Volume 36, Issue 1 e70041
SURVEY ARTICLE
Open Access

Smart Homes of the Future

Absalom E. Ezugwu

Corresponding Author

Absalom E. Ezugwu

Unit for Data Science and Computing, North-West University, Potchefstroom, South Africa

Correspondence:

Absalom E. Ezugwu ([email protected])

Laith Abualigah ([email protected])

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Olutosin Taiwo

Olutosin Taiwo

School of Mathematics, Statistics and Computer Science, University of Kwazulu-Natal, Westville Campus, Durban, South Africa

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Ojonukpe S. Egwuche

Ojonukpe S. Egwuche

Unit for Data Science and Computing, North-West University, Potchefstroom, South Africa

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Laith Abualigah

Corresponding Author

Laith Abualigah

Centre for Research Impact & Outcome, Chitkara University Institute of Engineering and Technology, Chitkara University, Rajpura, 140401 Punjab, India

University of Technology Sydney, Mafraq, 25113 Jordan

Correspondence:

Absalom E. Ezugwu ([email protected])

Laith Abualigah ([email protected])

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Annette Van Der Merwe

Annette Van Der Merwe

Unit for Data Science and Computing, North-West University, Potchefstroom, South Africa

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Jayanta Pal

Jayanta Pal

Department of IT, Tripura University, Suryamaninagar, Tripura, India

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Apu K. Saha

Apu K. Saha

Department of Mathematics, National Institute of Technology Agartala, Agartala, Tripura, India

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Ahmed Ibrahim Alzahrani

Ahmed Ibrahim Alzahrani

Computer Science Department, Community College, King Saud University, Riyadh, Saudi Arabia

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Fahad Alblehai

Fahad Alblehai

Computer Science Department, Community College, King Saud University, Riyadh, Saudi Arabia

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Japie Greeff

Japie Greeff

School of Computer Science and Information Systems, Faculty of Natural and Agricultural Sciences, North-West University, Vanderbijlpark, South Africa

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Micheal O. Olusanya

Micheal O. Olusanya

Department of Computer Science and Information Technology, Sol Plaatje University, Kimberley, South Africa

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First published: 06 January 2025
Citations: 1

Funding: This work is funded by the Researchers Supporting Project number (RSP2025R564), King Saud University, Riyadh, Saudi Arabia.

ABSTRACT

The advent of the Internet of Things (IoT) has transformed the concept of smart home automation, thereby allowing users to remotely interact with their houses and control home appliances for resource efficiency. This technological development has significantly improved convenience, safety, and overall lifestyles for homeowners. The impact of smart home automation systems (SHAS) extends beyond individual households, positively influencing the global economy in various aspects. While research in smart home automation has proposed solutions to wireless control and monitoring issues, there are still challenges hindering the widespread deployment of these systems. This paper conducts a detailed systematic analysis of state-of-the-art SHAS, covering topics such as the concept of smart home automation, its application domains, architectural framework, enabling technologies, as well as the challenges involved. Furthermore, this paper provides reviews and discussions on the latest essential components, technologies, and protocols employed in designing and developing SHAS. By offering an in-depth examination of the current scenery, this study aims to provide readers with a comprehensive understanding of smart home automation, its significance, and future research directions. Through addressing the challenges and presenting potential solutions, this research contributes to adopting wider acceptance and successful deployment of SHAS.

1 Introduction

The concept of a smart home has evolved dramatically in recent years, transforming from a futuristic ideal into a tangible reality that is increasingly becoming an integral part of modern living [1, 2]. A smart home is a digitally connected dwelling that enables remote control, monitoring, and management of home appliances through devices like smartphones, tablets, or laptops. Referred to as intelligent homes, home automation, or domotics, the smart home (SH) environments provide users with enhanced comfort, convenience, home safety, security, and energy efficiency [3]. According to King [4], smart homes incorporate communication networks that connect major home appliances, that facilitate remote monitoring, control, and access from both nearby locations and outside the premises. Future smart homes represent the convergence of various advanced technologies, designed to create living spaces that are not only more convenient and efficient but also responsive to the needs and preferences of their inhabitants. The benefits of smart home automation systems (SHAS) encompass improved healthcare systems, reduced energy consumption, and enhanced home safety and security. This paper explores the components, benefits, and challenges associated with smart homes, providing a comprehensive overview of current advancements and future directions in this rapidly growing field.

At the center of smart home technology lies the integration of diverse internetworked systems and devices that communicate seamlessly with each other. These devices range from smart lightning and environmental control and monitoring to sophisticated security systems and interconnected appliances, which work together to enhance the comfort, safety, and efficiency of residential buildings and their environments [5-7]. More so, the advent of the Internet of Things (IoT) has played a very important role in the integration of smart home systems and devices, which has enabled everyday home appliances to connect to the Internet and interact with each other in novel ways [8, 9].

The increasing global focus on sustainability and energy conservation has further accelerated the development of smart home technologies [10-12]. As energy consumption becomes a pressing global concern, especially in the global south regions and some parts of the developed world, specific innovations that are aimed at reducing household energy consumption and promoting eco-friendly practices are gaining prominence [13-15]. Furthermore, the ability to monitor and control household energy consumption, home environments, and indoor and outdoor appliances remotely has expanded the possibilities for security and convenience, thereby allowing homeowners to manage their homes and properties anywhere in the world remotely.

The evolution of home automation has undergone various stages due to ongoing progress in microelectronics, as illustrated in Figure 1. In the initial phases of home automation development, diverse technologies such as Bluetooth [16], Wi-Fi [17], RFID [18], ZigBee, GSM/GPRS, and Raspberry Pi, among others, were employed in the design of these systems. Nevertheless, the shortcomings associated with these technologies, including limited coverage, unreliable network connections, and other deficiencies, have encouraged researchers to devise more innovative technologies capable of supporting home automation operations on a broader scale. Moreover, scholars and industry experts are continuously exploring diverse avenues to develop efficient and secure systems within the domain of smart home innovation. It is noteworthy that the successive stages of technological progress have also afforded users platforms to interact with household appliances, spanning from traditional wired media to IoT and artificial intelligence [19]. In the early stages of this advancement, home automation faced constraints due to significant technological limitations. However, with the emergence of AI-enabled IoT technologies, smart home automation has achieved remarkable flexibility, empowering users to remotely control home appliances and embedded systems from any location.

Details are in the caption following the image
Technological evolution in smart home automation.

An example scenario of a smart home generic framework is illustrated in Figure 2. This general architectural layout of a smart home automation system offers a visual representation of the smart home setting and its fundamental components. The system comprises three principal modules: the user, the home environment, and services. The user module encompasses devices facilitating connection to and control of the home, along with the ability to monitor its status. In healthcare contexts, this module includes devices facilitating communication between patients and healthcare providers. The home environment module encompasses sensors, electrical appliances, and connectivity mechanisms such as Bluetooth, Zigbee, or Wi-Fi modules, alongside surveillance cameras and other relevant IoT hardware. The services module encompasses intelligent control and monitoring of the home, its appliances, and the patient's health status. Cloud computing services play a key role in data storage and retrieval for these services.

Details are in the caption following the image
Smart home system architecture.

Cloud services embody a broad spectrum of cloud computing solutions tailored to the data generated by SHAS. These services comprise storage and data analysis, managed by cloud service providers who host applications and services demanding extensive computational resources, swift data processing, and rapid application deployment. At this intersection, artificial intelligence technologies come into play, facilitating precise analysis of continuous and unbounded sequences of data streams originating from myriad sensors and devices operating at lower levels [20]. Real-time big data analytics can be performed on massive datasets utilizing artificial intelligence for preprocessing before further decision-making or data storage in cloud servers. The outcomes of artificial intelligence analysis on smart home data serve as a decision-making foundation for third-party applications, including those in smart cities. Integrating artificial intelligence into the architecture of smart homes empowers the system to operate intelligently, thereby reducing the processing burden on the cloud server and optimizing the utilization of computing resources. Within the architecture of smart home systems, the device data store denotes a cloud comprising end users' devices linked to the smart home system to access the application's services. This application module facilitates straightforward audit trails of users when such inquiries arise. Through a comprehensive exploration, this paper underlines the transformative potential of IoT-driven smart home automation, addressing challenges and charting the course for future advancements in this dynamic domain.

Recently, SH has seen advancements through the integration of AI models, leading to the emergence of intelligent homes. IoT technologies, AI, and information technology (IT) play crucial roles in the design, development, and deployment of SHAS. These systems can be personalized to regulate or monitor electrical home appliances and environmental variables. Intelligent SHAS, however, go beyond mere monitoring and control; they possess the capability to predict and prevent potential incidents within a smart home environment. While conventional SHAS is limited to responding to predefined actions from sensors and actuators, intelligent SHAS leverages predictive capabilities to enhance home safety and security by identifying, analyzing, classifying, and forecasting situations within the home. Therefore, the integration of artificial intelligence models into IoT sensors, devices, modern analytic tools, and cloud computing significantly transforms smart home environments, offering enhanced applications for home automation.

Several countries have recognized the value of widespread SHAS deployment and have enacted laws, regulations, and subsidies to encourage its adoption, aiming to decrease energy demand rates [21]. The growing interest in research on home automation systems highlights the need for further exploration to enhance their functionality and accessibility. However, certain challenges still hinder the extensive adoption of SH automation systems, including cost considerations, data storage security, and the establishment of secure communication channels. To address these challenges, this paper aims to provide a comprehensive discussion on the field of smart home automation. The technical contributions of this work are outlined as follows:
  • Conducting an extensive review of relevant articles on IoT smart home automation, categorizing them based on application areas such as energy, healthcare, home safety and security, and home control and monitoring.
  • Presenting an IoT smart home automation system framework that focuses on the efficient functionality of its components.
  • Offering a detailed explanation of application areas, elements, and enabling technologies of SHAS, while also addressing key challenges and proposing potential solutions for future research.

The rest of the paper is structured as follows: Section 2: Provide taxonomy and extensive review of published articles on home automation, also a comprehensive analysis of published articles related to IoT home automation is presented in this section. The review comprises key findings, trends, and advancements in the field. Section 3 provides a comprehensive discussion of the smart home automation infrastructure and explores their diverse application areas. Section 4 covers the challenges associated with the adoption and acceptability of SHAS. Finally, the paper in Section 5, concludes by summarizing the key findings and highlighting the implications for future research in the field of smart home automation.

