An Adaptive Raptor Enabled Data Carousel for File Delivery in 802.11 Multicast Networks

WLANs currently do not provide a robust solution for reliable data multicast. Multicast packets are delivered to multiple users as a simple broadcast service without support for Automatic Repeat Request. Hence, a fixed low speed transmission mode is generally used to improve the reliability of multicast files. However, this results in the inefficient use of bandwidth. This paper proposes a reliable and efficient Wi-Fi multicast delivery solution for use in challenging outdoor environments. We proposed an adaptive Application Layer Forward Error Correction (AL-FEC) enabled data carousel for reliable multicast transmission over standard 802.11 WLANs. To quantify the benefits of the proposed system, results are presented from a cross-layer simulator combining novel outdoor ray-tracing, a physical layer abstraction simulator and a RaptorQ enabled multicast data carousel simulator. The simulation results demonstrate that adaptive FEC carousels significantly reduce the average download time, increase the percentage of satisfied users and bandwidth efficiency in a multicast network.