This mechanism, which is the focus of this paper, also allows differentiating the quality of service provided to the clients, polling their feedback independently. It uses a feedback repeat request mechanism per client and such requests are adequately scheduled by the streaming server. Therefore, we propose a novel reliable multicast protocol, tailored to streaming applications, that also scales to many clients under the same access point. In a severe scenario, packet losses may affect all video frames, preventing the clients from receiving the video stream at all. However, multicast packets are unacknowledged and may present a high loss rate under adverse conditions which may jeopardize the quality of the streaming. For example, when many wireless clients try to access the same video stream in the same hot spot, multicast transmission must be used. The number of mobile devices accessing the Internet is continuously increasing, creating new problems. Obtained results show that WEVCast is a valid solution to realize a simple and cost-effective wireless hot-spot for multimedia contents delivery. 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. 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. 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. In this paper we present the successful implementation of WEVCast (Wireless Eavesdropping Video Casting) a new mechanism to improve the performance of multicast streaming video over wireless networks.
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