Image Number 3 for United States Patent #7979767.
An Automatic Repeat-reQuest (ARQ) Reset method for an ARQ transmitter disables (120) transmission, starts (130) an ARQ transmitter window at a first unacknowledged block, and discards (140) service data units (SDUs) in the ARQ transmitter window having zero blocks in a `not-sent` state. Thus, for all SDUs having no blocks in a `not-sent` state, the blocks in an `outstanding` or `waiting-for-retransmission` state are changed to a `discard` state. Next, the ARQ transmitter sets (150) the state of all blocks in partially unsent SDUs of the ARQ transmitter window to `not-sent.` So, any remaining blocks in an `outstanding,` `waiting-for-transmission` or `discard` state are changed to `not-sent.` After the ARQ transmitter enables (160) transmission and ends (190) the ARQ Reset procedure, the ARQ transmitter will send blocks in the `not-sent` state. This ARQ Reset method avoids retransmitting blocks that might cause duplicate packets at the ARQ receiver, which some protocols cannot handle.