Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> This paper explores and fortifies the need for a robust communications infrastructure for the upcoming smart grid and computes the bandwidth requirement for a hypothetical grid infrastructure. It presents the architecture of the current distribution system and shows that even for a medium-sized grid, the latency requirements of messages on the smart grid will require optical fibers as the transmission medium. <s> BIB001 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> A communication infrastructure is an essential part to the success of the emerging smart grid. A scalable and pervasive communication infrastructure is crucial in both construction and operation of a smart grid. In this paper, we present the background and motivation of communication infrastructures in smart grid systems. We also summarize major requirements that smart grid communications must meet. From the experience of several industrial trials on smart grid with communication infrastructures, we expect that the traditional carbon fuel based power plants can cooperate with emerging distributed renewable energy such as wind, solar, etc, to reduce the carbon fuel consumption and consequent green house gas such as carbon dioxide emission. The consumers can minimize their expense on energy by adjusting their intelligent home appliance operations to avoid the peak hours and utilize the renewable energy instead. We further explore the challenges for a communication infrastructure as the part of a complex smart grid system. Since a smart grid system might have over millions of consumers and devices, the demand of its reliability and security is extremely critical. Through a communication infrastructure, a smart grid can improve power reliability and quality to eliminate electricity blackout. Security is a challenging issue since the on-going smart grid systems facing increasing vulnerabilities as more and more automation, remote monitoring/controlling and supervision entities are interconnected. <s> BIB002 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> As one of the fastest growing technologies, machine-to-machine (M2M) communications are expected to provide ubiquitous connectivity. M2M devices can be used for a wide range of emerging applications that have various communications requirements. While M2M communications have been developed for many years, major challenges still remain with their efficient implementation from the perspective of low energy consumption and wide coverage. To address these challenges, low power wide area (LPWA) technology is investigated as one of the potential candidate solutions. In this article, we first introduce some typical LPWA M2M application scenarios. Given their requirements, we highlight key techniques and standards that are explicitly designed for LPWA M2M communications. Finally, we present an LPWA prototype system to evaluate its performance and demonstrate its potential in bridging a technological gap for future Internet-of-Things (IoT) applications. <s> BIB003 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> This paper provides an overview of the Internet of Things (IoT) with emphasis on enabling technologies, protocols, and application issues. The IoT is enabled by the latest developments in RFID, smart sensors, communication technologies, and Internet protocols. The basic premise is to have smart sensors collaborate directly without human involvement to deliver a new class of applications. The current revolution in Internet, mobile, and machine-to-machine (M2M) technologies can be seen as the first phase of the IoT. In the coming years, the IoT is expected to bridge diverse technologies to enable new applications by connecting physical objects together in support of intelligent decision making. This paper starts by providing a horizontal overview of the IoT. Then, we give an overview of some technical details that pertain to the IoT enabling technologies, protocols, and applications. Compared to other survey papers in the field, our objective is to provide a more thorough summary of the most relevant protocols and application issues to enable researchers and application developers to get up to speed quickly on how the different protocols fit together to deliver desired functionalities without having to go through RFCs and the standards specifications. We also provide an overview of some of the key IoT challenges presented in the recent literature and provide a summary of related research work. Moreover, we explore the relation between the IoT and other emerging technologies including big data analytics and cloud and fog computing. We also present the need for better horizontal integration among IoT services. Finally, we present detailed service use-cases to illustrate how the different protocols presented in the paper fit together to deliver desired IoT services. <s> BIB004 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> DOE FEMP guide for metering best practices aligned with the DOE Metering Guidance revision required by the 12/2013 Presidential Memo. <s> BIB005 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> The emerging Internet of Things (IoT) is getting closer to reality every day, with standards and protocols tailored to specific