KR20050103558A - System and method for transmitting the data from server to clients in the internet network - Google Patents

Abstract

The present invention relates to a data transmission method between a server and clients in an Internet network, and to a server / client system for transmitting data between a server storing predetermined content and a plurality of clients that want to receive the content in the same network. A first client for receiving the content from the server for each sub-network; And a second client maintaining a connection with the server, the second client receiving the same content from the first client as the content received from the server by the first client in the same subnetwork as the first client. do.

Description

System And Method For Transmitting The Data From Server To Clients In The Internet Network

The present invention relates to a communication method between a server and clients in an internet network, and more particularly, to a server storing predetermined content and a server by traffic distribution among a plurality of clients that want to receive the content in the same network. A system and method for data transmission between clients.

Currently, broadcasting methods provided through the Internet network include a video on demand (hereinafter referred to as VOD) method and a real-time multicast service method.

The VOD type service is a new type of video service which is a combination of computer, communication, and broadcasting fields, and is a video service on demand that provides desired video material or viewing program according to a user's request. If the existing broadcast is a passive broadcast centered on an over-the-air station, the Internet broadcast may be called an on-demand, interactive broadcast. That is, the VOD method has an advantage that it can be viewed selectively only when the user wants it, rather than unilaterally spreading radio waves. Accordingly, in order to provide the VOD service, the multimedia server basically stores multimedia information, that is, a music server or a video file, a communication network through which huge multimedia information such as the video file can be delivered to the receiver, and compression and restoration of data. And components such as software (eg, set-top boxes or players) that enable playback in real time.

On the other hand, there are a download method and a streaming method as a method of receiving broadcast data from a server by a client. The download method is a method of receiving the entire broadcast data, storing it in a memory of the client, and playing the data. The streaming method is a method of receiving and decoding data from the server in real time. The above-described VOD scheme and real-time multicast service scheme reproduce multimedia data received using the streaming scheme.

The streaming method is a technology that optimally uses network and CPU resources by transmitting, receiving and decoding continuous media such as a large amount of video and audio in real time. In general, data that consumes the entire volume (e.g., extruded files) creates a momentary load because it uses a download method that downloads all data from the server and processes it, but continuous media provides instantaneous Since the required network bandwidth and CPU load are relatively small, only the necessary data need to be processed over time. In general, in order to apply the streaming technology, a priority allocation of network bandwidth and CPU load is required. However, since the Ethernet method widely used for the Internet is not able to statically allocate network resources, data transmission may be delayed depending on the state of the network. To solve this problem, the existing streaming technology has been used to maintain a buffer that can store a certain amount of data on the client.

The recent explosion of the Internet network is a global network, characterized by unspecified simultaneous connections by numerous netizens around the world. In other words, it should be able to send data to a large number of users at the same time.

Such data transmission methods of the Internet can be classified into unicast, broadcast, and multicast from the perspective of a transmitter / receiver participating in data transmission. Among them, the multicast transmission method is recognized as an optimal alternative to the multiple transmission, and various studies on the multicast transmission method are being conducted.

Unlike the unicast transmission method (a transmission method in which one sender transmits data to another receiver), which is generally used on the Internet, the multicast transmission method includes receivers participating in the header of the transmission packet instead of the address of the receiver. By displaying the group address, it is possible to minimize the waste of network resources due to redundant transmission of data by allowing data to be transmitted to multiple receivers at once.

In addition, for such multicast transmission, the sender uses a group address based on a class D IP address, not an actual host address, and a receiver receiving a multicast packet having the group address indicates whether the group is included in the group. It is determined whether to receive the data by determining. Therefore, a separate router is needed to support such a multicast transmission method.

However, since most routers in the Internet are configured to support only unicast, it is difficult to apply a multicast transmission method on the Internet in reality.

To overcome this, an IP multicast transmission scheme for transmitting an encapsulated packet using a concept of tunneling may be used.

In this case, in the multicast transmission method using tunneling, after the tunnel is established between the multicast routers and the multicast router routes the data packet for the multicast, the multicast router is configured between the multicast routers before the header of the packet. The IP address at both ends of the tunnel should be added for routing. That is, when such a multicast data packet passes through general routers that do not support multicast, the multicast data packet is routed in the same manner as the existing unicast packet by the IP addresses at both ends and finally transmitted to the end point of the tunnel, thereby providing the current Internet. Enable multicast transmission even in environments.

