Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> I. INTRODUCTION <s> This paper addresses the Internet of Things. Main enabling factor of this promising paradigm is the integration of several technologies and communications solutions. Identification and tracking technologies, wired and wireless sensor and actuator networks, enhanced communication protocols (shared with the Next Generation Internet), and distributed intelligence for smart objects are just the most relevant. As one can easily imagine, any serious contribution to the advance of the Internet of Things must necessarily be the result of synergetic activities conducted in different fields of knowledge, such as telecommunications, informatics, electronics and social science. In such a complex scenario, this survey is directed to those who want to approach this complex discipline and contribute to its development. Different visions of this Internet of Things paradigm are reported and enabling technologies reviewed. What emerges is that still major issues shall be faced by the research community. The most relevant among them are addressed in details. <s> BIB001 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> I. INTRODUCTION <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> BIB002 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> I. INTRODUCTION <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> BIB003 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> I. INTRODUCTION <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> BIB004 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> I. INTRODUCTION <s> Low power wide area (LPWA) networks are attracting a lot of attention primarily because of their ability to offer affordable connectivity to the low-power devices distributed over very large geographical areas. In realizing the vision of the Internet of Things, LPWA technologies complement and sometimes supersede the conventional cellular and short range wireless technologies in performance for various emerging smart city and machine-to-machine applications. This review paper presents the design goals and the techniques, which different LPWA technologies exploit to offer wide-area coverage to low-power devices at the expense of low data rates. We survey several emerging LPWA technologies and the standardization activities carried out by different standards development organizations (e.g., IEEE, IETF, 3GPP, ETSI) as well as the industrial consortia built around individual LPWA technologies (e.g., LoRa Alliance, Weightless-SIG, and Dash7 alliance). We further note that LPWA technologies adopt similar approaches, thus sharing similar limitations and challenges. This paper expands on these research challenges and identifies potential directions to address them. While the proprietary LPWA technologies are already hitting the market with large nationwide roll-outs, this paper encourages an active engagement of the research community in solving problems that will shape the connectivity of tens of billions of devices in the next decade. <s> BIB005 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> I. INTRODUCTION <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> BIB006 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> I. INTRODUCTION <s> Abstract By 2020, more than twenty five billion devices would be connected through wireless communications. In accordance with the rapid growth of the internet of things (IoT) market, low power wide area (LPWA) technologies have become popular. In various LPWA technologies, narrowband (NB)-IoT and long range (LoRa) are two leading technologies. In this paper, we provide a comprehensive survey on NB-IoT and LoRa as efficient solutions connecting the devices. It is shown that unlicensed LoRa has advantages in terms of battery lifetime, capacity, and cost. Meanwhile, licensed NB-IoT offers benefits in terms of QoS, latency, reliability, and range. <s> BIB007 </s> Low Power Wide Area Networks: A Survey of Enabling Technologies, Applications and Interoperability Needs <s> I. INTRODUCTION <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> BIB008
Internet of Things (IoT) technologies have improved the way we live. These technologies address many of the challenges that humans are facing today, such as population growth, energy concerns and increasing demands for better means of sensing our environment. Approximately 28 billion devices, including more than 15 billion machine-to-machine (M2M) and consumer electronic devices, are expected to be communicating over short-range radio technologies such as WiFi and Bluetooth and particularly over wide area networks (WANs) based on cellular technology by 2021  , BIB003 . This is mainly due to the continuous decrease in the cost of sensors and actuators as well as innovations in communication technologies. We refer interested readers to BIB002 - BIB001 for more details on the IoT technologies and applications. Low power wide area (LPWA) networks have attracted considerable attention from the research community and industry as strong potential solutions for satisfying the requirements of diverse IoT applications. Although the term LPWA is relatively new, the design goals of this technology have been pursued for some time under different terms, including M2M, wireless sensor networks (WSNs) and IoT. IoT applications are characterized by their low data rates, power consumption and cost. Various sectors, such as transportation, healthcare, agriculture and industry are expected to exploit the features of LPWA technology. Personal healthcare systems, smart cities, smart grids, on-street lighting control and metering systems are among the applications that require communications over a large geographical area based on cheap and low-power devices. Such devices can be deployed and moved around over a wide area with the support of LPWA networks. Figure 1 shows the main sectors in which LPWA technology can be deployed. The main target of the LPWA technology is IoT applications that run on affordable low-battery devices and require communications over a wide geographical area. The success FIGURE 3. Energy efficiency and terminal and connection costs of wireless technologies BIB003 . cellular generations) is another reason why cellular technologies are not sufficiently practical for IoT devices  . Similar efforts have previously been made to review the LPWA literature in BIB003 , BIB004 , BIB005 ,  - BIB008 , and BIB006 . Both BIB003 and BIB005 have explored the advantages and disadvantages of LPWA solutions as well as efforts to standardize the technologies; the current deployment status in Spain is also discussed in BIB003 . Reference BIB005 , on the other hand, is a more comprehensive survey. It mainly focuses on the goals of LPWA technology and the techniques used to achieve these goals. It also presents the efforts made by standard developing organizations (SDOs) such as IEEE, ETSI, 3GPP, and IETF as well as industrial consortia such as the Weightless SIG [17] , the LoRa Alliance  , and the DASH7 Alliance  to standardize LPWA technologies. As three major low-power, long-range M2M-enabling technologies, LPWA, IEEE 802.11ah  , and cellular-based M2M communication networks are compared in BIB004 . The work presented in BIB006 is limited to the review and comparison of LoRa and narrow band-IoT (NBIoT) with general packet radio service (GPRS), while BIB007 and BIB008 are merely comprehensive surveys limited to SigFox, LoRa and NB-IoT, and the focus of  is LoRa  . Although this paper offers distinctive contributions, LPWA is still considered a new area of research, and therefore, the need for similar work is justified. It surveys the current trends in the LPWA networks. Through this survey, we present the most dominant LPWA technologies and the needs for integration among them and also address ways that LPWA technology can support the rapid growth of IoT applications and the challenges associated with these technologies. Compared with other surveys, our paper justifies the need for integration among different LPWA solutions and recommends suitable technologies for diverse IoT application and service use-cases. Short-range and long-range M2M wireless enabling technologies are compared and analyzed for the IoT. Moreover, recent research undertaken on all aspects of the LPWA is compared and categorized, and contributions and techniques are identified. The market opportunities inspired by these technologies are analyzed. This review provides researchers with a thorough survey to get them up to speed on the discussed topics in a single article. It is therefore an informative and up-to-date survey for readers interested in the LPWA networks. The remainder of this paper is organized as follows: Enabling technologies of short-range and long-range wireless M2M are compared and analyzed for the IoT in Section II. Section III analyzes the market opportunities created by the LPWA industry. The need for integration among diverse LPWA technologies is justified in Section IV. Section V recommends suitable LPWA technologies for a wide range of IoT application use-cases. The main LPWA challenges are identified, and recommendations for future research are presented in Section VI. The paper is concluded in Section VII.