (hereinafter referred to as “transmission data”) used to transmit the encoded data generated by the encoder 111. As appropriate, it is referred to as “transmission session”) and the data distribution ratio to each transmission session.

  Here, the transmission data distribution unit 115 uses the network usage fee designated by the network usage fee designation unit 114 as U and the network usage fee per unit transmission rate of n sessions as Ki (i = 1, 2,... .., N) When the transmission rate of the transmission data distributed to the n sessions is MSi (i = 1, 2,..., N), the transmission session and the following expression (1) are satisfied. Determine the data distribution ratio for each transmission session.

  The method for determining the transmission session and the data distribution ratio to each transmission session will be further described by taking the case of n = 2 as an example. In this case, for example, two types of priority are established for the session to be established: “highest priority class” and “best effort class”. Assume that the session 1 established by the RTP session transmission unit 113-1 is the “highest priority class” and the session 2 established by the RTP session transmission unit 113-2 is the “best effort class”.

  Here, the network usage fee specified by the network usage fee specifying unit 114 is U, the network usage fee per unit transmission rate of session 1 is K1, and the network usage fee per unit transmission rate of session 2 is K2 (K1> K2). ) If the transmission rate of transmission data distributed to session 1 is MS1 [bps], and the transmission rate of transmission data distributed to session 2 is MS2 [bps], the transmission session and A data distribution ratio to each transmission session is determined. Note that when the transmission rate of the encoded data generated by the encoder 111 is M [bps], M = MS1 + MS2.

      U ≧ K1 × MS1 + K2 × MS2 (2)

  In this case, depending on the network usage fee U and the transmission rate M, all of the encoded data generated by the encoder 111 may be distributed as transmission data of the session 1. In that case, MS1 = M and MS2 = 0.

  In addition, the transmission data distribution unit 115 controls the encoder 111 to transmit the encoded data generated by the encoder 111 to each transmission session determined as described above among the session processing units 112-1 to 112-n. Are distributed and transmitted as transmission data at the data distribution ratio determined as described above.

  As described above, the encoder 111 performs hierarchical encoding on the video data VD. When the transmission data distribution unit 115 distributes the encoded data generated by the encoder 111 as the transmission data of each transmission session as described above, the hierarchical data having the higher importance of the encoded data has the higher priority. Sort as transmission data.

  For example, the encoded data generated by the encoder 111 is composed of layer 1, layer 2, and layer 3 hierarchical data in descending order of importance, and the ratio of layer 1, layer 2, and layer 3 hierarchical data is 50. %, 30%, and 20%. Further, there are two types of priority of the session to be established, the above-mentioned “highest priority class” and “best effort class”, the data distribution ratio to session 1 (highest priority class) is 70%, session 2 ( It is assumed that the distribution ratio to the “best effort class” is determined to be 30%.

  In this case, all layer 1 hierarchical data is distributed as transmission data of session 1 (the highest priority class). Further, 20% of layer 2 hierarchical data is allocated as transmission data for session 1 (highest priority class), and the remaining 10% is allocated as transmission data for session 2 (best effort class). Furthermore, all layer 3 hierarchical data is distributed as transmission data for session 2 (best effort class).

  As described above, the RTP session transmission units 113-1 to 113-n each establish a session via the NGN network 130. When the network usage fee is determined according to the reserved bandwidth at the time of session establishment, the RTP session transmission units 113-1 to 113-n control each session at the time of session establishment under the control of the transmission data distribution unit 115 described above. The bandwidth corresponding to the transmission rate of the transmission data allocated to is reserved.

  On the other hand, when the network usage fee is determined by the data transmission amount regardless of the reserved bandwidth, that is, in the case of pay-as-you-go, the RTP session transmission units 113-1 to 113-n set the transmission rate of transmission data distributed to each session. Regardless, it is sufficient to reserve a large amount of bandwidth in advance when a session is established.

  The data receiving device 120 will be described. The data receiving apparatus 120 includes n RTP session receiving units 121-1 to 121-n, n session processing units 122-1 to 122-n, and a decoder 123.

  The RTP session receiving units 121-1 to 121-n each establish a session via the NGN network 130. The RTP session reception units 121-1 to 121-n establish sessions with the RTP session transmission units 113-1 to 113-n of the data transmission device 110 described above.

