A Systematic Review of Energy-Efficient Routing Protocols for IoT Networks

A Systematic Review of Energy-Efficient Routing Protocols for IoT Networks | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Systematic Review A Systematic Review of Energy-Efficient Routing Protocols for IoT Networks Samuel BoahAkenten Appiah-Menka, Cecilia Ampofowaa, William Asiedu, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7611247/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract With the proliferation of the Internet of Things (IoT) in areas like healthcare, smart cities, and industrial automation systems, one herculean task that has been looming and must be addressed is the need to ensure that data transmission is energy-efficient because all IoT devices have limited resources. This article is a systematic literature review (SLR) of energy-efficient routing mechanisms designed to be used in IoT networks, and it focuses on comparing the energy-efficient routing schemes concerning their energy consumption, latency, and security parameters. The research protocol compiled 32 peer-reviewed scientific articles published between 2017 and 2025, following PRISMA guidelines and with strict inclusion and exclusion criteria. The results reveal that popular protocols like RPL, LEACH, TEEN/APTEEN, or AI-based solutions reflect different trade-offs. The cluster-based and chain-based approaches are known to minimize the energy consumed. In contrast, the hybrid protocols and the AI-based approaches provide trade-offs in optimizing the energy, delay, and security parameters, at the expense of complexity. The review also points out that there is a serious gap in the observance of integrated security mechanisms in numerous energy-oriented protocols. These results indicate that routing techniques that are adaptive and context-sensitive are required to comprehensively treat performance limitations of IoT. Researchers and practitioners who are interested in finding an optimal protocol choice and matching diverse IoT applications can draw important thoughts from the paper. Routing Protocol Energy Efficiency Wireless Sensor Networks (WSNs) Internet of Things (IoT) Network Lifetime Data Transmission Figures Figure 1 Figure 2 Figure 3 Figure 4 1. Introduction Internet of Things (IoT) may be regarded as a system of interconnected devices, which are empowered with sensors, software, and network connections, so they can collect and share data. The IoT has, in recent times, received substantial recognition because of its many implications, such as smart healthcare, home automation, transportation, and smart cities. Recently, Internet devices have been exploited in a variety of applications, such as manufacturing, supply chain, real-time equipment surveillance, environmental preservation, and industrial safety control. However, it is projected that each individual will be connected to the Internet by more than ten devices by 2050 [ 1 ]. Nevertheless, such a transition will not be an easy process, as many challenges and problems still have to be addressed in various ways to bring the best out of this technology [ 2 ]. In such IoT systems, wireless sensor networks (WSNs) are important to gather smart information required in smart environments [ 3 ]. These networks consist of many linked devices that communicate with each other via the internet, and hence, they require the application of energy-efficient routing algorithms to process the data transfer. Energy-efficient routing protocols in Internet of Things (IoT) networks have become a crucial issue to consider, as most devices in IoT networks operate on limited energy sources. Energy efficiency plays an essential role in the IoT to ensure optimal network performance on loosely scattered networks (Magubane et al., 2019). To support data exchange in IoT networks, efficient and reliable routing protocols are necessary to address issues such as bandwidth capacity, energy consumption, and scalability. To support data exchange in IoT networks, efficient and reliable routing protocols are necessary to address issues such as bandwidth capacity, energy consumption, and scalability. The issue of energy efficiency is a major concern in IoT networks, as most sensor nodes will be battery-powered and deployed in inaccessible locations where it will be cumbersome to replace the batteries regularly. Several reviews on energy-efficient routing protocols for IoT networks have been published in recent years, indicating that this research area is continually evolving with new contributions and constant improvement. Yadav & Kumar (2024) in their study present a survey on energy-efficient routing protocols, aiming to provide a holistic understanding of the state-of-the-art approaches, their characteristics, strengths, limitations, and performance metrics. Their survey encompasses a wide range of energy-efficient routing protocols proposed in the literature, including traditional routing protocols adapted for IoT scenarios and protocols specifically tailored for energy optimization. The study of Suryawanshi (2024) presents a comprehensive analysis of recent advancements in IoT routing techniques and energy-efficient solutions, focusing on multi-objective optimization algorithms such as fractional gravitational search, grey wolf optimization, and hybrid salp swarm-differential evolution algorithms. Additionally, the authors also highlight the critical role of energy-efficient routing in IoT applications, such as smart agriculture, healthcare, and smart cities, emphasizing its importance in prolonging network lifetime and reducing overall operational costs. Bekal et al. (2024) present a review of various energy-efficient routing protocols for wireless sensor networks in their study, comparing standard and enhanced protocols. In addition, the study also discusses trade-offs in energy efficiency, network lifetime, and scalability, providing a comparative table for future researchers to analyze these protocols effectively. Finally, Magubane et al. (2019) evaluate energy-efficient routing protocols for IoT networks, specifically comparing RPL and LOADng. The authors of the study conclude that RPL is the more energy-efficient option, which is crucial for prolonging the operational life of battery-powered IoT devices in constrained environments. Despite the existence of several reviews on energy-efficient routing protocols, a systematic literature review has not been well conducted to facilitate the process of selecting the most suitable energy-efficient routing protocols for different IoT applications. This study aims to address this gap by: (i) To identify and categorize the most frequently used energy-efficient routing protocols in IoT networks. (ii) To evaluate the comparative performance of these protocols in terms of energy consumption, latency, and security. The functionality of the IoT networks depends largely on routing. (iii) To analyze the trade-offs and limitations associated with protocol design and implementation in resource-constrained IoT environments. Proper routing protocols define through which nodes across the network the data packets should reach the target in a central sink or a base-station, and should guarantee the least amount of energy used as well as network lifetime. Therefore, in IoT, energy-efficient routing protocols became the subject of fundamental research. To give a more current, up-to-date view to the reader on the energy-efficient routing protocols for IoT networks, this systematic literature review focuses on studies published between 2017 and 2025. For this purpose, the remainder of this study is organized as follows: Section 2 provides an overview of the key concept addressed in this study, Section 3 outlines the methodology adopted for conducting the systematic review, Section 4 outlined the results derived from the systematic review, Section 5 presents the discussion, and Section 6 presents the conclusions. 2. Concepts To better understand the key concept related to energy-efficient routing protocols in IoT networks, this session provides a concise overview of the key concept, laying the groundwork for the systematic review. 2.1 Internet of Things Internet of Things (IoT) can be understood as a system of interconnected devices, which are empowered with sensors, software, and network connections, so they can collect and share data. These devices, integrated with sensors, actuators, and communication modules, are capable of gathering, transmitting, and processing data in real time [ 8 ]. IoT is a rapidly evolving paradigm, envisioned as a network of billions of interconnected devices designed to apply advanced technological solutions to real-world challenges [ 9 ]. With the expansion of the Internet, IoT has had an impressive effect on several fields, and there have been numerous IoT applications employed for enhancing the network operation and users’ quality of experience [ 9 ]. IoT applications can be employed in various areas, including healthcare, industry, cellular networks, smart cities, edge computing, cloud computing, wireless sensor networks (WSNs), software-defined networks (SDNs), and many more. The architecture of IoT is commonly organized into layers, enabling seamless interaction and communication among diverse devices and systems [ 8 ]. The architecture of IoT is divided into 4 different layers, i.e., Sensing Layer, Network Layer, Data Processing Layer, and Application Layer. The architecture of IoT is shown in Fig. 1 2.2 Energy-efficiency Energy efficiency refers to the approach or strategy that aims at minimizing the amount of energy needed to deliver products and services by utilizing advanced technologies, techniques, or processes that limit energy waste while maintaining or improving performance (energy conservation). The objective of energy-efficient Internet of Things (IoT) networks is to reduce power usage, thereby extending the lifespan of devices, especially those that are battery-powered or located in remote areas [ 10 ]. IoT energy efficiency is created with an architecture that forecasts sensor sleep times guided by battery levels and usage patterns to enable maximum resource usage and maximum energy savings, resulting in the life extension of IoT systems [ 11 ]. The energy-efficient architecture for IoT networks consists of layers, namely, sensing and control, information processing, and presentation. The architectural design enables the system to estimate the sensors’ sleep duration by considering factors such as their remaining battery power, past usage patterns, and the quality of information needed for a specific application[ 11 ]. 2.3 Routing Protocol Routing protocols can be termed as the method that determines how routers share routing information, enabling them to determine routes between any two nodes on a computer network. Routing protocols are guidelines used to determine the optimal path for transferring data among nodes in a network. Through these protocols, communication among routers is established to transmit network packets using the most efficient paths [ 12 ]. A routing protocol involves receiving a packet as incoming traffic at an internal node of a distributed router, which contains a global destination address (Yeh et al., 2020). Many routing protocols have been developed since then, and these protocols differ according to network structure and field of application [ 13 ]. There are mainly three kinds of routing protocols applied on the Internet, which are distance vector, link state, and path vector. Every type has basic principles and traits. Also, there are other problems that might be experienced during the temporary occurrence of routing protocols, like looping, and hence, there are different ways of minimizing the occurrence of these problems. 3. Methodology This paper employs a systematic review methodology to present a comprehensive literature review of energy-efficient routing protocols for IoT networks, evaluating the performance of these protocols based on key factors such as energy efficiency, latency, packet delivery rates, and security. The current research requires a systematic review, as it allows for the systematic, thorough, and unbiased analysis of existing research on energy-efficient routing protocols. To achieve the proposed objectives, this study employs the Preferred Reporting Items for Systematic Reviews (PRISMA) methodology, a framework designed to support the reporting and systematic review of literature[ 14 ]. The choice of this research design was compared to research designs like Case studies or trials based on the ability to combine and analyze the results of different places, which facilitates the validity and broad applicability of the conclusions. The use of peer-reviewed articles and reliable scholarly resources will provide a strong and valid analysis that will contribute to a profound interpretation and critique of energy-efficient routing protocols applied to IoT networks. Several advantages make a systematic review the most suitable approach in this research. It enables the involvement of different research contributions in different geographical regions of the world, institutional setups, and technological methods of implementation. This method will guarantee full coverage and a better understanding of the subject of energy-efficient routing in IoT networks. Moreover, a systematic review presents the results of research compiled by different reliable sources, which is a more stable base regarding the scale of results and conclusions to make and some recommendations to follow than a case study or case study-like scientific research findings. 3.1 Research Question This systematic literature review focuses on energy-efficient routing protocols in Internet of Things (IoT) networks. The scope includes identifying frequently used protocols, evaluating their performance based on energy consumption, delay, and security, and analyzing associated trade-offs. The following specific research questions were formulated to guide the study: RQ1: Which energy-efficient routing protocols are most frequently applied in IoT networks between 2017 and 2025? RQ2: How do various protocols compare in terms of energy usage, delay minimization, and data security? RQ3: What trade-offs are evident in the implementation of these protocols across different IoT deployment scenarios? 