{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T05:08:09Z","timestamp":1781672889366,"version":"3.54.5"},"reference-count":44,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2024,12,6]],"date-time":"2024-12-06T00:00:00Z","timestamp":1733443200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Future Internet"],"abstract":"<jats:p>The rapid advancement of Internet of Things (IoT) networks has revolutionized modern connectivity by integrating many low-power devices into various applications. As IoT networks expand, the demand for energy-efficient, batteryless devices becomes increasingly critical for sustainable future networks. These devices play a pivotal role in next-generation IoT applications by reducing the dependence on conventional batteries and enabling continuous operation through energy harvesting capabilities. However, several challenges hinder the widespread adoption of batteryless IoT devices, including the limited transmission range, constrained energy resources, and low spectral efficiency in IoT receivers. To address these limitations, reconfigurable intelligent surfaces (RISs) offer a promising solution by dynamically manipulating the wireless propagation environment to enhance signal strength and improve energy harvesting capabilities. In this paper, we propose a novel deep reinforcement learning (DRL) algorithm that optimizes the phase shifts of RISs to maximize the network\u2019s achievable rate while satisfying IoT devices\u2019 energy harvesting constraints. Our DRL framework leverages a novel six-dimensional chimp optimization algorithm (6DChOA) to fine-tune the hyper-parameters, ensuring efficient and adaptive learning. The proposed 6DChOA-DRL algorithm optimizes RIS phase shifts to enhance the received power of IoT devices while mitigating interference from direct and RIS-cascaded links. The simulation results demonstrate that our optimized RIS design significantly improves energy harvesting and achievable data rates under various system configurations. Compared to benchmark algorithms, our approach achieves higher gains in harvested power, an improvement in the data rate at a transmit power of 20 dBm, and a significantly lower root mean square error (RMSE) of 0.13 compared to 3.34 for standard RL and 6.91 for the DNN, indicating more precise optimization of RIS phase shifts.<\/jats:p>","DOI":"10.3390\/fi16120460","type":"journal-article","created":{"date-parts":[[2024,12,6]],"date-time":"2024-12-06T06:25:16Z","timestamp":1733466316000},"page":"460","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["A Novel Six-Dimensional Chimp Optimization Algorithm\u2014Deep Reinforcement Learning-Based Optimization Scheme for Reconfigurable Intelligent Surface-Assisted Energy Harvesting in Batteryless IoT Networks"],"prefix":"10.3390","volume":"16","author":[{"given":"Mehrdad","family":"Shoeibi","sequence":"first","affiliation":[{"name":"The WPI Business School, Worcester Polytechnic Institute, Worcester, MA 01605, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-3090-4134","authenticated-orcid":false,"given":"Anita Ershadi","family":"Oskouei","sequence":"additional","affiliation":[{"name":"School of Systems and Enterprises, Stevens Institute of Technology, Hoboken, NJ 07030, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0752-8054","authenticated-orcid":false,"given":"Masoud","family":"Kaveh","sequence":"additional","affiliation":[{"name":"Department of Information and Communication Engineering, Aalto University, 02150 Espoo, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Subashini, S., Kamalam, G.K., and Vanitha, P. (2024). A Survey of IoT in Healthcare: Technologies, Applications, and Challenges. Artificial Intelligence and Machine Learning, CRC Press.","DOI":"10.1201\/9781003388319-13"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"101228","DOI":"10.1016\/j.segan.2023.101228","article-title":"An efficient authentication protocol for smart grid communication based on on-chip-error-correcting physical unclonable function","volume":"36","author":"Kaveh","year":"2023","journal-title":"Sustain. Energy Grids Netw."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2440","DOI":"10.1016\/j.egyr.2023.01.085","article-title":"Key communication technologies, applications, protocols and future guides for IoT-assisted smart grid systems: A review","volume":"9","author":"Qays","year":"2023","journal-title":"Energy Rep."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1109\/JSYST.2023.3270620","article-title":"Industrial Internet of Things: A review of improvements over traditional SCADA systems for industrial automation","volume":"18","author":"Babayigit","year":"2023","journal-title":"IEEE Syst. J."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1928","DOI":"10.1080\/00207543.2023.2290229","article-title":"The applications of Internet of Things (IoT) in industrial management: A science mapping review","volume":"62","author":"Mu","year":"2024","journal-title":"Int. J. Prod. Res."