Industrial Internet of things (IIoT) and machine-to-machine (M2M) connectivity are strictly related and represent the next step in the ever-evolving world of industrial communications. The lack of a single wireless technology capable of satisfying new requirements in terms of flexibility, scalability, and low-power consumption led to the proposal of many different protocols to support the plethora of brand new offered services. In this chapter, an overview of low-power wide-area network (LPWAN) technologies is provided. After a discussion about the common features of available LPWAN solutions, the focus will be moved to the LoRaWAN standard, which is attracting the most significant interest from both the industrial and academic domains. Finally, some considerations on the use of LPWAN solutions for industrial applications, and the need and availability of network simulation tools, will be sketched.