3.1 Data Source and Search Strategy The following databases, including IEEE Xplore, Google Scholar, Web of Science, Scopus, and MDPI, were used as part of the comprehensive literature search. These platforms have been chosen to give a wider picture of the up-to-date research in the domain by spanning a wide variety of peer-reviewed journals, conference publications, and technical articles. The search employed the combination of search keywords that constitute routing protocols, energy-efficient. Among significant keywords applied were “Energy-Efficient routing”, “IoT Network”, “Wireless Sensor Networks”, “Routing Protocols”, Network lifetime”, “Latency”, “Packet delivery”. Boolean operators and filters were applied to refine the search results and eliminate irrelevant studies. 3.2 Inclusion and Exclusion Criteria To ensure the quality and relevance of the selected studies, the following criteria were applied: Inclusion Criteria : Studies published between 2017 and 2025 Peer-reviewed journal articles or conference papers Articles written in English Research focused on energy-efficient routing protocols for IoT or WSNs Studies evaluating protocols using performance metrics such as energy consumption, latency, packet delivery ratio, and security Full-text articles that were openly accessible (open access)[ 15 ] Exclusion Criteria : Non-English language publications Studies lacking technical evaluation or performance comparison Articles unrelated to routing protocols or energy efficiency in IoT Grey literature, unpublished theses, or blog posts 3.3 The Systematic Literature Review. Screening and Eligibility To have a systematic and unbiased search process, all the search results obtained in the chosen academic databases were uploaded to a reference management tool, which helped eliminate duplicates among the sources automatically. After removing duplication, the authors carried out the two-stage screening independently. The initial step was searching and reading the titles and abstracts to remove the unwanted research, including those that have nothing to do with IoT, routing protocols, or energy efficiency of the IoT system. Articles that were unclear as to their relevance at this level were kept to be reviewed in their full text. The second step involved a full text evaluation to ensure that every article fitted the inclusion criteria. We were recording the reasons for exclusion during this stage as well. Papers were excluded if they were: Failure to use energy-efficient routing in an IoT or WSN environment. Didn't do quantitative performance evaluation (e.g., energy consumption, latency, packet delivery). Only dedicated to hardware designs or irrelevant network technologies. Talked about generic networking issues without mentioning modes of energy or routing. Clarity, relevance, and methodological rigor of all selected papers were reviewed. The final source pool was academically sound as the search confined itself to peer-reviewed journals and proceedings of the conference published in the reliable databases. Figure 4 (PRISMA Flow Diagram) shows the study selection process. The database search identified 180 records. The duplicates were eliminated, and 150 new records were left. After screening the titles and abstracts, 100 records were removed. The 50 full-text articles obtained were evaluated for their eligibility, of which 18 were excluded due to non-eligibility. Finally, the synthesis comprised 32 studies. Included in the search results, the 32 articles selected to form the final pool of this systematic literature review cover 2017–2025 as the latest years of studies, with the years of research in that time frame showing growth in the decade. We found a significant focus in 2024 (25% of the total articles), and the same level of contributions during 2021–2025. This trend indicates that there is an increasing academically perceived interest in undertaking research in energy-efficient routing in an IoT landscape. The annual breakdown of included studies is shown in Table 1 . Table 1 Yearly distribution of articles used for the SLR Year Number of Articles Percentage 2017 2 6.3% 2018 1 3.1% 2019 2 6.3% 2020 3 9.4% 2021 4 12.5% 2022 4 12.5% 2023 4 12.5% 2024 8 25.0% 2025 4 12.5% Total 32 100 4. Results 4.1 Categorization of Frequently Used Energy-Efficient Routing Protocols The systematic literature review revealed various low-energy routing protocols often used in IoT networks between 2017 and 2025. A notable example was RPL (Routing Protocol for Low-Power and Lossy Networks), with its hierarchical, IPv6-based protocol and user-definable objective functions, which would be used in a large number of constrained network contexts. LEACH and L3EACH-V2 (the latter being a variant of the former), are cluster-based protocols characterized by their low-overhead data transfer and energy-efficient clustering algorithm implementation. Since 2023, routing protocols based on AI became widespread, including those based on Grey Wolf Optimization (GWO) and the Salp Swarm Algorithm (SSA), in which the optimal routing paths are optimized in real-time using machine learning. In the meantime, hybrid systems such as HEERPOP and ESEERP provided additional power savings due to multi-path routing and integrated security. The range of protocols, including those based on a chain, SDN, and UAV, indicates the transformative nature of routing strategies that are increasingly adjusted to meet the new requirements and use cases of various IoT applications and deployment settings. These protocols differ in architecture, optimization strategies, and applicability in various IoT uses. Table 2 provides an overview of the most commonly used energy-saving routing protocols found in the literature reviewed. The protocols are organized by the type in which they can be separated, followed by major design features and the time frame in which they were most widely researched. Traceability and validation sources are given. This tabular presentation aids in tracing major tendencies and new breakthroughs in the sphere of energy-efficient routing in IoT settings Table 2 Frequently Utilized Energy-Efficient Routing Protocols in IoT Networks (2017–2025) Protocol Type Key Features Years Highlighted Reference Routing Protocol for Low-Power and Lossy Networks (RPL) Hierarchical IPv6 support, flexible objective functions (OFs), and reliable LLNs 2019, 2024 [ 7 ], [ 16 ] Low-Energy Adaptive Clustering Hierarchy (LEACH) Cluster-based Rotating cluster heads, low overhead, baseline WSN protocol 2017, 2023, 2024 [ 3 ], [ 17 ], [ 18 ] Power-Efficient GAthering Sensor Information System Chain-based Sequential transmission, reduced node-to-node distance 2018, 2022 [ 19 ] TEEN/APTEEN Threshold-based Reactive protocol, transmits only significant data 2020, 2022 [ 15 ] Lightweight On-demand Ad hoc Distance-Vector Next Generation (LOADng) Reactive Lightweight protocol for constrained IoT devices 2019 [ 7 ] ESEERP Secure Cluster Multi-path, QoS-aware, energy-efficient, secure 2022 [ 19 ] HEERPOP Hybrid Multi-path, QoS-aware, energy-efficient, secure 2024 [ 18 ] RVRR SDN-based In-network reducer routing, energy savings, and low RTT 2024 [ 20 ] AI-Based Protocol Metaheuristic/ Intelligent Uses ML, fuzzy logic, evolutionary algorithms (e.g., GWO, SSA) 2023–2025 [ 5 ], [ 10 ] L3EACH-V2 Cluster-based Local ID reuse, preamble modulation, underwater IoT, and high energy savings 2023 [ 21 ] PriNergy RPL-based (QoS-aware) Content-prioritized routing, TDMA optimization, multimedia support 2020 [ 22 ] UEE-RPL UAV-assisted Hierarchical Dual-mode UAV routing, energy-quality metrics (EEQ, DEQ), delay-efficient 2021 [ 23 ] 4.2 Performance Evaluation Based on Energy Consumption, Delay, and Security These energy-efficient routing protocols provide varying results when compared to essential parameters that include energy consumption, latency, and security. This subsection provides a presentation of how protocols fare in these critical dimensions. Regarding energy consumption, the majority of cluster- and chain-based protocols, including LEACH, L3EACH-V2, and PEGASIS, performed very well, decreasing node-to-node communication distances and enabling sleep scheduling[ 3 ], [ 19 ], [ 21 ]. RPL also exhibited high levels of energy optimization, especially in loss networks. The models of AI-intense routing, such as GWO-based and SSA-based models, significantly and always in normal routing mode, excelled their traditional counterparts in adaptive energy-saving, in particular, in the case of dynamic topologies. Another important performance indicator was latency or delay. Reactive protocols like TEEN and APTEEN were expected to only send out data when critical threshold conditions were encountered, hence low latency in data transmission [ 15 ]. Using UAVs to work out hierarchical routing, UEE-RPL showed that data forwarding incurred fewer delays compared to other schemes[ 23 ]. RVRR software-defined networking (SDN-based protocol) to further reduce round-trip delays, integrated in-network data reduction [ 20 ]. Other protocols, like TEEN and APTEEN, were devised to be reactive, and they sent blocks only when extreme threshold conditions were exceeded, which led to low data latency. UEE-RPL that hierarchically routes them with UAVs exhibited less delay in data forwarding. Software-defined networking (SDN)-based protocol RVRR then incorporates in-network data reduction to reduce round-trip delays further, and applies to real-time IoT applications. Security protection is the most poorly supported component in most protocols. Conventional protocols such as LEACH and TEEN have no inbuilt security measures, and the secure deployment needs extra overheads. However, more recent protocols, like HEERPOP, ESEERP, and PriNergy, included encryption, Qos-aware, and content prioritization techniques and saw enhanced security functionality [ 22 ], [ 24 ], [ 25 ]. Conventional protocols such as LEACH and TEEN have no inbuilt security measures, and the secure deployment needs extra overheads. Yet new protocols, like HEERPOP, ESEERP, and PriNergy, have included encryption, QoS-aware (quality of service), and content-prioritization processes, which have better security characteristics. The use of security, however, may add extra computational expenses, which may compromise energy efficiency in constrained devices. Table 3 Performance Evaluation Based on Energy Consumption, Delay, and Security Protocol Energy Consumption Delay Performance Security Support RPL High efficiency Moderate Low LEACH Moderate-high Low Low TEEN/APTEEN High (Threshold) Very Low Low HEERPOP High Moderate high ESEERP High Moderate High AI-Based Very high (ML-based) Variable Moderate RVRR(SDN) high Low RTT Moderate UEE-RPL high Very Low Moderate PriNergy Moderate Low Moderate – high 4.3 Trade-Offs and Implementation Considerations The protocols discussed have underlying tradeoffs between energy efficiency, delay reduction, and security design [ 18 ], [ 19 ], [ 22 ], [ 26 ]. These trade-offs and practical implications of IoT deployment are discussed in this subsection. To explain these trade-offs further, Table 4 provides a synthesis of the literature on the performance of various protocols in the areas of energy efficiency, latency, security, and the generic implementation approach. Each protocol can be viewed comparatively in the table, highlighting the strengths and limitations. As an example, roadmaps such as HEERPOP and ESEERP exhibit high levels of security and energy efficiency, but with the drawback of high implementation complexity, which is well suited to high-stakes applications that consume more computational resources. Conversely, the solutions provided by less-complex protocols like LEACH and TEEN/APTEEN, although being low-complexity protocols with low latency, do not lend themselves well to sensitive applications due to security sacrifice. The AI-supported and UAV-supported protocols demonstrate promising results with high levels of adaptability and performance under changing conditions but might demand more specific infrastructure and increased processing capabilities. This comparison profile will be instrumental in helping researchers and developers to choose unique best-fit routing protocols to the conditions of various IoT applications. Table 4 Trade-Offs and Implementation Considerations Protocol Energy Efficiency Delay Performance Security Support Implementation Complexity HEERPOP High Moderate High High ESEERP High Moderate High High AI-Based Very High Variable Moderate High LEACH Moderate-High Low Low Low TEEN/APTEEN High (Threshold-based) Very low Low Low UEE-RPL High Very Low Moderate Moderate Also, deployment context plays a significant role in determining a protocol. Specifically, reactive protocols such as TEEN can work well when time is of concern (e.g., industrial monitoring), whereas UAV-supported protocols like UEE-RPL might be more suited to mobile and aerial networks. There is a lack of coherent evaluation metrics of protocols in the literature, which makes it difficult to standardize comparisons; thus, implementing frameworks of benchmarks could be considered in future works. 5. Discussion 5.1. Protocol Design Diversity and Trends The outcome of this systematic literature review provides results that inform about the challenges and opportunities amid developing and deploying energy-efficient routing protocols within IoT networks. The classification of protocols underscores the variety of methods employed, including clustering and chain-based routing, AI-empowered and SDN-aided [ 21 ], [ 26 ], [ 27 ]. This diversity is representative of the diversity of performance needs and environmental limitations encountered in practical IoT systems. The sheer prevalence of RPL and LEACH in published literature designates their seminal status, but more recent protocols such as HEERPOP, ESEERP, and AI-based models are becoming popular because of their enhanced efficiency and adaptability [ 16 ], [ 18 ], [ 19 ]. 5.2. Performance Analysis: Energy, Delay, and Security Energy usage is a predominant issue, sometimes taking preference over latency or security. Energy-efficient protocols such as LEACH and PEGASIS rely on data aggregation and node rotation and are therefore restricted in terms of providing secure and low-latency communication [ 3 ], [ 21 ]. Hybrid protocols (e.g., HEERPOP and ESEERP), on the other hand, and models with AI offer a more even solution, where QoS and basic security options are accompanied by energy savings. Their complexity and computational requirements also might not be compatible with low power settings [ 25 ], [ 26 ]. Latency-based protocols like TEEN and UEE-RPL have the advantage of real-time data processing, but might drop updates that do not present specific consequences or have the overhead of extra infrastructure such as UAVs [ 15 ], [ 23 ]. Despite AI-based solutions fitting the dynamics of networks relatively well, they are quite resource-intensive and can cause learning-induced delay. The fact that no universal protocols score universally high shows that performance is highly contextual. 