Coding based broadcast for wireless layered video streaming

There is an increasing demand for layered video streaming applications in wireless networks, which need data packets to be strictly in-order on time at the receivers. In this paper we study network coding based wireless broadcast scheduling problem in layered video streaming applications, aiming at minimizing the number of packets which miss their deadlines. Using a weighted graph model, we formulate the problem as an integer linear programming and prove that it is NP-hard. We propose a packet encoding and broadcasting algorithm based on the maximum weight clique in the graph. Detailed analysis shows that the appropriate setting of weight function can ensure that the packet with low layer and early deadline be encoded and broadcast first. Simulation results show that our algorithm significantly reduce the deadline miss ratio in most cases, which is an important performance metric in layered video streaming applications.