2 Review of Related Works

This section provides a comprehensive review of research works conducted in the domain of smart home automation from 2010 to the present. The development of a smart home automation system typically involves a communication gateway module and various IoT hardware components such as sensors, microcontrollers, and relay modules. The focus of this review is to assess existing works that specifically address topics related to smart home automation, including the technologies employed, communication methods utilized, the methodology employed, and the targeted domains of application.

To gather relevant literature, popular scholarly online databases such as Scopus, Web of Science, IEEE Xplore, JSTOR, and PubMed were examined. Figure 3 presents a visual representation of the research trends observed in the application areas of smart home automation. The keywords used in our search include “smart home automation,” “IoT smart home automation system,” “smart home automation energy system,” “smart home safety and security system,” and “smart home healthcare system.” Through this comprehensive review, this section aims to provide insights into the advancements, methodologies, and application domains covered in research works on smart home automation. Analyzing the technologies, communication methods, and trends in these studies, contributes to a deeper understanding of the field and identifies potential areas for future research and innovation.

Details are in the caption following the image
Trend of research in smart home automation application areas.

Figure 4 presents the taxonomy of IoT smart home automation publications, showcasing the technologies, elements, and application areas discussed in this paper. This taxonomy provides a visual representation of the comprehensive coverage of the field. In this section, a thorough review of recent literature is presented, focusing on the application areas and methodologies employed in smart home automation research. To enhance readability and understanding, the review is segmented into subsections, each dedicated to a specific application area. The areas covered in this review include healthcare, home control and monitoring, energy efficiency, and safety and security. By examining the literature in each subsection, readers can gain insights into the advancements and methodologies explored within these specific domains.

Details are in the caption following the image
Taxonomy of publications in smart home automation.

Another objective of our approach is to compare the methodologies employed in different studies and establish the need for a hybrid smart home automation system as a focus for future research. Efficient SHAS should extend beyond the automated control of heating, ventilation, and lighting appliances to encompass the monitoring and management of other devices within the home. This includes monitoring environmental factors, providing users with notifications or alarms regarding the home's conditions, and ensuring energy efficiency. Therefore, existing works are reviewed based on their methodologies and the medium of control employed. Table 1 summarizes the published articles related to smart home automation within the years of our consideration. This table provides a consolidated overview of the research output in the field, highlighting the key studies and their contributions to the advancement of smart home automation.

TABLE 1. Published related work on smart home automated control systems.
References Functionality User control interface Controller (Board) Application area(s) SH application areas (s)
Stolojescu-Crisan, Crisan, and Butunoi [22]

Control of home appliances.

Energy consumption management.

Home security.

Mobile and web-based applications. ESP8266 and Raspberry Pi Wi-Fi

Control and Monitoring.

Energy management.

Security.

Govindraj, Sathiyanarayanan, and Abubakar [23]

Monitoring of environmental factors.

Remote control of home appliances.

Detection of harmful gases and motion.

Android-based mobile application. Arduino Mega and ESP8266 Wi-Fi and Radio frequency

Home control and monitoring.

Home safety and security.

Salhi et al. [24]

Detection of flames and gas leakages.

Measurement of temperature and humidity around the home.

Web-based and mobile applications. Raspberry Pi Zigbee Home safety.
Liao et al. [25]

Cloud-based control of home appliances.

Detection of harmful gases and motion.

Measurement of humidity and temperature.

Android-based mobile applications. Arduino Yun Wi-Fi

Home monitoring and control.

Home safety.

Jabbar et al. [26]

Control of electrical appliances.

Monitoring of environmental conditions.

Web-based and mobile applications. Mode MCU Wi-Fi

Home control and monitoring.

Home safety.

Hoque and Davidson [27]

Intrusion detection.

Control of doors.

Android-based mobile application. Elgo Mega 2560 and Raspberry Pi Radio frequency Home safety and security.
ElShafee and Hamed [28]

Control of home appliances.

Measurement of temperature and humidity.

Control of door locks and windows.

Web-based application. Arduino Wi-Fi

Home control and monitoring.

Home security.

Li [29]

Secured energy management.

Control of door access.

Web-based application. MSP430 microcontroller Zigbee

Energy management.

Home security.

Abdulrahman, Isiwekpeni, Surajudeen-Bakinde, and Otuoze [30]

Motion detection.

Control of home appliances.

Web-based application. ESP8266 Not discussed Home control, monitoring and security.
Bissoli et al. [31] Control of home appliances for people living with severe disabilities. Web-based application. ESP8266 Wi-Fi

Healthcare.

Home control.

Monteriù et al. [32]

Monitoring of user's physiological data.

Monitoring of energy consumption.

Monitoring of environmental factors.

Web-based and mobile applications. Not specified Bluetooth

Healthcare.

Home monitoring.

Chhabra and Gupta [33]

Monitoring of energy consumption level.

Voice-based control of home appliances.

Mobile application. Intel Galileo Wi-Fi and Bluetooth

Energy management.

Home security.

Gu et al. [34]

Cloud-based control of home appliances.

Monitoring of environmental conditions.

Web-based application. Not specified Zigbee and Bluetooth Home control and monitoring.
Hu and Li [35]

Energy management based on machine learning.

Control of electrical appliances.

Web-based application. Not specified Zigbee and Wi-Fi

Energy management.

Home control.

Umer and Khan [36]

Control of home appliances.

Detection of light intensity.

Detection of water level in a tank.

Mobile application.

Arduino Uno

ATMEGA328

Bluetooth Home control and monitoring.
Sasipriya et al. [37]

Control of home appliances.

Measurement of patient's ECG and other body vitals.

Web-based application. Node MCU and ESP8266 Wi-Fi

Home control.

Healthcare.

2.1 Smart Home Services

Smart home automation is implemented to offer tailored services to homeowners, prioritizing convenience, energy optimization, security, and timeliness within the residential premises. These services are briefly discussed as outlined below.

2.1.1 Measurement of Home Conditions

Sensors are integral to smart home automation, tasked with gauging environmental parameters like humidity, temperature, and motion. Different sensors are tailored to measure diverse phenomena within the environment, categorized as environmental sensors, as illustrated in Figure 4 [38]. The sensory data is initially stored temporarily within the sensor and can subsequently be relayed to a processing center via the onboard communication module of the sensors for additional analysis.

2.1.2 Home Appliances Management

Smart home automation offers homeowners the ability to oversee their household appliances via cloud infrastructure. This technology empowers users to manage their appliances conveniently from any location, eliminating distance or time constraints. Such seamless control is made feasible through the integration of the IoT. Through appliance management, users can dictate the operations of actuators based on data collected by sensors. This approach optimizes energy utilization, contributing to enhanced efficiency.

2.1.3 Home Access Control

Home access control stands as a central service provided by smart home automation. Through this service, it becomes exceedingly challenging for unauthorized individuals to gain entry into private residences or public facilities. The integration of technologies such as smart doors and access cameras in both private dwellings and public spaces has streamlined the provision of home access control services within IoT-enabled SHAS. This service operates by gathering user samples, storing them in a database, and subsequently comparing real-time data with the records in the database to determine whether access should be granted or denied based on the outcome of the comparison. Technologies supporting access control in smart home automation encompass RFID, Wi-Fi, Bluetooth, and ZigBee, among others [16].

2.1.4 Entertainment Services

Smart home automation offers entertainment services to homeowners. These services include virtual assistants in the form of voice commands to control home appliances, service personalization, content information, utilizing users' preferences to make recommendations, integrated audio and video systems, and so on. Smart home automation systems are intended to be user-friendly for these services to be accessible, especially to people living with disabilities. These services allow centralized and customized management of distributed home appliances simultaneously.

2.1.5 Personal Assistance Services

Smart home automation system performs personalized tasks to home owners. These tasks could include automatic responses to predefined possible inputs such as location awareness, weather or traffic location alerts, schedule management, and so on. Smart home automation systems leverage artificial intelligence to provide personalized and intelligent services to smart home users. The possibilities of voice technology in connected home devices powered by machine learning provide more convenient and more intuitive smart home services since users do not necessarily need to search their mobile devices for the right applications before accessing the service.

2.2 Smart Home Control and Monitoring System

Smart home control and monitoring systems integrate different household appliances and other devices into an automatically controlled ecosystem for remote and intelligent management of home gadgets and other connected devices. In this context, the focus is on remote control and monitoring of home appliances and all other devices on the smart home system. The control and monitoring are multimodal and include lighting controls, security breaches and alerts, real-time monitoring of home conditions, and other personalized user preference services.

Khan et al. [39] introduced an automation system that enables remote control of lights in a smart home environment. The system utilizes a real-time algorithm for controlling lights and monitoring environmental conditions. The algorithm makes use of motion sensors to generate inferences for light control. Additionally, the algorithm is employed for monitoring power consumption in the home via the Wi-Fi module and triggering an alarm based on gas levels. While the real-time algorithm offers intelligent light switching, the limitation of using a web page for home control is acknowledged.

Rani et al. [40] proposed a voice-controlled home automation system that leverages natural language processing (NLP) and artificial intelligence techniques. Users can issue voice commands through a mobile phone to control home appliances, which are interpreted using a predefined NLP medium. However, this system is focused solely on controlling home appliances and does not extend its functionality to other aspects of home automation, such as environmental condition monitoring, intruder detection, or motion sensing. Bimenyimana et al. [41] designed and implemented a web-based home control and monitoring system for electrical appliances. The prototype implementation utilized an Arduino Board, Node MCU, Light Emitting Diodes (LED), relays, and other hardware components. The control system's design aims to reduce energy consumption levels. However, the web-based control interface may result in longer control times compared to a mobile-based application. The aforementioned studies highlight different approaches to smart home automation, showcasing various techniques and technologies employed for controlling lights, implementing voice control, and managing electrical appliances. While each study presents innovative solutions, they also acknowledge limitations and suggest potential areas for improvement in terms of control interfaces and system capabilities.

