Computation Offloading in Energy Harvesting aided Heterogeneous Mobile Edge Computing

Abstract

Computation offloading from multiple mobile devices (MDs) to multiple MEC servers (MEC-ss) in heterogeneous MEC systems with energy harvesting is investigated from a game theoretic perspective. The objective is to minimize the average response time of an MD that consists of data communication time, waiting time and processing time. M/G/1 queueing models are established for MDs and MEC-ss. The interference among MDs, the randomness in computation task generation, harvested energy arrival, wireless channel state, queueing at the MEC-s, and the power budget constraint of each MD are taken into consideration. A noncooperative computation offloading game is formulated. Furthermore, we reconstruct the optimization problem of an MD. A 2-step decomposition is presented and performed. Thereby, we arrive at a one-dimensional search problem and a greatly shrunken sub-problem. The sub-problem is nonconvex, but its Karush-Kuhn-Tucker (KKT) conditions have finite solutions. Therefore, we can obtain the optimal solution of the sub-problem by seeking the finite solutions. Thereafter, a distributive iterated best-response algorithm is designed. Simulations are carried out to illustrate the convergence performance and parameter effect of the proposed algorithm.