Enabling realistic cross-layer analysis based on satellite physical layer traces

Abstract

We present a solution to evaluate the performance of transport protocols as a function of link layer reliability schemes (i.e. ARQ, FEC and Hybrid ARQ) applied to satellite physical layer traces. As modelling such traces is complex and may require approximations, the use of real traces will minimise the potential for erroneous performance evaluations resulting from imperfect models. Our Trace Manager Tool (TMT) produces the corresponding link layer output, which is then used within the ns-2 network simulator via the additionally developed ns-2 interface module. We first present the analytical models for the link layer with bursty erasure packets and for the link layer reliability mechanisms with bursty erasures. Then, we present details of the TMT tool and our validation methodology, demonstrating that the selected performance metrics (recovery delay and throughput efficiency) exhibit a good match between the theoretical results and those obtained with TMT. Finally, we present results showing the impact of different link layer reliability mechanisms on the performance of TCP Cubic transport layer protocol.

CLIFT: A Cross-Layer InFormation Tool for latency analysis based on real satellite physical traces

“…If we use traces that do not enable reliability mechanisms at the MAC level (e.g. ARQ or H-ARQ), we could also perform a pre-treatment over this traces with a tool such as TMT [13], PPR [14] or DUMMYNET NETEM [15] that allow to apply reliability mechanisms up the MAC level. Basically, these tools allow to modify the PHY traces, following a given reliability mechanism used at the MAC level, by recomputing the transmission slots.…”