Apparatus and method for peer to peer vod system

Abstract

Video On Demand system providing video programs between a program provider and a plurality of clients coupled over a peer to peer network. Transmitting a requested video program from a first client on a first channel. Allocating a second channel for transmitting the video program requested by a second client. The first client forwarding the video program to the second client on the second channel from the beginning of the video program received and stored. Controlling the second client to receive and store the video program sent on the first channel in synchronization with the first client. Merging the second channel into the first channel in response to notification that the program received from the first client by the second client reaches a starting point of the program received and stored by the second client. Notifying the first client to stop sending the video program to the second client.

1 . A video program providing apparatus in a peer to peer video on demand system, connected to a plurality of clients through a peer to peer network, said video program providing apparatus comprising: 
 transmitting means, in response to a request for a video program from a first client among said plurality of clients, for transmitting the requested video program to said first client on a first channel;    channel allocating means, in response to a request for the same video program from a second client among said plurality of clients, for allocating a second channel for transmitting the video program;    forwarding designation means, in response to the request for the video program from said second client, for notifying said first client which receives the same video program on said first channel prior to said second client to forward said video program to said second client on said second channel from the beginning of said video program which has been received from the video program providing apparatus and stored by said first client, and for controlling said second client to receive and store said video program transmitted from the video program providing apparatus on said first channel in synchronization with said first client;    wherein, in response to a notification that the video program received from said first client by said second client reaches a starting point of the program which was received and stored by said second client from the video program providing apparatus, said channel allocating means merges said second channel into said first channel, and said forwarding designation means notifies said first client to stop forwarding said video program to said second client.    
   
   
       2 . The video program providing apparatus as set forth in  claim 1 , wherein in response to the merging of said second channel and said first channel, while continuing receiving and storing the succeeding video program transmitted from said video program providing apparatus on said first channel, said second client reads and plays said stored video program in first-in first-out manner to ensure the continuity of the video program being played on said second client.  
   
   
       3 . The video program providing apparatus as set forth in  claim 1 , wherein any one of the clients requesting the video program providing apparatus for the same video program before said second client plays the role of said first client.  
   
   
       4 . The video program providing apparatus as set forth in  claim 1 , wherein said video program providing apparatus is a video server.  
   
   
       5 . The video program providing apparatus as set forth in  claim 1 , wherein said clients are secondary video servers in the peer to peer network.  
   
   
       6 . The video program providing apparatus as set forth in  claim 1 , wherein said video program comprises multimedia contents.  
   
   
       7 . The video program providing apparatus as set forth in  claim 1 , wherein said first channel and second channel are multicast channels.  
   
   
       8 . The video program providing apparatus as set forth in  claim 1 , wherein said video program providing apparatus further comprises a client software downloading unit for providing a client software which can be downloaded by said clients to perform forwarding of the video program.  
   
   
       9 . A peer to peer video on demand system, comprising a video program providing apparatus and a plurality of clients which are connected through a peer to peer network, characterized in that: 
 each of said clients comprising: 
 storing unit for storing a video program received from said video program providing apparatus by said client; and  
 forwarding unit for forwarding said video program to other clients;  
   said video program providing apparatus comprising: 
 transmitting means, in response to a request for a video program from a first client among the clients, for transmitting the requested video program to the said first client on a first channel;  
 channel allocating means, in response to a request for the same video program from a second client among said plurality of clients, for allocating a second channel for transmitting the video program;  
 forwarding designation means, in response to the request for the video program from said second client, for notifying said first client which receives the same video program on said first channel before said second client to forward said video program to said second client on said second channel from the beginning of said video program which has been received from the video program providing apparatus and stored by said first client, and for controlling said second client to receive and store the said video program transmitted from the video program providing apparatus on said first channel in synchronization with said first client;  
 wherein, in response to a notification that the video program received from said first client by said second client reaches a starting point of the program which was received and stored by said second client from the video program providing apparatus, said channel assigning means merges said second channel into said first channel, and said forwarding designation means notifies said first client to stop sending said video program to said second client.  
   
   
   
       10 . The peer to peer video on demand system as set forth in  claim 9 , wherein, in response to the merging of said second channel and said first channel, while continuing receiving and storing the succeeding video program transmitted from said video program providing apparatus on said first channel, said second client reads and plays said stored video program in first-in first-out manner to ensure the continuity of the video program being played on said second client.  
   
   
       11 . The peer to peer system as set forth in  claim 9 , wherein said video program providing apparatus is a video server.  
   
   
       12 . The peer to peer system as set forth in  claim 9 , wherein said clients are secondary video servers in the peer to peer network.  
   
   
       13 . The peer to peer system as set forth in  claim 9 , wherein said video program comprises multimedia contents.  
   
   
       14 . The peer to peer system as set forth in  claim 9 , wherein any one of the clients requesting the video program providing apparatus for the same video program before said second client plays the role of said first client.  
   
   
       15 . The peer to peer system as set forth in  claim 14 , wherein said first channel and second channel are multicast channels.  
   
   
       16 . A computer program product comprising a computer usable medium having readable program code means embodied therein for causing provision of video programs, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect the functions of  claim 9 .  
   
   
       17 . A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing for causing provision of video programs, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect the functions of  claim 1.