Due to the increase in diversity of wireless devices, streaming media systems must be capable of serving multiple types of users. Scalable coding allows for adaptations without re-encoding. To account for various viewing capabilities of each user, such as different spatial resolutions, multiple distortion measures are used [1]. In this paper, we examine the question of how to broadcast media packets with multiple distortion measures to multiple users. We cast the problem as a stochastic shortest path problem and use Dynamic Programming to find the optimal policy. We generate an offline algorithm to generate the optimal transmission policy for the general case. We then show the optimal policy can be done online via a simple threshold policy for the case of independent Bernoulli packet losses. Through experimental results, we show that our policy, which considers multiple distortion measures, achieves up to 2dB gains over conventional approaches.
Carri W. Chan, Nicholas Bambos, Susie Wee, John G.