5.3. Performance Analysis: Energy, Delay, and Security Security is a significant issue in the design of routing protocols. Not many protocols have built-in encryption or prioritization strategies. The majority relies on an external layer to provide data security, which further complicates the overall design of systems and can impact energy performance [ 19 ], [ 19 ], [ 22 ]. This presents a possibility of cross-layer protocol designs focusing on combining energy efficiency and lightweight, in-protocol security features. 5.4. Contextual Suitability and Future Direction The review signifies the importance of end-to-end, application-conscious protocol design. Depending on deployment requirements in terms of topology, node capacity, mobility, and sensitivity of the data being transmitted, protocol designers need to balance trade-offs in terms of energy consumed, latency, and security. The work in the future should be concentrated under adaptive and scalable solutions, where an optimization of cross-layer as well as the real-world validation should be encompassed to provide further robustness and practicality in routing protocols in various IoT applications. 6. Conclusion The present systematic literature review presents analyses of 32 peer-reviewed articles published in 2017–2025, covering the topic of energy-efficient routing protocols within IoT networks. Three decisive research questions guided the study: what are the widely adopted protocols, how well do they fare regarding energy consumption, latency, and security, and what are their trade-off characteristics? It was established in the review that the widely used protocols like RPL, LEACH, TEEN, and hybrid schemes like HEERPOP and ESEERP have been used because of their energy-conservation features and structural optimization potentials. But no scheme performed well in all measurements. Although some protocols emphasize their low energy consumption, they tend to lack delay mitigation or security measures. On the other hand, those with more secure protocols would consume more computation resources, and therefore, they would be less compatible with limited devices. The results indicate that protocol choice in IoT is context-specific. Design decisions must reflect the needs of a given application, real-time communication, sensitive data, or device constraints. Moreover, not many protocols have extensively incorporated native security tools, which leads to the urgent necessity of lightweight, extensible, and dynamic solutions. 6.1. Limitations of the Study Although the research was conducted as per PRISMA 2020 to guarantee methodological rigor, it is worth mentioning a few limitations. First, being restricted to English publications and published (grey) literature might have reduced the range of reflective perspectives included in this review. Second, the search itself was limited by date and type to peer-reviewed articles within 2017–2025, which could either miss the earlier formative texts or the latest breakthroughs after the search date. The study also omitted those protocols that had not been explicitly focused on energy-efficient protocols, potentially at the expense of routing models that might be successful in practice but not formulated in the context of energy-saving requirements. 6.2. Future Research In future work, more emphasis should be placed on creating holistic routing schemes that establish a balance between energy, performance, and security, and are scalable and feasible to implement. Benchmarking models and practical validation will also be critical to the development of energy-efficient routing protocol design and selection within next-generation IoT networks. Declarations Funding No funding was received to support this study Author Contribution 1. Substantial contributions to concept or designAcquisition, analysis, or interpretation of dataDrafting of the manuscriptCritical review of the manuscript for important intellectual contentAgreed to be accountable for all aspects of the workWill review the final version to be published2. Substantial contributions to concept or designAcquisition, analysis, or interpretation of dataCritical review of the manuscript for important intellectual contentAgreed to be accountable for all aspects of the workWill review the final version to be published3. Substantial contributions to concept or designCritical review of the manuscript for important intellectual contentAgreed to be accountable for all aspects of the workWill review the final version to be publishedSupervised the work4. Substantial contributions to concept or designCritical review of the manuscript for important intellectual contentAgreed to be accountable for all aspects of the workWill review the final version to be publishedSupervised the work References Zhang, J. A., et al. (2021). Enabling joint communication and radar sensing in mobile networks—A survey. Ieee Communication Surveys And Tutorials , 24 (1), 306–345. Mouha, R. A. R. A. (2021). Internet of things (IoT). J Data Anal Inf Process , 9 (02), 77. Kaur, G., Chanak, P., & Bhattacharya, M. (2021). Energy-efficient intelligent routing scheme for IoT-enabled WSNs. IEEE Internet Things J , 8 (14), 11440–11449. Yadav, R. and V. and, & Kumar, A. (May 2024). Systematic Review Paper on Energy-Efficient Routing Protocols in Internet of Things. IETE J Res , 70 (5), 4721–4743. 10.1080/03772063.2023.2230169 Suryawanshi, V. (Sep. 2024). Advancements in IoT Routing and Energy Efficiency: A Comprehensive Review of Algorithms and Technologies. Sci Manag Des J , 2 (3). 10.70295/SMDJ.2409024 Bekal, P., Kumar, P., Mane, P. R., & Prabhu, G. (2024). A comprehensive review of energy efficient routing protocols for query driven wireless sensor networks [version 3; peer review: 2 approved]. Magubane, Z., Tarwireyi, P., & Adigun, M. O., Evaluating the Energy Efficiency of IoT Routing Protocols, in 2019 International Multidisciplinary Information Technology and Engineering Conference (IMITEC) , Nov. 2019, pp. 1–7. 10.1109/IMITEC45504.2019.9015904 Dubey, A., & Yadav, S. K. (Oct. 2024). Basics of Internet of Things. INTERNATIONAL J Sci Res Eng Manag , 08 (10), 1–6. 10.55041/IJSREM37970 Ud Din, I., et al. (2019). The Internet of Things: A Review of Enabled Technologies and Future Challenges. Ieee Access : Practical Innovations, Open Solutions , 7 , 7606–7640. 10.1109/ACCESS.2018.2886601 A. T. S, Energy-Efficient IoT Networks: Optimizing Resource Management through Machine Learning, Commun. Appl. Nonlinear Anal. , vol. 32, no. 1s, Art. no. 1s, (2025). 10.52783/cana.v32.2168 Kaur, N., & Sood, S. K. (Jun. 2017). An Energy-Efficient Architecture for the Internet of Things (IoT). Ieee Systems Journal , 11 (2), 796–805. 10.1109/JSYST.2015.2469676 Mwewa, W., & Lubobya, S. C. (Mar. 2022). Performance Evaluation of Routing Protocols in Enterprise Networks. Am J Comput Eng , 5 (1), 24–35. 10.47672/ajce Rani, P., & Sangwan, A. A Review on Routing Protocols in Wireless Sensor Networks. Eng Technol . Page, M. J., et al. (Mar. 2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. PLOS Med , 18 (3), e1003583. 10.1371/journal.pmed.1003583 Goswami, P., et al. (Feb. 2022). AI-Based Energy Efficient Routing Protocol for Intelligent Transportation System. Ieee Transactions On Intelligent Transportation Systems , 23 (2), 1670–1679. 10.1109/TITS.2021.3107527 Yadav, R., & Kumar, V. (May 2024). A Systematic Review Paper on Energy-Efficient Routing Protocols in Internet of Things. IETE J Res , 70 (5), 4721–4743. 10.1080/03772063.2023.2230169 Dass, R., et al. (Jul. 2023). A Cluster-Based Energy-Efficient Secure Optimal Path-Routing Protocol for Wireless Body-Area Sensor Networks. Sensors (Basel, Switzerland) , 23 (14), 6274. 10.3390/s23146274 Shial, R. K., Rath, P., Patnaik, S. R., & Ghuar, U. (2024). HEERPOP: Hybrid Energy Efficiency Routing Protocol for Optimal Path in the Internet of Things-Based Sensor Networks, Int. J. Comput. Netw. Appl. , vol. 11, no. 4, pp. 494–505, Aug. 10.22247/ijcna/2024/31 Dogra, R., Rani, S., Kavita, J., Shafi, S., Kim, & Ijaz, M. F. (Aug. 2022). Enhanced Smart Energy Efficient Routing Protocol for Internet of Things in Wireless Sensor Nodes. Sensors (Basel, Switzerland) , 22 (16), 6109. 10.3390/s22166109 Hadi, T. H. (Apr. 2024). IoT Protocols: Connecting Devices in Smart Environments. ICST Trans Scalable Inf Syst . 10.4108/eetsis.5665 Ghazy, A. S., Kaddoum, G., & Singh, S. (2023). Low-Latency Low-Energy Adaptive Clustering Hierarchy Protocols for Underwater Acoustic Networks. Ieee Access : Practical Innovations, Open Solutions , 11 , 50578–50594. 10.1109/access.2023.3277395 Safara, F., Souri, A., Baker, T., Al Ridhawi, I., & Aloqaily, M. (2020). PriNergy: a priority-based energy-efficient routing method for IoT systems, J. Supercomput. , vol. 76, no. 11, pp. 8609–8626, Nov. 10.1007/s11227-020-03147-8 Yang, Z., Liu, H., Chen, Y., Zhu, X., Ning, Y., & Zhu, W. (2021). UEE-RPL: A UAV-Based Energy Efficient Routing for Internet of Things, IEEE Trans. Green Commun. Netw. , vol. 5, no. 3, pp. 1333–1344, Sep. 10.1109/TGCN.2021.3085897 Dogra, R., Rani, S., & Gianini, G. (2023). REERP: A Region-Based Energy-Efficient Routing Protocol for IoT Wireless Sensor Networks, Energies , vol. 16, no. 17, p. 6248, Aug. 10.3390/en16176248 Shial, R. K., Rath, P., Patnaik, S. R., & Ghuar, U. (2024). HEERPOP: Hybrid Energy Efficiency Routing Protocol for Optimal Path in the Internet of Things-Based Sensor Networks, Int. J. Comput. Netw. Appl. , vol. 11, no. 4, pp. 494–505, Aug. 10.22247/ijcna/2024/31 Suryawanshi, V. (Sep. 2024). Advancements in IoT Routing and Energy Efficiency: A Comprehensive Review of Algorithms and Technologies. Sci Manag Des J , 2 (3). 10.70295/SMDJ.2409024 Magubane, Z., Tarwireyi, P., & Adigun, M. O., Evaluating the energy efficiency of IoT routing protocols, in 2019 International Multidisciplinary Information Technology and Engineering Conference (IMITEC) , IEEE, 2019, pp. 1–7. Accessed: May 21, 2025. [Online]. Available: https://ieeexplore.ieee.org/abstract/document/9015904/?casa_token=cQSQ3suJzJ8AAAAA:p4sjyvMSD926_v3_4FHMewekyHjRebXaZ4jq77sJVI-8SkAAnZRrsaT484E7tJpywQadRxwi8WORVdiz Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7611247","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Systematic Review","associatedPublications":[],"authors":[{"id":530104149,"identity":"d7a62654-85bf-4cad-b083-68d94b7c0ad4","order_by":0,"name":"Samuel BoahAkenten Appiah-Menka","email":"","orcid":"","institution":"University of Skills Training and Entrepreneurial Development (AAMUSTED)","correspondingAuthor":false,"prefix":"","firstName":"Samuel","middleName":"BoahAkenten","lastName":"Appiah-Menka","suffix":""},{"id":530104150,"identity":"ceda0444-0f91-4884-b8ff-ff04030ad162","order_by":1,"name":"Cecilia Ampofowaa","email":"","orcid":"","institution":"Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development (AAMUSTED)","correspondingAuthor":false,"prefix":"","firstName":"Cecilia","middleName":"","lastName":"Ampofowaa","suffix":""},{"id":530104151,"identity":"1eecd917-2e43-4128-9f5d-72f4f7e1f746","order_by":2,"name":"William Asiedu","email":"","orcid":"","institution":"Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development (AAMUSTED)","correspondingAuthor":false,"prefix":"","firstName":"William","middleName":"","lastName":"Asiedu","suffix":""},{"id":530104152,"identity":"f116efcb-8975-4013-a836-e23e6a3c5ffe","order_by":3,"name":"Franco Osei-Wusu","email":"data:image/png;base64,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","orcid":"","institution":"Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development (AAMUSTED)","correspondingAuthor":true,"prefix":"","firstName":"Franco","middleName":"","lastName":"Osei-Wusu","suffix":""}],"badges":[],"createdAt":"2025-09-14 08:08:18","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7611247/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7611247/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":93694231,"identity":"a7627777-6189-45c6-ab3f-b40e9266346a","added_by":"auto","created_at":"2025-10-16 14:28:03","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":146486,"visible":true,"origin":"","legend":"","description":"","filename":"Energyefficientroutingprotocol.docx","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/92c82830dae28313f083bb97.docx"},{"id":93694766,"identity":"78b44f4e-f492-4466-901f-054364a3d456","added_by":"auto","created_at":"2025-10-16 14:36:03","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":6589,"visible":true,"origin":"","legend":"","description":"","filename":"bf0c3e3368ad4954999dbd067a72cd34.json","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/420905c757409a70659e6832.json"},{"id":93694233,"identity":"a8599e63-b6ec-4036-876e-2c64b7e4946c","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":100819,"visible":true,"origin":"","legend":"","description":"","filename":"bf0c3e3368ad4954999dbd067a72cd341enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/266d0c8398939566753e4774.xml"},{"id":93694227,"identity":"b4fb0937-6909-419f-b335-caa7903de750","added_by":"auto","created_at":"2025-10-16 14:28:03","extension":"eps","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":621,"visible":true,"origin":"","legend":"","description":"","filename":"drawingimage10.eps","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/1ebaab7fd8bdce9a31fbf537.eps"},{"id":93694768,"identity":"4223aaf4-a2c9-447a-8194-ea7b4836f851","added_by":"auto","created_at":"2025-10-16 14:36:04","extension":"eps","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":72336,"visible":true,"origin":"","legend":"","description":"","filename":"drawingimage11.eps","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/c9a77d72b56db0387924b22a.eps"},{"id":93694229,"identity":"31089706-3de2-431f-a273-b67d76674383","added_by":"auto","created_at":"2025-10-16 14:28:03","extension":"eps","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":623,"visible":true,"origin":"","legend":"","description":"","filename":"drawingimage12.eps","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/7b355660761ef3b7d88b2c28.eps"},{"id":93694295,"identity":"5e3da40d-4a5a-4afc-8fd6-10339b75a39b","added_by":"auto","created_at":"2025-10-16 14:28:09","extension":"eps","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":75953,"visible":true,"origin":"","legend":"","description":"","filename":"drawingimage13.eps","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/fa9f0b1e6f3abc71f8bb1122.eps"},{"id":93694241,"identity":"48c12e8d-da03-428f-a10e-9bd001ddfa69","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"eps","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":260542,"visible":true,"origin":"","legend":"","description":"","filename":"drawingimage4.eps","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/3e03634b797879e45fa7a16b.eps"},{"id":93695770,"identity":"ecc2980e-bd21-4b56-ba62-33fc5eb96730","added_by":"auto","created_at":"2025-10-16 14:44:04","extension":"eps","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":920,"visible":true,"origin":"","legend":"","description":"","filename":"drawingimage6.eps","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/3f666ecdc6964ca0d5e03bfa.eps"},{"id":93694242,"identity":"031d9b21-0bb5-4e51-bf8b-000564ecfafb","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"eps","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":137292,"visible":true,"origin":"","legend":"","description":"","filename":"drawingimage7.eps","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/e58c60ad3e3adc466dea3299.eps"},{"id":93694240,"identity":"522e47f4-be6b-4a19-9226-32fc321e1732","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"eps","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":220730,"visible":true,"origin":"","legend":"","description":"","filename":"drawingimage9.eps","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/de3041bd384cc1ae752c6fae.eps"},{"id":93694778,"identity":"bde46c02-a29e-407d-823d-a42e52b8d539","added_by":"auto","created_at":"2025-10-16 14:36:04","extension":"jpeg","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":22802,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/fcc958939799250a5ccec98b.jpeg"},{"id":93694776,"identity":"37341cb0-e099-4609-b52e-9b5b499d9ec0","added_by":"auto","created_at":"2025-10-16 14:36:04","extension":"jpeg","order_by":17,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1074,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage10.