KR101137248B1 - System and Method for Multimedia Streaming of Distributed Contents Using Mobile Agent - Google Patents

Abstract

The present invention relates to a content distributed storage multimedia streaming system and method using a mobile agent. According to the present invention, in a distributed storage system for distributing and storing multimedia content in a plurality of nodes, periodically updating the meta information of the content by using a mobile agent that traverses each node, and the node receiving the streaming request from the client receives the meta information. Use to return the best server to perform streaming. The present invention collects and updates content information through a mobile agent that traverses nodes without being directly involved in obtaining content information, thereby greatly reducing the burden on the network.

Description

System and Method for Multimedia Streaming of Distributed Contents Using Mobile Agent}

The present invention relates to a multimedia streaming service, and more specifically, in a distributed storage system for distributing and storing multimedia content in multiple nodes, periodically updating meta information of content using a mobile agent that traverses each node and streaming the client. The present invention relates to a streaming system and a method in which a node receiving a request returns an optimal server to a client to perform streaming using meta information.

With the development of internet technology, a streaming service that receives multimedia content such as video or animation through the internet in real time is being activated. Streaming refers to a technique of playing in real time while buffering a certain amount of the entire file, unlike a download method of playing after receiving all multimedia content files. Since the rest is continuously transmitted while playing back the buffered part, it is called 'streaming' because the transmitted data is treated as if it were a continuous, continuous stream of water. Such streaming services include real time broadcast services or video on demand services.

Meanwhile, with the explosive increase in video content including user created contents (UCC), Internet traffic has been increasing rapidly in recent years. The growth rate of Internet bandwidth (supply) is not able to keep pace with the growth rate of Internet traffic (demand). In 2007 alone, global Internet traffic grew 75 percent, but Internet bandwidth grew only 44 percent.

As a way to solve the shortage of Internet bandwidth, CDN (content delivery network) technology is attracting attention. CDN technology is a technology that can utilize the internet network more efficiently by using active traffic distribution to increase average network utilization and lower peak traffic. According to the CDN technology, the content provider replicates the content to be provided to the client to a plurality of locally distributed servers, and when requested by the client, the content provider can receive the content from the optimal server.

In the case of a streaming service, a distributed storage system for distributing and storing multimedia contents in various nodes is known. This distributed storage method can improve the quality of streaming services by distributing the load of each node and increasing network efficiency. However, in order for such a distributed storage system to operate efficiently, each node must be able to acquire information about multimedia contents stored in other nodes in real time and efficiently. However, the conventional general method of requesting and gathering content information from a large number of nodes at once increases the network load and incurs an initial buffering delay due to response delay as the bandwidth used increases, resulting in poor service quality and data distributed storage. The effect will be halved.

Accordingly, the present invention is to solve the conventional problems, to efficiently obtain, maintain, and manage information on the multimedia content stored in each node in the content distributed storage multimedia streaming service.

In addition, the present invention is to reduce the burden on the network in the content distributed storage multimedia streaming service to obtain content information of another node without a response delay.

In order to achieve this object, the present invention provides a content distributed storage multimedia streaming system and method using a mobile agent.

The content distributed storage multimedia streaming system according to the present invention includes a plurality of nodes distributed and distributed locally between a content provider and a plurality of clients, each of which is a streaming server, a content server, a meta information server, and a mobile agent. A server, wherein the content server stores multimedia content, the meta information server stores meta information about the multimedia content stored in the nodes, and the mobile agent server generates a mobile agent to generate the mobile agent. Control to collect and update the meta information while traversing the nodes, and the streaming server receives the streaming request of the client, retrieves the meta information from the meta information server, and selects an optimal streaming node based on a search result. decision Returning to the client and if the mobile node belongs to the optimal node, the multimedia content is obtained from the content server and transmitted to the client.

In the content distributed storage multimedia streaming system of the present invention, the mobile agent may have a meta information list in which meta information of all contents stored in the nodes is recorded, and the meta information list is obtained each time it arrives at each node. The meta information list may be updated by receiving the meta information of the content being stored and stored by each node.

