The current mobile networks provide seamless and reliable streaming (voice/video) services to an increasing number of mobile users. From Global System for Mobile Communications (GSM) General Packet Radio Service (GPRS) and Universal Mobile Telecommunication System (UMTS) to Long Term Evolution (LTE) and LTE-Advanced (LTE-A), the transmission data rates have increased tremendously. Relying on the deployment of a heterogeneous network (HetNet) [1–5] involving macrocells, small cells (femtocells and picocells), and/or relay nodes, ubiquitous support for basic multimedia and Internet browsing applications has been tractable. In addition to mobile networks, wireless local area networks (WLANs) such as IEEE 802.11a/b/g/e/n/ac/ax also support moderate distance data exchange with best effort services or a certain level of quality of service (QoS). As a result, it seems that the needs of human-to-human (H2H) communication applications can be satisfied using the existing network architectures and technologies. However, to substantially facilitate human daily activities, providing only basic voice/video and Internet access services may be insufficient.
Recently, a novel communication paradigm known as machine-to-machine (M2M) communications has had a significant impact on the development of the next generation of wireless applications. Achieving “full automation” and “everything-to-everything” (X2X) connection facilitated byM2M communications has been regarded as two urgent and ultimate targets not only in the industry but also in the context of economics, social communities/activities, transportation, agriculture, and energy allocation . “Full automation” implies a significant enhancement of human beings’ sensory and processing capabilities, which embraces unmanned or remotely controlled vehicles/ robots/offices/factories/stores, augmented/virtual/kinetic reality, and immersive sensory experiences. On the other hand, X2X connection implies that diverse entities, including human and machines, will be able to form new types of communities in addition to those based on H2H communication, such as social networks using human-to-machine (H2M) and M2M communication [7–12]. The applications include intelligent transportation systems (ITSs) , volunteer information networks (in which each entity in the network shares information with other entities to obtain a global view of the environment and the community) , the Internet of Things (IoT) [15–17], and smart buildings/cities/grids [18–20], to name but a few.