Data repair enhancements for multicast/broadcast data distribution

Abstract

A method, system, device, and computer code product is disclosed in which a sender transmits data to a plurality of receivers via a point-to-multipoint session. The receiver sends data repair requests to the sender requesting data expected but not received and the sender retransmits the expected but not received data via the point-to-multipoint session. The sender can also schedule point-to-point data repair sessions with individual receivers if the retransmission via the point-to-multipoint session does not correct all errors. The sender can be configured to delay point-to-point repair sessions using a randomization mechanism based on the number of receivers using the point-to-multipoint session.

1 . A method for data repair in a point-to-multipoint communications system, the method comprising:
 transmitting data from a sender to a plurality of receivers via a point-to-multipoint session;   determining if any expected data was not received;   if some expected data was not received, sending a data repair request to the sender requesting that the expected-but-not-received data be resent; and   retransmitting from the sender all of the requested expected-but-not-received data via the point-to-multipoint session.   
   
   
       2 . A point-to-multipoint communication system for repairing data, the system comprising:
 a sender device for transmitting data via point-to-multipoint communications;   a plurality of receivers for receiving data from the sender device;   wherein the sender device is configured to transmit data to the plurality of receivers via a point-to-multipoint session;   the plurality of receivers are configured to receive data transmitted by the sender device, determine if any expected data was not received, and, if so, send a data repair request back to the sender device requesting that the expected-but-not-received data be resent; and   the sender device is configured to receive data repair requests from the plurality of receivers and to retransmit all of the requested expected-but-not-received data to the plurality of receivers via the point-to-multipoint session.   
   
   
       3 . A computer code product embodied on a computer readable storage medium, the computer code product comprising:
 computer code, that when executed by a processor, causes a computer to perform the following:
 transmit data from a sender to a plurality of receivers via a point-to-multipoint session; 
 determine if expected data was not received at any of the plurality of receivers; 
 make a data repair request if any expected data was not received at any of the plurality of receivers; and 
 retransmit all of the requested expected-but-not-received data to the plurality of receivers via the point-to-multipoint session. 
   
   
   
       4 . The computer code product of  claim 3  wherein the computer code is further configured to determine the number of receivers on the point-to-multipoint session and schedule the point-to-point data repair sessions based on the determined number of receivers. 
   
   
       5 . A sender device for use in a point-to-multipoint communication system, the sender device comprising:
 means for transmitting data to a plurality of receivers via a point-to-multipoint session;   means for receiving data repair requests from the plurality of receivers requesting expected-but-not-received data;   means for retransmitting all of the requested expected-but-not-received data via a point-to-multipoint session.   
   
   
       6 . The sender device of  claim 5  wherein the sender device further comprises means for determining the number of receivers using the point-to-multipoint session wherein the sender is configured to schedule the point-to-point data repair sessions based on the determined number of receivers.