CN101212646A - A system and method for realizing video on demand by using peer-to-peer network technology - Google Patents

Abstract

The present invention relates to a system and method for realizing video on demand by using peer-to-peer network technology, wherein the central media server and the central directory server of the system are connected to the router of the metropolitan area/wide area network, and the edge media server is connected to the metropolitan area/wide area network and the interface The edge router connected to the network constitutes a P2P-based content distribution network; the edge directory server is also connected to the edge router connected to the edge media server, and the home media terminal is connected to the edge router connected to the edge media server through the access network , forming a P2P-based video-on-demand network. The method of the present invention is that the home media terminal first requests and downloads data in the P2P mode in the edge P2P domain where it is located, and when the requested data does not exist in the edge P2P domain where it is located, the edge media server downloads the corresponding data in the central P2P domain and provides it to Home media terminal. The invention has low cost and strong expansibility, and the more users there are, the less pressure the server is under.

Description

A system and method for realizing video on demand by using peer-to-peer network technology

technical field

The invention belongs to the field of network technology, in particular, the invention relates to a system and method for realizing video on demand on the Internet and other data networks by using peer-to-peer network technology.

Background technique

It is a huge challenge for operators to provide video on demand (Video On Demand, abbreviated as VOD) services on the network, especially VOD services in metropolitan areas (or even wide areas). The source of video programs with standard definition or even high definition quality is very large. Although the gradual maturity of video compression standards MPEG-4 and H.264 has greatly reduced the storage capacity required for video programs, the largest number is still video in MPEG-2 format. programme. At the same time, in order to provide large-scale VOD services in metropolitan areas or wide areas, the bottleneck of network bandwidth is a serious problem that must be faced.

At present, there are services such as file downloading, Internet TV, and VOD using peer-to-peer (Peer-to-Peer, abbreviated as P2P) technology on the Internet. Since the Internet is a best-effort network, the quality of service is not guaranteed, and the joining and leaving behaviors of each peer node (Peer Node) are random. Although there are many P2P algorithms to optimize in various ways, the video quality obtained by users Still not ideal.

At present, network operators can use content distribution network (Contend Delivery Network, abbreviated as CDN) to solve the problem of cross-city/wide-area transmission of video streams, in order to provide large-scale high-quality VOD services. Video programs are stored in multiple CDN nodes in advance, and when a user terminal requests a service, the most suitable node is selected from multiple nodes that can serve the user to serve the user. Due to the client/server (C/S) model, its service capability is limited by the server capability and its network bandwidth. China Telecom's Internet Star is such a deployment method. Deploying a dedicated CDN network on the WAN/MAN leads to high costs. In terms of user services, due to the use of the C/S model, it is limited by bandwidth and server capabilities. Impact, poor scalability, when the number of online users is huge, users cannot get good video services.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and solve the problems of high cost, low service quality and poor scalability encountered in the deployment of large-scale VOD systems, thereby proposing a method of utilizing peer-to-peer network technology to realize video System and method for broadcasting on demand.

In order to realize the foregoing invention object, the system provided by the present invention utilizing peer-to-peer network technology to realize video on demand includes: media server, catalog server and home media terminal; It is characterized in that, described media server comprises center media server (Center Media Server, abbreviated CMS) and Edge Media Server (Edge Media Server, abbreviated as EMS), the directory server includes a central directory server (CenterDirectory Server, abbreviated as CDS) and an edge directory server (Edge Directory Server, abbreviated as EDS); the center The media server and the central directory server are connected to the router of the MAN/WAN, and the edge media server is connected to the edge router connecting the MAN/WAN and the access network, thereby forming a central P2P domain, which constitutes a network based on P2P content distribution network; the edge directory server is in one-to-one correspondence with the edge media server, and is also connected to the edge router connected to the edge media server, and the home media terminal is connected to the edge router connected to the edge media server through the access network connected to form an edge P2P domain, which constitutes a P2P-based video-on-demand network.

In the above-mentioned technical scheme, also comprise the operation support system server (operation support system English is Business Operation&Support System, abbreviated as BOSS) that is connected to the MAN/WAN router.

The above-mentioned technical solution also includes a digital rights management server (Digital Rights Management System is Digital Rights Management System in English, abbreviated as DRMS) connected to the MAN/WAN router.

In the above-mentioned technical scheme, also comprise being connected to the service portal server (service portal English is Service Portal, abbreviated as SP) on the metropolitan area/wide area network router.