Mehmood et al. [42] developed an automation system for controlling smart home appliances based on an object detection mechanism. The system utilizes an object detection algorithm, model-view-controller architecture, and a cloud of things. Communication between IoT devices and home appliances is facilitated through the message queuing telemetry transport (MQTT) mode. However, a limitation of the system lies in the requirement of object detection before control, which may introduce delays or inaccuracies. Vaidya et al. [43] proposed a smart home automation system targeting the elderly, implemented as an Android application. The system enables remote control of appliances through voice or touch commands. The door monitoring system incorporates face detection using an installed camera. Additionally, the system includes an energy efficiency option, featuring a module that can analyze the usage of each electrical appliance. Although the proposed system offers valuable functionalities, the implementation details are not specified. Wibowo, Muhammad, and Alif [44] presented a smart home control and monitoring system based on the database replication method. User access is granted through a single online master database, requiring login with username and password. The system can control and monitor multiple systems online; however, the specific implementation details are not mentioned. It is worth noting that the system's functionality heavily relies on the availability and reliability of the online database. Any issues or disruptions with the database may impact the effectiveness of the system. More, these studies highlight different approaches to smart home automation, focusing on object detection, elderly-friendly interfaces, and database replication. Each system offers unique features and functionalities but also acknowledges certain limitations or potential challenges. Further research and development are needed to address these limitations and improve the overall effectiveness and robustness of SHAS.

Taiwo et al. [45, 46] proposed a framework for controlling electrical home appliances, enabling both on-site and off-site control. The framework utilizes Bluetooth and Zigbee technologies for communication, with commands issued through an Android mobile application. However, the communication range of the system was limited due to the proposed Bluetooth technology, which may restrict the usability of the system in larger homes or buildings. Obeidat et al. [47] presented a GSM and IoT-based smart home automation system that allows for the control of home appliances and environmental monitoring through a short messaging service (SMS) notification. Users communicate with the home and issue commands to the microcontroller via SMS. The use of GSM protocol for communication enables remote control; however, it should be noted that GSM technology can be slower compared to newer technologies like 3G and 4G due to shared bandwidth and potential interference [48]. Nonetheless, the system's strength lies in its ability to automatically control the lighting system, contributing to energy consumption reduction.

Hassan et al. [49] introduced a smart control and monitoring system for home automation, specifically targeting the detection of kitchen temperature and gas leakage. The system automatically detects gas pressure levels and notifies the user if it deviates from the expected range. Remote control and monitoring of appliances are facilitated through an Android application. The authors conducted simulations using MATLAB 2016b and implemented a prototype using ESP32, a DHT11 sensor, a 5 V Relay, and an MQ-135 gas sensor. The system prioritizes the safety of home occupants by promptly detecting and notifying gas leakages. These studies demonstrate different approaches to smart home automation, considering various communication technologies such as Bluetooth, Zigbee, and GSM. Each system offers unique features and addresses specific aspects of home automation, including appliance control, energy efficiency, and safety. However, certain limitations and considerations, such as communication range, bandwidth limitations, and potential interference, need to be taken into account for the successful deployment and scalability of such systems.

2.3 Energy Management

The primary focus in the design and deployment of some SHAS is energy management and optimization. In that case, the target is to design a smart home system that allows users to manage electricity usage in the home by remotely turning off appliances when they are not in use. The systems provide information on the appliances that consume more electricity, thereby providing insights into making informed decisions either on when to minimize usage or turn off the appliance. Energy management in smart home automation not only optimizes energy efficiency and costs but also contributes to environmental sustainability in the green economy.

Zhuang et al. [50] utilized a power scheduling approach to propose a smart home system for optimal energy management. The system introduces a smart grid-based scheduling method for power usage within the home environment. To improve the operation start time of appliances, a genetic algorithm was utilized. The algorithm considered Real-Time Electricity Pricing to schedule power, taking into account residents' preferences. The primary objective of the system was to optimize user power consumption while also providing benefits to utility companies through the pricing scheme. Singh, Sajwan, and Pal [51] designed a solar-powered home automation application that integrates solar power with a microcontroller. The system enables the control of household appliances and doors using a mobile phone. A prototype demonstration was implemented using IoT hardware. The system aims to reduce electricity load by utilizing solar power as an alternative energy source. However, if the solar system's battery is drained, the system might become nonfunctional, and control of the home cannot be achieved until the battery is recharged. These studies present innovative approaches to energy management in smart homes. Zhuang et al. [50] focused on optimizing power consumption through intelligent scheduling, considering real-time pricing and user preferences. On the other hand, Singh et al. emphasized the utilization of solar power for household automation, promoting energy efficiency. However, potential limitations, such as system functionality during low battery levels or in the absence of solar power, should be taken into account for reliable operation and user satisfaction.

Priya and Kannammal [52] introduced an energy management system for automation that focuses on load scheduling and cargo balancing. The system utilizes sensor data to generate information for automatic control. Control of the overall system was conducted through an online browser on a local PC. However, it should be noted that control via mobile applications tends to be faster compared to PC-based control. Mahmud, Ahmed, and Shikder [53] introduced an automated system for metering in smart homes. This system empowers homeowners to oversee and regulate the energy consumption of household appliances and electronic devices via a specialized website. The primary objective was to simplify energy monitoring for individuals while advocating for energy-efficient behaviors. Furthermore, the design incorporates an online metering mechanism capable of detecting potential household power distribution issues, along with a billing system aimed at enhancing energy efficiency even further.

Additionally, Popa et al. [54] experimented with a smart home automation system to detect unusual energy patterns. Their approach was based on neural network models, and they utilized cloud computing services to establish a modular platform for data collection, aggregation, and storage in the smart home environment. The authors demonstrated that the proposed machine learning algorithms contributed to the enhancement of smart home automation by reducing energy consumption. These studies highlighted different aspects of energy management and automation in smart homes. Priya and Kannammal focused on load scheduling and cargo balancing, Mahmud et al. emphasized metering, control, and observation of appliances, and Popa et al. explored the detection of unusual energy patterns using machine learning. Each approach contributed to promoting energy efficiency and optimizing the performance of SHAS.

Similarly, Khan, Nazir, and Ullah Khan [55] reported the efficacy of Convolutional Neural Network (CNN) for tasks involving image detection and processing within smart home technology. Their study showcased CNN's utilization of extracting spatial features of objects through an IoT camera integrated into Raspberry Pi hardware. Concurrently, Long Short-Term Memory (LSTM) was employed for extracting temporal features and classification. The integration of CNN and LSTM aims to attain optimal detection and recognition results of objects captured by cameras within the smart home automation system. Notably, image preprocessing techniques and pretrained models can be employed to extract salient features of objects within the surveillance boundary of the smart home for object detection tasks. These features are subsequently inputted into CNN and LSTM for recognition [56].

Parsa, Najafabadi, and Salmasi [57] introduced an automated control system aimed at optimizing the management of electrical home appliances. This system is engineered to regulate device energy consumption by intelligently activating and deactivating smart plugs connected to particular appliances at suitable intervals. Employing an optimization methodology, the system identifies the most opportune times to operate the appliances, adhering to predetermined constraints, before executing the automated switching process. However, it should be noted that the designed system appears to prioritize the electricity supplier's interests over those of the home's consumer. Rajesh, Shajin, and Kannayeram [58] proposed a hybrid energy management method for smart homes using IoT. The methods employed in this approach involve the Sailfish Optimizer (SFO) and Adaptive Neuro-Fuzzy Interference System (ANFIS). These methods are applied to achieve optimal power management and data collection within the home. By predicting load demand and effectively managing energy, the methods contribute to energy conservation in the smart home environment. Khajeh, Laaksonen, and Simoes [59] introduced a fuzzy logic controller for energy conservation in a smart home setting. The proposed method aims to conserve energy by managing congestion and enhancing the distribution system within the smart home. Flexibility of energy resources is promoted to control the power system frequency through balancing services. These studies highlight different approaches to managing and conserving energy in smart homes. Parsa et al. focus on automatic control and optimization, Rajesh et al. utilize hybrid techniques for energy management, and Khajeh et al. propose a fuzzy logic controller for energy conservation. Each approach contributes to the efficient utilization of energy and promotes sustainability in the smart home environment.

2.4 Home Safety and Security System

Saravanan, Nainar, and Marichamy [60] proposed a home automation safety and security system by utilizing Bluetooth technology. This system comprises a smartphone application responsible for overseeing home devices, monitoring security, and regulating door access. The design incorporates various features, such as automatically turning off lights during nighttime, detecting gas leaks or smoke, and managing home appliances. Additionally, an authentication module was integrated to automatically secure and release door locks. Communication between the user's smartphone and the hardware relies on Bluetooth, which, although offering a narrower coverage range compared to Wi-Fi-based technologies, provides a secure mechanism according to the proposed approach.

Vasyl et al. [61] presented a smart home system for the prevention of domestic accidents. The system aims to alert home users in the event of potential dangers or accidents, particularly fire outbreaks. Sensors for fire, gas, smoke, and water leak detection are employed to identify and prevent such incidents. The system design incorporates a neuro-controller that interfaces with the sensors, appliances, and alarms. Arduino microcontrollers and Artificial Neural Network-based programming models were used to build and test the system's reliability and functionality. However, there was no specific mention of implemented home appliances or their functionality.

Ajao et al. [62] introduced a smart home security system that focuses on revitalizing the home entry points. Access is granted through rigorous authorization and authentication processes, with users notified of access or denial of access through in-app messages. Moreover, motion sensors are integrated to detect any movement within the premises. The operation of the system is managed through an Android mobile application utilizing wireless IoT communication. Despite its ease of use and flexibility, the system lacks the capability to capture images of intruders for monitoring purposes.

Singh et al. [63] devised a smart home system prioritizing home appliance safety and control, door access, and intruder detection. The system is engineered to alert users of low gas levels in cylinders or the presence of individuals as detected by sensors. The initial version of the system utilized components such as an Arduino Uno board, IR, Node MCU, and LDR sensor modules. However, the authors did not provide specific details regarding the controllable home appliances or the overall functionality of the system.

Taiwo et al. [64] presented an enhanced intelligent smart home system that encompasses monitoring, control, security, and safety features. The system performs dual functionality of appliance control and home security. A deep learning model is employed to develop an algorithm for motion detection and classification based on motion patterns. By classifying images from surveillance cameras, the deep learning model can determine whether an individual is an intruder or a homeowner and send notifications accordingly.

Lee et al. [65] pioneered the integration of image and voice recognition to devise a smart home security system. Recognizing the evolving scenery of security breaches, relying solely on a single mode of identification for authorization is no longer deemed reliable. Thus, the fusion of voice and image recognition, particularly facial recognition, establishes a two-step authentication process before granting access to home services. This innovation has gained substantial acceptance, evidenced by the deployment of security measures such as facial recognition-enabled doors and access to facilities.

These studies demonstrate various approaches to enhancing safety and security in SHAS. Saravanan et al. focus on Bluetooth-based control with a secured mechanism, Vasyl et al. present an accident prevention subsystem, Ajao et al. [62] emphasize home security and access control, Singh et al. propose a system for safety and appliance control, and Taiwo et al. introduce an intelligent system with deep learning-based motion detection. Each approach contributes to ensuring the safety and security of smart homes, providing users with peace of mind.

