A method and server for broadcasting a data file to talk groups. The method includes fragmenting the data file into data blocks and broadcasting the data blocks to the talk groups. The method also includes detecting a voice call start event based on a first change is a received voice call status. The method further includes detecting a voice call end event based on a second change in the received voice call status. The method also includes generating a backlog item. The backlog item includes a subset of data blocks of the plurality of data blocks. The subset of data blocks were broadcasted on the broadcast data channel after the voice call start event and prior to the voice call end event. The method further includes broadcasting the subset of data blocks on the broadcast data channel upon detection of the voice call end event.