In the above technical solution, both the central media server and the edge media server store a number of audio and video media files, wherein each audio and video media file is divided into several data blocks, and each data block is numbered according to its order in the file. is coded as the first block, and, when the audio-video media file has a metadata field, its metadata is divided into a data block separately, and is coded as the zeroth block; except the metadata block and the last data block, The sizes of other data blocks are equal, and the value is between 5MB and 30MB.

For realizing above-mentioned invention object, the method (as shown in Figure 4) that utilizes peer-to-peer network technology provided by the present invention to realize video on demand comprises the following steps:

1) The home media terminal browses the service portal, selects a media file as the target media file to play on demand,

2) The home media terminal sends a request to play the target media file to the edge media server in the edge P2P domain;

3) After the edge media server receives the on-demand request, it immediately responds to the request of the home media terminal and sends the first piece of data of the target media file to it. If the media file has the zeroth piece, the edge media server sends it first. The zeroth block, and then send the first block; after the home media terminal receives the first block of the target media file, it immediately starts playing the media file;

4) The home media terminal sends a query request to the edge directory server in the edge P2P domain;

5) The edge directory server returns a node information list that can provide subsequent data blocks to the home media terminal; the nodes in the node information list include other home media terminals in the edge P2P domain where the home media terminal is located; the nodes also include all The edge media server in the edge P2P domain where the home media terminal is located, the edge media server is at the end of the node information list;

6) The home media terminal sends data download requests to the nodes sequentially according to the received node information list until the data download service is obtained; The directory server sends a query request;

7) The home media terminal plays the downloaded data blocks in sequence.

In the above technical solution, in the step 5), when the edge directory server cannot find a node that can provide the subsequent data blocks of the target media file in the edge P2P domain, it will notify the edge media server to download the data from the central P2P domain. Describe the target media file.

In the above technical solution, the process of downloading the target media file from the central P2P domain by the edge media server is as follows:

51) The edge media server sends a query request to the central directory server;

52) The central directory server returns a node information list that can provide the target media file to the edge media server; the nodes in the node information list include at least the central media server, and are arranged at the end of the node information list; the node information list The nodes in also include other edge media servers in the central P2P domain;

53) The edge media server simultaneously requests multiple nodes according to the node information list, and downloads subsequent data blocks of the target media file.

In the above technical solution, in the step 7), when the user performs the jump operation, if the data block at the jump position has been downloaded, the data block will be played immediately; if the data block at the jump position has not been downloaded yet, Then the home media terminal downloads and plays the data block from the edge media server, and at the same time, re-executes step 4) to step 6), and then the home media terminal plays successively downloaded subsequent data blocks located after the jump position.

In the above technical solution, the edge media server sends status reports to the central directory server and the edge directory server respectively after downloading new data blocks; after the home media terminal downloads new data blocks, sends status reports to the edge directory server.

Compared with the prior art, the present invention has the following advantages:

The present invention proposes a VOD system based on a two-layer P2P structure. By implementing P2P-based content distribution measures in the metropolitan area/wide area, the pressure on the central server is reduced, and by implementing P2P video-on-demand in the access network , reducing the pressure on edge media servers. At the same time, the edge media server undertakes data transmission tasks in the two P2P domains respectively, reducing the demand for infrastructure dedicated to media distribution. The biggest advantage of this system is that it can provide high-quality video-on-demand services for a large number of users with less construction cost. And the deployment of this system can be across metropolitan areas or even wide areas. At the same time, this system has good scalability. The more users there are, the less pressure on the deployed servers.

The method of the invention has the advantages of high service quality, can reduce the pressure of the central server, and reduce the construction cost.

Description of drawings

Fig. 1 is a schematic diagram of network architecture of a preferred embodiment of the present invention;

Fig. 2 is a schematic diagram of the data relation of starting to play;

Fig. 3 is a schematic diagram of the data relationship after entering the normal playback mode;

Fig. 4 is a sequence diagram of video on demand.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and examples.

Example 1

See Figure 1. Fig. 1 is a schematic diagram of the network architecture of a preferred embodiment of the present invention. The VOD system of this embodiment includes a central media server, a central directory server, a business operation support system server, a digital rights management server, an edge media server, an edge directory server, a home media terminal, and a service portal server.