However, this IP multicast transmission method also has a problem in that the number of simultaneous accessors that can be accommodated is limited.

In addition, there are network-level multicast and application-level multicast.

The dual network level multicast scheme is a method of inserting a hardware additional function into a router to cause the router to perform distributed transmission. In order to apply it to the Internet, all routers on the Internet must be replaced with a router that performs this function. There is this. Thus, network level multicast schemes are not practical.

On the other hand, the application-level multicast scheme is a method that allows the primary receiver receiving data from the sender to retransmit the data to the secondary receiver, and manages when an unspecified number of simultaneous accessors occur and there are many connection paths between them. It is difficult to do Accordingly, there is a serious problem that the number of concurrent users is substantially limited, and when the upper receiver is disconnected, there is a serious problem that it is not possible to guarantee the reliability of data transmission and maintaining the connection state of a number of lower receivers.

As described above, the VOD method has a disadvantage in that a load (including a network) is placed on the server because all clients (users) access the server and receive the desired content. Therefore, although the above-described method is a multicasting broadcast, it is limited to real time broadcasting, and there is a problem in that a router or the like must support multicasting.

Accordingly, an object of the present invention is to provide a server and clients by traffic distribution in which the remaining clients in the same network receive content through one client selected from a predetermined network that receives the content from a server storing the predetermined content. The present invention provides a system and method for transmitting data between the objects.

In addition, an object of the present invention, in the real-time broadcasting service, traffic distribution for unicasting only one client selected from a network to which a client belongs to the server, and the clients of the same network receive data through the selected client The present invention provides a system and method for transmitting data between a server and clients.

In addition, another object of the present invention is a VOD broadcast service, in which only one client selected within a given network receives data from a server and other clients receive data from a previously connected client in the same network. The present invention provides a system and method for transmitting data between a server and clients.

In addition, another object of the present invention is a VOD broadcast service, in which only one selected client within a given network receives data from a server, and other clients receive data from the selected client by multicasting, and simultaneously within the same network. The present invention provides a system and method for transmitting data between a server and clients by traffic distribution for receiving data from another client.

The system of the present invention for achieving the above object; A server / client system for transmitting data between a plurality of clients that want to receive the content in the same network as a server storing predetermined content, the server / client system comprising: a first client receiving the content from the server for each sub-network; And a second client maintaining a connection with the server, the second client receiving the same content from the first client as the content received from the server by the first client in the same subnetwork as the first client. do.

In addition, the method of the present invention for achieving the above object; A data transmission method between a server and clients in an internet network in which data is transmitted between a plurality of clients that want to receive the content in the same network as a server storing predetermined content, the method comprising: a predetermined client belonging to a predetermined subnetwork Requesting the predetermined content by accessing the server; Searching whether there is a client other than the client that receives the same content as the requested content in the corresponding subnetwork from the server; And receiving the requested content from the other client when the other client receiving the same content exists in the corresponding subnetwork as a result of the search.

Hereinafter, a detailed description of a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, detailed descriptions of well-known functions or configurations will be omitted when it is determined that the detailed descriptions of the known functions or configurations may unnecessarily obscure the subject matter of the present invention.

The present invention provides a client that receives content from the server when there is a client that receives the same content in the network in order to reduce the server load caused by all the clients connected to the server to get the content. The present invention proposes a method of receiving the same content.

In the following description, "server" refers to a content provider holding predetermined content in a database, and "client" refers to each terminal that receives content by connecting to the "server" through a predetermined network. it means. On the other hand, the server and the client is connected through a predetermined communication network, the network includes a wired / wireless network. In addition, a plurality of networks may be interworked and connected between the server and the client.

Meanwhile, in the following description, the term "sub-network" refers to a collection of a plurality of clients connected by the same or similar transmission line among large networks connecting the server and the network. For example, the sub-network may be a predetermined local area network (hereinafter, referred to as a 'LAN') or a local network service provider network (eg, a double-net). Therefore, the plurality of clients in the same network may use some classes of IP (Internet Protocol) addresses of each terminal in the same manner.