2.5 Smart Home Healthcare

Minh et al. [66] introduced a cloud-dependent smart home automated healthcare system that monitors patients' daily activities, rehabilitation progress, and behavioral changes to facilitate their recovery. The system not only enables home control but also allows healthcare providers to remotely monitor patients' physiological conditions through data captured by noninvasive wearable sensors. Human motion and activity information are collected using environmental sensors. However, a limitation of the system is the high-energy consumption resulting from the type of sensors used and data transmission. Lin et al. [67] developed a smart home mobile healthcare system specifically designed for wheelchair users. The system utilizes nodes of wireless body sensor networks (WBSN) and ECG sensors to measure vital signs such as heart rate and ECG. Additionally, the system can sense and monitor the home environment and human activities efficiently.

Taiwo and Ezugwu [68] presented a smart home monitoring and healthcare system tailored for patients in Covid-19 quarantine. This system remotely monitors specific physiological conditions and transmits recorded vitals to the doctors. It also controls essential home devices and monitors environmental conditions such as humidity and temperature. The system enables doctors to remotely monitor their patients, minimizing the need for physical contact during treatment. Patients can also comfortably manage their living environment by remotely controlling lights, fans, and other appliances. However, the feasibility of the system was not evaluated through a hardware implementation.

Eren et al. [69] introduced an integrated smart home system personalized for individuals with dementia, aimed at facilitating ambient living. Operating on the Android platform, this system is designed to gather, record, and transmit data through a cloud-based platform. It incorporates diverse sensors capable of detecting an individual's location, identifying flames, and monitoring the usage of specific household appliances. Furthermore, the system can issue alerts to prompt the patient's response to scheduled tasks based on sensor inputs and includes a switch to monitor light status. Its primary goal is to recognize patient activities and relay pertinent information to healthcare providers or caregivers. Data collected from various sensors positioned throughout the home are processed for subsequent analysis.

Neeraj et al. [70] developed a smart home automation software designed specifically for individuals with short-term memory loss. This system aids them in executing tasks easily, including automatic management of lighting, plant watering, gate operation, and notification for the dustbin. Meanwhile, Bilal and Khaled [71] introduced a wireless system design that allows for the remote control of household appliances. Targeted at elderly and disabled individuals, this system facilitates convenient control and monitoring of home appliances. It permits users to regulate electronic devices via a remote control device, transmitting commands wirelessly through XBee transceivers. The remote control features distinct buttons for various appliances and an LCD for message notifications. However, the system's communication range may encounter disruptions if obstructed by obstacles.

Bhardwaj, Joshi, and Gaur [72] presented an IoT-enabled smart healthcare monitoring system specifically for COVID-19 patients. The system allows doctors to remotely monitor patients by collecting real-time data on temperature, blood pressure, and pulse rate. Detectors and sensors deployed in the home environment enable continuous monitoring. A prototype implementation of the system utilized Raspberry Pi, a blood pressure sensor, and a temperature sensor. The data capturing and transmission modules enhance real-time monitoring capabilities for COVID-19 patients. In summary, these studies introduce a range of smart home healthcare systems that aim to enhance the monitoring, safety, and well-being of patients. The systems leverage various sensors, wearables, and remote control functionalities to enable remote monitoring, data collection, and automation of essential tasks.

Table 2 presents highlights of related studies on smart home automation taking into consideration the methodology adopted, the IoT technologies utilized, the application areas, and the strengths and weaknesses identified in the study. As shown in the studies, the early designs of home automation systems did not integrate artificial intelligence for users' preferences and multi-modal input commands. At this stage, SHAS lacks the functionality of personalized services, and the ability to learn and adapt to environmental conditions.

TABLE 2. Review of selected related work in smart home automation.
S/N Author(s) Method IoT technologies Application area Strength Weakness
1. Andrea et al. [73] Home stimulation management system using a set of rules to control washing machine. The system can be applied to other scheduling devices, such as micro-wave. No IoT technology is involved. Only set of rules for simulation. Smart Home Energy. The proposed system will enhance the reduction in energy consumption. The proposed system is limited to only devices that are based on a schedule.
2. Otuoze et al. [74] Cloud-based home automation system. The system is for interaction among users, appliances, and the environment. Web Socket, AVR Microcontrollers, Arduino UNO, Wi-Fi. Smart Home Environment.

Lower implementation cost because it is cloud-based.

Use of robust distributed computing approach aimed at tackling the problem of complexity and incompatible standards.

Need for improved security and higher storage capacity in the system.
3. Khusvinder et al. [75] The design and implementation of a flexible home automation system that supports network interoperability, a simple user interface, and remote access to the system was presented. Zigbee. Smart Home Automation and Monitoring. Provision of network interoperability. Limited devices were involved in the system, and no home appliance was implemented with the system.
4. Sudharani, Siva, and Vijaya Raju [76] The authors presented a system to control and monitor home appliances and doors using Arduino and sensors. Arduino UNO, Wi-Fi, Arduino IDE, Fire Sensor, Flame Sensor. Smart Home Monitoring and Automation.

Alert system that notifies the user when there is a bridge of security in the home.

Monitoring of the status of connected home appliances from mobile phones or laptops.

Dependence on finger gestures for control of appliances.

5. Haijun et al. [77] The authors proposed providing smart home Web services based on cloud computing. The user monitors the system through the browser. Zigbee, Z-Stack. Smart Home Automation (Monitoring/Control). The use of cloud computing services guarantees the security of data for users. No provision for home appliances that make use of electricity in the home system.
6. Moataz et al. [78] The authors presented a design of a smart home automation system that integrates the Internet of Things with Web services and Cloud computing to facilitate interaction between the user and their home from a remote location. Zigbee, Arduino, Cloud Service. Smart Home Monitoring and Control Automation. The system measures home conditions and also monitors home appliances. The system uses a mobile phone for control of home devices. The ability and capability of home devices the system can accommodate were not specified. Hence workload of the system was not determined.
7. Nahuseen et al. [79] The authors proposed a smart system that enables the user to know the situation of appliances at home and switch appliances on/off from any location. Zigbee, Microcontroller, and IC. Smart Home Monitoring and Control Automation.

The use of Zigbee made the proposed system wireless.

The system is password protection enabled to authenticate users of the system.

Getting notifications through mail or SMS can breach the security of the proposed system.
8. Arti and Somani [80] A proposal was made for a smart home energy management system to manage electricity load from the supplier's end, using a price-responsive control tactic for domestic load management. The proposed system aims to minimize consumers' electricity payments and increase demand and supply. Zigbee, Sensors. Smart Home Energy Management. The system can detect human activities and facilitate load management on the supplier's side. The system is restricted in the sensor interface because adding a new appliance has not yet been considered.
9. Wan et al. [81] Home Automation system aims to make life convenient for disabled and older adults through a system that performs basic house chores such as turning ON/OFF lights and switches on smartphones or laptops. Raspberry Pi. Smart Home Automation (Monitoring/Control). The designed system is not limited to switching on/off appliances but also accommodates speed control for certain home appliances such as fans. Using a webcam for monitoring devices will limit the performance in case of internet failure or low battery on the laptop. Also, the coverage will not be wide enough.
10. Pratiksha et al. [82] The authors presented the development of a cloud-based smart home application. The cloud server was used to manage and control the information of users and the activities of home devices. Arduino Uno microcontroller. Smart Home Monitoring and Control Automation. Security and availability of data are enhanced through the cloud. The connection of devices to the controller in the home system is wired. Advances have been made toward wireless links and communication in smart home automation.
11. Shiu [83] The author presented a flexible, standalone low-cost system. The user communicates with home appliances through the Android app. The system can switch functionalities in the home, control the environment automatically, and detect intrusion. Arduino Ethernet micro webserver, RESTful web service. Smart Home/Environment Automation. The system is flexible and can be deployed on any device that supports the Android application. Use of wired connection.
12. Abhishek, Saurabh, and Mohit [84] Development of smart home systems using technologies such as Bluetooth, GSM, and Android-operated devices. The system allows remote control of home devices on a smart phone. PIC series microcontroller. Smart Home Monitoring and Control Automation. The system controls energy consumption and provides an easy and manageable web interface for the user.

The range of Bluetooth is not wide, which might limit connections in the system.

GSM notification when there is an intruder in the home might not be effective, as network failure can prevent messages from being delivered on time.

13. Shinde et al. [85] The authors proposed an android-based home automation design. Signals are sent from appliances to the Arduino board using a relay board while the android app controls the appliances. Arduino board, relays, and Wi-Fi. Smart Home Automation (Monitoring/Control). Ensuring that a system is easy to control and use in accordance with the user's requirements. Access to the system is restricted to only users present on the same network.
14. Harshit, Abhishek, and Ameer [86] The authors utilized Bluetooth technology and smart hand held devices to design an automatic door lock system. Arduino Uno, Bluetooth circuit. Smart Home Monitoring and Control Automation. The mobile application is based on Bluetooth. This will limit the location of control by the user.
15. Harsh et al. [87] Home automation application for operational control of home appliances such as light bulbs. A working protocol PIC 16F72 enhances the system's security, flexibility, and cost-effectiveness. PIC 16F72 microcontroller. Smart Home Automation (Monitoring/Control). PIC 16F72 technology enables cost-effectiveness and security in the system. Task switching cannot be implemented in the PIC 16F72 microcontroller.
16. Shruti and Makrand [88] The authors proposed a system with multiple sensors for home automation. The work aims to develop a system that senses different conditions in the home, such as motion in the room, intrusion detection, gas leakage, etc. It also takes into consideration the care of the elderly in the home.

PIR sensor, MAX232, and RS232 serial.

PIC18F4520 controller.

Smart Home Automation (Monitoring/Control). The system provides monitoring of home parameters and tends toward safety.

Work is limited to sensing levels of appliances and not control and automation.

The connection in the system is wired.

17. Rasika and Manita [89] Wireless sensor networks were utilized to design a smart home system for the care of elderly users. The system was developed to sense and monitor environmental temperature, gas leakage, and doors. Zigbee, MQ-6 Gas Sensor, LM35 sensor, Arduino MEGA 2560. Smart Home Monitoring and Control Automation. Zigbee is cost-effective, and energy-efficient for longer systems however, the data rate is low. The system is limited to monitoring and sensing home appliances.
18. Punit and Jasmeet [90] An intelligent smart home system that monitors energy consumption by home appliances was presented. The proposed system allows remote monitoring and controlling of electrical devices and switches on the smartphone. PIR motion sensors, Intel Galileo Board. Smart Home Monitoring and Control Automation.

