Impact of retransmission policies on performance of concurrent multipath transfers in wireless heterogeneous networks

Mobile devices with oodles of interfaces communicating concurrently through multi-homed access networks with a blend of wired and wireless transmission parameters need efficient data delivery. To suffice the need this paper investigates the impact of various retransmission policies, viz. RTX-SAME, RTX-ASAP, RTX-LOSSRATE, RTX-SSTRESH, RTX-CWND, AllRtxSame, AllRtxAlt and FrSameRtoAlt on the throughput of concurrent multipath transfers (CMT). The performance analysis for the first five policies being extended with partial reliability extension of Stream Control Transmission Protocol (PR-SCTP). The simulation was conducted using NS-2.35 on a multi-homed heterogeneous network with wired links and WiMAX, 3G, 4G and 5G specifications supporting wireless links. The paper validates that among the five basic retransmission policies RTX-ASAP performs best both for CMT using SCTP and for CMT using PR-SCTP. AllRtxAlt performs best for aggressive fail over case under dissimilar path loss rates.