WEVCast: Practical implementation and testing of effective multicast services for Wi-Fi networks

In this paper we present the successful implementation of WEVCast (Wireless Eavesdropping Video Casting) [2] a new mechanism to improve the performance of multicast streaming video over wireless networks. It is well known that the standard IEEE 802.11 protocol has no specific mechanism for multicast transmission and it always uses the base transmission rate (i.e., 1/6 Mbps for 802.11 b/g) because it simply implements multicasting using broadcasting. On the contrary, WEVCast system allows network devices to switch in overhearing mode in order to capture video packets; moreover, a simply feedback mechanism, based on RSSI messages periodically sent by the client nodes, has been added and managed by the sender node to dynamically adjust the transmission data rate. A detailed testbed has been implemented to validate our study and the quality of the received video content has been analyzed throughout the BVQM software. Obtained results show that WEVCast is a valid solution to realize a simple and cost-effective wireless hot-spot for multimedia contents delivery.