3.1. Wireless Sensors Networks Categorization
Wireless sensor networks offer versatile solutions for a variety of applications and can be categorized in several ways, each shedding light on their unique characteristics:
3.1.1. Categorized by Physical Environment
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Underground: WSNs deployed beneath the Earth’s surface, often used in mining or geological monitoring.
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Terrestrial: these networks operate on land, making them suitable for a wide range of applications such as environmental sensing and smart agriculture.
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Underwater: submerged WSNs are essential for oceanographic research, aquatic habitat monitoring, and underwater exploration. Multimedia: these networks handle multimedia data and are valuable in applications like surveillance, video streaming, and multimedia content distribution.
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Mobile WSNs: mobile WSNs are dynamic and adaptable, making them ideal for scenarios like wildlife tracking, vehicular networks, or mobile healthcare solutions
[18].
3.1.2. Categorized by Different Network Topologies
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Star: in a star topology, all sensors communicate directly with a central hub or gateway, offering simplicity in deployment.
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Mesh: sensors in a mesh network communicate through neighboring nodes, ensuring self-healing capabilities and redundancy.
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Tree: with a hierarchical structure, data flow from leaf nodes to a central sink node, enabling efficient data aggregation.
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Hybrid: combine elements of various topologies to strike a balance between reliability, efficiency, and network coverage
[18][19][20].
3.1.3. Categorized by Applications
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Health monitoring: WSNs play a crucial role in healthcare, employing advanced medical sensors to monitor patients both in hospital and at home. These WSNs facilitate real-time monitoring of vital signs through wearable hardware. The health applications of WSNs encompass patient-wearable monitoring, home assisting systems, and hospital patient monitoring.
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Urban: WSNs offer diverse sensing capabilities that open the door to obtaining extensive information about a specified area, whether indoor or outdoor. WSNs serve as a versatile tool for measuring the spatial and temporal characteristics of various phenomena within urban settings, presenting numerous applications. In the urban context, WSNs find widespread use in areas such as smart homes, smart cities, transportation systems, and structural health monitoring.
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Flora and fauna: The essential aspects of both plant life (flora) and animal life (fauna) are crucial for any nation. The primaries are greenhouse monitoring, crop monitoring, and livestock farming. The illustration also highlights the prevalent types of sensors commonly employed in these applications.
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Environmental: The use of WSNs can enhance environmental applications requiring constant monitoring in challenging and distant locations. This includes subcategories like water monitoring, air monitoring, and emergency alerting, each involving specific types of sensors. The subsequent subsection delves into the examination of WSNs designed for these environmental applications.
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Military: The military pioneered WSNs, with early research (such as Smart Dust in the late 1990s) aiming at creating minuscule yet efficient sensor nodes for espionage. Subsequent technological advancements expanded WSN applications in the military, with a focus on battlefield surveillance, combat monitoring, and intruder detection. Various sensor types are now commonly employed in these military WSN applications.
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Industrial: Industrial wireless sensor networks (IWSNs) present numerous benefits for facilitating the intricate and dynamic processes within industrial settings. Thanks to their effortless setup, unrestricted mobility, and smart data routing capabilities, IWSNs are emerging as a promising communication option for industrial applications
[18][19][20][21].
3.2. Standards and Protocols
Standards play a paramount role in security and in the electronic components manufacturing domain and, therefore, for critical infrastructure. Standards ensure a seamless and reliable integration of technology into essential systems. Standards in critical infrastructure are the linchpin for reliability, safety, security, innovation, and regulatory adherence, collectively contributing to the robustness of essential systems that underpin modern society. They define criteria for materials, tolerances, testing procedures, and security, aiming to achieve consistency and interoperability of electronic components. Adhering to these standards enhances product performance, longevity, and compatibility while facilitating industry-wide collaboration.
3.2.1. Standardization Organizations
In alignment with their philosophy, standardization organizations operate extensively across various developed nations, spanning a broad spectrum of scientific domains.
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IEEE (Institute of Electrical and Electronics Engineers): On 1 January 1963, the American Institute of Electrical Engineers (AIEE) and the Institute of Radio Engineers (IRE) joined forces to establish the Institute of Electrical and Electronics Engineers (IEEE). Initially, IEEE boasted 150,000 members, with 140,000 based in the United States. As the early 21st century unfolded, IEEE’s influence spanned 39 societies, 130 journals, and over 300 annual conferences, with a focus on diverse areas like nanotechnologies, bioengineering, and robotics. From jet cockpits to medical imaging, electronics have become omnipresent. As of 2020, IEEE’s membership exceeded 395,000 across 160 countries, solidifying its status as the largest global technical professional organization through a network of units, publications, and conferences
[22].
