Delay-Sensitive Retransmission Method Based on Network Coding in Wireless LANs

Abstract

Recently network coding (NC) has been popularly applied to wireless networks in order to improve scarce wireless capacity In wireless LANs NC can be applied to packet retransmission and a base station can simultaneously retransmit multiple packets destined to different wireless stations by a single retransmission trial On the other hand NC creates additional packet delay at both base station and wireless stations and hence packet transfer delay may increase seriously However existing NC based retransmission methods do not consider this additional delay explicitly In addition when the number of flows is small NC exhibits less benefit because the chances of NC based retransmission are highly reduced Therefore in this paper we propose a novel NC based retransmission method in order to improve packet transfer delay and jitter of received packets Moreover to achieve further improvement of delay jitter and retransmission efficiency even when there exist a small number of traffic flows we propose a retransmission method in which NC based re transmission cooperates with the typical ARQ method We overcome the disadvantage of NC based retransmission by combining with ARQ cooperatively Finally we show the effectiveness of the proposed methods by extensive computer simulation