Implementation of Hybrid ARQ

This paper proposes enhancements to the radio link protocol that works underneath TCP by identifying decisive frames and categorizing them as crucial and non-crucial. The fact that initial frames from the same upper layer segment can afford a few trials of retransmissions and the later frames cannot, motivates this work. The frames are treated differentially with respect to FEC coding and ARQ schemes. Specific cases of FEC and ARQ strategies are then considered and it is shown qualitatively that the differential treatment of frames can improve the performance of the RLP over wireless networks.