Among them, the central media server and the central directory server are connected to the routers of the MAN/WAN, and the edge media servers are connected to the edge routers connecting the MAN/WAN and the access network, thereby forming a central P2P domain. The central P2P domain is based on P2P content distribution network; the edge directory server is connected to the edge router connected to the edge media server, and the home media terminal is connected to the edge router connected to the edge media server through the access network, thereby forming an edge P2P domain, which constitutes P2P-based video-on-demand network. The operation support system server, digital rights management management server and business portal server are all connected to the router of the central P2P domain.

In this embodiment, the audio and video media files are divided into blocks, and the size of the block can be selected from 5MB to 30MB, and the value in this embodiment is 10MB. If the file has a metadata field, separate the metadata of the file into one piece. The metadata here refers to the encoding format and data arrangement information of the media file. The data transmission services in this system are all performed in units of data blocks generated in this way. For media file formats with metadata fields, refer to ISO/IEC 14496 part 12 and part 14. The file formats that can be used in the present invention include but are not limited to the aforementioned two formats.

In this embodiment, the central media server is a server that divides and stores original audio and video media files, and stores all online audio and video media data and its metadata. The central media server also participates in the data distribution process of the central P2P domain as a P2P node. The central media server includes a management module for media data and an external service module for media data.

In this embodiment, the edge media server is a media server deployed at the junction of the metropolitan area network and the access network, and serves as a node between the central P2P domain and the edge P2P domain at the same time. obtained in the P2P domain, and provides media services for home media terminals in a P2P manner. The edge media server can accept the command of the central directory server to actively initiate a data request, and can also initiate a data request according to the command of the edge directory server.

In this embodiment, the home media terminal is an embedded system device placed but not limited to a built-in hard disk in the user's home (it may also be a computer with corresponding software installed). The home media terminal acquires media data blocks based on P2P, and after acquiring subsequent The acquired data blocks are played during the process of data blocks, giving the user a streaming media playback experience.

In this embodiment, the central directory server (CDS) and the central media server (CMS) can be physically located in the same server as two functional modules, or can be implemented by separate server hardware. The central directory server counts and manages the distribution of media data in the central P2P domain, responds to data query requests from central P2P domain nodes, and returns a list of nodes that can provide data blocks. These nodes can be central media servers or other edge media servers. The central directory server can issue a data deployment instruction to the edge media server, so as to actively send the media data to the edge media server.

In this embodiment, the edge directory server (EDS) and the edge media server (EMS) can be physically located in the same server as two functional modules, or can be implemented by separate server hardware. The edge directory server counts and manages the distribution of media data in the edge P2P domain, responds to the data query request sent by the home media terminal in the edge P2P domain, and returns a list of nodes that can provide services. The edge directory server can issue a data deployment instruction to the home media terminal, so as to actively deploy the media data to the home media terminal. If there is no corresponding media data in the edge P2P domain to provide services, the edge directory server triggers its corresponding edge media server to request media data from the central P2P domain.

In this embodiment, the service portal (SP) is a site that organically organizes and presents the media data of the VOD system to users. The business portal server is the only entrance to the video-on-demand system. Users can browse and choose to play corresponding media programs only after entering the portal website. The service portal provides users with functions such as search and collection, and provides users with personalized experience.

In this embodiment, the operation support system (BOSS) mainly provides support for the operation of the video multimedia on-demand service, and its specific functions include: customer management, user management, account management, service billing, service authentication, service authorization, statistics, etc. Function. The operation support system supports the system to become an operable video-on-demand system through the management of users, services and resources. The home media terminal can use the services of this VOD system only after the account opening and authentication of the operation support system (BOSS).

In this embodiment, the digital rights management system (DRMS) is a support system for realizing the secure distribution of the operator's movie content, including three parts: movie encryption processing, user authorization management, and client decryption control. Only after the user is authorized can he watch the media program.

In this embodiment, the P2P mode in which home media terminals store video media data and provide services to other peers is adopted, which reduces the pressure on the edge media server, so that the number of home media terminals in the P2P domain to which the edge media server belongs can be independent of the performance of the edge media server. The limitation of the network grows, and with the growth of the number of home media terminals, the quality of video service will be better.

In this embodiment, if the edge media server breaks down, the home media terminal will send a request to the central directory server when it cannot get the timely service from the edge media server in the edge P2P domain where it is located. Other edge media servers closest to the edge media server provide services for it, which is equivalent to merging all the home media terminals of this faulty edge media server into the scope of another edge media server, expanding the edge P2P domain of this edge media server.

