Using Wi-Fi to save energy via P2P remote execution

Mobile devices are becoming increasingly powerful with regards to processing speed, networking capabilities, storage capacity etc. While these improvements open up new possibilities on handheld devices such as smart phones, the battery remains a limiting factor. Using the powerful CPUs of modern mobile devices depletes the energy resources very rapidly; as does using wireless networking. Cyber foraging is a pervasive computing technique where small mobile devices offload resource intensive tasks to stronger computers in the vicinity to improve performance and battery life. This comes at the cost of spending energy on wireless networking, and it is commonly assumed that wireless networking is too costly on small mobile devices. We investigate this claim in this paper, and show that it does not always hold, and that energy may indeed be preserved by utilising cyber foraging - even for relatively small tasks. This paper presents energy measurements of a modern mobile computing device, showing that utilising the relatively large CPU of such a device is very expensive - even more so than using Wi-Fi. Experiments performed with the Scavenger cyber foraging system are presented; a system enabling easy development of lightweight, highly mobile cyber foraging applications. It is shown how the energy usage of performing large tasks can be brought down drastically, and that even for relatively small tasks the total energy usage can be almost halved.