A new ARQ mechanism for multicast traffic over IEEE 802.11 WLANs

In the IEEE 802.11 networks a data packet is delivered to multiple receivers through the multicast paradigm. Since multicast has not a feedback scheme, the reliability of the service provided to the user is penalized. This issue is more important as the network load or the coverage area increases. These two facts cause collisions or corrupted delivery due to bad channel conditions, respectively. In one of our previous works, we introduced a high-efficient collision avoidance delivery multicast mechanism to tackle only the collision problem of multicast packets. In this paper, we include in our scheme a new Automatic Repeat-reQuest (ARQ) mechanism to also be able to retransmit corrupted packets due to bad channel conditions. Through our simulation results, we prove that our feedback mechanism, combined with the collision avoidance, is able to properly deliver more multicast packets than other proposals while the network performance is maintained.