In addition, the meta-information is the minimum number of available playbacks, which means the number of accessible users, which means the number of users who can access each content of each node, and the remaining playing time of the first user who is connected to each content of each node. It may include at least one of the time.

The streaming server may determine, as the optimal streaming node, a node having the largest number of accessable nodes among the nodes that have the content requested by the client as a result of the search for the meta information.

Also, the streaming server may determine, as the optimal streaming node, a node having the smallest remaining minimum playing time among nodes that have content requested by the client as a result of the search for the meta information.

On the other hand, according to the present invention, the distributed content streaming multimedia streaming method, a plurality of nodes are distributed and distributed locally between a content provider and a plurality of clients, each of the nodes to provide the multimedia content and meta information about the multimedia content. A multimedia streaming method in a content distribution and storage system for storing, comprising the steps of: a mobile agent generated at at least one of the nodes, collecting and updating the meta information while traversing the nodes; Searching for the meta-information at the specific node when a streaming request is received from a specific node; determining an optimal streaming node based on a search result of the meta-information at the specific node and returning it to the client; Client The request comes streaming from transmitting the multimedia content to the client in the best streaming node.

In the content distributed storage multimedia streaming method of the present invention, the mobile agent may have a meta information list in which meta information of all contents stored in the nodes is recorded, and each meta information list arrives at each node. In this case, each node receives the meta information of the content being stored and updates the meta information list.

In addition, the meta-information is the minimum number of available playbacks, which means the number of accessible users, which means the number of users who can access each content of each node, and the remaining playing time of the first user who is connected to each content of each node. It may include at least one of the time.

In addition, the specific node may determine, as the optimal streaming node, a node having the largest number of accessible nodes among nodes that have content requested by the client as a result of the search for the meta information.

In addition, the specific node may determine, as the optimal streaming node, a node having the smallest remaining minimum play time among nodes that have content requested by the client as a result of the search for the meta information.

The present invention collects and updates content meta information while the mobile agent traverses each node that distributes and stores multimedia content in a content distributed storage multimedia streaming service, so that the information can be efficiently obtained, maintained, and managed. There is this.

In addition, the present invention collects and updates content information through a mobile agent that traverses nodes without being directly involved in obtaining content information, thereby greatly reducing the burden on the network.

In addition, since the present invention periodically generates a mobile agent and collects and updates content information through the mobile agent, the streaming service can be started immediately without a response delay when a streaming request is received from a client.

In addition, the present invention uses a mobile agent that uses a constant network bandwidth, there is an advantage that can maintain a constant network load even if the scale of the distributed multimedia service environment.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention. In describing the embodiments, descriptions of technical contents that are well known in the art to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly communicate without obscure the core of the present invention by omitting unnecessary description. In addition, like reference numerals designate like or corresponding elements throughout the accompanying drawings.

1 is a view schematically showing the configuration of a multimedia streaming system according to the present invention, Figure 2 is a diagram showing a node configuration of a multimedia streaming system according to an embodiment of the present invention.

Referring to FIG. 1, in the multimedia streaming system of the present invention, a plurality of nodes are locally distributed and distributed between a content provider CP and a plurality of clients C1, C2, C3, C4, C5,..., Cn. N1, N2, N3, ..., Nn).

Content provider (CP) is a server that stores the original of the multimedia content to provide a streaming service, also called an origin server (origin server), a multimedia server. The content provider CP distributes and stores a copy of the multimedia content in each node N1, N2, N3, ..., Nn according to a predetermined content distribution storage policy.

Clients C1, C2, C3, C4, C5, ..., Cn receive multimedia content from a specific node through a streaming service and play it while temporarily storing it. To this end, the client has one or more buffers to temporarily store the received data. Clients cover a variety of electronic devices that can receive, decode and play streaming data. For example, the client C1 may be a computer, a set top box, a personal digital assistant (PDA), a mobile phone, a game machine, an MP3 player, or the like.

As illustrated in FIG. 2, each node N1, N2, N3, N4 includes a streaming server 11, a content server 12, a meta information server 13, and a mobile agent server 14. do.