applications. Although some technologies follow a ‘make once, fit all’ approach, others are designed for specific applications such as smart-metering where the devices are often stationary with low jitter and throughput requirements. ETSI is already working towards a new standard for such applications, having specified a Specification Group to study what they call Low Throughput Networks (LTN) and propose a communications standard. In the meantime industrial solutions have entered the market such as, among others, Sigfox's and OnRamp Wireless technologies and LoRaWAN. Although this may lead to fragmentation of the IoT, they are worth examining to gain insights from their innovations and approaches to solving problems that are common in IoT technologies, and more specifically, security, energy management and resource constrains. This paper examines the wireless technologies of LoRaWan, Sigfox and OnRamp Wireless, the emerging leaders in IoT smart metering applications. These have so far not been studied in any peer-reviewed paper. Furthermore we discuss the suitability of Low Throughput Networks for certain applications and how the above technologies would work in such scenarios. <s> BIB006 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> Machine-to-machine (M2M) systems enable machines or devices to collect data, exchange information, and act on the environment without direct human intervention. A device in an M2M system not only collects data for its own usage but also shares the data with other devices automatically to achieve certain goals. Therefore, emerging M2M systems for civil transportation, electric power grid, medical treatment, industrial automation, etc., can be set up based on the networking of devices. In this survey paper, we first introduce the general architecture and communication networks for M2M systems. Then, we categorize emerging M2M systems according to the types of M2M context, M2M task, and M2M objective. We further survey recent solutions for M2M systems from both academia and industry with the insights of the M2M system categorization. Finally, we summarize challenges in developing M2M system solutions. <s> BIB007 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> Increasing attention has been paid to air quality monitoring with a rapid development in industry and transportation applications in the modern society. However, the existing air quality monitoring systems cannot provide satisfactory spatial and temporal resolutions of the air quality information with low costs in real time. In this paper, we propose a new method to implement the air quality monitoring system based on state-of-the-art Internet-of-Things (IoT) techniques. In this system, portable sensors collect the air quality information timely, which is transmitted through a low power wide area network. All air quality data are processed and analyzed in the IoT cloud. The completed air quality monitoring system, including both hardware and software, is developed and deployed successfully in urban environments. Experimental results show that the proposed system is reliable in sensing the air quality, which helps reveal the change patterns of air quality to some extent. <s> BIB008 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> The emergence of low-cost connected devices is enabling a new wave of sensorization services. These services can be highly leveraged in industrial applications. However, the technologies employed so far for managing this kind of system do not fully cover the strict requirements of industrial networks, especially those regarding energy efficiency. In this article a novel paradigm, called Low-Power Wide Area Networking (LP-WAN), is explored. By means of a cellular-type architecture, LP-WAN–based solutions aim at fulfilling the reliability and efficiency challenges posed by long-term industrial networks. Thus, the most prominent LP-WAN solutions are reviewed, identifying and discussing the pros and cons of each of them. The focus is also on examining the current deployment state of these platforms in Spain. Although LP-WAN systems are at early stages of development, they represent a promising alternative for boosting future industrial IIoT (Industrial Internet of Things) networks and services. <s> BIB009 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> A new breed of wireless technologies has emerged under the generic name of low-power, wide-area (LPWA), with a number of common characteristics that make these technologies uniquely suitable for Internet of Things (IoT) applications. These common characteristics include a power-optimized radio network, a simplified network topology, frame sizes in the order of tens of bytes transmitted a few times per day at ultralow speeds, and a mostly upstream transmission pattern that allows the devices to spend most of their time in low-energy deep-sleep mode. These characteristics enable a range of several kilometers and long battery lifetimes, possibly ten years of operation on a single coin-cell. It also enables simple and scalable deploymen <s> BIB010 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> Internet of Things (IoT) technology has attracted much attention in recent years for its potential to alleviate the strain on healthcare systems caused by an aging