Monitoring and tracking of real-time devices in the home through the android app.

Prevention of fire outbreaks in the house through smoke and temperature sensors embedded for notification in the system.

Better energy management.

There could be a lack of accuracy or misinterpretation in the voice control of devices.
19. Jun et al. [91] The authors presented the architectural framework of a smart home environment that can be monitored and controlled wirelessly. Zigbee. Smart Home Monitoring and Control Automation. Wireless sensors and actuators were utilized to monitor and manage energy consumption in the home. The design does not include control of home devices.
20. Sandeep et al. [92] The authors presented a secured IoT-based smart home design. Triangle Based Security Algorithm (TBSA) method was proposed for data encryption in an energy-efficient manner. Intel Galileo-based microcontroller board. Security in Smart Home.

Secure transmission of data among nodes in the smart home network.

Low energy consumption with TBSA for data encryption.

21. Ravi et al. [93] The study presented a smart wireless home surveillance application. The design aims to send alerts to the home owner on his mobile phone. The smart home system makes use of Wi-Fi connected microcontroller. TI-CC3200 Launchpad board/microcontroller, PIR Motion sensor. Smart Home Automation (Monitoring/Control). The ability for the user to receive an alert of the situation at home through mobile phone with/without Internet, irrespective of the location. Control of home appliances is not embedded in the system.
22. Muhammad and Khalil [94] The authors proposed a low-cost home automation system based on Bluetooth technology. The design allows users to control home gadgets configured on the system through a smartphone. The system can detect water levels and can also serve as an irrigation system. Arduino Uno, Bluetooth HC 06. Smart Home/Environment Automation. Ability to monitor, control, and detect water from a smartphone. Communication will be limited due to the short-range of Bluetooth connectivity.
23. Chandramohan et al. [95] A smart home design that monitors and controls the home environment with access via a phone is presented. Arduino Uno, ESP 8266 node MCU Wi-Fi shield, and PIR sensor. Smart Home System/Environment.

The system is not dependent on the PC as a dedicated server in the home.

Control of home devices.

Control of sockets and fan air conditioner is limited to the home's temperature.
24. Kim et al. [96] The authors presented an energy-efficient smart home system. The system obtains information and controls the house environment through wired and wireless connections. The system is also capable of suggesting task scheduling. Zigbee, Wired X10, Arduino board. Smart Home System/Environment. The ability of the system to perform task scheduling.
25. Rozita et al. [97] A home automation system that GSM controls home gadgets such as lights, security, and conditional home appliances through SMS is presented. PIC16F887 microcontroller. Smart Home Automation (Control/Monitoring). The system is not Internet-based for control. Control of the system will be limited due to the frequency bandwidth of the GSM as the control device.
26. Rajalekshmi and SivaSankari [98] The authors proposed a smart home design that functions via a gateway, microcontrollers, and in-cloud architecture. The design interface allows users to control many home appliances via a smartphone. AT89S52 microcontroller, Relays. Smart Home Automation (Monitoring/Control). Ability to control multiple devices via smartphone. The system does not have any form of authenticating users.
27. Yogitha and Alamelumangai [99]

The authors presented a technique based on ZigBee communication standards for monitoring and controlling environmental phenomena including humidity, temperature, and pressure with the use of smart sensors.

Zigbee. Smart Environment.

The system is based on a wireless network connection.

The ability of the system to measure and control the industrial environment via smartphone.

Security and authentication of the system were not discussed.
28. Baoan and Jianjun [100] The authors presented a smart home design powered by IoT and based on service-oriented architecture (SOA) and a component technology approach. SOA. Smart Home Automation. Service-Oriented Architecture is scalable and allows service to be used by multiplication. SOA tends toward system overload with extra computation.
29. Christian et al. [101] The authors proposed a multi-layer architecture approach for flexible design easy to implement in smart home applications using the WS4D-PipesBox software tool. WS4D-PipesBox. Smart Home Automation. The proposed multi-layer approach addressed interoperability in the smart home.

Time-related capabilities could not be realized, and usability is not yet guaranteed.

30. Yu-Liang et al. [102] The authors presented three different designs for building an intelligent smart home application. The system was based on different technologies such as wearable intelligence technology, sensor fusion technology, and artificial intelligence. Smart Home Environment. The wearable design of the system might inconvenience users, and one of the aims of a smart home is convenience.

2.6 Artificial Intelligence in Smart Home

The integration of artificial intelligence into smart home sensors and actuators fosters enhanced interaction among household appliances, thereby yielding valuable data for understanding the habits of home occupants. Data generated within a smart home environment can be harnessed and processed to forecast user behavior. Moreover, artificial intelligence equips home appliances to better serve the needs of the elderly and disabled, fostering security awareness, and inclusivity and ensuring safety within smart home environments. The applications of artificial intelligence extend across various domains within smart home automation and environment. In-home security, artificial intelligence contributes to face detection [103], automated movement pattern detection [64], voice-controlled security systems [104], and anti-theft measures [105]. For smart home safety, artificial intelligence facilitates swift detection and notification of fire and smoke incidents [106]. Furthermore, artificial intelligence models and algorithms play a crucial role in efficient smart energy management, monitoring, and consumption [107, 108].

Similarly, recent advancements in smart home automation are evident in the integration of voice commands to control home appliances and the application of artificial intelligence techniques to rapidly process the generated data. This facilitates the extraction of valuable insights, unveiling hidden patterns that offer actionable insights for decision-making. Adopting a machine learning approach allows for the prediction of smart home occupants' behavior and preferences, as well as the estimation of future energy consumption during peak periods, tasks that are challenging for traditional methods of trend analysis.

Table 3 provides a comparative overview of recent publications on AI-driven and IoT smart home solutions. Numerous authors have documented recent advancements in the utilization of IoT and artificial intelligence in smart home designs, either through survey studies or experimental investigations, as outlined in the table. Artificial intelligence serves as the fundamental technology adopted to make smart home automation learn, adapt to personalized services, and make intelligent decisions. For example, natural language processing has impressively gained attention for AI-powered voice assistants in smart home automation.

TABLE 3. Recent applications of AI-driven and IoT-based smart home systems.
Ref. Objective Experimental Review AI Findings
Singh et al. [109] To build a smart home system that is powered by IoT efficiently and securely. Using blockchain technology, a secure and efficient smart home system was implemented, with service extensions on the cloud computing platform.
Sepasgozar et al. [110] To investigate the effectiveness of using Geographic Information Systems (GIS), IoT, and AI in building smart home systems. The existing smart home designs have paid less consideration to energy efficiency, and there is a notable gap in the literature on the application of IoT, AI, and the use of location-dependent data for smart home automation.
Belgaum et al. [111] Investigation of the roles of AI for scalable and reliable IoT-enabled systems. Artificial intelligence provides flexibility, intelligence, and security if integrated into smart home automation in the context of IoT.
Dasgupta et al. [17] To provide remote access to household appliances affordably. Design of an extensible smart home system supported with AI assistant for access and remote monitoring of home appliances.
Rego et al. [112] Designing an intelligent system driven by artificial intelligence in smart home automation. Integration of AI in IoT-enabled smart home automation for efficient multimedia services.
Rock, Tajudeen, and Chung [113] Assessing the usability level and impact of IoT-based smart home system among Malaysian urban residents. The study findings revealed that IoT-based smart home automation has improved lifestyle in terms of time efficiency, security, and convenience of remotely monitoring home activities.
Sharif et al. [114] To design a flexible and cost effective home automation system by utilizing IP connectivity to remotely control and manage common home appliances and other connected devices.

A user-friendly home automation system that utilizes edge computing for computational efficiency and reliability.

Alahi et al. [115] Exploration of the potentials of IoT architecture to connect physical objects for sustainable smart city systems. Artificial intelligence techniques enhance the instant analysis of massive volumes of data that IoT devices such as cameras and sensors generate.
Gøthesen, Haddara, and Kumar [116] Investigative study of factors that influence the pace of deployment of smart home systems among Norwegian citizens. The analysis of the study shows that technological enthusiasm, social influence, and price value significantly influenced the adoption of smart home systems in Norway.
Ullah et al. [117] To carry out a literature study on the concept of smart cities driven by IoT and how artificial intelligence is contributing to the realization of data-focused smart environments. A comprehensive detail on smart city applications, different components, and their fundamental design for IoT-enabled smart cities was presented. The roles of artificial intelligence to process massive volume of data generated from smart city applications are also highlighted.
Majeed and Aliesawi [16] Development of a voice-enabled IoT-powered smart home application. A low-range smart home prototype was presented for controlling home appliances. However, the system's access is significantly limited as it operates offline and does not connect to the Internet or any wide-range computer networks.
Irugalbandara et al. [118] Development of an offline home automation technology. A speech-integrated smart home solution with support for the elderly and disable users was proposed.
Alturki et al. [119] To design a smart home automation system that supports automatic decision-making based on the environmental phenomenon captured from home appliances.

Development of a customized user-friendly smart home automation system that supports automatic decision-making based on rules defined by AI techniques.

Ożadowicz [120] A literature survey of recent developments in smart home automation with state-of-art technologies. A generic framework for designing an IoT-driven smart home system with emphasis on the advantages and disadvantages of the new solutions.
Nguyen, Nawara, and Kashef [121] To provide an understanding of the concepts of smart city, development, and technologies that drive IoT-based smart city. Recent developments and breakthroughs in IoT-driven smart cities powered by AI techniques were presented. Smart home automation was presented as a component of smart cities initiatives.
Netinant et al. [122] To develop a smart home application integrated with IoT platforms for home security using buttons or voice commands as inputs to the system. An IoT-supported smart home solution that functions with voice commands that detect intruders with high precision was developed.

3 Smart Home Automation Infrastructure

Home automation applications are designed and developed to reduce the workload on individuals and give them convenient and remote access to their homes without a barrier of transmission range, connectivity, or user location at any time. Therefore, a smart home must have the intellectual ability, efficient control and monitoring capability, computational power, and communication skills to improve daily healthy living [123]. This section presents a detailed discussion of the SHAS taxonomy, focusing on the functioning parts, enabling technologies, and communication modes. The IoT smart home comprises different categories of smart devices, home appliances, sensors, and actuators that are interconnected to exchange information without the barriers of time and location. This section presents a detailed discussion of components and devices needed to make a home smart, effectively communicate with users, and ensure seamless interaction between the devices installed in the home. A summary of the layers and their functionality is presented in Figure 5.