  Session processing units 122-1 to 122-n analyze RTP packets received by RTP session receiving units 121-1 to 121-n. Then, the session processing units 122-1 to 122-n execute analysis on the header and payload in the RTP packet, and reconstruct data before packetization. The data reconstructed by the session processing units 122-1 to 122-n in this way is the session processing units 112-1 to 112- of the encoded data generated by the encoder 111 in the data transmission device 110 described above. Corresponds to data distributed as transmission data in n.

  The decoder 123 decodes the data (encoded data) reconstructed by the session processing units 112-1 to 112-n to generate video data VD. Here, the data reconstructed by the session processing units 112-1 to 112-n correspond to the encoded data generated by the encoder 111 of the data transmission device 110 described above. Further, the video data VD obtained by decoding corresponds to the video data VD input to the encoder 111 of the data transmission device 110 described above.

  Next, the operation of the data transmission system 100 shown in FIG. 1 will be described.

  First, the operation of the data transmission device 110 will be described. Video data VD as multimedia data to be transmitted is input to the encoder 111. The encoder 111 performs hierarchical encoding on the video data VD to generate encoded data.

  When the user inputs the fee U to the network usage fee specifying unit 114, the network usage fee is specified as the fee U. Then, in the transmission data distribution unit 115, one or a plurality of sessions (transmission sessions) used for transmitting the encoded data generated by the encoder 111 based on the designated network usage fee U, and each transmission The ratio of data distribution to the session is determined. In this case, the transmission session and the data distribution ratio to each transmission session are determined so that the network usage fee does not exceed the designated network usage fee U (see equations (1) and (2)).

  Based on the transmission session determined in this way and the distribution ratio to each transmission session, the encoded data generated by the encoder 111 is supplied to a session processing unit corresponding to each transmission session. In this case, hierarchical data with higher importance of the encoded data is distributed as transmission data of a session with higher priority.

  In the session processing units 112-1 to 112-n, among the encoded data generated by the encoder 111, data distributed as transmission data to itself is converted into RTP packets (see FIG. 2). The RTP packets generated by the session processing units 112-1 to 112-n are respectively supplied to the corresponding RTP session transmission units 113-1 to 113-n.

  The RTP session transmission units 113-1 to 113-n establish at least a session corresponding to the transmission session, and RTP packets generated by the session processing units 112-1 to 112-n are transmitted via the NGN network 130. . In this case, in the RTP session transmission units 113-1 to 113-n, for example, priority in DS Field, IEEE 802.3p in RFC 2474 is added, and priority transmission is performed.

  The flowchart of FIG. 3 schematically shows an operation flow of the data transmission device 110 described above.

  First, in step ST1, the network usage fee is designated as the fee U by the user's input of the network usage fee U. Next, in step ST2, the data transmission device 110 transmits one or more of the encoded data generated by the encoder 111 by the transmission data distribution unit 115 based on the network usage fee U specified in step ST1. A session (transmission session) and a data distribution ratio to each transmission session are determined.

  Next, in step ST3, the data transmission apparatus 110 uses the encoder 111 to hierarchically encode the video data VD as multimedia data. In step ST4, the data transmitting apparatus 110 distributes the encoded data generated by the encoder 111 to the session processing units 112-1 to 112-n according to the data distribution ratio of each transmission session.

  Next, in step ST5, the data transmission apparatus 110 converts the transmission data into RTP packets in the session processing units 112-1 to 112-n, and converts the generated packets into the RTP session transmission units 113-1 to 113, respectively. -n is transmitted to the receiving side via the NGN network 130. After the process of step ST5, the data processing apparatus 110 returns to the process of step ST2, and repeats the same process as described above.

  Next, the operation of the data receiving apparatus 120 will be described. The RTP packets received by the RTP session receiving units 121-1 to 121-n are supplied to the session processing units 122-1 to 122-n. In the session processing units 122-1 to 122-n, analysis is performed on the header and payload in the RTP packet, and data before packetization is reconfigured.

  Data (encoded data) reconstructed by the session processing units 122-1 to 122-n is supplied to the decoder 123. In the decoder 123, data (encoded data) supplied from the session processing units 122-1 to 122-n is decoded to generate video data VD.