population and a rise in chronic illness. Standardization is a key issue limiting progress in this area, and thus this paper proposes a standard model for application in future IoT healthcare systems. This survey paper then presents the state-of-the-art research relating to each area of the model, evaluating their strengths, weaknesses, and overall suitability for a wearable IoT healthcare system. Challenges that healthcare IoT faces including security, privacy, wearability, and low-power operation are presented, and recommendations are made for future research directions. <s> BIB011 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> Low-power wide area networking technology offers long-range communication, which enables new types of services. Several solutions exist; LoRaWAN is arguably the most adopted. It promises ubiquitous connectivity in outdoor IoT applications, while keeping network structures and management simple. This technology has received a lot of attention in recent months from network operators and solution providers. However, the technology has limitations that need to be clearly understood to avoid inflated expectations and disillusionment. This article provides an impartial and fair overview of the capabilities and limitations of LoRaWAN. We discuss those in the context of use cases, and list open research and development questions. <s> BIB012 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> Occupancy detection for buildings is crucial to improving energy efficiency, user comfort, and space utility. However, existing methods require dedicated system setup, continuous calibration, and frequent maintenance. With the instrumentation of electricity meters in millions of homes and offices, however, power measurement presents a unique opportunity for a non-intrusive and cost-effective way to detect occupant presence. This study develops solutions to the problems when no data or limited data is available for training, as motivated by difficulties in ground truth collection. Experimental evaluations on data from both residential and commercial buildings indicate that the proposed methods for binary occupancy detection are nearly as accurate as models learned with sufficient data, with accuracies of approximately 78 to 93 percent for residences and 90 percent for offices. This study shows that power usage contains valuable and sensitive user information, demonstrating a virtual occupancy sensing approach with minimal system calibration and setup. <s> BIB013 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> In this paper, we review the background and state-of-the-art of the narrow-band Internet of Things (NB-IoT). We first introduce NB-IoT general background, development history, and standardization. Then, we present NB-IoT features through the review of current national and international studies on NB-IoT technology, where we focus on basic theories and key technologies, i.e., connection count analysis theory, delay analysis theory, coverage enhancement mechanism, ultra-low power consumption technology, and coupling relationship between signaling and data. Subsequently, we compare several performances of NB-IoT and other wireless and mobile communication technologies in aspects of latency, security, availability, data transmission rate, energy consumption, spectral efficiency, and coverage area. Moreover, we analyze five intelligent applications of NB-IoT, including smart cities, smart buildings, intelligent environment monitoring, intelligent user services, and smart metering. Finally, we summarize security requirements of NB-IoT, which need to be solved urgently. These discussions aim to provide a comprehensive overview of NB-IoT, which can help readers to understand clearly the scientific problems and future research directions of NB-IoT. <s> BIB014 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> Utilities have traditionally employed or contracted meter readers to collect natural gas usage data, which is expensive and time consuming, and thus necessitates the need of smart natural gas metering. Existing gas metering systems mainly focus on measuring the amount of gas flowing through an microelectro mechanical system (MEMS) thermal gas flow sensor and simply ignore the detailed gas composition. From computational fluid mechanics simulations, however, we discover that gases with different compositions will cause different effects on the reading of an MEMS sensor. Based on a thorough analysis of the working principle of MEMS thermal gas flow sensor, we propose an innovative mechanism to compensate the errors caused by different types of natural gases on the sensor’s reading. The proposed solution first measures the physical property of metered gas to derive the composition correction coefficient that will then be used to correct the meter’s reading errors, considering the relation between the calorific value and physical property of natural gases. In this way, the proposed solution realizes a real-time multicomposition gas metering via thermal gas flow sensors. We implement and evaluate the proposed gas metering technique in various Internet of Things systems, including industrial flow metering, gas metering in smart home, and gas metering in low-power wide-area networks. Experiment results verify the