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/b615ca7d0ed7f875369c1aec.jpeg"},{"id":93694239,"identity":"f195f5f2-2ce3-4712-97a9-8845b3d55b0e","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"jpeg","order_by":18,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":164651,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage11.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/fe1019b735f361e52aee5f86.jpeg"},{"id":93694767,"identity":"8d8ddcd8-737e-48b3-aaba-c18706b6e7b0","added_by":"auto","created_at":"2025-10-16 14:36:03","extension":"jpeg","order_by":19,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1966,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage12.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/28e5ffb27add4d6f1e637dc7.jpeg"},{"id":93694769,"identity":"649baa02-67f0-48a7-a01b-6d385fc2714f","added_by":"auto","created_at":"2025-10-16 14:36:04","extension":"jpeg","order_by":20,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":63185,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage13.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/52c207e4734e94ea13f24cbb.jpeg"},{"id":93694251,"identity":"a42dfb39-2ae6-42b3-ad0f-1870eccdb9cd","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"jpeg","order_by":21,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":143571,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage14.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/0d5d7e127533d5ec2a32d917.jpeg"},{"id":93694247,"identity":"1c210178-8986-4c8c-87cf-5ea84415992a","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"jpeg","order_by":22,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":71167,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage15.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/7f38ff0365393f72bbc655cf.jpeg"},{"id":93694773,"identity":"1d003fb0-56b6-492d-9c34-dab20a04d0a2","added_by":"auto","created_at":"2025-10-16 14:36:04","extension":"jpeg","order_by":23,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":37192,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage16.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/5ac952aaf0edffa5b0c8bd7e.jpeg"},{"id":93694782,"identity":"94828a50-5e89-4f87-b171-b7b92cfe8139","added_by":"auto","created_at":"2025-10-16 14:36:05","extension":"jpeg","order_by":24,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1074,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage10.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/9b0f310d7f0562285bb38054.jpeg"},{"id":93694273,"identity":"09b58870-08ea-4398-819d-069ab36c6f59","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"jpeg","order_by":25,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":207389,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage18.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/12bc2eb4da988d384ce9df73.jpeg"},{"id":93694250,"identity":"34ade74e-3aae-4c2d-a237-4329b4550eb9","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"jpeg","order_by":26,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":90733,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage19.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/cbb22a20f8f7ba6510bf06f8.jpeg"},{"id":93694268,"identity":"31b0d307-dc63-4913-a249-22aaed2e3d5b","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"jpeg","order_by":27,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64930,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/446b29e3171df469d4ee121a.jpeg"},{"id":93694276,"identity":"b26ae944-aeed-4799-85e1-b5fcea0d9905","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"jpeg","order_by":28,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1966,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage12.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/d79b0c9a0d1d996d662d7db7.jpeg"},{"id":93694266,"identity":"3a3fb524-a098-4b06-8076-89580be4a098","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"jpeg","order_by":29,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":66467,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/84ceddcff77d4271df06c99c.jpeg"},{"id":93694248,"identity":"7e4424af-a3fb-496c-963c-b20bcc06e52a","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"jpeg","order_by":30,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":42070,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/9ba4d10bf59450c14f9c9db2.jpeg"},{"id":93694774,"identity":"fd3bcdd4-71c3-439e-ba40-65917952e3f7","added_by":"auto","created_at":"2025-10-16 14:36:04","extension":"jpeg","order_by":31,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":36205,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/3254f9a1c2c6f06975ca371f.jpeg"},{"id":93694281,"identity":"fc32a2c0-100b-450d-9e1e-66c70449e29b","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"jpeg","order_by":32,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":44574,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage6.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/2d14d3be1873c7d161ab4bf1.jpeg"},{"id":93694235,"identity":"363ad6b9-08dc-43be-ab47-ea8d3c404dff","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"jpeg","order_by":33,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":30781,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage7.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/9bfeb9453415d4b6432c3bf3.jpeg"},{"id":93694259,"identity":"9496763c-0122-455b-9a66-e2631ee20b82","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"jpeg","order_by":34,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1074,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage10.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/d16c2e072db05bef34241a0d.jpeg"},{"id":93694771,"identity":"0c8fb85f-72ee-40ce-b7d9-b1e239e4c7cb","added_by":"auto","created_at":"2025-10-16 14:36:04","extension":"jpeg","order_by":35,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64787,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage9.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/0ad8bc78c404f978f5da696f.jpeg"},{"id":93694772,"identity":"afe0f662-015b-4f2e-ac6f-cf1b9e1e7b65","added_by":"auto","created_at":"2025-10-16 14:36:04","extension":"png","order_by":36,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":5183,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/4fbacdff352403828211c3c9.png"},{"id":93694270,"identity":"1145d3c1-7314-4215-9dd8-da21fdc957d0","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"png","order_by":37,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":935,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage10.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/9073e6beaf81d40106461ed8.png"},{"id":93694253,"identity":"b3c9f029-5813-4a14-84ee-f70be0960786","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"png","order_by":38,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":32916,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage11.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/5af3e294c4e7613562f2fa3b.png"},{"id":93694252,"identity":"5beb468a-46cf-4b17-ba93-7605cad31521","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"png","order_by":39,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":999,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage12.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/813efcf0d03a1d53bea8ccbe.png"},{"id":93694243,"identity":"6e9a2b1e-6399-4e4c-8b85-676d28fc7038","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"png","order_by":40,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":11944,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage13.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/b5780f220d1a73b971dda5d0.png"},{"id":93694255,"identity":"863b9bf5-682d-4dd4-9ee3-1311dc3cfa33","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"png","order_by":41,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":24240,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage14.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/b4386fc23237653baea0e305.png"},{"id":93694261,"identity":"5a7340f1-3201-4799-8493-dbf016c02cf8","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"png","order_by":42,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":14096,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage15.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/5db1db3479fee652bb4a0f3c.png"},{"id":93694257,"identity":"54afd85d-799b-4ba4-96a0-aaa947bd2aa3","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"png","order_by":43,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":8276,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage16.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/a642055ade913ee9181f078b.png"},{"id":93694260,"identity":"e15c7a3b-7bf4-4e98-9f67-eefa9718fbbb","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"png","order_by":44,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":935,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage17.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/4cc7f4e1c25c586238f7da8c.png"},{"id":93694780,"identity":"3fd141a3-6b0f-4900-8a7f-34e5c2c13d1f","added_by":"auto","created_at":"2025-10-16 14:36:05","extension":"png","order_by":45,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":39642,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage18.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/4b9356b8364f4b9646f68afe.png"},{"id":93694264,"identity":"4c7e0832-22ec-4094-b7bd-94e42a354d39","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"png","order_by":46,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":15431,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage19.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/9b5e18d54a2ac26dcfb1376c.png"},{"id":93694777,"identity":"f5e4e378-4cfc-48d0-9fbc-6f66a85cb464","added_by":"auto","created_at":"2025-10-16 14:36:04","extension":"png","order_by":47,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":13356,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/ca25e8a8644d506e60987b43.png"},{"id":93694267,"identity":"b1934f24-34a2-43b7-981b-a43fe2a1a617","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"png","order_by":48,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":999,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage12.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/eef23fe111d3f7d31800f70e.png"},{"id":93694779,"identity":"a73ee6ff-3256-4ef2-80fc-b6ea8317dc40","added_by":"auto","created_at":"2025-10-16 14:36:04","extension":"png","order_by":49,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":14005,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/77289751e6a04dc8cff66b7b.png"},{"id":93694279,"identity":"1ab55dc7-3863-48b5-a857-efdd35207bf8","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"png","order_by":50,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":8835,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/59bed20f421b7c374207ff02.png"},{"id":93694274,"identity":"f07c1ef3-4d8d-4e91-aa47-3a4df6b0039f","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"png","order_by":51,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":8011,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/67e3587c36a16bbd37f80311.png"},{"id":93694783,"identity":"78bf990e-1d19-4989-97ad-b56c6dd88183","added_by":"auto","created_at":"2025-10-16 14:36:05","extension":"png","order_by":52,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":8702,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/a0e6f91aafa17daf7f6f7610.png"},{"id":93694775,"identity":"bb19d4ed-ce27-48fc-a0e0-3147e79ace54","added_by":"auto","created_at":"2025-10-16 14:36:04","extension":"png","order_by":53,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":7289,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/eee51c7b71e60f9228dfa0b7.png"},{"id":93694282,"identity":"75deed5a-ff96-4895-8cbe-17f0441d1b97","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"png","order_by":54,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":935,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage17.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/05f5faafdffe610cf80549f9.png"},{"id":93694254,"identity":"62fd82d0-2eb5-4e45-9aa1-1c44cd60bdb6","added_by":"auto","created_at":"2025-10-16 14:28:04","extension":"png","order_by":55,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":13905,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage9.