Point-to-point repair request mechanism for point-to-multipoint transmission systems

Abstract

This invention relates to a method, system, transmitter, network element, receiver and software application for a system capable of point-to-multipoint transmission, where one or more data packets are transmitted from a transmitter to one or more receivers, where at least at one specific receiver of said receivers, a reception of repair data packets is required, where repair information is signaled to a repair server in order to trigger a transmission of the repair data packets, and where the repair information comprises information related to the number of transmitted data packets correctly received at the specific receiver. The system may for instance be the 3GPP Multimedia Broadcast Multicast System, the transmission of data packets may for instance be controlled by the File Delivery Over Unidirectional Transport protocol and the signaling of the repair information may for instance be controlled by the Hypertext Transfer Protocol.

1 - 30 . (canceled) 
   
   
       31 . An apparatus comprising:
 a reception component configured to receive, at a receiver of one or more receivers, one or more data packets transmitted from a transmitter to said one or more receivers; and   a signaling component configured to signal repair information from said receiver, at which receiver a reception of repair data packets is required, to a repair server in order to trigger a transmission of said repair data packets, wherein said data packets and said repair data packets are generated from a data object by forward error correction encoding, wherein said forward error correction encoding has a property that only a sub-set of all transmitted data packets that are related to said data object have to be correctly received by said receiver to be able to reconstruct said data object, and wherein said repair information allows said repair server to determine how many repair data packets need to be transmitted to said receiver to enable said receiver to reconstruct said data object and does not comprise an identification of the data packets required at said receiver.   
   
   
       32 . The apparatus according to  claim 31 , wherein said repair data packets are required due to loss or incorrect reception of at least one of said transmitted data packets at said receiver. 
   
   
       33 . The apparatus according to  claim 31 , wherein said repair data packets are required to reconstruct said data object at said receiver. 
   
   
       34 . The apparatus according to  claim 31 , wherein said data object is a transport object, and wherein said repair information comprises an identifier of said transport object. 
   
   
       35 . The apparatus according to  claim 31 , wherein said data object is a portion of a transport object, and wherein said repair information comprises an identifier of said portion and an identifier of the corresponding transport object. 
   
   
       36 . The apparatus according to  claim 34 , wherein said transport object is related to a transport session, and wherein said repair information comprises an identifier of said transport session. 
   
   
       37 . The apparatus according to  claim 31 , wherein said repair information comprises one of a number of transmitted data packets correctly received at said receiver and a number of transmitted data packets not correctly received at said receiver. 
   
   
       38 . The apparatus according to  claim 31 , wherein said encoding is at least partially based on encoding keys that are included into said data packets and repair data packets. 
   
   
       39 . The apparatus according to  claim 31 , wherein said forward error correction is at least partially based on one of an LT code and a raptor code. 
   
   
       40 . The apparatus according to  claim 31 , wherein said transmission of one or more data packets to one or more receivers is at least partially controlled by a session-based protocol directed to unidirectional point-to-multipoint transfer. 
   
   
       41 . The apparatus according to  claim 31 , wherein said transmission of one or more data packets to one or more receivers is at least partially controlled by the File Delivery Over Unidirectional Transport protocol. 
   
   
       42 . The apparatus according to  claim 31 , wherein said signaling of said repair information is performed in a point-to-point session between said receiver and said repair server. 
   
   
       43 . The apparatus according to  claim 31 , wherein said signaling of said repair information is at least partially controlled by the Hypertext Transfer Protocol. 
   
   
       44 . The apparatus according to  claim 33 , wherein the GET or POST methods of the Hypertext Transfer Protocol are used for said signaling of said repair information. 
   
   
       45 . The apparatus according to  claim 31 , wherein said transmission of said repair data packets from said repair server to said receiver is performed in a point-to-point session. 
   
   
       46 . The apparatus according to  claim 31 , wherein said apparatus is useable in a Multimedia Broadcast Multicast Service system according to the standards of the Third Generation Partnership Project. 
   
   
       47 . An apparatus comprising:
 means for receiving, at a receiver of one or more receivers, one or more data packets transmitted from a transmitter to said one or more receivers; and   means for signaling repair information from said receiver, at which receiver a reception of repair data packets is required, to a repair server in order to trigger a transmission of said repair data packets, wherein said data packets and said repair data packets are generated from a data object by forward error correction encoding, wherein said forward error correction encoding has a property that only a sub-set of all transmitted data packets that are related to said data object have to be correctly received by said receiver to be able to reconstruct said data object, and wherein said repair information allows said repair server to determine how many repair data packets need to be transmitted to said receiver to enable said receiver to reconstruct said data object and does not comprise an identification of the data packets required at said receiver.   
   
   
       48 . A computer-readable medium encoded with a computer program, the computer program comprising:
 program code for causing a processor to receive, at a receiver of one or more receivers, one or more data packets transmitted from a transmitter to said one or more receivers; and   program code for causing a processor to signal repair information from said receiver, at which receiver a reception of repair data packets is required, to a repair server in order to trigger a transmission of said repair data packets, wherein said data packets and said repair data packets are generated from a data object by forward error correction encoding, wherein said forward error correction encoding has a property that only a sub-set of all transmitted data packets that are related to said data object have to be correctly received by said receiver to be able to reconstruct said data object, and wherein said repair information allows said repair server to determine how many repair data packets need to be transmitted to said receiver to enable said receiver to reconstruct said data object and does not comprise an identification of the data packets required at said receiver.   
   
   
       49 . The computer-readable medium according to  claim 48 , wherein said repair information comprises one of a number of transmitted data packets correctly received at said receiver and a number of transmitted data packets not correctly received at said receiver. 
   
   
       50 . The computer-readable medium according to  claim 48 , wherein said transmission of one or more data packets to one or more receivers is at least partially controlled by the File Delivery Over Unidirectional Transport protocol. 
   
   
       51 . The computer-readable medium according to  claim 48 , wherein said computer program is useable in a Multimedia Broadcast Multicast Service system according to the standards of the Third Generation Partnership Project. 
   
   
       52 . A computer-readable medium encoded with a computer program, the computer program comprising:
 program code for causing a processor to receive repair information signaled from a receiver, at which receiver a reception of repair data packets is required after reception of one or more data packets transmitted from a transmitter, in order to trigger a transmission of said repair data packets, wherein said data packets and said repair data packets are generated from a data object by forward error correction encoding, wherein said forward error correction encoding has the property that only a sub-set of all transmitted data packets that are related to said data object have to be correctly received by said receiver to be able to reconstruct said data object, and wherein said repair information allows said apparatus to determine how many repair data packets need to be transmitted to said receiver to enable said receiver to reconstruct said data object and does not comprise an identification of the data packets required at said receiver.   
   
   
       53 . The computer-readable medium according to  claim 52 , wherein said repair information comprises one of a number of transmitted data packets correctly received at said receiver and a number of transmitted data packets not correctly received at said receiver. 
   
   
       54 . The computer-readable medium according to  claim 52 , wherein said transmission of one or more data packets to one or more receivers is at least partially controlled by the File Delivery Over Unidirectional Transport protocol. 
   
   
       55 . The computer-readable medium according to  claim 52 , wherein said computer program is useable in a Multimedia Broadcast Multicast Service system according to the standards of the Third Generation Partnership Project.