1 is a diagram illustrating a concept of a data transmission system between a server and a client according to the present invention.

Referring to FIG. 1, a data transmission system between a server and clients according to the present invention includes a server 100, a first client 110, and a second client 120.

Here, 'first' and 'second' named to the client mean an order of requesting content reception by accessing the server 100. Accordingly, the first client 110 accesses the server 100 before the second client 120 and requests content.

The first client 110 connects to the server 100 and receives predetermined content. Meanwhile, although the second client 120 accesses the server 100, when the second client 120 requests the same content as the content received by the first client 110, the second client 120 does not receive the content from the server 100 according to the present invention. Instead, the same content is received from the first client 110. In this case, the first client 110 will be referred to as a "quasi server" for convenience of description. That is, the first client 110 receives the content from the server 100, while the second client 120 receives the content from the second client 110, that is, the quasi-server, not the server 100. . Therefore, the load on the server 100 can be significantly reduced by doing the above. In this case, the first client 110 and the second client 120 may be provided with content in the form of VOD or real-time broadcast.

Hereinafter, a process of receiving content from the quasi-server by the second client 120 will be described with reference to FIG. 2.

2 is a flowchart illustrating a data transmission method between a server and a client according to the present invention.

Referring to FIG. 2, first, a predetermined client accesses a server holding the corresponding content in order to receive the predetermined content (step 200).

When a client connected to the server requests reception of the content, the server retrieves information of clients belonging to the network for the client that requested the content. That is, when there is another client receiving the same content as the content requested by the client in the predetermined sub-network to which the client belongs, the corresponding content is received from the other client according to the present invention.

Therefore, when the client requests content reception from the server, the server searches (210) whether there is the same content user (ie, client) of the corresponding network. If there is no client receiving the same content in the network as a result of the search (step 220), the client becomes a quasi-server and receives data directly from the server (step 230).

On the other hand, if there is a client receiving the same content in the search result, the client accesses the client receiving the same content in the searched network and receives the content (240).

At this time, the server should monitor and store the connection status and data reception status of clients for each network in a predetermined table. The table will be described later in the description of FIG. 12.

Hereinafter, embodiments of each service (eg, a real time broadcast service and a VOD broadcast service) according to the present invention will be described with reference to the drawings.

First Embodiment-Real Time Broadcasting

First, the method of the present invention applied to real time broadcasting will be described with reference to FIGS. 3 to 5.

3 is a diagram illustrating a network system configuration according to a first embodiment of the present invention.

Referring to FIG. 3, the server 300 may include a first client 311 and 321 (eg, a client first requesting the same content) for each sub-network 310 and 320 (that is, network A, network B, etc.). Alternatively, the content is provided in a unicast manner with a client having the best communication speed with the server among the clients that request the same content. That is, the first clients 311 and 321 for each sub network 310 and 320 directly receive data from the server 300.

Meanwhile, other clients (ie, the second client 312 and 322 and the third client 313 and 323) requesting the same content as the first client 311 and 321 in each of the sub-networks 310 may be used. Receive the same content from the first client (311, 321) in a multicasting manner respectively.

In this case, other clients receiving content from the first clients 311 and 321 connect with the server 300 in preparation for when the first client 311 and 321 is disconnected from the server 300. It is desirable to hold. That is, only the connection with the server 300 is maintained, and actual data is received from the first clients 311 and 321.

4 is a flowchart illustrating a data transmission method between a server and a client according to a first embodiment of the present invention.

Referring to FIG. 4, a predetermined client that wants to receive predetermined content from the server connects to the server (step 400).

If the client connected to the server is a user capable of multicasting with the server (step 410), data is received from the server by the multicasting method (step 420).

On the other hand, if a client connected to the server is a user who cannot multicast with the server, it is possible to receive content from other clients in the network according to the present invention.

Accordingly, the same content user of the corresponding network to which the client accessing the server belongs is searched (step 430), and if there is no same content user, the server receives the data in a unicast manner with the server (step 450). On the other hand, when there is the same content user, the first client receives information about the first client (ie, the first client), and the first client is connected (step 460) to receive data (step 470).

As described above, the server preferably monitors and stores the data reception status of the clients connected to each sub-network, and reduces the load on the server by providing the stored information to the clients requesting the content.