The streaming server 11 receives the streaming request from the client C1, and accesses the meta information of the multimedia content requested from the client C1 to the meta information server 13 to search. In addition, the streaming server 11 determines the optimal streaming node based on the meta information search result and returns it to the client C1. If the streaming server 11 is the optimal streaming server, the streaming server 11 obtains the corresponding content from the content server 12 and the client. Send to (C1). The streaming server 11 supports the real-time streaming protocol (RTSP) of the international standard IETF RFC2326 and the real-time transport protocol (RTP) / RTP (RTP control protocol) of the IETF RFC3550 to perform streaming.

The content server 12 stores multimedia content provided by a content provider. Multimedia content includes UCC and other video content, online education, mass media content such as movies, broadcasts, music, recording and live broadcast content. The content server 12 provides the multimedia content to the streaming server 11 at the request of the streaming server 11.

The meta information server 13 stores information on the multimedia content stored in each node N1, N2, N3, N4, that is, meta information. In particular, the meta information server 13 of each node stores not only the meta information of the contents stored by the node, but also the meta information of the contents stored by other nodes. As will be described in detail later by way of example, the meta information includes items such as a node ID, a content name, a content type, a content size, a content playing time, a number of accessible times, a minimum remaining playing time, and a meta information storing time. Among these, the number of available accesses means the number of users who can access the corresponding content of the corresponding node, and the minimum remaining playing time means the remaining playing time of the first user who accesses the corresponding content of the corresponding node. In addition, the meta information storage time means a time at which the meta information is recorded in the meta information list of the mobile agent at each node. The meta information will be described later in detail with reference to Table 1.

The meta information server 13 provides the streaming server 11 with the meta information search result of the content. In addition, the meta information server 13 provides the mobile agent with meta information that is being stored, or receives new meta information from the mobile agent to update the meta information that is being stored.

The mobile agent server 14 periodically generates a mobile agent and specifies a movement path to control the mobile agent to traverse other nodes. In addition, the mobile agent server 14 controls the mobile agent or a mobile agent from another node to exchange meta information with the meta information server 13.

Next, a multimedia streaming system and method according to an embodiment of the present invention will be described in more detail with reference to FIGS. 2 and 3. 3 is a flowchart illustrating a multimedia streaming method according to an embodiment of the present invention.

First, in order to obtain and maintain information on multimedia content distributed and stored in each node, the mobile agent server 14 of the specific node N1 generates a mobile agent. A mobile agent is a software processor that autonomously moves and collects various hosts necessary in a network in a distributed environment such as the Internet, and provides information. Mobile agents are well known in the art, for example, mobile agents are introduced in the following papers.

-V. A. Pham and A. Karmouch, "Mobile Software Agents: An Overview", IEEE Communication Magazine, Jul. 1998

-W. R. Cockayne and M. Zyda, "Mobile Agents", Manning Publications Co., 1999

The mobile agent is generated at one or more preset nodes, traverses the nodes, and collects and updates the multimedia content information of each node. The mobile agent server 14 periodically generates a mobile agent in order to collect the latest content information. The mobile agent traverses the other nodes N2, N3, N4 along the movement path designated by the mobile agent server 14, and exchanges content information with the corresponding node (steps S1, S2, S3). That is, the mobile agent has a meta information list in which meta information of contents stored in all nodes is recorded. When the mobile agent arrives at a specific node, the mobile agent transmits its meta information list to the node and the latest meta information of the content stored in the node. Receives and updates its meta information list. The mobile agent via all nodes N2, N3, N4 of the designated path returns to the starting node N1 again and delivers the meta information list (step S4).

Table 1 below is an example of a meta information list.