Details are in the caption following the image
Smart home automation layers.

3.1 Smart Home Automation Layers

The smart home automation system functions based on a layered architecture. Several layers, components, and infrastructures have been presented in previous research articles. For instance, Zaidan and Zaidan [124] presented an approach for achieving a home automation system. The approach encourages the use of intelligence by incorporating deep learning. However, cloud computing, which is an important aspect of SHAS, was left out. Also, Liu, Yang, and Liu [125] presented naming and profiling services for the IoT sensory environment. The service infrastructure includes naming addresses, networking, and storage. Their work proposed a middleware for easier integration of existing applications. However, cloud storage was not factored into their consideration. Based on this and extensive reading, we propose a six-layered architecture for an IoT smart home. The layers are the smart device and sensor layer, a communication and gateway layer, the intelligent management and decision layer, the cloud computing layer, the presentation and control layer, and the security layer. These six layers are detailed in the following subsections.

3.1.1 Smart Device and Sensor (SDS) Layer

The smart home environment comprises intelligent devices and sensors that enable remote control of appliances, environment, detection, and monitoring of certain factors within and outside the house. This layer consists of the hardware involved in setting up the system, such as home appliances, devices, different types of sensors, and environmental elements [126, 127]. Appliances such as lights, microwaves, lamps, heating and ventilation devices, smart sockets and plugs, televisions [9], and other electrical appliances fall into the smart device layer. This layer is important because it is the heart of the system. Without the proper functioning of appliances and devices in this layer, the aim of having a smart home automation system is defeated. As a definition, SDS is a combination of devices and sensors that makes home appliances smart and controllable.

3.1.2 Communication and Gateway Layer

A smart home makes the devices in the home automated for intelligent control and response without human effort. The devices and services that allow communication between the user and home are available through communication networks [128]. The communication and gateway layer comprises the networking mode and the medium used for smart home control and monitoring by the user [129]. The gateway layer is responsible for the unified connectivity and communication between home networks, devices, protocols, and the remote-control mechanism. This layer also transmits information from sensors and other devices to a centralized information processing center via RFID, Wi-Fi, and other communication technologies [126]. The gateway also links the home with the outside system for control. This layer also serves as a communication channel to other network entities in the system architecture [130].

3.1.3 Intelligent Management and Decision Layer

Sensors and devices in the house generate data about the environment and condition of the home. Input and output signals are received for the control and monitoring of the home through these sensors and devices. The intelligent management layer is responsible for the prompt and accurate functionality of the home. It also involves the classification, decision-making, prediction, and analysis for intelligent control and home monitoring. This layer enhances the smart home system in different areas such as automatic switching of devices, security, privacy, authorization, authentication, reduction of energy consumption, intrusion, and detection [124]. Machine learning algorithms, artificial intelligence, and deep learning algorithms for smart home automation are embedded in this layer.

3.1.4 Cloud Computing Layer

Cloud computing refers to services rendered over the Internet for storage, analytics, servers, and networking. It offers services that give the client access to information from any location and at any time [131]. With cloud computing, a user does not need to be in the same location as the storage device before modifying the data. Cloud computing offers benefits such as reduced service charges, large storage space capacity, data loss prevention, ease, speed of data access, and flexibility [132]. The collection of data is essential for analysis, presentation, and predictions. The services provided by cloud computing have enabled smart home systems to benefit from the resources available for communication, transmission, storage, and retrieval of data used in the home. This layer ensures that sensor-generated data and data from other home devices are stored directly in the cloud for home monitoring, analysis, and future prediction. Combining smart home technologies and cloud computing makes a smart home system robust and scalable with extended service delivery. Merging cloud computing services with IoT smart home automation results in resource optimization at both local and central computing environments [9]. Cloud computing enhances and complements the functionality of a smart home system through the services rendered. Cloud computing services facilitate cost reduction in setting up a smart home system because it saves the cost of purchasing hardware and eliminates maintenance costs and energy consumption associated with the use of hardware for storage and retrieval of data.

3.1.5 Control Layer

The control layer, also referred to as the presentation layer or application interface, plays a crucial role in smart home automation by providing the control interface. This layer encompasses the software and applications that enable remote management, control, and monitoring of the home. The primary application interfaces in smart homes are web-based and mobile-based applications, which facilitate user interaction with the home and its activities. In this layer, the user interacts with the application interface, which serves as a gateway to control and monitor various aspects of the smart home. Control commands are issued through this interface, allowing the user to manage appliances or access information remotely. The presentation module within this layer defines the interface design that delivers data and enables users to select specific appliances for remote control or monitoring [133]. The interface design includes screens, tabs, and graphical representations of sensor outputs, allowing users to carry out various tasks and visualize changes in the status of the home and its surroundings. This module ensures that users have a user-friendly and intuitive interface to interact with their smart home system.

3.1.6 Security Layer

The security layers ensure data, system, and information security in a smart home environment. A smart home design should be secure and easy to use for users' acceptability. Therefore, this layer is essential in developing a smart home automation system. The responsibilities of this layer are confidentiality, authentication, transparency, access control, monitoring, and privacy [134]. The home's communication and gateway channels must be properly secured to avoid security breaches and attacks. Also, the confidentiality of information sent and received over the Internet via the smart home platform must be ensured. Patients using the smart home automation system in the healthcare platform should have their information protected. Hence, incorporating this layer into the development of every smart home automation system is essential.

3.2 Smart Home Application Areas

A smart home can be described as a residence that is equipped with intelligent devices and automated services that offer users convenience, safety, comfort, and security while minimizing resource wastage. The advancements in smart home technology with the integration of IoT aims to enhance the overall quality of life, enable independent living for the elderly, provide a comfortable and convenient lifestyle for individuals with health conditions, reduce energy consumption, and offer other essential services that contribute to enhanced living comfort [45, 46]. To cater to the diverse needs of users and achieve these objectives, a smart home is divided into various application areas. Figure 6 provides a concise graphical representation of the taxonomy of these application areas. Additionally, Figure 7 illustrates a typical scenario showcasing different smart home application areas and their key functions. In the subsequent subsections, we will provide detailed explanations for each of these areas, highlighting their significance and the services they offer.

Details are in the caption following the image
Taxonomy of smart home application areas.
Details are in the caption following the image
Real-world illustration of smart home application areas.

3.2.1 Smart Home Automation for Control and Monitoring

The primary functions of most SHAS are monitoring, control, and measurement of devices, appliances, and environmental factors. The smart home is applicable in this area for automated home control. It also facilitates remote monitoring and control of appliances. The advantages of automated intelligent control for the house are reduced stress, automatic switching of heating and ventilation systems, remote control of lighting devices, and environmental factors for comfortable and healthy living. The home control and monitoring system enables the user to remotely monitor the temperature around the home and take necessary actions. For instance, if an older adult is at home, the user can comfortably adjust the room's temperature without being on the home premises. Another benefit is the home's remote control of lighting systems and electrical gadgets. Suppose the user forgets to switch off an appliance before leaving the house. In that case, the system will notify the device's state, thus averting energy wastage or danger that might result from such action. Overall, the main functionalities of the systems in this area are:
  • Remote or automatic switching of electrical appliances.
  • Measurement of humidity and temperature around the home.
  • Remote control of home's temperature to a desirable state.
  • Control of home appliances regardless of user's location.
  • Reduction in human efforts for home control.

3.2.2 Smart Home Automation for Healthcare

Recently, the prevention, management, and treatment of ailments have been encouraged to be done remotely to reduce stress on the sick, avoid long queues at hospitals or healthcare facilities, and reduce the spread of infectious diseases [68]. Smart home healthcare aims at improving the lifestyle of the elderly, sick, disabled, and those in isolation or quarantine. This area of smart home automation often performs a dual role of control of appliances and health care. With the aid of IoT sensors and technologies, doctors can remotely monitor their patients, recommend treatment, prescribe drugs, and get accurate readings of their physiological vitals. Smart home healthcare has been applied to monitor patients' glucose levels to predict and treat diabetes and hypertension, according to Chatrati et al. [135]. Remote monitoring of a patient's health condition via speech and video for doctor's treatment and prescription is another application in the literature [136]. Some of the functions of a smart home healthcare system are:
  • Remote monitoring of health status.
  • Measurement, recording, transmission, and storage of vital physiological values.
  • Remote prescription of medications.
  • It ensures independent living for the elderly, sick, and disabled.
  • Assistance for memory recovery in patients living with amnesia and dementia.
  • Appointment booking and hospital visit scheduling
  • Assistance with alerts for the administration of medications.
  • It enhances the recovery process for patients.
  • Remote monitoring of patients observing isolation or quarantine.
  • Reduction in the transmission of infectious diseases.

3.2.3 Smart Home Automation for Energy Management

Efficient monitoring and management of electricity generation, storage, and consumption are called smart home energy management (SHEM) systems [137]. IoT-supported smart home designs assist in the reduction of energy utilization in the home. This application area benefits the user and impacts the economy through load balancing. Sensors, detectors, and intelligence are used to achieve energy efficiency through automatic light controls, detection of light and darkness, and remote control of electrical gadgets from any location. We highlight the benefits of the smart home management system as follows:
  • Automatic and remote switching of electrical appliances.
  • Reduction in energy consumption level of households.
  • Balancing electricity loads in homes and smart cities.
  • Energy saving through demand response and time of use techniques.
  • Prediction of an appliance run time.
  • Monitoring, and analysis of energy consumption and generation in the home.

3.2.4 Smart Home Surveillance, Safety, and Security

Ensuring the security and safety of both individuals and their properties is a crucial aspect that should be given utmost priority. In a smart home environment, a comprehensive security system is implemented to provide intelligence and surveillance capabilities, allowing for continuous monitoring, control, and reporting of any detected anomalies within and around the home. The primary objective of the smart home security system is to enhance the safety, security, convenience, and control of the home, ensuring a robust and reliable automation system. This application area plays a vital role in managing various home activities and promptly alerting the user through notifications or alarms whenever any suspicious or abnormal activities are detected. The smart home safety and security system is designed to ensure the user's overall safety by actively measuring and detecting harmful substances present in the air, such as smoke or gas leaks. Additionally, it focuses on safeguarding the security and privacy of user data, ensuring that unauthorized access is prevented and data integrity is maintained. By incorporating advanced technologies and intelligent algorithms, the smart home security system creates a secure environment for individuals and their properties. It provides real-time monitoring, access control, intrusion detection, and video surveillance, enabling homeowners to have peace of mind knowing that their homes are protected and secure. The functions of systems in this area are:
  • Detection of falls.
  • Monitoring and detection of gases, movement, intrusion, leaks, and damages.
  • Surveillance of the home and its environment.
  • Network, data, and information security.
  • Data protection and privacy.