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/60d32a611c77e83543ce9f6c.png"},{"id":93694269,"identity":"767defdf-c401-4708-b7bd-ece548e6763e","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"xml","order_by":56,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":98754,"visible":true,"origin":"","legend":"","description":"","filename":"bf0c3e3368ad4954999dbd067a72cd341structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/bce74f26aeb4e41fec9d18b9.xml"},{"id":93694278,"identity":"221f5952-d24c-453c-b938-493f7694ebf0","added_by":"auto","created_at":"2025-10-16 14:28:05","extension":"html","order_by":57,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":112166,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/c3eb54f9d6a04c9cb4a8319c.html"},{"id":93694226,"identity":"96545f97-f0b6-48f4-ac91-b6aaaca9a096","added_by":"auto","created_at":"2025-10-16 14:28:03","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":31891,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eInternet of Things (IoT) architecture\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/3b8b6a005113670971a1c9da.png"},{"id":93694318,"identity":"0ed0e2d8-156d-4d87-ba9d-f527195586d3","added_by":"auto","created_at":"2025-10-16 14:28:20","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":25503,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eEnergy-efficient Architecture for IoT Networks\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/965ab0c900498e08c911bff4.png"},{"id":93694228,"identity":"09a21f78-ef57-40af-8228-219fed59a2d0","added_by":"auto","created_at":"2025-10-16 14:28:03","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":38912,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eTypes of Routing Protocols\u003c/em\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/d5272f7dac3bcae9aacfa95b.png"},{"id":93694230,"identity":"fc77923e-c8eb-494b-9b1e-57ccf648ba16","added_by":"auto","created_at":"2025-10-16 14:28:03","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":49017,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eshows the PRISMA framework for this study\u003c/em\u003e\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/f5479e82e462b4656f95cf9d.png"},{"id":94505610,"identity":"7605cda3-4668-4bf6-bcce-842d674d9fba","added_by":"auto","created_at":"2025-10-28 16:16:46","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1043117,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7611247/v1/851f1e3a-17c8-4c22-8ef0-fec4a25a4a0e.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Systematic Review of Energy-Efficient Routing Protocols for IoT Networks","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eInternet of Things (IoT) may be regarded as a system of interconnected devices, which are empowered with sensors, software, and network connections, so they can collect and share data. The IoT has, in recent times, received substantial recognition because of its many implications, such as smart healthcare, home automation, transportation, and smart cities. Recently, Internet devices have been exploited in a variety of applications, such as manufacturing, supply chain, real-time equipment surveillance, environmental preservation, and industrial safety control. However, it is projected that each individual will be connected to the Internet by more than ten devices by 2050 [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Nevertheless, such a transition will not be an easy process, as many challenges and problems still have to be addressed in various ways to bring the best out of this technology [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. In such IoT systems, wireless sensor networks (WSNs) are important to gather smart information required in smart environments [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. These networks consist of many linked devices that communicate with each other via the internet, and hence, they require the application of energy-efficient routing algorithms to process the data transfer. Energy-efficient routing protocols in Internet of Things (IoT) networks have become a crucial issue to consider, as most devices in IoT networks operate on limited energy sources. Energy efficiency plays an essential role in the IoT to ensure optimal network performance on loosely scattered networks (Magubane et al., 2019). To support data exchange in IoT networks, efficient and reliable routing protocols are necessary to address issues such as bandwidth capacity, energy consumption, and scalability. To support data exchange in IoT networks, efficient and reliable routing protocols are necessary to address issues such as bandwidth capacity, energy consumption, and scalability. The issue of energy efficiency is a major concern in IoT networks, as most sensor nodes will be battery-powered and deployed in inaccessible locations where it will be cumbersome to replace the batteries regularly. Several reviews on energy-efficient routing protocols for IoT networks have been published in recent years, indicating that this research area is continually evolving with new contributions and constant improvement. Yadav \u0026amp; Kumar (2024) in their study present a survey on energy-efficient routing protocols, aiming to provide a holistic understanding of the state-of-the-art approaches, their characteristics, strengths, limitations, and performance metrics. Their survey encompasses a wide range of energy-efficient routing protocols proposed in the literature, including traditional routing protocols adapted for IoT scenarios and protocols specifically tailored for energy optimization. The study of Suryawanshi (2024) presents a comprehensive analysis of recent advancements in IoT routing techniques and energy-efficient solutions, focusing on multi-objective optimization algorithms such as fractional gravitational search, grey wolf optimization, and hybrid salp swarm-differential evolution algorithms. Additionally, the authors also highlight the critical role of energy-efficient routing in IoT applications, such as smart agriculture, healthcare, and smart cities, emphasizing its importance in prolonging network lifetime and reducing overall operational costs. Bekal et al. (2024) present a review of various energy-efficient routing protocols for wireless sensor networks in their study, comparing standard and enhanced protocols. In addition, the study also discusses trade-offs in energy efficiency, network lifetime, and scalability, providing a comparative table for future researchers to analyze these protocols effectively. Finally, Magubane et al. (2019) evaluate energy-efficient routing protocols for IoT networks, specifically comparing RPL and LOADng. The authors of the study conclude that RPL is the more energy-efficient option, which is crucial for prolonging the operational life of battery-powered IoT devices in constrained environments. Despite the existence of several reviews on energy-efficient routing protocols, a systematic literature review has not been well conducted to facilitate the process of selecting the most suitable energy-efficient routing protocols for different IoT applications. This study aims to address this gap by: (i) To identify and categorize the most frequently used energy-efficient routing protocols in IoT networks. (ii) To evaluate the comparative performance of these protocols in terms of energy consumption, latency, and security. The functionality of the IoT networks depends largely on routing. (iii) To analyze the trade-offs and limitations associated with protocol design and implementation in resource-constrained IoT environments. Proper routing protocols define through which nodes across the network the data packets should reach the target in a central sink or a base-station, and should guarantee the least amount of energy used as well as network lifetime. Therefore, in IoT, energy-efficient routing protocols became the subject of fundamental research. To give a more current, up-to-date view to the reader on the energy-efficient routing protocols for IoT networks, this systematic literature review focuses on studies published between 2017 and 2025.\u003c/p\u003e\u003cp\u003eFor this purpose, the remainder of this study is organized as follows: Section 2 provides an overview of the key concept addressed in this study, Section 3 outlines the methodology adopted for conducting the systematic review, Section \u003cspan refid=\"Sec11\" class=\"InternalRef\"\u003e4\u003c/span\u003e outlined the results derived from the systematic review, Section 5 presents the discussion, and Section 6 presents the conclusions.\u003c/p\u003e"},{"header":"2. Concepts","content":"\u003cp\u003eTo better understand the key concept related to energy-efficient routing protocols in IoT networks, this session provides a concise overview of the key concept, laying the groundwork for the systematic review.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Internet of Things\u003c/h2\u003e\u003cp\u003eInternet of Things (IoT) can be understood as a system of interconnected devices, which are empowered with sensors, software, and network connections, so they can collect and share data. These devices, integrated with sensors, actuators, and communication modules, are capable of gathering, transmitting, and processing data in real time [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. IoT is a rapidly evolving paradigm, envisioned as a network of billions of interconnected devices designed to apply advanced technological solutions to real-world challenges [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eWith the expansion of the Internet, IoT has had an impressive effect on several fields, and there have been numerous IoT applications employed for enhancing the network operation and users\u0026rsquo; quality of experience [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. IoT applications can be employed in various areas, including healthcare, industry, cellular networks, smart cities, edge computing, cloud computing, wireless sensor networks (WSNs), software-defined networks (SDNs), and many more.\u003c/p\u003e\u003cp\u003eThe architecture of IoT is commonly organized into layers, enabling seamless interaction and communication among diverse devices and systems [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. The architecture of IoT is divided into 4 different layers, i.e., Sensing Layer, Network Layer, Data Processing Layer, and Application Layer. The architecture of IoT is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Energy-efficiency\u003c/h2\u003e\u003cp\u003eEnergy efficiency refers to the approach or strategy that aims at minimizing the amount of energy needed to deliver products and services by utilizing advanced technologies, techniques, or processes that limit energy waste while maintaining or improving performance (energy conservation).\u003c/p\u003e\u003cp\u003eThe objective of energy-efficient Internet of Things (IoT) networks is to reduce power usage, thereby extending the lifespan of devices, especially those that are battery-powered or located in remote areas [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIoT energy efficiency is created with an architecture that forecasts sensor sleep times guided by battery levels and usage patterns to enable maximum resource usage and maximum energy savings, resulting in the life extension of IoT systems [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe energy-efficient architecture for IoT networks consists of layers, namely, sensing and control, information processing, and presentation. The architectural design enables the system to estimate the sensors\u0026rsquo; sleep duration by considering factors such as their remaining battery power, past usage patterns, and the quality of information needed for a specific application[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3 Routing Protocol\u003c/h2\u003e\u003cp\u003eRouting protocols can be termed as the method that determines how routers share routing information, enabling them to determine routes between any two nodes on a computer network. Routing protocols are guidelines used to determine the optimal path for transferring data among nodes in a network. Through these protocols, communication among routers is established to transmit network packets using the most efficient paths [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eA routing protocol involves receiving a packet as incoming traffic at an internal node of a distributed router, which contains a global destination address (Yeh et al., 2020).\u003c/p\u003e\u003cp\u003eMany routing protocols have been developed since then, and these protocols differ according to network structure and field of application [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThere are mainly three kinds of routing protocols applied on the Internet, which are distance vector, link state, and path vector. Every type has basic principles and traits. Also, there are other problems that might be experienced during the temporary occurrence of routing protocols, like looping, and hence, there are different ways of minimizing the occurrence of these problems.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"3. Methodology","content":"\u003cp\u003eThis paper employs a systematic review methodology to present a comprehensive literature review of energy-efficient routing protocols for IoT networks, evaluating the performance of these protocols based on key factors such as energy efficiency, latency, packet delivery rates, and security. The current research requires a systematic review, as it allows for the systematic, thorough, and unbiased analysis of existing research on energy-efficient routing protocols.\u003c/p\u003e\u003cp\u003eTo achieve the proposed objectives, this study employs the Preferred Reporting Items for Systematic Reviews (PRISMA) methodology, a framework designed to support the reporting and systematic review of literature[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The choice of this research design was compared to research designs like Case studies or trials based on the ability to combine and analyze the results of different places, which facilitates the validity and broad applicability of the conclusions. The use of peer-reviewed articles and reliable scholarly resources will provide a strong and valid analysis that will contribute to a profound interpretation and critique of energy-efficient routing protocols applied to IoT networks. Several advantages make a systematic review the most suitable approach in this research. It enables the involvement of different research contributions in different geographical regions of the world, institutional setups, and technological methods of implementation. This method will guarantee full coverage and a better understanding of the subject of energy-efficient routing in IoT networks. Moreover, a systematic review presents the results of research compiled by different reliable sources, which is a more stable base regarding the scale of results and conclusions to make and some recommendations to follow than a case study or case study-like scientific research findings.