Joint Broadcast Scheduling and User’s Cache Management for Efficient Information Delivery

In information delivery through broadcasting, a server con-tinuously pushes information in a broadcast channel and the users ZCCH it by tuning in and waiting until the informa-tion they are interwted in is transmitted. The server follows a schedule that attempts to match the user access statistics in order to reduce the ace = latency. In c=e of inhomog~ neous user populations with several ~erent ace = profila, the users have local cache to smooth out the mismatch = of their profle with the broadcast schedule statistics. In this work we propose a method for joint dwign of the server broadcast schedule and the user ctilng strate ~ such that the zccw delay is minimized. We identify a fluid model of the joint problem on which the joint optimization is per-formed and subsequently the dynamic schedule is dmigned to match the optimal fluid model parameters. It turns out that with joint d=ign of the broadcast schedule and the user cache management policy significant performance im-provement is tileved, particularly for inhomogeneous user user community without any feedback about the user’s needs due to the hmited upfink communication capability from the user to the server. Data broadcast by the server are organized into units called information items. When a user needs a certain information item, it monitors the broadcmt channel until the desired item is detected and captures it for use. There is some latency from the time the need of an information item arises until the time the item is actu-sdly broadcast by the server. This latency depends on the broadcast schedule of the server, as well as the user access pattern