Mouais, alors j'ai lu l'article de korben!!! Rien que le graphique pose des questions. On nous dit que l'on a jusqu’à 5% de perte de paquet si on se déplace. 2% en wifi, 3G, 4G etc.
Si l'on prête attention au graphique on voit que le gain diminue fortement avec le nombre d'erreur. (c'est logique, on peut combler un petit trou mais pas créer à partir de rien). A 1% il n'y a déjà plus de gain et on est en courbe exponentiel décroissante... Bref je vous laisse réfléchir.
Après je suis aller voir le papier des chercheurs. Il ont principalement fait des simulations. De plus je ne voit nullement le gain cité dans l'article de korben.
abstract:
We analyze the performance of TCP and TCP with network coding (TCP/NC) in lossy wireless networks. We build
upon the simple framework introduced by Padhye et al.
and characterize the throughput behavior of classical TCP
as well as TCP/NC as a function of erasure rate, roundtrip time, maximum window size, and duration of the connection. Our analytical results show that network coding
masks random erasures from TCP, thus preventing TCP’s
performance degradation in lossy networks (e.g. wireless
networks). It is further seen that TCP/NC has signifi-
cant throughput gains over TCP. Our analysis and simulation results show very close concordance and support that
TCP/NC is robust against erasures. TCP/NC is not only
able to increase its window size faster but also to maintain a
large window size despite the random losses, whereas TCP
experiences window closing because losses are mistakenly
attributed to congestion. Note that network coding only
masks random erasures, and allows TCP to react to congestion; thus, when there are correlated losses, TCP/NC also
closes its window.
WiFi