  The flowchart of FIG. 4 schematically shows the flow of operation of the data receiving apparatus 120 described above.

  First, in step ST11, the data reception device 120 receives RTP packets by the RTP session reception units 121-1 to 121-n, and depacketizes the RTP packets by the session processing units 122-1 to 122-n. To reconstruct the data before packetization.

  Next, in step ST12, the data reception device 120 decodes the data (encoded data) obtained by the session processing units 122-1 to 122-n by the decoder 123, and outputs video data VD. The data receiving apparatus 120 returns to the process of step ST12 after the process of step ST12, and repeats the same process as described above.

  As described above, in the data transmission system 100 shown in FIG. 1, in the data transmission device 110, the encoded data of the video data VD is n pieces having different priorities according to the designated network fee U. The data is distributed as transmission data of one or a plurality of sessions selected from the session, and transmitted to the data reception device 120 via the NGN network 130 by the corresponding RTP session transmission unit.

  Therefore, in the data transmission device 110, simply by specifying the network usage fee, transmission is performed with the priority optimized for the fee, and the labor of the user is reduced. In addition, when only a single priority session is used, the network usage fee can be specified only at a non-continuous stage. However, in the data transmission apparatus 110, encoded data is stored in a session with a plurality of priorities. Since it is distributed, continuous charge designation can be performed, and the use charge can be reduced according to the user's wishes.

  Also, in the data transmission apparatus 110, when the video data VD is hierarchically encoded by the encoder 111 and the encoded data is distributed to sessions having a plurality of priorities as described above, hierarchical data with higher importance is assigned. It is sorted as transmission data for sessions with high priority. Therefore, it is possible to optimize charges while guaranteeing QoS.

  Next, another embodiment of the present invention will be described. FIG. 5 shows a configuration example of a data transmission system 100A as another embodiment. 5, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  The data transmission system 100A includes a data transmission device 110A and a data reception device 120A. The data transmission device 110A and the data reception device 120A are connected via the NGN network 130. The NGN network 130 can make a bandwidth reservation, and constitutes a network with a different network usage fee according to the priority of the session for which the bandwidth is reserved.

  The data transmission device 110A will be described. The data transmission apparatus 110A includes an encoder 111, n (n is an integer of 2 or more) session processing units 112-1-112-n, n RTP session transmission units 113-1 to 113-n, a network It has a usage charge designation unit 114, a transmission data distribution unit 115A, a target packet loss rate designation unit 116, and n RTCP (RTP Control Protocol) session units 117-1 to 117-n.

  The encoder 111 encodes video data VD as multimedia data to be transmitted to generate encoded data. The encoder 111 performs hierarchical encoding on the video data VD. The encoder 111 uses, for example, JPEG2000, SVC (Scalable Video Codec) as a hierarchical encoding method, and performs hierarchical encoding on image quality (SNR), resolution, frame rate, and the like.

  The session processing units 112-1 to 112-n convert the data distributed as transmission data among the encoded data generated by the encoder 111 into RTP packets (see FIG. 2).

  The RTP session transmission units 113-1 to 113-n each establish a session via the NGN network 130. The RTP session transmission units 113-1 to 113-n transmit the RTP packets generated by the session processing units 112-1 to 112-n through the established session. Here, the sessions established by the RTP session transmitters 113-1 to 113-n have different priorities. That is, the RTP session transmission units 113-1 to 113-n add priority in the DS Field, IEEE 802.3p in RFC 2474, and perform priority transmission.

  Further, the usage fee for the NGN network 130 is set higher as the priority is higher. For example, when the priority of the sessions established by the RTP session transmission units 113-1 to 113-n is PR1 to PRn and the network usage charges per unit transmission rate (1 bps) are K1 to Kn, PR1> PR2> ...> PRn, K1> K2> ...> Kn.

  The network usage fee designation unit 114 is a part for the user to designate a network usage fee. The user can designate the network usage fee as the fee U by inputting the fee U into the network usage fee designation unit 114. The network usage fee U specified by the network usage fee specifying unit 114 is a user's desired fee when the encoded data generated by the encoder 111 described above is transmitted via the NGN network 130.

