Publication Phare-Lip6

[ Publication ]

RP-LIP6-2014-06-16-j4j55

Dynamic Coding for TCP Transmission Reliability in Multi-hop Wireless Networks
The 11th IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks
Vu Thuong Van, Boukhatem Nadia, Nguyen Thi-Mai-Trang and Pujolle Guy
Sydney, June, 2014
Anglais - 6 p - Abstract
Recent research shows that random linear network coding is adapted to current network systems to provide transmission reliability. In lossy wireless networks, TCP traffic has to resist against losses by a suitable network coding scheme and redundancy control. Whenever TCP wants to transmit a packet, the original TCP/NC could send more than one coded packets which combine all non-ACKed packets remained in the TCP congestion window. Packet losses are essentially masked by TCP/NC from the congestion control algorithm. The original TCP/NC lacks an adaptive redundancy control to compensate errors in time. We present Dynamic Coding - DynCod, a new coding scheme, to address this problem. In DynCod, when TCP wants to transmit a packet, DynCod will code this packet with others non-ACKed in TCP congestion window. Therefore, the latest data is always transformed and presented by only one coded packet at a time. Thank to this progressive encoding of DynCod, any decoding failures at destination can be seen as a signal of loss. The source can be informed via TCP ACKs and adjust the number of redundant packets accordingly. We have compared the performances of DynCod and TCP/NC using NS-2. The simulation results show that DynCod outperforms the original TCP/NC in terms of throughput and packet delivery time.