## 1 Introduction  
According to Cisco, it is predicted that 500 billion devices will be connected with the Internet of Things (IoT) paradigm by 2030. On the other hand, Industrial Internet of Things (IIoT) and machine-to-machine (M2M) connectivity are directly interconnected concepts and are key players in the next step of Industry 4.0 evolution and intelligent manufacturing [1, 2]. These concepts (IoT, IIoT, M2M, and IR 4.0) have changed the method of interaction between people, devices, and machines around them. They pave the way for building ubiquitously connected infrastructures for supporting pioneering services and applications. Such paradigms with promising features are attractive to both customers and industry. Recently, we have witnessed massive IoT devices connected to the Internet in various solutions and purposely designed applications. The IoT and M2M devices are connected via low-power wide-area network (LPWAN) technologies wirelessly. They can react, sense their environment, and turn on anytime and anywhere to update data in real time to the cloud [3, 4]. LPWANs are meant to solve several problems with existing short-range and communication cellular network technologies to address the IIoT applications. Massive IoT devices are connected in various applications (Figure 1) such as smart buildings, smart meters, smart agriculture, capillary networks, remote health care, connected cars, smart streets, traffic safety and control, remote manufacturing, smart grids, logistics, tracking, and fleet management [5; 6; 7]. Current LPWAN technologies can be apportioned to three categories of networks according to their needs for additional infrastructure: (1) based on a cellular infrastructure such as narrowband IoT (NB-IoT) [8; 9] and (2) employing a third-party infrastructure such as SigFox [10], although autonomous LPWANs do not need any third-party infrastructure such as long range (LoRa) or long-range wide-area networks (LoRaWANs) [11]. For the first category, cellular technology-based LPWANs have a wide converge area, high capacity, long battery life, quality of service (QoS) provisions, and security. This type of LPWAN can be classified further into three main types: NB-IoT, LTE-M (Cat-M1), and extended coverage GSM IoT (EC-GSM-IoT). Figure 2 compares the main features of the three types of narrowband technologies. However, such networks do not use a license-free frequency band, are operated by commercial networks based on data subscription, and are controlled by the mobile operator companies. It is not cost-effective in the long term due to the continuous subscription fees for the cellular network operators. Thus, it does not meet the standalone operation requirements, should follow the conditions of the operator company in terms of coverage availability, service cost, and number of connected devices, and cannot handle the heavy interference wave of IoT devices due to the dense population of cellular devices [12]. SigFox [10] and Telensa [13] are patented networks for the second category as service providers. The growth of SigFox started a speedy innovation cycle that raised the competition between various LPWAN technologies like LoRaWAN, LTE-M, and NB-IoT. The lack of fitting IoT standards and technologies encourages the development of such focused networks as SigFox, which is mainly developed for low data rate M2M IoT applications. Both SigFox and Telensa are similar to cellular networks that connect remote devices using ultra narrowband (UNB) technology. On the other hand, Ingenu Random Phase Multiple Access (RPMA) operates at the 2.4-GHz band. It is in the task group of IEEE 802.15.4 K as a founding member. Ingenu suffers interference from other technologies like Wi-Fi at high frequencies, with its propagation loss increasing. Furthermore, it utilizes RPMA modulation, including the coverage and higher link budget with high power consumption. Figure 1: Variety of LPWAN applications.