  The target packet loss rate designation unit 116 is a part where the user designates the target packet loss rate. The user can designate the target packet loss rate as the packet loss rate Pt by inputting the packet loss rate Pt to the target packet loss rate designation unit 116.

  The RTCP session units 117-1 to 117-n communicate RTCP packets with the data reception device 120A. The RTCP session units 117-1 to 117-n obtain the packet loss rate of each session established by the RTP session transmission units 113-1 to 113-n as described above from the data reception device 120A. For example, when the priority of the session established by the RTP session transmission units 113-1 to 113-n is PR1 to PRn and the packet loss rate is P1 to Pn, usually PR1> PR2>. In some cases, P1 <P2 <... <Pn.

  The transmission data distribution unit 115A includes a network usage fee U specified by the network usage fee specifying unit 114, a target packet loss rate Pt specified by the target packet loss rate specifying unit 116, and RTCP session units 117-1 to 117-. Based on the packet loss rate Pt of each session acquired in n, one or a plurality of sessions (hereinafter referred to as “transmission sessions” as appropriate) used to transmit the encoded data generated by the encoder 111; Determine the data distribution ratio to each transmission session.

  Here, the transmission data distribution unit 115A uses the network usage fee designated by the network usage fee designation unit 114 as U and the network usage fee per unit transmission rate of n sessions as Ki (i = 1, 2,... ., N), MSi (i = 1, 2,..., N), the transmission rate of the transmission data distributed to the n sessions, M, the transmission rate of the encoded data generated by the encoder 111, and the target packet When the target packet loss rate designated by the loss rate designation unit 116 is Pt and the packet loss rate of n sessions is Pi (i = 1, 2,..., N), the following equation (3): The transmission session and the data distribution ratio to each transmission session are determined so as to satisfy the equation (4).

  The method for determining the transmission session and the data distribution ratio to each transmission session will be further described by taking the case of n = 2 as an example. In this case, for example, two types of priority are established for the session to be established: “highest priority class” and “best effort class”. Assume that the session 1 established by the RTP session transmission unit 113-1 is the “highest priority class” and the session 2 established by the RTP session transmission unit 113-2 is the “best effort class”.

  Here, the network usage fee specified by the network usage fee specifying unit 114 is U, the network usage fee per unit transmission rate of session 1 is K1, and the network usage fee per unit transmission rate of session 2 is K2 (K1> K2). ) MS1 [bps] for the transmission rate of the transmission data allocated to session 1, MS2 [bps] for the transmission data allocated to session 2, and the target packet loss rate specified by the target packet loss rate specifying unit 116 Assuming Pt, the packet loss rate of session 1 is P1, and the packet loss rate of session 2 is P2 (P1 <P2), to the transmission session and each transmission session so as to satisfy the following equations (5) and (6): The data distribution ratio is determined. Note that when the transmission rate of the encoded data generated by the encoder 111 is M [bps], M = MS1 + MS2.

U ≧ K1 × MS1 + K2 × MS2 (5)
Pt ≧ P1 × (MS1 / M) + P2 × (MS2 / M) (6)

  In this case, in order to reduce the user's payment fee (K1 × MS1 + K2 × MS2) as much as possible, MS2 should be set as large and MS1 as small as possible as long as Expression (6) is satisfied.

  For example, when Pt = 10 ^ (-6) and P1 = 10 ^ (-9) and P2 = 10 ^ (-9) at the start of communication, the transmission quality of session 2 deteriorates during communication. When P1 = 10 ^ (-9) and P2 = 10 ^ (-3), M1 = 0 and M2 = M between P1 = 10 ^ (-9) and P2 = 10 ^ (-9) After P1 = 10 ^ (− 9) and P2 = 10 ^ (− 3), it is assumed that M1≈M and M2≈0 (most data is allocated to session 0).

  In this way, by dynamically changing the bandwidth allocation for each session according to the network conditions, the user's payment fee is reduced compared with the case where the distribution ratio is fixed while satisfying the target packet loss rate Pt. it can.

  In addition, the transmission data distribution unit 115A controls the encoder 111 to transmit the encoded data generated by the encoder 111 to each transmission session determined as described above among the session processing units 112-1 to 112-n. Are distributed and transmitted as transmission data at the data distribution ratio determined as described above.