3.3 Smart Home Automation Communication Protocol

Smart home communication protocol plays a major role in smart home automation. It serves as a major link for devices to “speak” the same language for easy control by the user. It is a communication protocol enabling hardware devices to wirelessly transmit and receive digital signals or utilize a wired communication channel. [138] and for interoperability among many smart devices. Wireless protocols are faster and compatible with a wider range of devices. The following points explain the major protocols deployed in most SHAS, while Table 4 summarizes the communication protocols.
  1. X10: The X10 system is an established home automation protocol that utilizes powerlines to facilitate communication between devices and appliances within a household. Developed in the 1970s, X10 is considered one of the earliest home automation protocols [139]. When transmitting data via the X10 protocol, packets are composed of three key elements. Firstly, there is a 4-bit House Code (A-P) that distinguishes different areas or zones within the home. Secondly, a 4-bit Unit Code (1-16) is used to identify specific devices or appliances within each designated area. Lastly, a 4-bit Command (in binary format) specifies the desired action or instruction for the targeted device. Through the X10 protocol, devices within the home can respond and react to commands or sequences of commands that are transmitted to them. This enables users to control and automate various aspects of their home environment using the X10 system [138].
  2. Radio Frequency Identification (RFID): RFID is a wireless protocol for transmitting object identity through radio waves. The transmission speed is 124–135 kHz low, 13.56 MHz high, and 860–960 MHz ultra-high. It is compatible with various standards, widely acceptable, and deployed and adopted for home automation. It is a stable communication technology [123, 141]. The advantages of RFID are the ability to capture data automatically and efficiently without human intervention, tagging for item identification, and tracking [143]. The most significant application area is healthcare.
  3. Zigbee: Zigbee is a low-power, cost-effective, wireless mesh network topology and a radio frequency-based protocol [139]. The transmission speed is 250 kbps(2.4 GHz) with an operation range of 40 kbps(915 MHz), and the transmission distance is between 10 and 100 m. The standard is IEEE 802.15.4 [123]. Network, information, and devices are secured with Zigbee because it uses the same level of encryption financial institutions use [144]. The advantages of using Zigbee are its low power usage and ability to accommodate a higher number of nodes.
  4. Z-Wave: Z-Wave is a widely adopted wireless standard and protocol that is designed for remote control of applications in both residential and commercial settings [123]. It operates on a radio frequency and utilizes a mesh network topology to establish reliable communication between devices. With Z-Wave, hardware devices form a network where each device can share data with neighboring devices, creating a robust and flexible system. The indoor range of Z-Wave is approximately 30 m, while the outdoor range extends up to 100 m. Z-Wave operates at frequencies below 1 GHz, with specific frequencies allocated for different regions. In the United States, the frequency operates at 908.42 MHz, in Europe, it is 868.42 MHz, in Israel the frequency is at 916 MHz, in Hong Kong, it is 919.82 MHz, and in Australia and New Zealand, it is 921.42 MHz [139]. The ability of Z-Wave to operate without interference from other household devices, ensuring reliable and uninterrupted communication makes it a standard and protocol of choice than other protocols. Additionally, Z-Wave employs a straightforward command structure, making it easy to use and integrate into various home automation systems.
  5. Bluetooth: Bluetooth is a low-cost, low-energy communication protocol that uses radio waves for communication [144]. The coverage range of Bluetooth is 10 m, making it very low. However, it is fast for data exchange and widely spread and available. The maximum transmission speed is 721 kbps for v1, 2.1 Mbps for v2.0+, 24 Mbps for v3+, and 25 Mbps for v4. The advantages are secured connection, ease of access, and unnecessary configuration [123].
  6. Wi-Fi: Wi-Fi is a common wireless communication technology with limited coverage that is used to connect handheld devices, and personal computers to network gateways. It uses the IEEE 802.11 standard with a speed of 300 Mbps and a 100 m transmission distance [145]. The support for Wi-Fi communication is available on numerous devices. Thus, its compatibility is very high. Wi-Fi technology allows communication over the Internet without requiring a protocol transfer [123].
TABLE 4. Summary of major communication protocols in smart home automation.
Protocol Compatible appliances Application areas Frequency Media Features Advantages Disadvantage References
X10

Lighting/Electrical appliances.

Motion sensors.

Control and monitoring. 120 kHz Wired

Makes use of power lines.

It can only perform about 16 commands with one command at a time.

Control loads range from approximately 40–500 watts.

Wireless protocol.

Inexpensive and many devices are available for it. Transmission is one at a time. Stojkoska and Trivodaliev [139]
KNX Heating, ventilation, air conditioning systems, remote controls, audio, video, and display energy management. Control and automation. Both wired and wireless Interworking and distributed application models for building various automation tasks.

Supports different configuration modes.

Low energy consumption.

Does not allow loop topologies.

Lobaccaro, Carlucci, and Löfström [123]
Z-Wave Lighting, heating, ventilation, audio and video, robotics, and security. Control and monitoring. 908.42 MHz Wireless Wireless mesh networking technology. It supports layer interoperability of devices from different vendors in smart home control applications.

Greater signal range.

Low power and low data rate.

Z wave devices are interoperable with other devices.

It supports a limited number of nodes (232 nodes) as compared to Zigbee.

Limited coverage.

Stojkoska and Trivodaliev [139]
Zigbee Lighting, heating, ventilation, audio and video, robotics, security. Control, monitoring, healthcare, security. 2.4 GHz, 868 MHz Wireless

Fast communication. Lower power consumption.

Possesses facilities for carrying out secure communications.

Can connect and communicate without depending on the use of a powerline.

Easy to install. Low power consumption.

Low transmission rate.

It cannot be used for outdoor wireless communication.

Dou et al. [140]
Bluetooth Lighting, locks. Control, monitoring, and healthcare. 2.4 GHz Wireless Wireless technology uses radio waves to communicate. Used in a short-range transmission of data. Saves energy. Limited range of connection. Dou et al. [140]
RFID Automation, door locks, tagging, and lighting. Control, monitoring, healthcare, and energy management. 120 kHz to 10 GHz Wireless

Wireless transmission of object identity through radio waves.

Operates on tags and reader identification systems.

Stable connectivity. Expensive chips and low bandwidth. El-Azab ([21]; [141])
Wi-Fi All IoT devices and appliances. Health, control and monitoring, energy management, and security. 2.4–5 GHz Wireless

Wide support technology for most IoT devices.

Popularly used for home area networks.

High speed.

Flexible.

Easy installation.

Low cost.

Interference with other technologies in the same building. Han et al. [142]

3.4 Smart Home Microcontroller

In IoT smart home automation, several physical components are essential for controlling and automating the system. Existing literature identifies the key components as microcontroller boards, sensors, relay boards, connectors (jumper cables), and other devices commonly used in prototyping SHAS. One of the primary hardware platforms for developing smart home projects is the microcontroller board. These small-sized development boards are connected to various devices within the home to enable automation and control. There are different types of microcontroller boards used in smart home development and the major ones are described below:
  1. ESP8266 Board: The ESP8266 is a popular microcontroller chip and board used in home automation. It is known for its cost-effectiveness, minimal energy utilization, and ease of use. The ESP8266 modules can operate as standalone devices without the need for additional microcontrollers or Wi-Fi modules. They provide IoT capabilities with built-in Wi-Fi connectivity, allowing developers or companies to connect them directly to the internet without requiring an intermediary gateway [146].
  2. Raspberry Pi: The Raspberry Pi is a computer that comes in a single-board design. It was developed by the Raspberry Pi Foundation. It is widely used as a small and affordable computing board in various applications, including data aggregation, device gateways, and hubs, or serves as edge servers at different levels of IoT applications. The latest version, Raspberry Pi 3 Model B+, offers a powerful 64-bit ARM processor, dual-band Bluetooth, Wi-Fi, Gigabit Ethernet, and USB with multiple ports. Its 1 GB LPDDR2 SDRAM ensures fast performance for IoT-related tasks [146].
  3. Arduino: Arduino is an electronic platform that is open-source and user-friendly for both hardware and software-dependent applications. Arduino boards are capable of reading various inputs, such as sensory data or button clicks, and actuate like tunning on motors or LEDs. Arduino-based systems are easy to program and have a plug-and-play nature. While early Arduino boards used GSM and Wi-Fi modules to connect to the internet, specialized boards with IoT support were later developed. Examples include Arduino 101 (developed by Intel), Arduino Wi-Fi Rev 2, MKR1000, and MKR Vidor 4000, which incorporates an FPGA chip [146].

These microcontroller boards, along with sensors, relay boards, and connectors, form the foundation of smart home design, enabling communication, monitoring, and control of devices and sensors within the home [146].

3.5 Sensors

A sensor is a device that detects certain external factors in the environment and responds distinctively [147]. It measures or monitors factors such as pressure, fire, smoke, gases, position, temperature, humidity, and acceleration. Sensor technology stands at the center of SHAS. Sensors are also applied for safety and security through detection and alarm for harmful gases, fire, motion detection, and surveillance. With the progression of IoT technology, smart home-embedded sensors offer preventive measures against both property and human damage within the household. A variety of sensor types are available in today's market to support the creation and implementation of practical smart home applications [18]. These sensors include environmental sensors (such as temperature, humidity, smoke, rain, wind, lighting, water, gas, movement, etc.) for monitoring environmental conditions, multimedia sensors (such as smart cameras, microphones, etc.), physiological sensors (capable of measuring heart rate, blood pressure, respiration, body temperature, etc.), and wearable sensors (which users can wear by embedding them in shoes, eyeglasses, earrings, clothes, or inserting them into the body).
  1. Environmental Sensor: These are sensors used in measuring, detecting, and monitoring environmental conditions and activities such as humidity, pressure, temperature, smoke, gas, and so on. Environmental sensors can be attached to walls, doors, furniture, and so on, to detect motion and identify or get information about someone or something. Examples of environmental sensors are Passive Infrared (PIR) and Active Infrared (AIR) for motion detection/identification and Radio Frequency Identification (RFID) for information about an object.
  2. Physiological Sensors: These are used to monitor or collect information about the human body. They are mainly used in health care to monitor or get blood pressure, pulse rate, and body temperature. Table 5 summarizes sensors, their category, and their functions.
TABLE 5. Summary of sensors.
Sensor Category Function Example(s)
Fire, smoke, flame, and gas sensors detector Environmental sensor

To measure, sense, or detect the level of gases, carbon monoxide, smoke, methane, and other substances that may be harmful in the home environment.