\u003c/p\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e3.1 Research Question\u003c/h2\u003e\u003cp\u003eThis systematic literature review focuses on energy-efficient routing protocols in Internet of Things (IoT) networks. The scope includes identifying frequently used protocols, evaluating their performance based on energy consumption, delay, and security, and analyzing associated trade-offs. The following specific research questions were formulated to guide the study:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eRQ1: Which energy-efficient routing protocols are most frequently applied in IoT networks between 2017 and 2025?\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eRQ2: How do various protocols compare in terms of energy usage, delay minimization, and data security?\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eRQ3: What trade-offs are evident in the implementation of these protocols across different IoT deployment scenarios?\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003e3.1 Data Source and Search Strategy\u003c/h2\u003e\u003cp\u003eThe following databases, including IEEE Xplore, Google Scholar, Web of Science, Scopus, and MDPI, were used as part of the comprehensive literature search. These platforms have been chosen to give a wider picture of the up-to-date research in the domain by spanning a wide variety of peer-reviewed journals, conference publications, and technical articles. The search employed the combination of search keywords that constitute routing protocols, energy-efficient. Among significant keywords applied were \u0026ldquo;Energy-Efficient routing\u0026rdquo;, \u0026ldquo;IoT Network\u0026rdquo;, \u0026ldquo;Wireless Sensor Networks\u0026rdquo;, \u0026ldquo;Routing Protocols\u0026rdquo;, Network lifetime\u0026rdquo;, \u0026ldquo;Latency\u0026rdquo;, \u0026ldquo;Packet delivery\u0026rdquo;. Boolean operators and filters were applied to refine the search results and eliminate irrelevant studies.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003e3.2 Inclusion and Exclusion Criteria\u003c/h2\u003e\u003cp\u003eTo ensure the quality and relevance of the selected studies, the following criteria were applied:\u003c/p\u003e\u003cp\u003e\u003cb\u003eInclusion Criteria\u003c/b\u003e:\u003c/p\u003e\u003cp\u003eStudies published between 2017 and 2025\u003c/p\u003e\u003cp\u003ePeer-reviewed journal articles or conference papers\u003c/p\u003e\u003cp\u003eArticles written in English\u003c/p\u003e\u003cp\u003eResearch focused on energy-efficient routing protocols for IoT or WSNs\u003c/p\u003e\u003cp\u003eStudies evaluating protocols using performance metrics such as energy consumption, latency, packet delivery ratio, and security\u003c/p\u003e\u003cp\u003eFull-text articles that were openly accessible (open access)[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/p\u003e\u003cp\u003e\u003cb\u003eExclusion Criteria\u003c/b\u003e:\u003c/p\u003e\u003cp\u003eNon-English language publications\u003c/p\u003e\u003cp\u003eStudies lacking technical evaluation or performance comparison\u003c/p\u003e\u003cp\u003eArticles unrelated to routing protocols or energy efficiency in IoT\u003c/p\u003e\u003cp\u003eGrey literature, unpublished theses, or blog posts\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\u003ch2\u003e3.3 The Systematic Literature Review.\u003c/h2\u003e\u003cp\u003e\u003cb\u003eScreening and Eligibility\u003c/b\u003e\u003c/p\u003e\u003cp\u003eTo have a systematic and unbiased search process, all the search results obtained in the chosen academic databases were uploaded to a reference management tool, which helped eliminate duplicates among the sources automatically. After removing duplication, the authors carried out the two-stage screening independently. The initial step was searching and reading the titles and abstracts to remove the unwanted research, including those that have nothing to do with IoT, routing protocols, or energy efficiency of the IoT system. Articles that were unclear as to their relevance at this level were kept to be reviewed in their full text. The second step involved a full text evaluation to ensure that every article fitted the inclusion criteria. We were recording the reasons for exclusion during this stage as well. Papers were excluded if they were: Failure to use energy-efficient routing in an IoT or WSN environment. Didn't do quantitative performance evaluation (e.g., energy consumption, latency, packet delivery). Only dedicated to hardware designs or irrelevant network technologies. Talked about generic networking issues without mentioning modes of energy or routing. Clarity, relevance, and methodological rigor of all selected papers were reviewed. The final source pool was academically sound as the search confined itself to peer-reviewed journals and proceedings of the conference published in the reliable databases. Figure\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e (PRISMA Flow Diagram) shows the study selection process. The database search identified 180 records. The duplicates were eliminated, and 150 new records were left. After screening the titles and abstracts, 100 records were removed. The 50 full-text articles obtained were evaluated for their eligibility, of which 18 were excluded due to non-eligibility. Finally, the synthesis comprised 32 studies.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eIncluded in the search results, the 32 articles selected to form the final pool of this systematic literature review cover 2017\u0026ndash;2025 as the latest years of studies, with the years of research in that time frame showing growth in the decade. We found a significant focus in 2024 (25% of the total articles), and the same level of contributions during 2021\u0026ndash;2025. This trend indicates that there is an increasing academically perceived interest in undertaking research in energy-efficient routing in an IoT landscape. The annual breakdown of included studies is shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eYearly distribution of articles used for the SLR\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYear\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNumber of Articles\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePercentage\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2017\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.3%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2018\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.1%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2019\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.3%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2020\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9.4%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2021\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12.5%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2022\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12.5%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2023\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12.5%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2024\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e25.0%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2025\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12.5%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003e32\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003e100\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"4. Results","content":"\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003e4.1 Categorization of Frequently Used Energy-Efficient Routing Protocols\u003c/h2\u003e\u003cp\u003eThe systematic literature review revealed various low-energy routing protocols often used in IoT networks between 2017 and 2025. A notable example was RPL (Routing Protocol for Low-Power and Lossy Networks), with its hierarchical, IPv6-based protocol and user-definable objective functions, which would be used in a large number of constrained network contexts. LEACH and L3EACH-V2 (the latter being a variant of the former), are cluster-based protocols characterized by their low-overhead data transfer and energy-efficient clustering algorithm implementation. Since 2023, routing protocols based on AI became widespread, including those based on Grey Wolf Optimization (GWO) and the Salp Swarm Algorithm (SSA), in which the optimal routing paths are optimized in real-time using machine learning. In the meantime, hybrid systems such as HEERPOP and ESEERP provided additional power savings due to multi-path routing and integrated security. The range of protocols, including those based on a chain, SDN, and UAV, indicates the transformative nature of routing strategies that are increasingly adjusted to meet the new requirements and use cases of various IoT applications and deployment settings. These protocols differ in architecture, optimization strategies, and applicability in various IoT uses. Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e provides an overview of the most commonly used energy-saving routing protocols found in the literature reviewed. The protocols are organized by the type in which they can be separated, followed by major design features and the time frame in which they were most widely researched. Traceability and validation sources are given. This tabular presentation aids in tracing major tendencies and new breakthroughs in the sphere of energy-efficient routing in IoT settings\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eFrequently Utilized Energy-Efficient Routing Protocols in IoT Networks (2017\u0026ndash;2025)\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProtocol\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eType\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eKey Features\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eYears Highlighted\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eReference\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRouting Protocol for Low-Power and Lossy Networks (RPL)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHierarchical\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eIPv6 support, flexible objective functions (OFs), and reliable LLNs\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2019, 2024\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLow-Energy Adaptive Clustering Hierarchy\u003c/p\u003e\u003cp\u003e(LEACH)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCluster-based\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRotating cluster heads, low overhead, baseline WSN protocol\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2017, 2023, 2024\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePower-Efficient GAthering\u003c/p\u003e\u003cp\u003eSensor Information System\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eChain-based\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSequential transmission, reduced node-to-node distance\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2018, 2022\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTEEN/APTEEN\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eThreshold-based\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eReactive protocol, transmits only significant data\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2020, 2022\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLightweight On-demand Ad hoc Distance-Vector Next Generation\u003c/p\u003e\u003cp\u003e(LOADng)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eReactive\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLightweight protocol for constrained IoT devices\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2019\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eESEERP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSecure Cluster\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMulti-path, QoS-aware, energy-efficient, secure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2022\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHEERPOP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHybrid\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMulti-path, QoS-aware, energy-efficient, secure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2024\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRVRR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSDN-based\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eIn-network reducer routing, energy savings, and low RTT\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2024\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAI-Based Protocol\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMetaheuristic/ Intelligent\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eUses ML, fuzzy logic, evolutionary algorithms (e.g., GWO, SSA)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2023\u0026ndash;2025\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eL3EACH-V2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCluster-based\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLocal ID reuse, preamble modulation, underwater IoT, and high energy savings\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2023\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePriNergy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eRPL-based (QoS-aware)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eContent-prioritized routing, TDMA optimization, multimedia support\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2020\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUEE-RPL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eUAV-assisted Hierarchical\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eDual-mode UAV routing, energy-quality metrics (EEQ, DEQ), delay-efficient\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2021\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003e4.2 Performance Evaluation Based on Energy Consumption, Delay, and Security\u003c/h2\u003e\u003cp\u003eThese energy-efficient routing protocols provide varying results when compared to essential parameters that include energy consumption, latency, and security. This subsection provides a presentation of how protocols fare in these critical dimensions. Regarding energy consumption, the majority of cluster- and chain-based protocols, including LEACH, L3EACH-V2, and PEGASIS, performed very well, decreasing node-to-node communication distances and enabling sleep scheduling[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. RPL