  As described above, the encoder 111 performs hierarchical encoding on the video data VD. When the transmission data distribution unit 115A distributes the encoded data generated by the encoder 111 as the transmission data of each transmission session as described above, the hierarchical data having the higher importance of the encoded data has the higher priority. Sort as transmission data.

  For example, the encoded data generated by the encoder 111 is composed of layer 1, layer 2, and layer 3 hierarchical data in descending order of importance, and the ratio of layer 1, layer 2, and layer 3 hierarchical data is 50. %, 30%, and 20%. Further, there are two types of priority of the session to be established, the above-mentioned “highest priority class” and “best effort class”, the data distribution ratio to session 1 (highest priority class) is 70%, session 2 ( It is assumed that the distribution ratio of “best effort class” is determined to be 30%.

  In this case, all layer 1 hierarchical data is distributed as transmission data of session 1 (the highest priority class). Further, 20% of layer 2 hierarchical data is allocated as transmission data for session 1 (highest priority class), and the remaining 10% is allocated as transmission data for session 2 (best effort class). Furthermore, all layer 3 hierarchical data is distributed as transmission data for session 2 (best effort class).

  As described above, the RTP session transmission units 113-1 to 113-n each establish a session via the NGN network 130. When the network usage fee is determined according to the reserved bandwidth at the time of session establishment, the RTP session transmission units 113-1 to 113-n control each session at the time of session establishment under the control of the transmission data distribution unit 115A. The bandwidth corresponding to the transmission rate of the transmission data allocated to is reserved.

  On the other hand, when the network usage fee is determined by the data transmission amount regardless of the reserved bandwidth, that is, in the case of pay-as-you-go, the RTP session transmission units 113-1 to 113-n set the transmission rate of transmission data distributed to each session. Regardless, it is sufficient to reserve a large amount of bandwidth in advance when a session is established. As described above, in the case of dynamically changing the bandwidth allocation for each session in accordance with the packet loss rate of each session, the case of weight charging is applied.

  The data receiving device 120A will be described. The data receiving apparatus 120A includes n RTP session receiving units 121-1 to 121-n, n session processing units 122-1 to 122-n, a decoder 123, and n RTCP session units 124-. 1 to 124-n.

  The RTP session receiving units 121-1 to 121-n each establish a session via the NGN network 130. The RTP session reception units 121-1 to 121-n establish sessions with the RTP session transmission units 113-1 to 113-n of the data transmission apparatus 110A described above.

  Session processing units 122-1 to 122-n analyze RTP packets received by RTP session receiving units 121-1 to 121-n. Then, the session processing units 122-1 to 122-n analyze the header and payload in the RTP packet, and reconstruct the data before packetization. The data reconstructed by the session processing units 122-1 to 122-n in this way is the session processing units 112-1 to 112- of the encoded data generated by the encoder 111 in the data transmission device 110 described above. Corresponds to data distributed as transmission data in n.

  The decoder 123 decodes the data (encoded data) reconstructed by the session processing units 112-1 to 112-n to generate video data VD. Here, the data reconstructed by the session processing units 112-1 to 112-n correspond to the encoded data generated by the encoder 111 of the data transmission device 110 described above. Further, the video data VD obtained by decoding corresponds to the video data VD input to the encoder 111 of the data transmission device 110 described above.

  The RTCP session units 124-1 to 124-n perform RTCP packet communication with the data transmission apparatus 110A. The RTCP session units 124-1 to 124-n transmit the packet loss rates P1 to Pn of the sessions established by the RTP session transmission units 121-1 to 121-n as described above to the data transmission apparatus 110A. .

  Next, the operation of the data transmission system 100A shown in FIG. 5 will be described.

  First, the operation of the data transmitting apparatus 110A will be described. Video data VD as multimedia data to be transmitted is input to the encoder 111. The encoder 111 performs hierarchical encoding on the video data VD to generate encoded data.

  When the user inputs the fee U to the network usage fee specifying unit 114, the network usage fee is specified as the fee U. Further, when the user inputs the packet loss rate Pt to the target packet loss rate specifying unit 116, the target packet loss rate is specified as the packet loss rate Pt.