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Spanoudakis, N.I., Akasiadis, C., Iatrakis, G., and Chalkiadakis, G. (2023). Engineering IoT-based open MAS for large-scale V2G\/G2V. Systems, 11.","DOI":"10.3390\/systems11030157"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Bathre, M., and Das, P.K. (2020, January 28\u201329). Review on an Energy Efficient, Sustainable and Green Internet of Things. Proceedings of the 2nd IEEE International Conference on Data, Engineering and Applications (IDEA), Bhopal, India.","DOI":"10.1109\/IDEA49133.2020.9170736"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"107385","DOI":"10.1016\/j.comnet.2020.107385","article-title":"Battery-less Internet of Things\u2013A survey","volume":"180","author":"Muratkar","year":"2020","journal-title":"Comput. Netw."},{"key":"ref_9","first-page":"1","article-title":"Intelligent Networking for Energy Harvesting Powered IoT Systems","volume":"20","author":"Zhang","year":"2024","journal-title":"ACM Trans. Sens. Netw."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Mishu, M.K., Rokonuzzaman, M., Pasupuleti, J., Shakeri, M., Rahman, K.S., Hamid, F.A., Tiong, S.K., and Amin, N. (2020). Prospective efficient ambient energy harvesting sources for iot-equipped sensor applications. Electronics, 9.","DOI":"10.3390\/electronics9091345"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Kaveh, M., Rostami Ghadi, F., J\u00e4ntti, R., and Yan, Z. (2023). Secrecy performance analysis of backscatter communications with side information. Sensors, 23.","DOI":"10.3390\/s23208358"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2021","DOI":"10.1109\/COMST.2023.3278239","article-title":"Backscatter communication meets practical battery-free Internet of Things: A survey and outlook","volume":"25","author":"Jiang","year":"2023","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"170","DOI":"10.23919\/ICN.2020.0013","article-title":"Backscatter technologies and the future of internet of things: Challenges and opportunities","volume":"1","author":"Yao","year":"2020","journal-title":"Intell. Converg. Netw."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2412","DOI":"10.1109\/LWC.2024.3416700","article-title":"Performance Analysis of FAS-Aided Backscatter Communications","volume":"13","author":"Ghadi","year":"2024","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Vougioukas, G., Dimitriou, A., Bletsas, A., and Sahalos, J. (2018). Practical energy harvesting for batteryless ambient backscatter sensors. Electronics, 7.","DOI":"10.3390\/electronics7060095"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"5593","DOI":"10.1109\/TVT.2022.3152269","article-title":"Capacity of backscatter communication under arbitrary fading dependence","volume":"71","author":"Ghadi","year":"2022","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Garg, N., and Garg, R. (2017, January 7\u20138). Energy harvesting in IoT devices: A survey. Proceedings of the 2017 IEEE International Conference on Intelligent Sustainable Systems (ICISS), Palladam, India.","DOI":"10.1109\/ISS1.2017.8389371"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"39530","DOI":"10.1109\/ACCESS.2021.3064066","article-title":"Energy harvesting techniques for Internet of Things (IoT)","volume":"9","author":"Sanislav","year":"2021","journal-title":"IEEE Access"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Elahi, H., Munir, K., Eugeni, M., Atek, S., and Gaudenzi, P. (2020). Energy harvesting towards self-powered IoT devices. Energies, 13.","DOI":"10.3390\/en13215528"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"109901","DOI":"10.1016\/j.rser.2020.109901","article-title":"Design architectures for energy harvesting in the Internet of Things","volume":"128","author":"Zeadally","year":"2020","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1109\/MCOM.2015.7120024","article-title":"Wireless energy harvesting for the Internet of Things","volume":"53","author":"Kamalinejad","year":"2015","journal-title":"IEEE Commun. Mag."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"4336","DOI":"10.1109\/JSEN.2018.2820644","article-title":"Power management for kinetic energy harvesting IoT","volume":"18","author":"Ju","year":"2018","journal-title":"IEEE Sens. J."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"109994","DOI":"10.1016\/j.nanoen.2024.109994","article-title":"Advancement in indoor energy harvesting through flexible perovskite photovoltaics for self-powered IoT applications","volume":"129","author":"Qamar","year":"2024","journal-title":"Nano Energy"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Soy, H. (2023). Coverage Analysis of LoRa and NB-IoT Technologies on LPWAN-Based Agricultural Vehicle Tracking Application. Sensors, 23.","DOI":"10.20944\/preprints202308.2037.v1"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"9970","DOI":"10.1109\/JIOT.2021.3050445","article-title":"Edge-based hybrid system implementation for long-range safety and healthcare IoT applications","volume":"8","author":"Wu","year":"2021","journal-title":"IEEE Internet Things J."},{"key":"ref_26","first-page":"14891","article-title":"Energy-efficient RIS-assisted satellites for IoT networks","volume":"9","author":"Kurt","year":"2021","journal-title":"IEEE Internet Things J."