innovative design and confirm that the proposed solution features high sensitivity, high precision, and high range ratio. <s> BIB015 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> In 3GPP LTE Release 13, Narrowband Internet of Things (NB-IoT) was standardized for providing wide-area connectivity for massive machine-type communications for IoT. In LTE Release 14, NB-IoT was further developed to deliver enhanced user experience in selected areas through the addition of features such as increased positioning accuracy, increased peak data rates, the introduction of a lower device power class, improved non-anchor carrier operation, multicast, and authorization of coverage enhancements. In this article, we provide an overview of these features introduced for NB-IoT in LTE Release 14. An analysis is given on the applicability of these features and their benefits to enhance the NB-IoT radio access technology. <s> BIB016 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> Low power and long range machine-to-machine (M2M) communication techniques are expected to provide ubiquitous connections for the wireless devices. In this paper, three major low power and long range M2M solutions are surveyed. The first type of solutions is referred to as the low power wide area (LPWA) network. The design of the LPWA techniques features low cost, low data rate, long communication range, and low power consumption. The second type of solutions is the IEEE 802.11ah which features higher data rates using a wider bandwidth than the LPWA-based solutions. The third type of solutions is operated under the cellular network infrastructure. Based on the analysis of the pros and cons of the enabling technologies of the surveyed M2M solutions, as well as the corresponding deployment strategies, the gaps in knowledge are identified. The paper also presents a summary of the research directions for improving the performance of the surveyed low power and long range M2M communication technologies. <s> BIB017 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> Abstract Under intense environmental pressure, the global energy sector is promoting the integration of renewable energy into interconnected energy systems. The demand-side management (DSM) of energy systems has drawn considerable industrial and academic attention in attempts to form new flexibilities to respond to variations in renewable energy inputs to the system. However, many DSM concepts are still in the experimental demonstration phase. One of the obstacles to DSM usage is that the current information infrastructure was mainly designed for centralized systems, and does not meet DSM requirements. To overcome this barrier, this paper proposes a novel information infrastructure named the Internet of Energy Things (IoET) in order to make DSM practicable by basing it on the latest wireless communication technology: the low-power wide-area network (LPWAN). The primary advantage of LPWAN over general packet radio service (GPRS) and area Internet of Things (IoT) is its wide-area coverage, which comes with minimum power consumption and maintenance costs. Against this background, this paper briefly reviews the representative LPWAN technologies of narrow-band Internet of Things (NB-IoT) and Long Range (LoRa) technology, and compares them with GPRS and area IoT technology. Next, a wireless-to-cloud architecture is proposed for the IoET, based on the main technical features of LPWAN. Finally, this paper looks forward to the potential of IoET in various DSM application scenarios. <s> BIB018 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> The communication needs of the different stages of production proposed in the new industrial generation (INDUSTRY 4.0), demand devices that can handle high availability protocols. This paper presents an architecture of a cyber physical production system gateway that can be implemented in an SoC, integrating high availability communication interfaces as the high-availability seamless redundancy/ parallel redundancy protocol (HSR/PRP), industrial ethernet communication interfaces (e.g. Profinet), and connections to sensors and actuators (e.g. Modbus series). Considering the software and hardware adaptability that the architecture should have, field programmable gate array and reconfigurable devices, in general, are considered as the best options for implementation, since the architecture requires high levels of hardware and software flexibility. The proposed architecture was validated in an experimental environment that is implemented utilizing electronic design automation tools, IP cores, and Python libraries developed by third parties is presented, to achieve a device which handles high availability communication HSR/PRP, Profinet, Profibus, and Modbus. <s> BIB019 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> V. LPWA SUITABILITY FOR IOT APPLICATION AND SERVICE USE-CASES <s> Abstract By 2020, more than 50 billion devices will be connected through radio communications. In conjunction with the rapid growth of the Internet of Things (IoT) market, low power wide area networks (LPWAN) have become a popular low-rate long-range radio communication technology. Sigfox, LoRa, and NB-IoT are the three leading LPWAN technologies that compete for large-scale IoT deployment. This paper provides a comprehensive and comparative study of these technologies, which serve as efficient solutions to connect smart, autonomous, and heterogeneous devices. We show that Sigfox and LoRa are advantageous in terms of battery lifetime, capacity, and cost. Meanwhile, NB-IoT offers benefits in terms of latency and quality of service. In addition, we analyze the IoT success factors of these LPWAN technologies, and we consider application scenarios and explain which technology is the best fit for each of these scenarios. <s> BIB020