  The RTCP session units 117-1 to 117-n communicate RTCP packets with the data reception device 120A, and the RTP session transmission units 113-1 to 113-n establish the communication with the data reception device 120A. The packet loss rates P1 to Pn of each session to be acquired are acquired.

  The network usage fee U specified by the network usage fee specifying unit 114, the target packet loss rate Pt specified by the target packet loss rate specifying unit 116, and the sessions acquired by the RTCP session units 117-1 to 117-n The packet loss rates P1 to Pn are supplied to the transmission data distribution unit 115A.

  In the transmission data distribution unit 115A, one or a plurality of data used for transmitting the encoded data generated by the encoder 111 based on the network usage fee U, the target packet loss rate Pt, and the packet loss rates P1 to Pn. A session (transmission session) and a data distribution ratio to each transmission session are determined. In this case, the transmission session and the data distribution ratio to each transmission session are determined so that the network usage fee does not exceed the specified network usage fee U and the packet loss rate does not exceed the target packet loss rate Pt. (See formulas (3), (4), (5), and (6)).

  Based on the transmission session determined in this way and the distribution ratio to each transmission session, the encoded data generated by the encoder 111 is supplied to a session processing unit corresponding to each transmission session. In this case, hierarchical data with higher importance of the encoded data is distributed as transmission data of a session with higher priority.

  In the session processing units 112-1 to 112-n, among the encoded data generated by the encoder 111, data distributed as transmission data to itself is converted into RTP packets (see FIG. 2). The RTP packets generated by the session processing units 112-1 to 112-n are respectively supplied to the corresponding RTP session transmission units 113-1 to 113-n.

  The RTP session transmission units 113-1 to 113-n establish at least a session corresponding to the transmission session, and RTP packets generated by the session processing units 112-1 to 112-n are transmitted via the NGN network 130. . In this case, in the RTP session transmission units 113-1 to 113-n, for example, priority in DS Field, IEEE 802.3p in RFC 2474 is added, and priority transmission is performed.

  The flowchart in FIG. 6 schematically shows an operation flow of the above-described data transmission apparatus 110A. This operation example assumes the above-described case of weight billing.

  First, in step ST21, the network usage fee is designated as the fee U by inputting the user's network usage fee U, and the target packet loss rate is designated as the packet loss rate Pt by inputting the user's packet loss rate Pt.

  Next, in step ST22, the data transmission apparatus 110A uses the RTCP session units 117-1 to 117-n to receive packet loss rates of the sessions established by the RTP session transmission units 113-1 to 113-n from the reception side. P1 to Pn are acquired.

  Next, in step ST23, the data transmitting apparatus 110A transmits based on the network usage fee U specified in step ST21, the target packet loss rate Pt, and the packet loss rates P1 to Pn of each session acquired in step ST22. The data distribution unit 115A determines one or a plurality of sessions (transmission sessions) for transmitting the encoded data generated by the encoder 111 and a data distribution ratio to each transmission session.

  Next, in step ST24, data transmission apparatus 110A uses encoder 111 to hierarchically encode video data VD as multimedia data. Then, in step ST25, the data transmission apparatus 110A distributes the encoded data generated by the encoder 111 to the session processing units 112-1 to 112-n according to the data distribution ratio of each transmission session.

  Next, in step ST26, the data transmission device 110A performs RTP packetization of transmission data in the session processing units 112-1 to 112-n, and converts the generated packets to the RTP session transmission units 113-1 to 113, respectively. -n is transmitted to the receiving side via the NGN network 130. The data processing apparatus 110 returns to the process of step ST22 after the process of step ST26, and repeats the same process as described above. As a result, the bandwidth allocation for each session can be dynamically changed according to the variation of the packet loss rate of each session, and the user's payment fee is fixed when the distribution rate is fixed after satisfying the target packet loss rate Pt. Can be less than

  Next, the operation of the data receiving apparatus 120A will be described. The RTP packets received by the RTP session receiving units 121-1 to 121-n are supplied to the session processing units 122-1 to 122-n. In the session processing units 122-1 to 122-n, analysis is performed on the header and payload in the RTP packet, and data before packetization is reconfigured.