To detect smoke or flame and monitor overall air quality in the home environment.

MQ-2 gas sensor, MQ-7 carbon monoxide sensor, and smoke sensor, Nest Protect, Birdi Smart Air Monitor [148]
Leak/Moisture detector Environmental sensor Gives prior information on the possible occurrence of pipe leaks, water leakage, etc. The sensor can work in sinks, washers, refrigerators, and geysers. Fibaro Flood Sensor, Utilitech Water Leak Detector [149]
Motion or proximity sensors Environmental/Home sensor Detection of movement in the area. These sensors serve as guards to monitor the home when users are not around and can also be used to keep track of babies.

HC-SR501 PIR

Ultrasonic sensor.

Body sensors Physiological/Wearable sensor To measure/monitor the human body's blood pressure, pulse, and glucose level. This type of sensor can be worn on the body. Glucometer.
Humidity and temperature sensor Environmental sensor It is utilized to sense and measure humidity and temperature in the environment. LM 35, DHT11, DHT22
Light sensor Home and energy sensor Used to measure light intensity. LDR

4 Challenges in Smart Home Automation

The IoT smart home automation is rapidly growing and widely acceptable. Research trends show the field is interesting and important to human lives and the economy. Commercial products are frequently developed to meet the needs of users. Each month brings several innovative methods, designs, and developments for SHAS by researchers to improve existing systems. These factors show that IoT smart home automation is a field that has a long-term stay. However, challenges identified from existing literature may limit the systems' efficient functionality and future acceptance. In the following subsections, we discuss the identified challenges and suggest possible solutions.

4.1 Security and Information Privacy

The smart home environment has sensors and devices that frequently generate data. Most data generated in home environments are private and, if attacked, can leak vital information about the user and his home [150]. Security of data and information transmitted over the channels should be ensured. The security issues of smart home automation are network attacks, data security, data privacy, cybersecurity, and information security. Network and data attacks can either be passive or active. Passive attacks are discreet attacks that do not directly affect the system's functionality while data are being fetched from the system. Examples of such attacks are eavesdropping, spying, footprinting, and spying on networks. Active attacks are direct attacks on the network, leaving a trail or damage to the network or system. Active attacks include worms, denial of service attacks, malware, passwords, and phishing [151].

Data privacy is another challenge mitigating against users of IoT smart home systems. Most developed systems for home automation do not put measures in place for data handling and protection. Transmission of data in IoT home automation systems, healthcare, and energy management are there for justifiable reasons. However, sensitive data are involved and hence should be protected. Medical history data, passwords, and energy usage are information transmitted in a smart home environment. If attackers lay hold of such information, the user's life might be in danger.

To overcome security and information privacy challenges, we suggest that developers go beyond the security measures that come with the hardware used to integrate additional security measures to prevent attacks, breaches, stolen data, and privacy intrusion. Also, the users should ensure that the systems they are installing in their homes have authentication, authorization, confidentiality, secured access, and other security mechanisms incorporated into them. The government can also assist by setting up safety laws and rules governing the deployment and home automation systems. A framework termed EclipseIoT presented by Anthi et al. [134] also provides solutions to security attacks and heterogeneity in smart home automation.

4.2 Internet Connectivity

Smart home technology, enabled by the Internet of Things, relies heavily on a robust and reliable Internet connection to operate effectively and fulfill the needs of end users. Nonetheless, in societies where access to Internet services remains a luxury, realizing the full potential of IoT smart home automation becomes increasingly distant. Challenges such as poor Internet connectivity or restricted access to Internet services may arise due to various factors, including insufficient or inadequate network infrastructure, unreliable electricity supply, and the high cost of subscribing to available services, among others [118].

4.3 Incompatibility of Devices

Developers use a variety of hardware from diverse manufacturers to design and develop home automation systems. Therefore, most home automation systems are not scalable, interoperable, and ubiquitous. The incompatibility of devices also leads to communication and connectivity issues, as most IoT manufacturers adopt different manufacturing hardware standards [152]. The inability of a system not to be able to communicate with devices from different manufacturers can limit the growth of home automation systems and lead to a high cost of the system for the users. To overcome the challenges associated with device incompatibility, developers can create an avenue for middleware in the architectural design of smart home systems as proposed by authors in [153, 154] for solving heterogeneity in sensors, devices, and networks of smart home automation.

4.4 High Energy Consumption

Smart home environments are filled with sensors, actuators, and devices requiring a power supply. This, in turn, will affect the home's energy consumption level. Efficient smart home automation is always expected to be available and controlled. Connection of all sensors, appliances, and devices to the home and use during peak periods will pose a challenge of high energy utilization and defeats one of the aims of a smart home automation system (energy efficiency). To overcome this challenge, we propose using solar systems or batteries as a source of energy for some of the devices to reduce the load on the energy. Also, the use of machine learning algorithms for load balancing could be incorporated into home automation systems. Developing scheduling algorithms or processes can also enhance energy consumption in smart home applications. Table 6 shows challenges identified with application areas of smart home automation.

TABLE 6. Some major challenges identified in some application areas of SHAS.
Application area Challenges
Healthcare

Reliability of the system in case of electricity failure or network failure.

Integrity and confidentiality of patients' information sent over the system.

Effective communication between a patient at home and a doctor/caregiver.

Inability to operate the device due to health challenges.

Energy management

Electrical leakage control.

Control of energy wastage on some devices that would need a constant power supply.

Overload of power for complex devices.

Incompatibility of devices/technologies.

Safety/Security Interoperability between different detectors for alarms, notifications, and monitoring of appliances in a smart home is a challenge that needs to be addressed. Managing energy in keeping the system running is another challenge to avoid high energy consumption levels.
Environmental monitoring

High energy consumption level. The use of sensors for monitoring specific parameters will need constant energy and can thus increase the level of energy consumed in the applied domain.

Another challenge is integrating devices and technologies in building smart home systems that are different from the same manufacturer.

4.5 Computational Resources

Recent innovations in smart home automation embrace artificial intelligence techniques for comprehensive processing of the sensed data. This approach allows learning, adaptation, and personalized service delivery based on the users' preferences thereby guaranteeing inclusivity for all users. However, the implementation of artificial intelligence techniques requires sufficient computational resources for high performance. These resources include high-computing power, sufficient storage space, stable electricity, and supporting core network infrastructure. These resources are fundamental for the successful integration of AI technology in smart home applications. To overcome these challenges, optimized AI algorithms that leverage cloud resources can be considered for implementation in SHAS, especially in low-computational resource regions.

4.6 Integration With Existing Infrastructure

Older homes were not designed with the integration of modern technologies in sight. Retrofitting these homes with modern devices and other home appliances to achieve a smart home automation system can be challenging. As identified in Section 4.3, the challenge of incompatibility of devices is partly occasioned by the difficulty in integrating modern smart devices in older homes because of the notable lack of features and devices that the older homes are designed with. In realizing the full potential of smart home devices, improved efforts in collaboration should be promoted among smart device vendors and home designers for a seamless and user-friendly smart home system.

4.7 Standards and Regularizations

The lack of standard protocols for communication and regularizations of smart devices that are utilized in designing SHAS does not favor the interoperability of smart home devices. In large-scale smart automation systems such as industrial automation and smart cities, establishing industry standards and regulations that guarantee data privacy, security, and interoperability is essential in building the trust of end users on smart home applications. Key stakeholders from the industry, regulatory bodies, and researchers play a crucial role in the early stages of designing, developing, and implementing these standards effectively. Moreover, such collaborations can derive innovations while addressing specific challenges that are related to compatibility, security, and user satisfaction in smart home ecosystems.

4.8 Lack of User Education and Supports

Prospective users of SHAS may not have a basic understanding of smart home systems and their potential. It is difficult for intended end users of any innovative system to believe in the functionality of the system if adequate information on the system's usage is not provided. In low-resource regions where technological developments evolve, the gap in user education and support hinders the development of SHAS in such regions. Creating awareness and providing relevant information to the target users of smart home applications can facilitate the decisions of users to embrace the technology. Smart home automation systems play critical roles in the realization of smart cities. Relevant government authorities and other stakeholders in the advancements of modern technologies for improved service delivery should prioritize prospective users' education and support frameworks that facilitate users' acceptance of applications such as SHAS.

5 Conclusion and Future Direction

Smart home automation systems have become increasingly prevalent in residential settings, driving the need for efficient and intelligent automation solutions. This research work aims to provide a comprehensive survey, taxonomy, and description of the essential elements and technologies required for developing such systems. By examining the technologies and protocols discussed, readers can gain a broad understanding of the existing and suitable technologies that have been applied in building SHAS. The study highlighted the major communication protocols in building smart home automation. In addition to exploring the technologies, this work addresses the challenges that exist within this domain and proposes possible solutions. By highlighting these challenges and offering potential remedies, this research work aims to assist new researchers in finding direction and serve as a guide for future developers and researchers seeking areas of improvement. Furthermore, the scope of this research extends beyond individual homes to envision the realization of efficient smart cities. By expanding on the findings and insights gained from this study, the knowledge can be applied to enhance automation systems in broader urban contexts.

Recognizing the importance of incorporating machine learning and deep learning models into SHAS, the next phase of this work aims to review possible artificial intelligence models and their applications in all areas of smart home automation. This exploration will provide researchers with valuable insights into leveraging artificial intelligence for security enhancements and decision-making within smart home environments. Additionally, future work may involve reviewing existing commercial products and applications and considering their application domains, strengths, and weaknesses. This evaluation will equip researchers with informed knowledge about existing products and guide them on how to improve these systems through further research and development. By advancing the understanding of SHAS and exploring opportunities for integration with artificial intelligence models, this research work contributes to the continued enhancement and evolution of smart home environments.

Acknowledgments

This work is funded by the Researchers Supporting Project number (RSP2025R564), King Saud University, Riyadh, Saudi Arabia.

    Ethics Statement

    The authors have nothing to report.

    Consent

    Informed consent was obtained from all individual participants included in the study.

    Conflicts of Interest

    The authors declare no conflicts of interest.

    Data Availability Statement

    The data that support the findings of this study are available from the corresponding author upon reasonable request.

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