Node
ID contents
name contents
type contents
size contents
Play time connect
Possible number Minimum residual
Play time Meta Information
Storage time
N1 A movie 1.5 GB 100 minutes 3 9:15 am
N1 C broadcast 0.9 GB 60 minutes One 9:15 am
N2 B UCC 300 MB 20 minutes 0 0:05:38 9:16 am
N2 C broadcast 0.9 GB 60 minutes 7 9:16 am
N3 A movie 1.5 GB 100 minutes 5 9:18 am
N3 B UCC 300 MB 20 minutes 0 0:08:41 9:18 am
N4 A movie 1.5 GB 100 minutes 0 0:13:20 9:19 am
N4 B UCC 300 MB 20 minutes 0 0:01:50 9:19 am
N4 C broadcast 0.9 GB 60 minutes 12 9:19 am

In the example of Table 1, node N4 stores contents A, B, and C. Content A is a movie with a size of 1.5 GB and a 100 minute duration, and content B is a 300 MB size and 20 minutes duration UCC. The content C is 0.9GB in size and 60 minutes in duration. Content A is stored in node N1 and node N3 in addition to node N4, content B is stored in node N2 and node N3 in addition to node N4, and content C is stored in node N1 and node N2 in addition to node N4.

On the other hand, in the case of the content A, the number of connectable nodes of node N1 is 3, the number of connectable nodes of node N3 is 5, and the number of connectable nodes of node N4 is zero. That is, three more users are connected to node N1 and five more users are connected to node N3 to receive content A, but there is no user currently accessible to node N4. At this time, in the case of node N4, the minimum remaining playing time is 13 minutes and 20 seconds, which means that the remaining playing time of the first user who is connected to node N4 and is currently receiving content A is 13 minutes and 20 seconds. do. That is, unless the user terminates the service midway, the service is completed after 13 minutes and 20 seconds.

Meta information storage time is shown as node N1, node N2, node N3, and node N4 at 9:15 am, 9:16, 9:18, and 9:19 respectively, as the mobile agent traverses the nodes. It means the time of updating meta information.

In the description of updating meta information, the mobile agent generated at a specific node N1 updates its meta information list by exchanging meta information with each node while traversing all other nodes N2, N3, and N4. In addition to updating the meta information stored in the nodes.

For example, when a mobile agent created and departed at node N1 arrives at node N2, the mobile agent passes its meta information list to node N2. In the meta information list, meta information of all the nodes N1 to N4 is recorded. The node N2 receives meta information of other nodes N1, N3, N4 from the meta information list, updates the meta information with the stored meta information, and provides its meta information to record its meta information recorded in the meta information list. Update the information. Through all nodes in this way, each node can keep up to date with the meta information of itself as well as other nodes.

As such, when all nodes maintain the latest meta information through the mobile agent, when the client C1 connects to a specific node N1 and makes a streaming request, the streaming server 11 of the node N1 A streaming request from the client C1 is received (step S5).

The streaming server 11 of the node N1 receiving the streaming request from the client C1 connects to the meta information server 13 and retrieves meta information about the content requested by the client (step S6). In addition, the streaming server 11 determines an optimal streaming node (that is, an optimal streaming server) based on the meta information search result and returns it to the client C1 (step S7). Meta information retrieval and optimal server determination method are as follows.

(1) Search for the node that holds the content requested by the client.

(2) Compare the accessible numbers of the retrieved nodes.

(3) The node with the largest possible number of connections is determined as the optimal server.

(4) When the number of accessible nodes of the found nodes is all '0', the minimum remaining reproduction time is compared.

(5) The node with the smallest remaining play time is determined as the optimal server.

Referring to the example of Table 1, when a client requests content A, the content holding node is searched for N1, N3, N4. Since the number of accessible nodes of the retrieved node is 3, 5, and 0, respectively, the optimum server is determined as the node N3 having the largest possible number of connection results. If the client requests the content B, the content holding node is retrieved N2, N3, N4. Since the connectable number of the retrieved nodes is all zeros, the minimum remaining reproduction time is compared again. As a result of comparing the minimum remaining reproduction time, the optimum server is determined as the node N4 having the smallest minimum remaining reproduction time.

As such, when node N1, which has received a streaming request from client C1, retrieves meta information of the requested content and determines an optimal server therefrom (for example, node N3), the client C1 returns to the client. It connects to N3 and requests streaming (step S8). The optimum server N3 receiving the streaming request acquires the corresponding content from its content server 12 and starts the streaming service to the client C1 (step S9).