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ISO (International Organization for Standardization): In 1946, a gathering of 65 representatives from 25 nations convened to deliberate on the future of international standardization. This culminated in the official establishment of ISO in 1947, comprising 67 technical committees. Since its inception, ISO has regularly disseminated information on its technical committees and published standards and organizational updates. Functioning as an independent non-governmental international entity, ISO boasts a membership of 169 national standardization bodies. Through collaborative expertise, ISO facilitates the development of voluntary, consensus-driven, and globally pertinent international standards, fostering innovation and delivering solutions to worldwide challenges
[23].
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CEN (European Committee for Standardization): CEN, the European Committee for Standardization, serves as a consortium uniting national standardization bodies from 34 European nations. This collaborative platform is dedicated to formulating European standards and technical documents across diverse products, materials, services, and processes. Recognized by the European Union and the European Free Trade Association, CEN, along with CENELEC and ETSI, is entrusted with the task of devising voluntary standards at the European level. In the interest of international and European standardization, CEN collaborates with CIE, aiming to leverage the knowledge and expertise within each organization through a formalized agreement
[24].
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IEC (International Electrotechnical Commission): In 1906, the International Electrotechnical Commission (IEC) was established in London after a proposal at the 1904 International Electrical Congress. The congress recognized that the diversity in electrical systems worldwide was hindering progress. The IEC’s inaugural meeting included representatives from multiple countries, with Lord Kelvin elected as the first president. Today, the IEC, a global non-profit organization, unites over 170 countries and oversees 20,000 experts worldwide. Celebrating its centenary in 2006, the IEC has adapted to 21st-century technological advancements, establishing new technical committees for areas like fuel cells, assessment methods for human exposure to electric and electromagnetic fields (including 5G), avionics, electronic displays, nanotechnology, marine energy generation, solar thermal electric plants, printed electronics, electrical energy storage systems, wearable electronic devices, personal e-transporters, and more. This reflects the IEC’s commitment to staying current with evolving technologies and fostering standardization in diverse fields
[25].
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IPC (Institute of Printed Circuits): Founded in the autumn of 1957, the Institute of Printed Circuits, or IPC, has remained committed to eliminating supply chain challenges, establishing industry standards, and fostering industry progress. As a worldwide trade association, IPC is devoted to enhancing the competitive excellence and financial prosperity of its electronics industry members. To achieve these goals, IPC will allocate resources to management improvement, technology enhancement programs, formulation of pertinent standards, and environmental conservation. IPC aspires to be a globally respected organization, recognized for leadership and its significant role in providing standards and quality programs for the electronics industry
[26].
Other entities play a pivotal role in establishing and refining standards that govern diverse aspects of products, materials, services, and processes, such as ITU (International Telecommunication Union), BSI (British Standards Institution), ISA (International Society of Automation) MSS (Manufacturers Standardization Society), NEMA (National Electrical Manufacturers Association), JEDEC (Joint Electron Device Engineering Council), ANSI (American National Standards Institute), NIST (National Institute of Standards and Technology), and JEITA (Japan Electronics and Information Technology Industries Association). Their operations are not confined to a specific sector, reflecting a comprehensive approach to standardization that resonates with the global pursuit of quality, innovation, and harmonization. In numerous developed countries, these organizations serve as crucial pillars in fostering collaboration, ensuring adherence to best practices, and contributing to the advancement of standards across the scientific landscape.
3.2.2. Wireless Protocols
The cellular Internet of Things (IoT) refers to a category of communication technologies and protocols that enable Internet connectivity for a wide range of IoT devices using cellular networks. It allows these IoT devices to transmit and receive data over cellular infrastructures, which include technologies such as 2G, 3G, 4G, and 5G. Cellular IoT technologies encompass various standards and protocols designed for connecting IoT devices via cellular networks. Second-generation technology introduced digital voice encoding, enabling more efficient use of the radio spectrum compared with its analog predecessor. It enabled text messaging (SMS) for the first time, revolutionizing communication. In 1991, the European standard GSM (global system for mobile communications) became a global benchmark for 2G, ensuring interoperability and driving widespread adoption. This technology laid the foundation for mobile data services, paving the way for future generations of cellular networks and the evolution of modern smartphones and mobile data connectivity. The history of 3G cellular technology is a pivotal chapter in the evolution of mobile communication. Emerging in the early 2000s, 3G (or third-generation technology) marked a substantial advancement over its predecessors. It introduced high-speed data transmission, enabling not only voice calls but also video calls and mobile internet access. The rollout of 3G networks fostered the proliferation of mobile data services, leading to the birth of mobile applications, video streaming, and mobile browsing.
Fourth-generation cellular technology was a watershed moment in mobile communication. Launched in the late 2000s, 4G (or fourth-generation technology) represented a remarkable leap forward from its 3G predecessor. It introduced unprecedented data speeds and low latency, ushering in the era of high-definition video streaming and faster mobile internet. The long-term evolution (LTE) standard emerged as a global benchmark for 4G, enabling seamless data connectivity. Fourth-generation technology revolutionized communications, serving as the foundation for the mobile app ecosystem, enabling high-quality voice and video calls, and driving the widespread adoption of smartphones. Its impact extended beyond personal communication, supporting the growth of IoT and the development of smart cities and connected devices.
