I. Introduction
In Recent years, the vigorous development of Internet of Things (IoT) technology has led to the emergence of many intelligent applications such as intelligent agriculture, intelligent industry, and intelligent transportation, which makes a large number of daily stuff such as automobiles, household appliances, mobile phones, and traffic lights enter the network for data exchange [1]. This expansion will lead to a tremendous increase in the network scale and data volume [2], which far exceeds the existing network capacity. To support a large number of IoT terminals and to process a large amount of data in time, mobile edge computing (MEC) [3] was born, and it supports the delay-sensitive and computation-intensive applications by providing ubiquitous computing resources near mobile user devices [4], [5], [6].