the sectors of society, profession, and the industry. Such progression allows devices such as sensors, vehicles, robots, machines, or other such objects to connect to the Internet. The network enables them to send the sensed data and parameters to the remote centralized device or server, for example, the cloud. The cloud provides intelligence for making an appropriate decision or actuating action.  
In general, IoT applications require energy-efficient and low complexity nodes for a variety of uses that are to be deployed on scalable networks. Currently, wireless technologies such as IEEE 802.11 wireless local area networks (WLANs), IEEE 802.15.1 Bluetooth, and IEEE 802.15.3 ZigBee low rate wireless personal area networks (LR-WPANs) are being used for sensor applications in short-range environments. WLAN and Bluetooth were designed primarily for high speed data communication, whereas ZigBee and LR-WPAN are used for low data rate application in local environments. In contrast, wireless cellular networks such as 2G, 3G, and 4G are designed primarily for voice, data, and video communication, not for wireless sensor applications. These are used primarily for large coverage applications. Such cellular networks generally do not meet the performance metrics required for sensor applications.  
Hence, to support such requirements, a new paradigm of IoT, called a low power wide area network (LPWAN), has evolved. LPWAN is a class of wireless IoT communication standards and solutions with characteristics such as large coverage areas, low transmission data rates with small packet data sizes, and long battery life operation [2]. The LPWAN technologies are being deployed and have shown enormous potential for the vast range of applications in IoT and M2M, especially in constrained environments. The key expectations are device costs in the $3-$7 range, packet sizes from 10 to 1000 Bytes at uplink speeds of up to 200 kbps, battery life of 10+ years, support for 100K+ devices, and coverage from 2 km to 1000 km [3]. These characteristics are expanded in many cases to address new applications. Hence, in addition to these core LPWAN characteristics, there are applications that may require larger data sizes and varying bandwidth, may tolerate somewhat reduced coverage, and may allow some compromise on cost. A typical LPWAN technology is designed using a set of design considerations and architectural constructs derived from these core and additional characteristics. The design constructs result in various tradeoffs, especially cost, performance, and hardware and software complexity.  
This paper is primarily focused on defining a systematic and powerful approach of identifying the key characteristics of LPWAN applications, translating them into explicit requirements, and then deriving the associated design considerations [4] for present and future technological candidates. The remaining paper is organized as follows. Section 2 discusses the emerging and intelligent applications of LPWANs and their characteristics. Section 3 briefly describes and categorizes various wireless access technologies. Section 4 translates LPWAN application characteristics from Section 2 to corresponding requirements to provide specificity to the generic characteristics. Section 5 develops the associated design considerations for the requirements developed. LPWAN topologies and architectures are presented in Section 6. Proprietary and standards-based LPWAN candidate technologies are introduced in Section 7. Section 8 summarizes the interrelationship between LPWAN and cellular 5G technology. Concluding remarks are provided in Section 9.