The characteristics discussed in Section II-B make LPWA networks suitable for IoT applications. A wide range of IoT services mainly require low data rate reporting, constrained by low-power end devices. A few times a day, small delay-/loss-insensitive frames, on the order of tens of bytes, are sent by these devices BIB010 . Examples of such IoT applications include measurement (such as of soil features), monitoring (such as of natural materials), and prediction of failure (such as of car engines). In most industries to date (except for oil and gas), the cost of deploying wired or cellular networks to collect and report data has been too high. LPWA networks enable the monitoring and reporting of this information in a cost-effective way due to the low cost of devices, deployment and operation. LPWA technology can support IoT applications with lower costs for a given number of monitored objects and a given range of deployment. LPWA networks are expected to be increasingly used in various sectors. LPWA feasibility has been demonstrated for infrastructure monitoring, transportation, asset tracking, security and health care BIB003 . LPWA has also been used for receiving data from a lighting monitoring system  . The LPWA solutions that are investigated in this paper are recommended for a number of use-cases. Although LPWA technologies can be deployed in a wide range of sectors, we focus on the use-cases explained in Figure 1 . Our recommendations are based on the features of the LPWA technologies that best meet the requirements of each use-case. We further limit the recommendations to the technical parameters listed in Table 2 . Therefore, the implementation details such as the architecture, hardware and software are beyond the scope of this paper. Interested readers are referred to BIB004 , BIB003 , BIB011 , and BIB007 for details on the IoT system architecture and implementation. To make the proper suggestion for each use-case, we must first understand what is required by each application. We characterize the use-cases of Figure 1 according to their demands for bitrate, mobility and real-time communications. We take into account that other requirements such as low deployment costs, wide network coverage, high capacity, strong security and high energy efficiency are the design-tocriteria of LPWA, which are for the most part provided by the technologies listed in Table 2 . The suitability of LPWA technologies for real-time support is recommended based on a data rate of 28.8 kbps for realtime services, such as two-way control applications  , and between 130 kbps to 4 Mbps with MJPEG coding (low quality) and MPEG-4/H.264 coding (1920 × 1080 resolution and 30 fps) for IP-based video surveillance systems BIB012 . Generally, LoRaWAN, RPMA and NB-IoT meet the data rate requirements of two-way control applications, while only the latter two satisfy the minimum data rate requirements of IP-based video surveillance systems. Although each LPWA technology can support regular reporting by sending short periodic messages, not all are suitable for frequently changing environments (ex: smart healthcare where reporting eventdriven alerts is inevitable) such as SigFox due to local regulations and other operating restrictions. LoRaWAN with duty cycle regulation does not satisfy the requirements for deterministic monitoring and real-time operation BIB012 . Unlike other technologies, NB-IoT operates within a licensed network, and the service is not available in some areas such as outlying districts and agricultural lands. LoRaWAN must be carefully dimensioned for each use-case based on key limiting factors such as the number of devices, the selected SF, and the number of channels BIB012 . The comparative study in BIB020 found that SigFox and LoRa are efficient in terms of battery lifetime, network capacity and deployment cost, while NB-IoT has the advantage of low latency and support for QoS. Smart meters with sensors monitor and meter the usage of resources such as oil, gas, electricity and water or other relevant information such as soil and oil pipeline status and report this information to the monitoring center. This information is sent periodically or when events that require urgent attention occur such as device breakdown. LPWA networks have yet to be widely used for operating sophisticated meters. Smart meters are no longer only used for measuring the amount of resources passing through them. They should be capable of tracking peak demand, measure utility quality and meter temperature, enable communication between multiple meters BIB005 and even determine whether we are home BIB013 . These meters are normally stationed on premises and require low reliability and low to medium bitrates BIB003 ,  . Given these requirements, any