Optimal buffering policy for downloading music in heterogeneous wireless networks

We consider a heterogeneous network of wireless LAN providing cheap, high speed coverage to local areas and wide area cellular networks providing a more expensive and slower coverage to a wider region. The movement of the mobile is modeled with a two state continuous time Markov chain. We consider the application where the mobile wants to download and listen to music. To reduce the download cost, the mobile downloads and buffers a lot of music in the lower cost area and plays it when it is in the more expensive areas. We formulate a mathematical model for this problem and present the optimal buffering policy for the mobile.