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

Yosuke TANIGAWA  Jong-Ok KIM  Hideki TODE  

IEICE TRANSACTIONS on Communications   Vol.E93-B   No.12   pp.3345-3353
Publication Date: 2010/12/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E93.B.3345
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Wireless Distributed Networks)
IEEE 802.11 DCF,  Automatic Repeat reQuest (ARQ),  Network Coding (NC),  

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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 retransmission 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.