When the system starts to be deployed, the central media server firstly stores the media data that has been divided into blocks (that is, divided into several data blocks) and encrypted by the digital rights management server, and the operator specifies the popularity of the media content, and the central media server according to the uniform The principle of distribution stores different chunks of the media data in different edge media servers. Metadata block and header data block (the header data refers to the front part of the media file, which can usually be played for a few minutes. According to the size of the data block, this part of the data can be divided into one or more data blocks) in each edge media The servers are all stored, and the remaining data blocks are distributed and stored on the edge media servers according to their popularity. The more popular data blocks store more copies, and the less popular data blocks store fewer copies. This is called pre-distributed storage of media data. After the pre-distribution storage is over, the system can start to operate.

In the edge P2P domain, since the home media terminal usually starts to enjoy the VOD service when it is turned on for the first time, pre-distributed storage cannot be performed in the edge P2P domain. There are two cases of data distribution in the edge P2P domain. The first is that the home media terminal stores the media data that has been ordered. Since the storage space of the home media terminal is limited, the home media terminal deletes the previous media data by adopting the principle of first-in first-out when the media data that has been on-demand gradually increases. The second is that when the home media terminal is turned on to perform VOD services, the edge media server sends a control command to the home media terminal, specifying it to store certain media data. After obtaining a complete data block, the home media terminal sends a status report to the edge directory server to report the change of its own storage status. The status report includes information such as the name of the file to which the obtained data block belongs, the number of the data block, and the IP address of the home media terminal.

When a home media terminal wants to perform VOD services, it first visits the service portal to browse the media content provided by the system. When selecting a media content to watch, the home media terminal first requests the first piece of data of the media content from the edge media server. In order to minimize the delay, the edge media server must immediately respond to the request of the home media terminal and send the media data to it. Unless the edge media server has reached the upper limit of service capacity. After the home media terminal receives the media data, it starts playing immediately. At the same time, the home media terminal starts to send a query request to the edge directory server in the edge P2P domain, and the request can provide node information of subsequent data blocks, as shown in FIG. 2 . The edge directory server responds with some node information that can provide services. These nodes may be other home media terminals or edge media servers. These nodes all belong to the edge P2P domain. The home media terminal sends data requests to these nodes in turn until the service is obtained. If none of these nodes can provide services, the home media terminal will then query the edge directory server. Therefore, as the playback progresses, under normal circumstances, when the home media terminal plays the Nth block, the N+1, N+2,...N+M segments have been stored in its hard disk On, and the data segment it is receiving may be the N+M+1, N+M+2,...N+M+K segment data. As shown in Figure 3. By dividing the media data into blocks and trying to obtain subsequent data in this way, the user can be provided with a streaming media playback experience. When the user needs to jump in, if the media data corresponding to the moment of jumping is already on the hard disk of the home media terminal, the playback can be continued smoothly. At the same time, the user can also perform X-fold fast-forward operation on the data on the hard disk of the home media terminal. But when the media data corresponding to the jumping moment is not on the hard disk of the home media terminal, the home media terminal should immediately initiate a corresponding media data request to the edge media server, obtain the data and play it, just like the process when the playback was just started .

When the media data (except the title data stored by the edge media server) that the home media terminal wants to play is not stored in the edge P2P domain, after the edge directory server receives the media data query message of the home media terminal, it will notify the edge media server to send the information from the center to the edge media server. Download data within the P2P domain. The process is as follows: the edge media server first queries the central directory server for a list of nodes that can provide data, and the central directory server returns the list to the edge media server. This list may include multiple nodes that can provide media data. In the worst case That is, only the central media server can provide services. The edge media server selects a node and requests media data from it. The edge media server can request multiple different data blocks from multiple nodes at the same time. Since the data transmission between servers is based on the metropolitan area network, the rate at which the edge media server obtains data is much faster than the rate at which the home media terminal plays the required data. It can meet the demands of home media terminals for media data. After obtaining a complete data block, the edge media server sends a status report to the central directory server and the edge directory server, reporting the change of its own storage status. The status report includes information such as the file name to which the obtained data block belongs, the number of the data block, and the IP address of the edge media server.

Each home media terminal must report to the edge directory server the data information it provides externally during this power-on period, so as to make statistics on the contribution of the home media terminal.