Hereinafter, a data signal processing procedure between the above elements will be described.

5 is a flowchart illustrating a signal processing procedure between respective network elements according to the first embodiment of the present invention.

Referring to FIG. 5, first, the server 510 provides predetermined content to the first client 520 (ie, a quasi-server) (step 501). In this case, when a client other than the first client 520 in the network, that is, the second client 500 accesses the server 510 and requests the same content (step 502), the server 510 The second client 500 transmits information about another client (ie, the first client 520) that is receiving the same content in the corresponding network (step 503).

The second client 500 that has received the information about the first client 520 from the server connects to the first client 520 (step 504) and receives the corresponding content (step 505). .

The first embodiment described above is preferably applied to a real time broadcast, and the second and third embodiments described below are preferably applied to a VOD soundproofing service.

Hereinafter, a service method according to a second exemplary embodiment of the present invention will be described with reference to FIGS. 6 to 9.

<Second embodiment-VOD broadcast (case 1)>

6 is a diagram illustrating a network system configuration according to a second embodiment of the present invention.

Referring to FIG. 6, the server 600 includes a first client 611, 621 (eg, a client first requesting the same content) for each sub-network 610, 620 (ie, network A, network B, etc.). Alternatively, the content is provided in a unicast manner with a client having the best communication speed with the server among the clients that request the same content. That is, the first clients 611 and 621 receive data directly from the server 600 for each sub network 610 and 620.

Meanwhile, other clients requesting the same content as the first clients 611 and 621 in the sub-networks 610, that is, the second clients 612 and 622 and the third clients 613 and 623, respectively, respectively. The same content is received from the first clients 611 and 621 and the second clients 613 and 623 in a unicasting manner.

That is, the second client 612, 622 receives the corresponding content from the first client 611, 621 that has already received the same content from the server 600, and the third client 613, 623. Receives the corresponding content from the client connected immediately before receiving the same content from the server 600, that is, the second client 612 and 622. Therefore, all clients requesting the same content in the same network receive data serially in one unicast line. Therefore, the server 600 preferably stores information on the data reception state (ie, unicast connection relationship) of all clients requesting the same content for each sub-network.

In this case, as in the above-described first embodiment, other clients receiving content from the previously connected client may establish a connection with the server 300 in preparation for the case where the previously connected client is disconnected from the server 300. It is desirable to hold. That is, only the connection with the server 300 is maintained, and the actual data is received from the previously connected client.

On the other hand, in the second embodiment described above, since each client in the corresponding network provides content to the next connected clients in a unicast manner, it can be seen that all of the clients function as a given server.

7 is a flowchart illustrating a data transmission method between a server and a client according to a second embodiment of the present invention.

Referring to FIG. 7, a predetermined client that wants to receive predetermined content from the server connects to the server (step 700).

The client connected to the server can receive content from other clients in the network according to the second embodiment of the present invention described above.

Accordingly, the same content user of the corresponding network to which the client accessing the server belongs is searched (step 710). If there is no same content user, the server receives the data in a unicast manner with the server (step 730). On the other hand, if there is a user of the same content, information about a client immediately connected (step 740) is received, and a client (step 750) is connected to the client immediately connected (step 760) to receive data.

As in the first embodiment described above, it is preferable that the server monitors and stores the data reception status of clients connected to each sub-network, and loads the server by providing the stored information to the clients requesting the content. Can be reduced.

In addition, in the second embodiment, each client should act as a quasi-server, and for this purpose, the streamed data should be encrypted and stored in a memory or a disk. If each of the clients receives encrypted data (for example, data encrypted by DRM (Digital Right Management)) in a streaming manner, the clients can be stored in the encrypted state and transmitted to another client.

8 is a flowchart illustrating a data transmission method when a previous user disconnection occurs according to the second embodiment of the present invention.

Referring to FIG. 8, when the predetermined client is receiving content from a previously connected client according to the above-described method, a case in which the connection of the previous user (ie, the client) is disconnected may occur (step 800). Can be. For example, this is the case when the movie is paused while watching a movie. In this case, since the client maintains the connection with the server as described above, the client searches for whether there is another client that receives the same content from the information stored in the server in the corresponding subnetwork.

