Scheduling Announced Requests for Streamed Information

Abstract

We analyse a scheduling system in which users announce requests for information from a server some time before they actually need this information. Each constituent of the requested information has its own specific deadline, which is characteristic for applications that gradually consume a stream of information (e.g., video). For that purpose, a request fully specifies when the requesting user needs each constituent of this information. Since each user device is equipped with a buffer, the server can exploit this detailed timing information to deliver parts of the requested information upfront. The more the requests are announced in advance, the better the ability of the server to avoid deadline violations. We investigate for a given server capacity via semi-analytical techniques complemented with simulations how much the requests need to be announced in advance to essentially avoid violating all deadlines.