As described above, the present specification and drawings have been described with respect to preferred embodiments of the present invention, although specific terms are used, it is only used in a general sense to easily explain the technical contents of the present invention and to help the understanding of the present invention. It is not intended to limit the scope of the present invention. It is to be understood by those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

The present invention can be usefully used for a variety of multimedia streaming services that appear in a variety of forms, such as video content, online education, mass media content such as movies, broadcasts, music, recording and live broadcast, IPTV, including UCC.

1 is a view schematically showing the configuration of a multimedia streaming system according to the present invention.

2 is a diagram showing a node configuration of a multimedia streaming system according to an embodiment of the present invention.

3 is a flowchart illustrating a multimedia streaming method according to an embodiment of the present invention.

<Description of main parts of drawing>

CP: Content Provider

N1, N2, N3, N4,... , Nn: node

C1, C2, C3, C4, C5,... , Cn: Client

11: streaming server

12: content server

13: Meta Information Server

14: Mobile Agent Server

Claims (10)

In the content distributed storage multimedia streaming system comprising a plurality of nodes distributed locally distributed between a content provider and a plurality of clients, Each said node comprises a streaming server, a content server, a meta information server, a mobile agent server, The content server stores the multimedia content, The meta information server stores meta information about the multimedia content stored in the nodes, The mobile agent server generates a mobile agent to control the mobile agent to collect and update the meta information while traversing the nodes, The streaming server may be configured to, among the node ID, content name, content type, content size, content playback time, number of available connections, minimum remaining playback time, and metadata information storage time from the meta information server according to a streaming request received from at least one client. Searching for the meta information including at least one, determining a streaming node based on a search result, and returning the streaming node to the at least one client, and if the streaming node belongs to the streaming node, obtains the multimedia content from the content server and transmits the multimedia content to the client. Content distributed storage multimedia streaming system, characterized in that. The method according to claim 1, The mobile agent has a meta information list in which meta information of all contents stored in the nodes is recorded. The mobile agent delivers the meta information list each time it arrives at each node and receives the meta information of the content stored in each node. Content distributed storage multimedia streaming system, characterized in that for updating the information list. The method according to claim 2, The meta information includes the number of available accesses, which means the number of users that can access each content of each node, and the minimum remaining playback time, which indicates the remaining play time of the first user who is connected to each content of each node. Content distribution storage multimedia streaming system comprising at least one. The method of claim 3, And the streaming server determines, as the streaming node, the node having the largest number of accessable nodes among the nodes that have the content requested by the client as a result of the meta information search. The method of claim 3, And the streaming server determines, as the streaming node, a node having the smallest remaining minimum play time among nodes that have content requested by the client as a result of the meta information search. A multimedia streaming method in a content distributed storage system in which a plurality of nodes are distributed and distributed locally between a content provider and a plurality of clients, and wherein each of the nodes stores multimedia content and meta information about the multimedia content. Collecting and updating the meta information while traveling by the mobile agent generated by at least one of the nodes; When a streaming request is received from at least one client to a specific node, among the node ID, the content name, the content type, the content size, the content playback time, the number of accesses, the minimum remaining playback time, and the meta information storage time at the specific node. Retrieving the meta information including at least one; Determining, by the specific node, the streaming node based on the search result of the meta information and returning the streaming node to the client; Transmitting the multimedia content to the at least one client when the streaming request comes from the at least one client; Content distributed storage multimedia streaming method comprising a. The method of claim 6, The mobile agent has a meta information list in which meta information of all contents stored in the nodes is recorded. The mobile agent delivers the meta information list each time it arrives at each node and receives the meta information of the content stored in each node. Content distribution storage multimedia streaming method, characterized in that for updating the information list. The method of claim 7, The meta information includes the number of available accesses, which means the number of users that can access each content of each node, and the minimum remaining playback time, which indicates the remaining play time of the first user who is connected to each content of each node. Content distribution storage multimedia streaming method comprising at least one. The method according to claim 8, And the specific node determines, as the streaming node, the node having the largest number of accessable nodes among the nodes that have the content requested by the client as a result of the search for the meta information. The method according to claim 8, And the specific node determines, as the streaming node, a node having the smallest remaining minimum play time among the nodes that have the content requested by the client as a result of the search for the meta information.

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