摘要:
A method of recovering lost frames transmitted between a packet data sending unit and a packet data receiving unit in a data communications system is disclosed. When a frame is successfully received by the packet data receiving unit, it identifies a failure to successfully receive prior frames, i.e., at least one frame prior to the frame successfully received at the packet data receiving unit. The packet data receiving unit starts a selective reject wait timer and determines whether the number of frames missed so far is greater than or equal to a predetermined threshold. If the number of missed frames is greater than or equal to the preset limit, the packet data receiving unit generates a selective reject message that includes a payload indicating a first missed frame and subsequent missed frames. If the number of missed frames is less than the predetermined threshold, the packet data receiving unit waits until the expiration of the selective reject wait timer, or until after the next determination that the number of missed frames meets or exceeds the predetermined threshold. It then sends the selective reject message to the packet data sending unit. Upon successful receipt of the retransmitted missed frames from the packet data sending unit, the packet data receiving unit generates a receive ready message and sends the receive ready message to the packet data sending unit.