The Impact of the Reliability on the Fairness Between the Unicast and the Multicast in Highly Loaded WLANs

Yousri Daldoul (1, 2) , Djamal-Eddine Meddour (1) , Toufik Ahmed (2)

1 FT R&D - France Télécom Recherche & Développement
2 LaBRI - Laboratoire Bordelais de Recherche en Informatique

One of the major issues experienced by the IEEE 802.11 standard is the fair sharing of the channel between unicast and multicast flows. This problem is obviously caused by the use of the smallest Contention Window size to transmit the multicast packets compared to an exponentially incremented size for every unicast packet transmission retry. This pattern is due mainly to the reliability degree difference between the unicast and the multicast traffic. Currently, the unicast uses feedbacks to provide reliability, whereas the multicast does not rely on such a mechanism and is therefore considered as unreliable. In this paper we propose a reliable Multicast flow transport proposal called the Reliable PLCP-based Multicast Protocol (RPMP) and we study its impact on the fair channel sharing with unicast flows in high-load conditions. We show that RPMP solves the issues of the legacy multicast.

Mots clés: IEEE 802.11 WLAN; reliable multicast; NAK feedback; fair chairing of the bandwidth

Domaines: Informatique et langage [cs.CL]

Yousri Daldoul, Djamal-Eddine Meddour, Toufik Ahmed. The Impact of the Reliability on the Fairness Between the Unicast and the Multicast in Highly Loaded WLANs. IEEE 36th Conference on Local Computer Networks (LCN 2011), Oct 2011, Germany. pp.835-840, ⟨10.1109/LCN.2011.6115559⟩. ⟨hal-00657768⟩