On elastic traffic via contention resolution diversity slotted aloha satellite access

This paper presents a performance study relative to the coupling of the Transmission Control Protocol (TCP) with the franco.davoli@unige.it Contention Resolution Diversity Slotted Aloha (CRDSA) protocol, in the case of greedy TCP connections (also called elephants) on Digital Video Broadcasting-Return Channel via Satellite. CRDSA, which takes advantage of interference cancellation algorithms for collision/contention resolution, has already exhibited an interesting performance when the power levels of all received bursts are perfectly balanced. In this paper, we extend the study to a more realistic case that sees a certain spreading of the bursts' power levels. The consequent capture effect even facilitates the collision resolution mechanism and the overall TCP performance results improved with respect to the balanced case. Furthermore, in certain conditions, the adoption of packet level Forward Error Correction (FEC) allows handling system loads higher than the expected ones.