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"5415","DOI":"10.1109\/TII.2023.3333842","article-title":"Secrecy Performance Analysis of RIS-Aided Smart Grid Communications","volume":"20","author":"Kaveh","year":"2024","journal-title":"IEEE Trans. Ind. Inform."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"10162","DOI":"10.1109\/TWC.2022.3182773","article-title":"Energy-efficient power control and beamforming for reconfigurable intelligent surface-aided uplink IoT networks","volume":"21","author":"Wu","year":"2022","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1109\/TIV.2023.3337898","article-title":"Performance Analysis of RIS\/STAR-IOS-aided V2V NOMA\/OMA Communications over Composite Fading Channels","volume":"9","author":"Ghadi","year":"2024","journal-title":"IEEE Trans. Intell. Veh."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"23570","DOI":"10.1109\/JIOT.2022.3203890","article-title":"Reconfigurable intelligent surfaces for 6G IoT wireless positioning: A contemporary survey","volume":"9","author":"Chen","year":"2022","journal-title":"IEEE Internet Things J."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"103538","DOI":"10.1109\/ACCESS.2022.3209823","article-title":"Spectrum and energy-efficiency maximization in ris-aided iot networks","volume":"10","author":"Mondal","year":"2022","journal-title":"IEEE Access"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1109\/LWC.2022.3220158","article-title":"RIS-empowered ambient backscatter communication systems","volume":"12","author":"Galappaththige","year":"2022","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1350","DOI":"10.1109\/JIOT.2019.2954678","article-title":"Symbiotic radio: A new communication paradigm for passive Internet of Things","volume":"7","author":"Long","year":"2020","journal-title":"IEEE Internet Things J."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1296","DOI":"10.1109\/LCOMM.2018.2817555","article-title":"Blind channel estimation for ambient backscatter communication systems","volume":"22","author":"Ma","year":"2018","journal-title":"IEEE Commun. Lett."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"5394","DOI":"10.1109\/TWC.2019.2936025","article-title":"Intelligent reflecting surface enhanced wireless network via joint active and passive beamforming","volume":"18","author":"Wu","year":"2019","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1989","DOI":"10.1109\/TWC.2013.031813.120224","article-title":"MIMO broadcasting for simultaneous wireless information and power transfer","volume":"12","author":"Zhang","year":"2013","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"7656","DOI":"10.1109\/TCOMM.2022.3201119","article-title":"Mutualistic cooperative ambient backscatter communications under hardware impairments","volume":"70","author":"Ye","year":"2022","journal-title":"IEEE Trans. Commun."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1403","DOI":"10.1109\/OJCOMS.2020.3022316","article-title":"Performance analysis and resource allocations for a WPCN with a new nonlinear energy harvester model","volume":"1","author":"Wang","year":"2020","journal-title":"IEEE Open J. Commun. Soc."},{"key":"ref_39","unstructured":"Kay, S.M. (1993). Fundamentals of Statistical Signal Processing: Estimation Theory, Prentice-Hall."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"121101","DOI":"10.1007\/s11432-022-3696-5","article-title":"A survey on model-based reinforcement learning","volume":"67","author":"Luo","year":"2024","journal-title":"Sci. China Inf. Sci."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"120495","DOI":"10.1016\/j.eswa.2023.120495","article-title":"Reinforcement learning algorithms: A brief survey","volume":"231","author":"Shakya","year":"2023","journal-title":"Expert Syst. Appl."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"113338","DOI":"10.1016\/j.eswa.2020.113338","article-title":"Chimp optimization algorithm","volume":"149","author":"Khishe","year":"2020","journal-title":"Expert Syst. Appl."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Baniasadi, S., Salehi, R., Soltani, S., Mart\u00edn, D., Pourmand, P., and Ghafourian, E. (2023). Optimizing long short-term memory network for air pollution prediction using a novel binary chimp optimization algorithm. Electronics, 12.","DOI":"10.3390\/electronics12183985"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.inffus.2022.03.003","article-title":"Exploration in deep reinforcement learning: A survey","volume":"85","author":"Ladosz","year":"2022","journal-title":"Inf. Fusion"}],"container-title":["Future Internet"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1999-5903\/16\/12\/460\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:48:27Z","timestamp":1760114907000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1999-5903\/16\/12\/460"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,12,6]]},"references-count":44,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2024,12]]}},"alternative-id":["fi16120460"],"URL":"https:\/\/doi.org\/10.3390\/fi16120460","relation":{},"ISSN":["1999-5903"],"issn-type":[{"value":"1999-5903","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,12,6]]}}}