Joint scheduling and cloud offloading using single radio

Abstract

As discussed in the previous chapter, one of the ways to succinctly describe the structure of a mobile application is through the use of component dependency graphs. This chapter discusses computational offloading in the situations where the solutions are free to consider the arbitrary dependency graphs as is, without adhering to any pre-determined scheduling order that the compiler may introduce. Joint scheduling–offloading schemes that optimally maximize a net utility function for single radio enabled mobile devices are discussed in this chapter. The net utility function trades-off the energy saved at the resource-constrained device with the time and energy costs involved in offloading while meeting the precedence constraints and execution deadline of the application. Optimizing the scheduling of the individual components along with cloud offloading decisions, taking into account the wireless network parameters, allows for an overall better solution compared to optimizing only the offloading decisions using a pre-determined compiler-generated schedule order of execution for the individual components. Besides, using the general dependency graphs (without imposing a sequential ordering for processing) and an optimal joint scheduling–offloading scheme can potentially allow for parallel scheduling of components in the mobile and cloud at the same time, thus reducing time to completion for the application.