Application-specific workload shaping in multimedia-enabled personal mobile devices

Today, most personal mobile devices (e.g. cell phones and PDAs) are multimedia-enabled and support a variety of concurrently running applications such as audio/video players, word processors and web browsers. Media-processing applications are often computationally expensive and most of these devices typically have 100 - 400 MHz processors. As a result, the user-perceived application response times are often poor when multiple applications are concurrently fired. In this paper we show that by using application-specific dynamic buffering techniques, the workload of these applications can be suitably "shaped" to fit the available processor bandwidth. Our techniques are analogous to traffic shaping which is widely used in communication networks to optimally utilize network bandwidth. Such shaping techniques have recently attracted a lot of attention in the context of embedded systems design (e.g. for dynamic voltage scaling). However, they have not been exploited for enhanced schedulability of multiple applications, as we do in this paper.