studied technologies can be deployed taking into account the SigFox's daily limited number of packets and high latency, which may disqualify it for critical event-driven alerts. NB-IoT and RPMA both have preferences over other technologies for their long-range coverage and concerns and at the same time for their licensing requirements and power consumption. Wireless M-Bus is a European standard specified in EN 13757-5:2015  that is VOLUME 6, 2018 widely deployed in Europe for metering applications such as water, gas and electricity. LoRa and NB-IoT have been proposed for smart gas metering BIB014 , BIB015 , water metering BIB014 and electric metering BIB020 , BIB012 , BIB016 , whereas RPMA, SigFox, LoRaWAN and NB-IoT were recommended by BIB017 . LoRaWAN, SigFox, and RPMA were selected as suitable LPWA networks for smart metering applications BIB006 . Tens of thousands of electricity meters were set up with LoRa technology in the region of the Calenberg Land near Hanover, Germany  . Smart house and industrial use-cases require automations such as monitoring and control at bitrate ranges from low to high for smart house applications and low for industrial applications. These applications are commonly stationed and thus do not require mobility support. Smart house applications, however, may require video surveillance that can be supported by RPMA and NB-IoT considering the video surveillance minimum data rate requirement (130 kbps) as mentioned earlier in this section. LoRaWAN was found to be inappropriate for video surveillance due to its low data rate BIB012 . However, any LPWA technology can be deployed for periodic reports. NB-IoT was recommended by BIB018 , BIB016 , and BIB014 and LoRa and SigFox by BIB020 for a similar purpose. On the other hand, industrial application requirements for two-way control automation can be met by LoRaWAN, RPMA and NB-IoT. It is worth mentioning that LoRa, SigFox and NB-IoT have been recommended by BIB020 for manufacturing automation. However, BIB012 argues that LoRaWAN can only be a candidate solution for small networks with careful configuration of the SF and number of channels. KNX [84] and EN 50090-1:2011  are two standards for home automation. Modbus series are a number of protocols used for automation and monitoring in industry BIB019 . Health care systems should collect real-time measurements BIB011 of patients through relevant sensors, send them to health centers and prioritize critical conditions that require urgent attention. Furthermore, mobility support for remote clinics and patients is required. A number of licensed and unlicensed options are available for this use-case. Given that two-way real-time medical control requires at least 28.8 kbps  , LoRaWAN, RPMA and NB-IoT can be used. However, remote doctors occasionally need to have video sessions with their patients. Thus, similar to smart house applications, RPMA and NB-IoT can support realtime video based monitoring of health conditions. Finally, any investigated technology is suitable for medical periodic reports and event-driven alerts except SigFox for the same reason mentioned above. Systems that are deployed for smart healthcare obviously should be energy efficient and support a large number of devices over a wide range. The best options are NB-IoT (overlooking the licensing costs) and LoRaWAN in terms of network capacity and range, with 53,547+ versus 40,000 nodes and a 15 km (urban) versus 5 km (urban) range, respectively. NB-IoT was determine to be the most suitable long-range communications solution in healthcare BIB011 . The combination of short-range and long-range M2M communications is proposed for healthcare in which the central node of the wireless body area network (WBAN) and sensors are connected using technologies such as Bluetooth and ZigBee, whilst WBAN is connected to the provider's base station using a suitable LPWA technology BIB011 . Although such a system is good in the sense that available short-range M2M architectures may be employed, low power consumption, scalability and less complexity are unlikely to be achieved. LPWA supports devices equipped on vehicles or along the road in the transportation use-case to send road condition information such as car accidents and road congestion to the management center. They can also exchange information among themselves to organize traffic and increase road efficiency. LPWA technologies deployed in this environment must provide high throughput, reliable, real-time transmission of critical information, and real-time two-way control of mobile vehicles BIB003 ,  . LoRaWAN is not a fit for this environment due to its delay and jitter constraints and contention caused by the ALOHA protocol. RPMA and NBIoT can address the needs of smart transportation systems bearing in mind the high energy consumption of RPMA and the licensing cost of NB-IoT, for which trade-offs should be made. NB-IoT was found as an appropriate solution for vehicle and asset trading BIB016 . LPWA technologies can also be utilized to monitor and control environmental and agricultural processes such as land watering and leak detection using small periodic or eventdriven messages. Wide coverage areas and delay tolerance (except for reporting a fault or leak) are mainly the priorities of these