Claims (10)

1. system that utilizes the peer-to-peer network technology to realize video request program, comprise media server, LIST SERVER and home media terminal, it is characterized in that, described media server comprises center media server and edge media server, and described LIST SERVER comprises center LIST SERVER and edge LIST SERVER; Described center media server and center LIST SERVER are connected on the router of metropolitan area/wide area network, described edge media server is connected on metropolitan area/wide area network and the edge router that Access Network is connected mutually, thereby form center P 2P territory, this center P 2P territory constitutes the content distributing network based on P2P; Described edge LIST SERVER is corresponding one by one with the edge media server and be connected on the edge router that the respective edges media server connected, described home media terminal links to each other by the edge router that Access Network is connected with the edge media server, thereby form P2P territory, edge, P2P territory, this edge constitutes the VoD network based on P2P.

2. by the described system that utilizes the peer-to-peer network technology to realize video request program of claim 1, it is characterized in that, also comprise the OSS server that is connected on metropolitan area/WAN router.

3. by the described system that utilizes the peer-to-peer network technology to realize video request program of claim 1, it is characterized in that, also comprise the digital rights management service device that is connected on metropolitan area/WAN router.

4. by the described system that utilizes the peer-to-peer network technology to realize video request program of claim 1, it is characterized in that, also comprise the service portal server that is connected on metropolitan area/WAN router.

5. by claim 1,2, the 3 or 4 described systems that utilize the peer-to-peer network technology to realize video request program, it is characterized in that, all deposit some audio-video frequency media files in described center media server and the edge media server, wherein each audio-video frequency media file is divided into several data blocks, each data block is numbered according to its order hereof, top volume is first, and, when described audio-video frequency media file has metadata fields, its metadata is divided into a data block separately, and volume is the 0th piece; Described audio-video frequency media file is when the dividing data piece, and its data block size value is between 5MB～30MB.

6. a method of utilizing the peer-to-peer network technology to realize video request program comprises the steps:

1) home media terminal browse service door selects a media file to carry out program request as target media file;

2) the home media terminal request of sending this target media file of program request to the edge media server in P2P territory, edge, place;

3) after the edge media server receives described order request, respond the request of described home media terminal at once and send first blocks of data of target media file to it, if this media file has the 0th piece, then the edge media server sends the 0th piece earlier, sends first again; The home media terminal gets started and plays this media file after receiving first of target media file;

4) the edge LIST SERVER of home media terminal in P2P territory, edge, place sends query requests;

5) the edge LIST SERVER returns the nodal information tabulation that subsequent data blocks can be provided to the home media terminal; Node in the described nodal information tabulation comprises other home media terminal in the P2P territory, edge, described home media terminal place; Described node also comprises the edge media server in the P2P territory, edge, described home media terminal place, and described edge media server comes the last of described nodal information tabulation;

6) the home media terminal is sent the data download request according to the tabulation of the nodal information that receives successively to node wherein, till obtaining the data download service; If all nodes in the nodal information tabulation all can not provide the data download service, then the home media terminal sends query requests to the edge LIST SERVER again;

7) the home media terminal is play data downloaded piece successively.

7. by the described method of utilizing the peer-to-peer network technology to realize video request program of claim 6, it is characterized in that, in the described step 5), when the edge LIST SERVER can't find the node of the subsequent data blocks that described target media file can be provided in P2P territory, this edge, then notify the edge media server in P2P territory, center, to download described target media file.

8. by the described method of utilizing the peer-to-peer network technology to realize video request program of claim 7, it is characterized in that the process that described edge media server is downloaded described target media file in the P2P territory, center is as follows:

51) the edge media server sends query requests to the center LIST SERVER;

52) the center LIST SERVER returns the nodal information tabulation that target media file can be provided to the edge media server; Node in the described nodal information tabulation comprises center media server at least, and comes the last of described nodal information tabulation; Node in the described nodal information tabulation also comprises other edge media server in the center P 2P territory;

53) the edge media server is tabulated the while to wherein a plurality of node requests according to nodal information, and downloads the subsequent data blocks of described target media file.

9. by the described method of utilizing the peer-to-peer network technology to realize video request program of claim 6, it is characterized in that in the described step 7), when the user carries out jumping forward operation, as the data block of jumping into the place, position downloads, and then plays this data block immediately; As the data block of jumping into the place, position is not also downloaded, then this data block is downloaded and play to the home media terminal from the edge media server, simultaneously, re-execute step 4) to step 6), the home media terminal is play being positioned at of having downloaded successively and is jumped into position subsequent data blocks afterwards then.

10. by the described method of utilizing the peer-to-peer network technology to realize video request program of claim 7, it is characterized in that the edge media server is after download obtains new data block, to center LIST SERVER and edge LIST SERVER difference status report; The home media terminal is after download obtains new data block, to edge LIST SERVER status report.

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