Optimal proxy placement for coordinated en-route transcoding proxy caching

As audio and video applications have proliferated on the Internet, transcoding proxy caching has been considered as an important technique for improving network performance, especially for mobile networks. Due to several new emerging factors in the transcoding proxy, existing methods for proxy placement for web caching cannot be simply applied to solve the problem of proxy placement for transcoding proxy caching. This paper addresses the problem of proxy placement for coordinated enroute transcoding proxy caching for tree networks. We propose a model for this problem by including the new emerging factors in the transcoding proxy and present optimal solutions for this problem with/without constraints on the number of transcoding proxies using dynamic programming. Finally, we implement our algorithm and evaluate our model on various performance metrics through extensive simulation experiments. The implementation results show that our model outperforms the existing model for transcoding proxy placement for linear topology, as well as the random proxy placement model. The average improvements of our model over the other models are about 7.2 percent and 21.4 percent in terms of all the performance metrics considered.