I. Introduction
Incorporated with the fifth generation (5G) mobile communication technologies, the Internet of Things (IoT) network has rapidly advanced as a promising paradigm for revolutionizing various industries and domains, including transportation, energy, and agriculture, among others [2]. Effective deployment of IoT networks relies heavily on the seamless integration of various wireless communication technologies, such as Wi-Fi, Bluetooth, and ZigBee [3]. In face of these, it is imperative for us to address two key issues of efficient and secure transmission, so as to facilitate the network-wide connection and operation of ubiquitous terminals, which are employed with different communication mechanisms [4], [5].