Delay Constraint Energy Efficient Cooperative Offloading in MEC for IoT

Mobile edge computing (MEC) is a promising approach to execute delay-sensitive and computation-intensive applications in the resource-limited IoT mobile devices (IMDs) by offloading computing tasks to MEC servers. In this paper, we propose a neighbor-aided cooperative offloading scheme with delay constraint to improve the energy efficiency in MEC-based Internet of Things (IoT) networks. The network consists of a target IMD with some IMD neighbors, and an access point integrated with an MEC server. The latency-constrained tasks in the IMD can be partially offloaded to and executed by the selected neighboring IMD or the MEC server. Different from other works, our proposed offloading scheme selects the most energy-efficient one from all the neighboring IMDs as the offloading helper. Specifically, we formulate an optimization problem to minimize the total energy consumption while satisfying the computation delay constraint of each task, and obtain the most energy-efficient neighbor with the optimized division of tasks by solving the formulated problem. Moreover, we design an easy neighbor selection scheme with lower time complexity by the weighted value of the transmission rate for each neighbor. Numerical results show that the proposed scheme outperforms benchmark schemes significantly in terms of energy consumption and the supported maximum task length.