applications. LoRaWAN, SigFox and Telensa can support delay tolerant messages for periodic reports and event-driven alerts. LoRa and SigFox have been recommended by BIB020 . However, SigFox and Telensa are not suitable for real-time control due to their limitations on data rates (less than 28.8 kbps, the minimum required data rate for these types of applications). NB-IoT is also not suitable for smart agriculture services due to poor availability of the cellular network in these outskirt areas. High power consumption of RPMA is a major challenge for remote nodes and therefore excludes this technology as well. These recommendations consider mobility a requirement of these applications BIB003 . LoRaWAN has been recommended for agriculture applications by BIB018 and BIB012 with adequate deployment of gateways. Smart cities are perhaps the most vital area of IoT, with an increasing number of applications and services. They bring a number of benefits to drivers, authorities and society. These benefits include reducing traffic by directing drivers to less congested roads and parking spots, reducing driving risks through restricting cars to traffic light control, reducing energy consumption by controlling street lights based on vehicle movement and managing waste intelligently. These applications are common in the sense that a huge daily number of small delay sensitive messages is triggered by events such as parking status in the case of smart parking, traffic jams in the case of smart traffic and garbage load in the case of smart waste management. In smart lighting, however, messages are sent simultaneously during sunrise and sunset, increasing the possibility of collision, while smart waste management systems can tolerate some latency. The variation of these needs impose deployments of more than one technology in this use, for example, a technology for smart waste control and another one for smart parking. However, LPWA technologies deployed for smart cities are required to cover a wide range and provide high security for a huge number of energy efficient nodes. SigFox, LoRaWAN and Telensa (in order) are appropriate license-free technologies for smart lighting and smart waste control as they meet the requirements mentioned earlier at the cost of some delay. The daily generated number of event-driven messages and high energy consumption disqualify both SigFox and RPMA and favor LoRaWAN and Telensa as two adequate solutions for event-driven alerts and two-way real-time control of smart parking and safe driving applications. LoRaWAN has been proposed for smart cities BIB012 and successfully tested in real parking scenarios BIB018 . NB-IoT is also suitable for a number of smart city services BIB016 at the cost of a licensing charge and is being deployed for smart city applications and services [87] . Although NB-IoT was selected for streetlights, parking and waste management by BIB014 , the cellular signal is normally weak in underground car parking lots and remote areas, which shows that the NB-IoT is unsuitable for smart driving and parking. The IEEE 802.15.4k-based LPWA network has been proposed for air quality monitoring BIB008 and critical infrastructure monitoring  and Telensa for smart cities BIB009 . Although LPWA-based air monitoring systems have advantages over traditional WSN-based systems such as wide monitoring coverage, data accuracy and real-time reporting remain challenging. This is due to the restrictions some of the LPWA technologies place on the number of packets each end node is allowed to send. Smart grid is an IoT version of the legacy electricity network. It relies on bidirectional communications between the electricity supplier's distribution substation and consumer's electric meters to deliver and control the power in an efficient, optimized, safe, reliable and cost effective way. With smart grid, consumers' smart appliances are enabled to switch to other renewable energy sources such as solar during peak hours. In addition to the delivery of electricity, information is exchanged between the consumer's smart meter and supplier's controller to allow real-time control of power delivery BIB002 . Monitoring that allows detection of malfunction or failure and control that warrants proper actions are two main requirements of smart grid applications. A large number of messages BIB001 are expected to be communicated between a large number of consumers and the supplier in addition to securing the vulnerable stationed system elements. The LPWA technology should also be scalable to allow joining of a growing number of new devices. Given these requirements, LoRaWAN, RPMA (considering power consumption is not a concern of smart grid stationed devices) and NB-IoT (overlooking the licensing cost) are convenient for smart grid applications. Transportation, agriculture and remote healthcare applications are characterized by mobility of nodes, strong security measures, large network range and dense capacity. SigFox and Telensa can manage interference when the number of nodes grows using the UNB modulation as in LoRaWAN by adapting the data rates. On the other hand, smart metering requires a wide coverage area but not necessarily mobility. Based on our arguments, we recommend LPWA technologies to each of the discussed use-cases as listed in Table 3 .