Optimal energy management policy of a mobile cloudlet with wireless energy charging

A mobile cloudlet (also called a pocket cloudlet) is a small computing unit providing data processing and relay transmission services to other nearby mobile devices (i.e., offloading) opportunistically when its computation and communication resources are free. The mobile cloudlet can request for wireless energy transfer/charging and pay some price to a wireless charger. The mobile cloudlet can use that energy to run its own applications or process offloaded jobs, and earn some revenue from other mobile devices. In this paper, we study an energy management policy of a mobile cloudlet, which can be considered as mobile demand response management in smart grid context. Specifically, we formulate a Markov decision process for the mobile cloudlet to determine whether or not to charge its battery and to accept and process offloaded jobs. We show analytically that the optimal policy of the mobile cloudlet energy management is a threshold policy. Additionally, we can derive the power demand profile of the wireless charger serving multiple cloudlets given the optimal policy of each cloudlet.