also exhibited high levels of energy optimization, especially in loss networks. The models of AI-intense routing, such as GWO-based and SSA-based models, significantly and always in normal routing mode, excelled their traditional counterparts in adaptive energy-saving, in particular, in the case of dynamic topologies. Another important performance indicator was latency or delay. Reactive protocols like TEEN and APTEEN were expected to only send out data when critical threshold conditions were encountered, hence low latency in data transmission [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Using UAVs to work out hierarchical routing, UEE-RPL showed that data forwarding incurred fewer delays compared to other schemes[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. RVRR software-defined networking (SDN-based protocol) to further reduce round-trip delays, integrated in-network data reduction [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Other protocols, like TEEN and APTEEN, were devised to be reactive, and they sent blocks only when extreme threshold conditions were exceeded, which led to low data latency. UEE-RPL that hierarchically routes them with UAVs exhibited less delay in data forwarding. Software-defined networking (SDN)-based protocol RVRR then incorporates in-network data reduction to reduce round-trip delays further, and applies to real-time IoT applications. Security protection is the most poorly supported component in most protocols. Conventional protocols such as LEACH and TEEN have no inbuilt security measures, and the secure deployment needs extra overheads. However, more recent protocols, like HEERPOP, ESEERP, and PriNergy, included encryption, Qos-aware, and content prioritization techniques and saw enhanced security functionality [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e], [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Conventional protocols such as LEACH and TEEN have no inbuilt security measures, and the secure deployment needs extra overheads. Yet new protocols, like HEERPOP, ESEERP, and PriNergy, have included encryption, QoS-aware (quality of service), and content-prioritization processes, which have better security characteristics. The use of security, however, may add extra computational expenses, which may compromise energy efficiency in constrained devices.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePerformance Evaluation Based on Energy Consumption, Delay, and Security\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProtocol\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEnergy Consumption\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eDelay Performance\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSecurity Support\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRPL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHigh efficiency\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLow\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLEACH\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eModerate-high\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLow\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLow\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTEEN/APTEEN\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHigh (Threshold)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eVery Low\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLow\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHEERPOP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003ehigh\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eESEERP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAI-Based\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVery high (ML-based)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRVRR(SDN)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ehigh\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLow RTT\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUEE-RPL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ehigh\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eVery Low\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePriNergy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLow\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eModerate \u0026ndash; high\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\u003ch2\u003e4.3 Trade-Offs and Implementation Considerations\u003c/h2\u003e\u003cp\u003eThe protocols discussed have underlying tradeoffs between energy efficiency, delay reduction, and security design [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. These trade-offs and practical implications of IoT deployment are discussed in this subsection. To explain these trade-offs further, Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e provides a synthesis of the literature on the performance of various protocols in the areas of energy efficiency, latency, security, and the generic implementation approach. Each protocol can be viewed comparatively in the table, highlighting the strengths and limitations. As an example, roadmaps such as HEERPOP and ESEERP exhibit high levels of security and energy efficiency, but with the drawback of high implementation complexity, which is well suited to high-stakes applications that consume more computational resources. Conversely, the solutions provided by less-complex protocols like LEACH and TEEN/APTEEN, although being low-complexity protocols with low latency, do not lend themselves well to sensitive applications due to security sacrifice. The AI-supported and UAV-supported protocols demonstrate promising results with high levels of adaptability and performance under changing conditions but might demand more specific infrastructure and increased processing capabilities. This comparison profile will be instrumental in helping researchers and developers to choose unique best-fit routing protocols to the conditions of various IoT applications.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eTrade-Offs and Implementation Considerations\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProtocol\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEnergy Efficiency\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eDelay Performance\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSecurity Support\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eImplementation Complexity\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHEERPOP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eESEERP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAI-Based\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVery High\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLEACH\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eModerate-High\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLow\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLow\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eLow\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTEEN/APTEEN\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003cp\u003e(Threshold-based)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eVery low\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLow\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eLow\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUEE-RPL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHigh\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eVery Low\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eAlso, deployment context plays a significant role in determining a protocol. Specifically, reactive protocols such as TEEN can work well when time is of concern (e.g., industrial monitoring), whereas UAV-supported protocols like UEE-RPL might be more suited to mobile and aerial networks. There is a lack of coherent evaluation metrics of protocols in the literature, which makes it difficult to standardize comparisons; thus, implementing frameworks of benchmarks could be considered in future works.\u003c/p\u003e\u003c/div\u003e"},{"header":"5. Discussion","content":"\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e\u003ch2\u003e5.1. Protocol Design Diversity and Trends\u003c/h2\u003e\u003cp\u003eThe outcome of this systematic literature review provides results that inform about the challenges and opportunities amid developing and deploying energy-efficient routing protocols within IoT networks. The classification of protocols underscores the variety of methods employed, including clustering and chain-based routing, AI-empowered and SDN-aided [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e], [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. This diversity is representative of the diversity of performance needs and environmental limitations encountered in practical IoT systems. The sheer prevalence of RPL and LEACH in published literature designates their seminal status, but more recent protocols such as HEERPOP, ESEERP, and AI-based models are becoming popular because of their enhanced efficiency and adaptability [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e], [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\u003ch2\u003e5.2. Performance Analysis: Energy, Delay, and Security\u003c/h2\u003e\u003cp\u003eEnergy usage is a predominant issue, sometimes taking preference over latency or security. Energy-efficient protocols such as LEACH and PEGASIS rely on data aggregation and node rotation and are therefore restricted in terms of providing secure and low-latency communication [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Hybrid protocols (e.g., HEERPOP and ESEERP), on the other hand, and models with AI offer a more even solution, where QoS and basic security options are accompanied by energy savings. Their complexity and computational requirements also might not be compatible with low power settings [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e], [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Latency-based protocols like TEEN and UEE-RPL have the advantage of real-time data processing, but might drop updates that do not present specific consequences or have the overhead of extra infrastructure such as UAVs [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Despite AI-based solutions fitting the dynamics of networks relatively well, they are quite resource-intensive and can cause learning-induced delay. The fact that no universal protocols score universally high shows that performance is highly contextual.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e\u003ch2\u003e5.3. Performance Analysis: Energy, Delay, and Security\u003c/h2\u003e\u003cp\u003eSecurity is a significant issue in the design of routing protocols. Not many protocols have built-in encryption or prioritization strategies. The majority relies on an external layer to provide data security, which further complicates the overall design of systems and can impact energy performance [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. This presents a possibility of cross-layer protocol designs focusing on combining energy efficiency and lightweight, in-protocol security features.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec19\" class=\"Section2\"\u003e\u003ch2\u003e5.4. Contextual Suitability and Future Direction\u003c/h2\u003e\u003cp\u003eThe review signifies the importance of end-to-end, application-conscious protocol design. Depending on deployment requirements in terms of topology, node capacity, mobility, and sensitivity of the data being transmitted, protocol designers need to balance trade-offs in terms of energy consumed, latency, and security. The work in the future should be concentrated under adaptive and scalable solutions, where an optimization of cross-layer as well as the real-world validation should be encompassed to provide further robustness and practicality in routing protocols in various IoT applications.\u003c/p\u003e\u003c/div\u003e"},{"header":"6. Conclusion","content":"\u003cp\u003eThe present systematic literature review presents analyses of 32 peer-reviewed articles published in 2017\u0026ndash;2025, covering the topic of energy-efficient routing protocols within IoT networks. Three decisive research questions guided the study: what are the widely adopted protocols, how well do they fare regarding energy consumption, latency, and security, and what are their trade-off characteristics? It was established in the review that the widely used protocols like RPL, LEACH, TEEN, and hybrid schemes like HEERPOP and ESEERP have been used because of their energy-conservation features and structural optimization potentials. But no scheme performed well in all measurements. Although some protocols emphasize their low energy consumption, they tend to lack delay mitigation or security measures. On the other hand, those with more secure protocols would consume more computation resources, and therefore, they would be less compatible with limited devices. The results indicate that protocol choice in IoT is context-specific. Design decisions must reflect the needs of a given application, real-time communication, sensitive data, or device constraints. Moreover, not many protocols have extensively incorporated native security tools, which leads to the urgent necessity of lightweight, extensible, and dynamic solutions.\u003c/p\u003e\u003cdiv id=\"Sec21\" class=\"Section2\"\u003e\u003ch2\u003e6.1. Limitations of the Study\u003c/h2\u003e\u003cp\u003eAlthough the research was conducted as per PRISMA 2020 to guarantee methodological rigor, it is worth mentioning a few limitations. First, being restricted to English publications and published (grey) literature might have reduced the range of reflective perspectives included in this review. Second, the search itself was limited by date and type to peer-reviewed articles within 2017\u0026ndash;2025, which could either miss the earlier formative texts or the latest breakthroughs after the search date. The study also omitted those protocols that had not been explicitly focused on energy-efficient protocols, potentially at the expense of routing models that might be successful in practice but not formulated in the context of energy-saving requirements.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec22\" class=\"Section2\"\u003e\u003ch2\u003e6.2. Future Research\u003c/h2\u003e\u003cp\u003eIn future work, more emphasis should be placed on creating holistic routing schemes that establish a balance between energy, performance, and security, and are scalable and feasible to implement. Benchmarking models and practical validation will also be critical to the development of energy-efficient routing protocol design and selection within next-generation IoT networks.