Early-drop based hybrid ARQ in a cross-layer context

We aim to study a specific cross-layer optimized Hybrid Automatic Retransmission reQuest (HARQ) introduced and called early-drop HARQ. We remind that instead of giving a transmission credit per MAC packet (as usually done), it is proposed to share the transmission credit among all the MAC packets belonging to the same IP packet. The early-drop version stops the retransmission as soon as the number of remaining MAC packets is higher than the number of possible transmission attempts. As the early-drop has never been analyzed neither through simulations nor analytical derivations, the purpose of this paper is to fill this gap. As the packet error rate and the delay are not modified, we only focus on the efficiency which is expressed in closed-form.