  Data (encoded data) reconstructed by the session processing units 122-1 to 122-n is supplied to the decoder 123. In the decoder 123, data (encoded data) supplied from the session processing units 122-1 to 122-n is decoded to generate video data VD.

  The RTCP session units 124-1 to 124-n perform RTCP packet communication with the data transmission device 110A and are established in the data transmission device 110A by the RTP session transmission units 121-1 to 121-n. The packet loss rates P1 to Pn of each session are transmitted.

  The flowchart in FIG. 7 schematically shows the flow of operation of the above-described data receiving apparatus 120A.

  First, in step ST31, the data reception device 120A receives RTP packets by the RTP session reception units 121-1 to 121-n, and depacketizes the RTP packets by the session processing units 122-1 to 122-n. To reconstruct the data before packetization.

  Next, in step ST32, the data reception device 120A decodes the data (encoded data) obtained by the session processing units 122-1 to 122-n by the decoder 123, and outputs the video data VD. The data receiving device 120A

  Next, in step ST33, the data reception device 120A transmits the packet loss rates P1 to Pn of each session to the terminal side by the RTCP session units 124-1 to 124-n. After the process of step ST33, the process returns to the process of step ST31, and the same process as described above is repeated.

  As described above, in the data transmission system 100A shown in FIG. 5, in the data transmission device 110A, the encoded data of the video data VD has a priority according to the designated network fee U and the target packet loss rate Pt. The data is distributed as transmission data of one or a plurality of sessions selected from n different sessions, and transmitted to the data reception device 120A via the NGN network 130 by the corresponding RTP session transmission unit.

  Therefore, in the data transmitting apparatus 110A, only by specifying the network usage fee and the target packet loss rate, the transmission is performed with the priority optimized for the fee without causing deterioration of the transmission quality, and the user's trouble is reduced. Reduced. In other words, in this data transmitting apparatus 110A, in a network environment in which the network status is considered and high priority is not required, a large amount of data is distributed to the low priority session, and the network usage fee can be reduced. In addition, by allocating a large amount of data to the low priority session in this way, it is possible to reduce the amount of data for the high priority session and the reserved bandwidth, and to efficiently use the network bandwidth.

  In the data transmission system 100A shown in FIG. 5, information using the packet loss rates P1 to Pn of each session is shown as information indicating the network status, but other information, for example, transmission delay of each session is shown. A configuration using information such as (RTT) may be used.

  In the above embodiment, the multimedia data is video data VD. However, the multimedia data handled in the present invention is not limited to video data, such as audio data and text data. Handling is also possible.

  The present invention can be applied to a data transmission system in which bandwidth reservation is possible and multimedia data is transmitted via networks having different network usage charges according to the priority of the reserved bandwidth session.

It is a block diagram which shows the structural example of the data transmission system as embodiment of this invention. It is a figure which shows the format of a RTP packet. It is a flowchart which shows roughly the flow of operation | movement of the data transmitter which comprises a data transmission system. It is a flowchart which shows roughly the flow of operation | movement of the data receiver which comprises a data transmission system. It is a block diagram which shows the structural example of the data transmission system as other embodiment of this invention. It is a flowchart which shows roughly the flow of operation | movement of the data transmitter which comprises a data transmission system. It is a flowchart which shows roughly the flow of operation | movement of the data receiver which comprises a data transmission system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100,100A ... Data transmission system, 110, 110A ... Data transmission apparatus, 111 ... Encoder, 112-1 to 112-n ... Session processing part, 113-1 to 113-n ... RTP session transmission unit, 114... Network usage charge designation unit, 115, 115A... Transmission data distribution unit, 116... Target packet loss rate designation unit, 117-1 to 117-n. , 120, 120A, data receiving device, 121-1 to 121-n, RTP session transmission unit, 122-1 to 122-n, session processing unit, 123, decoder, 124-1. 124-n ... RTCP session part, 130 ... NGN network

Claims (10)

