*Article* **Energy Efficient Cooperative Computation Algorithm in Energy Harvesting Internet of Things**

**Haneul Ko 1, Jaewook Lee 2, Seokwon Jang 2, Joonwoo Kim <sup>2</sup> and Sangheon Pack 2,\***


Received: 12 October 2019; Accepted: 22 October 2019; Published: 24 October 2019

**Abstract:** The limited battery capacity of Internet of Things (IoT) devices is a major deployment barrier for IoT-based computing systems. In this paper, we propose an energy efficient cooperative computation algorithm (EE-CCA). In an EE-CCA, a pair of IoT devices decide whether to offload some parts of the task to the opponent by considering their energy levels and the task deadline. To minimize the energy outage probability while completing most of tasks before their deadlines, we formulate a constraint Markov decision process (CMDP) problem and the optimal offloading strategy is obtained by linear programming (LP). Meanwhile, an optimization problem of finding pairs of IoT devices (i.e., IoT device pairing problem) is formulated under the optimal offloading strategy. Evaluation results demonstrate that the EE-CCA can reduce the energy outage probability up to 78% compared with the random offloading scheme while completing tasks before their deadlines with high probability.

**Keywords:** offloading; Internet of Things (IoT); energy; constraint Markov decision process (CMDP); optimization