As a result of the search, if there is no other client (step 820), the client receives data directly from the server by the unicast method (step 830). On the other hand, if there is another client, it receives data from the retrieved client (step 840).

In this case, in the second embodiment, since disconnection has occurred to the previous client, and each client is connected in a unicast manner, it is preferable to connect to the previous client to which the previous client is connected. For example, when disconnection occurs in the N-th client, the N-th client preferably connects to the N-th client.

On the other hand, it is apparent that the disconnection of the connection can be equally applied to the above-described first embodiment and the third embodiment to be described later.

9 is a flowchart illustrating a data transmission method when a reception interruption of a previous user occurs according to a second embodiment of the present invention.

Referring to FIG. 9, when the predetermined client is receiving content from a previously connected client according to the above-described method, reception of the previous user (ie, the client) may occur (step 900). . In this case, the client determines whether the data received so far is data up to the stopping time received by the previous user (step 910). Accordingly, the client may continue to receive the data received by the previous client (step 920) even if the previous client is stopped.

On the other hand, when the client has received all the data received by the previous client until the interruption time can no longer receive data on the content from the previous client, the other user is searched from the server (step 930). Then, the client accessing the server receives the information about the other client of the corresponding subnetwork searched by the above-described method, and continues to receive data from the other client (step 940).

In this case, in the second embodiment, reception interruption has occurred to the previous client, and since each client is connected in a unicast manner, it is preferable to connect to the previous client to which the previous client is connected. For example, when reception interruption occurs in the N-th client, it is preferable that the N-th client connects to the N-th client.

On the other hand, if the reception interruption of the connection occurs it is obvious that the same can be applied to the first embodiment described above and the third embodiment to be described later.

Hereinafter, another embodiment to which the present invention can be applied in the case of VOD broadcasting will be described with reference to FIGS. 10 and 11.

<Third embodiment-VOD broadcast (case 2)>

10 is a diagram illustrating a network system configuration according to a third embodiment of the present invention.

Referring to FIG. 10, the third embodiment according to the present invention is a combination of the first and second embodiments described above.

That is, in the above-described first embodiment, the first client of each subnetwork transmits data in a multicast manner to other clients (eg, the second client and the third client) requesting the same content in the corresponding subnetwork. In the above-described second embodiment, data is received by a unicast method from a client previously connected in the order in which the clients of each subnetwork are connected.

Accordingly, the method according to the third exemplary embodiment of the present invention may allow other clients (eg, the first client 1011, 1021 for each subnetwork 1010, 1020) to request the same content in the corresponding subnetwork 1010, 1020. In addition, data is transmitted to the second client 1012, 1022, the third client 1013, 1023, and the fourth client 1014, 1024 in a multicast manner, and optionally, each sub-network 1010, 1020. Star clients may receive data in a unicast manner from previously connected clients in the order in which they are connected.

In this case, the first clients 1011 and 1021 in each of the sub-networks 1010 and 1020 receive data by the unicast method with the server 1000, and the other clients in the corresponding sub-networks 1010 and 1020 receive the data. While receiving data by the multicast method from the first clients 1011 and 1021, it is possible to selectively receive the data by the unicast method from its previously connected client.

In this case, the data already received by the multicast scheme does not need to be repeatedly received from other clients. That is, each client of the corresponding network double buffers the data received in the multicast method and the data currently being viewed.

11 is a flowchart illustrating a data transmission method between a server and a client according to a third embodiment of the present invention.

Referring to FIG. 11, a predetermined client that wants to receive predetermined content from a server accesses the server (step 1100).

Clients connected to the server can receive content from other clients in the network according to the third embodiment of the present invention described above.

Accordingly, the same content user of the corresponding network to which the client accessing the server belongs is searched (step 1110). If there is no same content user, the server receives the data in a unicast manner with the server (step 1130). On the other hand, if there is the same content user, the client receives the information about the client just previously connected, and accesses the client immediately connected (step 750) to receive data (step 1150). Meanwhile, according to the third embodiment of the present invention, the client may receive data 1140 from the first client of the corresponding sub network by the multicast method. That is, the same content can be selectively received and synthesized by the two methods (step 1160). As described above, the data already received by the multicast method is duplicated by the unicast method from other clients. There is no need to receive.