As 4G networks reached their capacity limits, there was a growing need for a faster, more efficient, and more robust network. The proliferation of IoT devices, smart cities, autonomous vehicles, and augmented reality applications demanded a new solution. Fifth-generation technology is designed to deliver faster data speeds, lower latency, and massive device connectivity. It utilizes higher radio frequencies and small-cell technology to provide faster data rates, often in the gigabit range, and can simultaneously connect a vast number of devices, something that makes it ideal for the IoT.
ZigBee serves as a wireless network data transmission protocol, supporting mesh and cluster tree architectures. Its functionality, akin to Wi-Fi, distinguishes itself through lower energy consumption, modest bit rates (up to 200 and 50 kbps), and an operational range of about 100 m. ZigBee enables two-way communication, allowing devices to both send and receive signals, with some capable of relaying signals. Developed by the ZigBee Alliance in 2002, this technology boasts collaboration from numerous globally recognized companies, including Samsung, Philips, Siemens, Bosch, Motorola, Amazon, and Xiaomi. The initial ZigBee specification, Version 1.0, emerged in 2004, followed by the introduction of ZigBee 3.0 in 2016.
The Narrowband Internet of Things (NB-IoT) is an emerging IoT technology created by the Third-Generation Partnership Project (3GPP). Operating alongside LTE in licensed cellular spectrums, NB-IoT aims to establish a low-power wide-area network (LPWAN). Devices utilizing NB-IoT are designed for extended battery life, with an expectancy of up to 10 years on a single battery charge, covering approximately 10 km in range. The modules are cost-effective and offer reliable connectivity through commercial LTE operators. These modules can incorporate sensors for measuring and transmitting data (uplink) or receiving data (downlink). In 3GPP’s release 13, the maximum data rates are set at 20 kbps for uplink and 100 kbps for downlink, with later releases significantly improving the uplink rate to 142.5 kbps
[27].
LoRaWAN—a prominent LPWAN technology—has garnered substantial attention from the research community. Developed by Semtech Corporation, it facilitates long-range data transmission with low data rates. Using a chirp spread spectrum (CSS) modulation, where the chirp signal frequency varies, LoRaWAN ensures robust coverage. The modulation employs spreading factors (SFs) ranging from 7 to 12, with higher SFs providing better coverage but at the expense of data rate and power efficiency
[28][29].
Bluetooth technology owes much of its success to the remarkable flexibility it affords developers. With two radio options, Bluetooth caters to a diverse range of wireless connectivity needs, making it a preferred choice for various applications. Whether facilitating high-quality audio streaming, data transfer between devices, or communication in building automation, Bluetooth Low Energy (LE) and Bluetooth Classic radios offer tailored solutions to developers worldwide. The Bluetooth LE radio, designed for ultra-low power operation, operates across 40 channels in the 2.4 GHz unlicensed ISM frequency band. This design grants developers significant flexibility in crafting products that align with the specific connectivity demands of their target markets. Bluetooth LE supports various communication topologies, extending from point-to-point to broadcast and, more recently, mesh, enabling the creation of dependable large-scale device networks. Initially renowned for device communication, Bluetooth LE has evolved into a prominent device positioning technology, meeting the rising demand for highly accurate indoor location services
[30].
WirelessHART—initiated in 2004 by 37 HART Communication Foundation companies—is a wireless sensor networking technology developed for process field device networks. Approved by the IEC in 2009, it is an open standard supported by various industry leaders. The latest version—IEC/PAS 62591:2016—was released in 2016. WirelessHART is an extension of the wired HART protocol, operating in the 2.4 GHz ISM band, using the IEEE 802.15.4 standard
[31]. Kevin B. Hall
[32] notes that, in rural American communities, electric companies managing supervisory control and data acquisition (SCADA) systems are increasingly adopting wireless administration. Given the absence of wired high-speed internet access in these rural areas, electric companies (vital components of CI) are turning to wireless sensor and mesh networks (WSMN) for communication over extensive distances. Nodes within the rural electric grids utilize WirelessHART to transmit information back to the central SCADA controller. Lastly, study
[33] highlights WirelessHART signalling as the predominant digital communication technology in process control industries, boasting over 40 million deployed devices. It emphasizes the growing challenges, particularly in anticipation of the exponential WirelessHART expansion projected until 2028, especially within sectors like oil, gas, chemical, and power generation.
Smita Sanjay Ambarkar
[34] explains the range of 6LowPAN from smart home to critical infrastructure and studies the enhancement of IoT network security against routing protocol for low-power and lossy networks (RPL) attacks. It highlights the vulnerability of IoT networks to various RPL attacks, like HELLO flood, version number, and rank attacks. The paper proposes a mutual authentication scheme to protect the network from these threats. The proposed method is evaluated for its effectiveness in mitigating these attacks, focusing on power consumption and network performance. The results demonstrate that the scheme effectively blocks unauthenticated nodes and improves network performance.