The increase in the number of mobile devices accessing information in the Internet creates new problems that need to be solved. Here we consider the problem of a large number of clients receiving simultaneously the same video streaming in multicast, as part of the CodeStream [2] project.
Previous works consider the use of acknowledgements to inform the video server of packets lost by the clients, which are then retransmitted. In particular the work in [1] uses network coding to reduce the network load in recovering lost packets sent through the WiFi network.
Video packets are sent using multicast to many clients at the same time. Multicast does not support packet loss recovery since there is no automatic acknowledgement of proper packet reception. Feedback from clients is required to provide an adequate Quality-of-Service (QoS), but it represents a significant increase in network load. Moreover, the uncoordinated transmission of acknowledges generates collisions, enormously reducing the network throughput and the streaming QoS.
In this work we propose a method to synchronize the acknowledgments (ACKs) from clients reducing collisions while also supporting differentiated Service Level Agreements (SLAs).