As in the first and second embodiments described above, the server preferably monitors and stores the data reception status of the clients connected to each sub-network, by providing the stored information to the clients requesting the content. You can reduce the load on the server.

On the other hand, if the same sub-network is assumed to be the same Internet Service Provider (ISP), many users may watch the same movie. Therefore, according to the embodiments of the present invention described above, since the network speed in the same ISP is very fast compared to the network speed with other ISPs, the effect according to the present invention can be said to be greater.

12 illustrates data fields in a client management database of a server according to an embodiment of the present invention.

Referring to FIG. 12, as described above, in the server storing predetermined content, information of clients requesting to receive the same content for each sub-network (eg, network A, network B, etc.) is preferably stored as a table. Do.

For example, if users a, b and c have requested the same content from network A, the first accessing user a receives data directly from the server, the user b receives data from the user a, and the user c receives the Receive data from user b. In addition, if users 1, 2, 3, and 4 have requested the same content from network B, user 2 who first connected receives data directly from the server, user 1 is from user 2, user 4 is from user 1 and User 3 may be configured to receive the same content data from the user 4. This can reduce the load on the server.

On the other hand, in the embodiment of the present invention has been described with respect to specific embodiments, various modifications are possible without departing from the scope of the invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the appended claims, but also by those equivalent to the claims.

According to the present invention, by distributing the content request for each client, there is an advantage in that the load on the server that can occur when a plurality of clients in the network want to receive the same content from the server can be reduced. In addition, each client has the advantage of a quasi-server to reduce the traffic of the entire network.

1 is a diagram illustrating a concept of a data transmission system between a server and a client according to the present invention.

2 is a flowchart illustrating a data transmission method between a server and a client according to the present invention.

3 is a diagram showing a network system configuration according to a first embodiment of the present invention;

4 is a flowchart illustrating a data transmission method between a server and a client according to a first embodiment of the present invention.

5 is a flowchart illustrating a signal processing procedure between respective network elements according to the first embodiment of the present invention.

6 is a diagram showing a network system configuration according to a second embodiment of the present invention;

7 is a flowchart illustrating a data transmission method between a server and a client according to a second embodiment of the present invention.

8 is a flowchart illustrating a data transmission method when a previous user disconnection occurs according to a second embodiment of the present invention.

9 is a flowchart illustrating a data transmission method when a reception interruption of a previous user occurs according to a second embodiment of the present invention.

10 is a diagram showing a network system configuration according to a third embodiment of the present invention.

11 is a flowchart illustrating a data transmission method between a server and a client according to a third embodiment of the present invention.

12 illustrates data fields in a client management database of a server according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100, 300, 600, 1000: Server

110, 311, 321, 611, 621, 1011, 1021: first client

120, 312, 322, 612, 622, 1012, 1022: second client

310, 610, 1010: network A 320, 620, 1020: network B

313, 323, 613, 623, 1013, 1023: third client

1014, 1024: fourth client

Claims (5)

In the server / client system for transmitting data between a plurality of clients that want to receive the content in the same network as the server that stores the predetermined content, A first client receiving the content from the server for each sub-network; And And a second client maintaining a connection with the server and receiving the same content from the first client as the content received from the server by the first client in the same sub-network as the first client. Data transfer system between servers and clients in an Internet network. The method of claim 1, And a third client maintaining a connection with the server and receiving content from the second client that is identical to the content received by the second client from the server within the same sub-network as the first and second clients. A data transmission system between servers and clients in an Internet network. The method according to claim 1 or 2, And the client transmits and receives the contents to and from the server and other clients in a unicast or multicast method. In the data transmission method between the server and the client in the Internet network for transmitting data between a plurality of clients that want to receive the content in the same network as the server that stores the predetermined content, Requesting the predetermined content by accessing the server by a predetermined client belonging to a predetermined subnetwork; Searching whether there is a client other than the client that receives the same content as the requested content in the corresponding subnetwork from the server; And And receiving the requested content from the other client when there is another client receiving the same content in the corresponding subnetwork as a result of the search. The method of claim 4, wherein If it is impossible to receive the requested content from another client receiving the same content, searching for the existence of another client receiving the same content from the server in the corresponding subnetwork; And And receiving the requested content from the another client when there is another client receiving the same content in the corresponding sub network as a result of the search. Data transfer method.