\u003c/p\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was received to support this study\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003e1. Substantial contributions to concept or designAcquisition, analysis, or interpretation of dataDrafting of the manuscriptCritical review of the manuscript for important intellectual contentAgreed to be accountable for all aspects of the workWill review the final version to be published2. Substantial contributions to concept or designAcquisition, analysis, or interpretation of dataCritical review of the manuscript for important intellectual contentAgreed to be accountable for all aspects of the workWill review the final version to be published3. Substantial contributions to concept or designCritical review of the manuscript for important intellectual contentAgreed to be accountable for all aspects of the workWill review the final version to be publishedSupervised the work4. Substantial contributions to concept or designCritical review of the manuscript for important intellectual contentAgreed to be accountable for all aspects of the workWill review the final version to be publishedSupervised the work\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eZhang, J. A., et al. (2021). Enabling joint communication and radar sensing in mobile networks\u0026mdash;A survey. \u003cem\u003eIeee Communication Surveys And Tutorials\u003c/em\u003e, \u003cem\u003e24\u003c/em\u003e(1), 306\u0026ndash;345.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMouha, R. A. R. A. (2021). Internet of things (IoT). \u003cem\u003eJ Data Anal Inf Process\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(02), 77.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKaur, G., Chanak, P., \u0026amp; Bhattacharya, M. (2021). Energy-efficient intelligent routing scheme for IoT-enabled WSNs. \u003cem\u003eIEEE Internet Things J\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e(14), 11440\u0026ndash;11449.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYadav, R. and V. and, \u0026amp; Kumar, A. (May 2024). Systematic Review Paper on Energy-Efficient Routing Protocols in Internet of Things. \u003cem\u003eIETE J Res\u003c/em\u003e, \u003cem\u003e70\u003c/em\u003e(5), 4721\u0026ndash;4743. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1080/03772063.2023.2230169\u003c/span\u003e\u003cspan address=\"10.1080/03772063.2023.2230169\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSuryawanshi, V. (Sep. 2024). Advancements in IoT Routing and Energy Efficiency: A Comprehensive Review of Algorithms and Technologies. \u003cem\u003eSci Manag Des J\u003c/em\u003e, \u003cem\u003e2\u003c/em\u003e(3). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.70295/SMDJ.2409024\u003c/span\u003e\u003cspan address=\"10.70295/SMDJ.2409024\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBekal, P., Kumar, P., Mane, P. R., \u0026amp; Prabhu, G. (2024). A comprehensive review of energy efficient routing protocols for query driven wireless sensor networks [version 3; peer review: 2 approved].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMagubane, Z., Tarwireyi, P., \u0026amp; Adigun, M. O., Evaluating the Energy Efficiency of IoT Routing Protocols, in 2019 \u003cem\u003eInternational Multidisciplinary Information Technology and Engineering\u003c/em\u003e Conference \u003cem\u003e(IMITEC)\u003c/em\u003e, Nov. 2019, pp. 1\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1109/IMITEC45504.2019.9015904\u003c/span\u003e\u003cspan address=\"10.1109/IMITEC45504.2019.9015904\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDubey, A., \u0026amp; Yadav, S. K. (Oct. 2024). Basics of Internet of Things. \u003cem\u003eINTERNATIONAL J Sci Res Eng Manag\u003c/em\u003e, \u003cem\u003e08\u003c/em\u003e(10), 1\u0026ndash;6. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.55041/IJSREM37970\u003c/span\u003e\u003cspan address=\"10.55041/IJSREM37970\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUd Din, I., et al. (2019). The Internet of Things: A Review of Enabled Technologies and Future Challenges. \u003cem\u003eIeee Access : Practical Innovations, Open Solutions\u003c/em\u003e, \u003cem\u003e7\u003c/em\u003e, 7606\u0026ndash;7640. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1109/ACCESS.2018.2886601\u003c/span\u003e\u003cspan address=\"10.1109/ACCESS.2018.2886601\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eA. T. S, Energy-Efficient IoT Networks: Optimizing Resource Management through Machine Learning, \u003cem\u003eCommun. Appl. Nonlinear Anal.\u003c/em\u003e, vol. 32, no. 1s, Art. no. 1s, (2025). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.52783/cana.v32.2168\u003c/span\u003e\u003cspan address=\"10.52783/cana.v32.2168\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKaur, N., \u0026amp; Sood, S. K. (Jun. 2017). An Energy-Efficient Architecture for the Internet of Things (IoT). \u003cem\u003eIeee Systems Journal\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e(2), 796\u0026ndash;805. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1109/JSYST.2015.2469676\u003c/span\u003e\u003cspan address=\"10.1109/JSYST.2015.2469676\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMwewa, W., \u0026amp; Lubobya, S. C. (Mar. 2022). Performance Evaluation of Routing Protocols in Enterprise Networks. \u003cem\u003eAm J Comput Eng\u003c/em\u003e, \u003cem\u003e5\u003c/em\u003e(1), 24\u0026ndash;35. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.47672/ajce\u003c/span\u003e\u003cspan address=\"10.47672/ajce\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRani, P., \u0026amp; Sangwan, A. A Review on Routing Protocols in Wireless Sensor Networks. \u003cem\u003eEng Technol\u003c/em\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePage, M. J., et al. (Mar. 2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. \u003cem\u003ePLOS Med\u003c/em\u003e, \u003cem\u003e18\u003c/em\u003e(3), e1003583. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1371/journal.pmed.1003583\u003c/span\u003e\u003cspan address=\"10.1371/journal.pmed.1003583\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGoswami, P., et al. (Feb. 2022). AI-Based Energy Efficient Routing Protocol for Intelligent Transportation System. \u003cem\u003eIeee Transactions On Intelligent Transportation Systems\u003c/em\u003e, \u003cem\u003e23\u003c/em\u003e(2), 1670\u0026ndash;1679. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1109/TITS.2021.3107527\u003c/span\u003e\u003cspan address=\"10.1109/TITS.2021.3107527\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYadav, R., \u0026amp; Kumar, V. (May 2024). A Systematic Review Paper on Energy-Efficient Routing Protocols in Internet of Things. \u003cem\u003eIETE J Res\u003c/em\u003e, \u003cem\u003e70\u003c/em\u003e(5), 4721\u0026ndash;4743. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1080/03772063.2023.2230169\u003c/span\u003e\u003cspan address=\"10.1080/03772063.2023.2230169\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDass, R., et al. (Jul. 2023). A Cluster-Based Energy-Efficient Secure Optimal Path-Routing Protocol for Wireless Body-Area Sensor Networks. \u003cem\u003eSensors (Basel, Switzerland)\u003c/em\u003e, \u003cem\u003e23\u003c/em\u003e(14), 6274. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/s23146274\u003c/span\u003e\u003cspan address=\"10.3390/s23146274\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShial, R. K., Rath, P., Patnaik, S. R., \u0026amp; Ghuar, U. (2024). HEERPOP: Hybrid Energy Efficiency Routing Protocol for Optimal Path in the Internet of Things-Based Sensor Networks, \u003cem\u003eInt. J. Comput. Netw. Appl.\u003c/em\u003e, vol. 11, no. 4, pp. 494\u0026ndash;505, Aug. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.22247/ijcna/2024/31\u003c/span\u003e\u003cspan address=\"10.22247/ijcna/2024/31\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDogra, R., Rani, S., Kavita, J., Shafi, S., Kim, \u0026amp; Ijaz, M. F. (Aug. 2022). Enhanced Smart Energy Efficient Routing Protocol for Internet of Things in Wireless Sensor Nodes. \u003cem\u003eSensors (Basel, Switzerland)\u003c/em\u003e, \u003cem\u003e22\u003c/em\u003e(16), 6109. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/s22166109\u003c/span\u003e\u003cspan address=\"10.3390/s22166109\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHadi, T. H. (Apr. 2024). IoT Protocols: Connecting Devices in Smart Environments. \u003cem\u003eICST Trans Scalable Inf Syst\u003c/em\u003e. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.4108/eetsis.5665\u003c/span\u003e\u003cspan address=\"10.4108/eetsis.5665\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGhazy, A. S., Kaddoum, G., \u0026amp; Singh, S. (2023). Low-Latency Low-Energy Adaptive Clustering Hierarchy Protocols for Underwater Acoustic Networks. \u003cem\u003eIeee Access : Practical Innovations, Open Solutions\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e, 50578\u0026ndash;50594. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1109/access.2023.3277395\u003c/span\u003e\u003cspan address=\"10.1109/access.2023.3277395\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSafara, F., Souri, A., Baker, T., Al Ridhawi, I., \u0026amp; Aloqaily, M. (2020). PriNergy: a priority-based energy-efficient routing method for IoT systems, \u003cem\u003eJ. Supercomput.\u003c/em\u003e, vol. 76, no. 11, pp. 8609\u0026ndash;8626, Nov. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11227-020-03147-8\u003c/span\u003e\u003cspan address=\"10.1007/s11227-020-03147-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYang, Z., Liu, H., Chen, Y., Zhu, X., Ning, Y., \u0026amp; Zhu, W. (2021). UEE-RPL: A UAV-Based Energy Efficient Routing for Internet of Things, \u003cem\u003eIEEE Trans. Green Commun. Netw.\u003c/em\u003e, vol. 5, no. 3, pp. 1333\u0026ndash;1344, Sep. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1109/TGCN.2021.3085897\u003c/span\u003e\u003cspan address=\"10.1109/TGCN.2021.3085897\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDogra, R., Rani, S., \u0026amp; Gianini, G. (2023). REERP: A Region-Based Energy-Efficient Routing Protocol for IoT Wireless Sensor Networks, \u003cem\u003eEnergies\u003c/em\u003e, vol. 16, no. 17, p. 6248, Aug. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/en16176248\u003c/span\u003e\u003cspan address=\"10.3390/en16176248\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShial, R. K., Rath, P., Patnaik, S. R., \u0026amp; Ghuar, U. (2024). HEERPOP: Hybrid Energy Efficiency Routing Protocol for Optimal Path in the Internet of Things-Based Sensor Networks, \u003cem\u003eInt. J. Comput. Netw. Appl.\u003c/em\u003e, vol. 11, no. 4, pp. 494\u0026ndash;505, Aug. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.22247/ijcna/2024/31\u003c/span\u003e\u003cspan address=\"10.22247/ijcna/2024/31\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSuryawanshi, V. (Sep. 2024). Advancements in IoT Routing and Energy Efficiency: A Comprehensive Review of Algorithms and Technologies. \u003cem\u003eSci Manag Des J\u003c/em\u003e, \u003cem\u003e2\u003c/em\u003e(3). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.70295/SMDJ.2409024\u003c/span\u003e\u003cspan address=\"10.70295/SMDJ.2409024\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMagubane, Z., Tarwireyi, P., \u0026amp; Adigun, M. O., Evaluating the energy efficiency of IoT routing protocols, in 2019 \u003cem\u003eInternational Multidisciplinary Information Technology and Engineering\u003c/em\u003e Conference \u003cem\u003e(IMITEC)\u003c/em\u003e, IEEE, 2019, pp. 1\u0026ndash;7. Accessed: May 21, 2025. [Online]. Available: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://ieeexplore.ieee.org/abstract/document/9015904/?casa_token=cQSQ3suJzJ8AAAAA:p4sjyvMSD926_v3_4FHMewekyHjRebXaZ4jq77sJVI-8SkAAnZRrsaT484E7tJpywQadRxwi8WORVdiz\u003c/span\u003e\u003cspan address=\"https://ieeexplore.ieee.org/abstract/document/9015904/?casa_token=cQSQ3suJzJ8AAAAA:p4sjyvMSD926_v3_4FHMewekyHjRebXaZ4jq77sJVI-8SkAAnZRrsaT484E7tJpywQadRxwi8WORVdiz\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Routing Protocol, Energy Efficiency, Wireless Sensor Networks (WSNs), Internet of Things (IoT), Network Lifetime, Data Transmission","lastPublishedDoi":"10.21203/rs.3.rs-7611247/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7611247/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eWith the proliferation of the Internet of Things (IoT) in areas like healthcare, smart cities, and industrial automation systems, one herculean task that has been looming and must be addressed is the need to ensure that data transmission is energy-efficient because all IoT devices have limited resources. This article is a systematic literature review (SLR) of energy-efficient routing mechanisms designed to be used in IoT networks, and it focuses on comparing the energy-efficient routing schemes concerning their energy consumption, latency, and security parameters. The research protocol compiled 32 peer-reviewed scientific articles published between 2017 and 2025, following PRISMA guidelines and with strict inclusion and exclusion criteria. The results reveal that popular protocols like RPL, LEACH, TEEN/APTEEN, or AI-based solutions reflect different trade-offs. The cluster-based and chain-based approaches are known to minimize the energy consumed. In contrast, the hybrid protocols and the AI-based approaches provide trade-offs in optimizing the energy, delay, and security parameters, at the expense of complexity. The review also points out that there is a serious gap in the observance of integrated security mechanisms in numerous energy-oriented protocols. These results indicate that routing techniques that are adaptive and context-sensitive are required to comprehensively treat performance limitations of IoT. Researchers and practitioners who are interested in finding an optimal protocol choice and matching diverse IoT applications can draw important thoughts from the paper.\u003c/p\u003e","manuscriptTitle":"A Systematic Review of Energy-Efficient Routing Protocols for IoT Networks","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-16 14:27:58","doi":"10.21203/rs.3.rs-7611247/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ace0131a-4e04-4bd7-bb23-1d95a1e1d427","owner":[],"postedDate":"October 16th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-10-27T14:22:16+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-16 14:27:58","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7611247","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7611247","identity":"rs-7611247","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}