A data transmission device that transmits bandwidth data through a network that allows bandwidth reservation and has different network usage charges depending on the priority of the bandwidth reserved session,
N session transmitters for establishing n sessions (n is an integer of 2 or more) having different priorities;
An encoder that encodes multimedia data to be transmitted to generate encoded data;
A network usage fee designating unit for specifying a network usage fee;
Transmission data distribution for distributing the encoded data generated by the encoder as transmission data of one or more sessions selected from the n sessions according to the network usage fee specified by the network usage fee specifying unit And a data transmission device. The encoder hierarchically encodes the multimedia data to be transmitted,
The data transmission apparatus according to claim 1, wherein the transmission data distribution unit distributes hierarchical data having higher importance among the encoded data as transmission data of a session having higher priority. The multimedia data is video data,
The data transmission apparatus according to claim 2, wherein the encoder uses image quality scalable, resolution scalable, or frame rate scalable as a hierarchical structure in the hierarchical encoding. The transmission data distribution unit
The network usage fee specified by the network usage fee specifying unit is U, the network usage fee per unit transmission rate of the n sessions is Ki (i = 1, 2,..., N), and the n When the transmission rate of transmission data distributed to a session is MSi (i = 1, 2,..., N),

2. The data transmission according to claim 1, wherein the encoded data generated by the encoder is distributed as transmission data of one or a plurality of sessions selected from the n sessions so as to satisfy the formula: apparatus. The transmission data distribution unit
The transmission data of one or more sessions selected from the n sessions of the encoded data generated by the encoder according to the network status together with the network usage fee specified by the network usage fee specifying unit. The data transmission device according to claim 1, wherein the data transmission device is distributed as follows. A packet loss rate acquisition unit that acquires the packet loss rate of the n sessions as information indicating the status of the network;
A target packet loss rate specifying unit for specifying the target packet loss rate,
The transmission data distribution unit
The network usage fee specified by the network usage fee specifying unit is U, the network usage fee per unit transmission rate of the n sessions is Ki (i = 1, 2,..., N), and the n The transmission rate of the transmission data distributed to the session is designated by MSi (i = 1, 2,..., N), the transmission rate of the encoded data generated by the encoder is designated by M, and the target packet loss rate designation unit is designated. If the target packet loss rate is Pt and the packet loss rate of the n sessions is Pi (i = 1, 2,..., N),

6. The data transmission according to claim 5, wherein the encoded data generated by the encoder is distributed as transmission data of one or a plurality of sessions selected from the n sessions so as to satisfy the formula: apparatus. A data transmission method for transmitting multimedia data via a network that allows bandwidth reservation and has different network usage charges depending on the priority of the bandwidth reserved session,
A session establishment step for establishing n sessions (n is an integer of 2 or more) having different priorities;
An encoding step of encoding multimedia data to be transmitted to generate encoded data;
A transmission data distribution step of distributing the encoded data generated in the encoding step as transmission data of one or a plurality of sessions selected from the n sessions according to a specified network usage fee. A characteristic data transmission method. A data receiving device for receiving multimedia data via a network that is capable of bandwidth reservation and has different network usage charges depending on the priority of the bandwidth reserved session,
N session receivers for establishing n sessions (n is an integer of 2 or more) having different priorities;
A data receiving apparatus comprising: a decoder that decodes encoded data received by the n session receiving units to generate multimedia data. A data receiving method for receiving multimedia data via a network capable of bandwidth reservation and having different network usage charges depending on the priority of the bandwidth reserved session,
A session establishment step for establishing n sessions (n is an integer of 2 or more) having different priorities;
And a decoding step for decoding the encoded data received in the n sessions to generate multimedia data. A data transmission system consisting of a data transmission device and a data reception device, capable of reserving multimedia data via a network that allows bandwidth reservation and has different network usage charges according to the priority of the bandwidth reserved session,
The data transmission device is
N session transmitters for establishing n sessions (n is an integer of 2 or more) having different priorities;
An encoder that encodes multimedia data to be transmitted to generate encoded data;
A network usage fee designating unit for specifying a network usage fee;
Transmission data distribution for distributing the encoded data generated by the encoder as transmission data of one or more sessions selected from the n sessions according to the network usage fee specified by the network usage fee specifying unit And
The receiving device is
N session receivers for establishing the n sessions having different priorities;
A data transmission system comprising: a decoder that decodes encoded data received by the n session receivers to generate multimedia data.

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