{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T22:55:48Z","timestamp":1772751348780,"version":"3.50.1"},"reference-count":29,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2019,5,9]],"date-time":"2019-05-09T00:00:00Z","timestamp":1557360000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Deanship of Scientific Research","award":["RG-1438 ? 034"],"award-info":[{"award-number":["RG-1438 ? 034"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Drone base stations (DBSs) have received significant research interest in recent years. They provide a flexible and cost-effective solution to improve the coverage, connectivity, quality of service (QoS), and energy efficiency of large-area Internet of Things (IoT) networks. However, as DBSs are costly and power-limited devices, they require an efficient scheme for their deployment in practical networks. This work proposes a realistic mathematical model for the joint optimization problem of DBS placement and IoT users\u2019 assignment in a massive IoT network scenario. The optimization goal is to maximize the connectivity of IoT users by utilizing the minimum number of DBS, while satisfying practical network constraints. Such an optimization problem is NP-hard, and the optimal solution has a complexity exponential to the number of DBSs and IoT users in the network. Furthermore, this work also proposes a linearization scheme and a low-complexity heuristic to solve the problem in polynomial time. The simulations are performed for a number of network scenarios, and demonstrate that the proposed heuristic is numerically accurate and performs close to the optimal solution.<\/jats:p>","DOI":"10.3390\/s19092157","type":"journal-article","created":{"date-parts":[[2019,5,9]],"date-time":"2019-05-09T11:22:35Z","timestamp":1557400955000},"page":"2157","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["Joint Placement and Device Association of UAV Base Stations in IoT Networks"],"prefix":"10.3390","volume":"19","author":[{"given":"Ashfaq","family":"Ahmed","sequence":"first","affiliation":[{"name":"Department of Electrical &amp; Computer Engineering, COMSATS University Islamabad, Wah Campus, Wah Cantt 47040, Pakistan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3791-4140","authenticated-orcid":false,"given":"Muhammad","family":"Awais","sequence":"additional","affiliation":[{"name":"Department of Electrical &amp; Computer Engineering, COMSATS University Islamabad, Wah Campus, Wah Cantt 47040, Pakistan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4578-3849","authenticated-orcid":false,"given":"Tallha","family":"Akram","sequence":"additional","affiliation":[{"name":"Department of Electrical &amp; Computer Engineering, COMSATS University Islamabad, Wah Campus, Wah Cantt 47040, Pakistan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7737-1569","authenticated-orcid":false,"given":"Selman","family":"Kulac","sequence":"additional","affiliation":[{"name":"Department of Electrical-Electronics Engineering, Faculty of Engineering, Duzce University, Konuralp, Duzce 81620, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Musaed","family":"Alhussein","sequence":"additional","affiliation":[{"name":"Computer Engineering Department, College of Computer and Information Sciences, King Saud University, Riyadh 11543, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3647-8578","authenticated-orcid":false,"given":"Khursheed","family":"Aurangzeb","sequence":"additional","affiliation":[{"name":"Computer Engineering Department, College of Computer and Information Sciences, King Saud University, Riyadh 11543, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,5,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"384","DOI":"10.1109\/LWC.2017.2779483","article-title":"Strategic Densification with UAV-BSs in Cellular Networks","volume":"7","author":"Lagum","year":"2018","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_2","unstructured":"Yin, S., Tan, J., and Li, L. (2017). UAV-assisted Cooperative Communications with Wireless Information and Power Transfer. arXiv."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"569","DOI":"10.1109\/LWC.2014.2342736","article-title":"Optimal LAP Altitude for Maximum Coverage","volume":"3","author":"Kandeepan","year":"2014","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"656","DOI":"10.1016\/j.future.2018.01.011","article-title":"Platform for controlling and getting data from network connected drones in indoor environments","volume":"92","author":"Pereira","year":"2019","journal-title":"Future Gener. Comput. Syst."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1109\/MIC.2018.112102519","article-title":"Toward practical privacy-preserving analytics for IoT and cloud-based healthcare systems","volume":"22","author":"Sharma","year":"2018","journal-title":"IEEE Internet Comput."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"626","DOI":"10.1016\/j.future.2017.04.004","article-title":"A reliable IoT system for Personal Healthcare Devices","volume":"78","author":"Woo","year":"2018","journal-title":"Future Gener. Comput. Syst."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"888","DOI":"10.1109\/COMST.2015.2401597","article-title":"A Survey on Radio Resource Allocation in Cognitive Radio Sensor Networks","volume":"17","author":"Ahmad","year":"2015","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Yan, Y., and Xu, C. (2013, January 20\u201323). A Development Analysis of China\u2019s Intelligent Transportation System. Proceedings of the 2013 IEEE International Conference on Green Computing and Communications and IEEE Internet of Things and IEEE Cyber, Physical and Social Computing, Beijing, China.","DOI":"10.1109\/GreenCom-iThings-CPSCom.2013.183"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Sanchez-Gomez, J., Sanchez-Iborra, R., and Skarmeta, A. (2017, January 4\u20138). Transmission Technologies Comparison for IoT Communications in Smart-Cities. Proceedings of the GLOBECOM 2017\u20142017 IEEE Global Communications Conference, Singapore.","DOI":"10.1109\/GLOCOM.2017.8254530"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"4519","DOI":"10.1109\/TII.2018.2793350","article-title":"Secure Data Storage and Searching for Industrial IoT by Integrating Fog Computing and Cloud Computing","volume":"14","author":"Fu","year":"2018","journal-title":"IEEE Trans. Ind. Inform."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"434","DOI":"10.1109\/LWC.2017.2700840","article-title":"3-D Placement of an Unmanned Aerial Vehicle Base Station (UAV-BS) for Energy-Efficient Maximal Coverage","volume":"6","author":"Alzenad","year":"2017","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Kalantari, E., Shakir, M.Z., Yanikomeroglu, H., and Yongacoglu, A. (2017, January 21\u201325). Backhaul-aware robust 3D drone placement in 5G+ wireless networks. Proceedings of the 2017 IEEE International Conference on IEEE Communications Workshops (ICC Workshops), Paris, France.","DOI":"10.1109\/ICCW.2017.7962642"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Shakhatreh, H., Khreishah, A., Alsarhan, A., Khalil, I., Sawalmeh, A., and Othman, N.S. (2017, January 4\u20136). Efficient 3D placement of a UAV using particle swarm optimization. Proceedings of the 2017 8th International Conference on Information and Communication Systems (ICICS), Irbid, Jordan.","DOI":"10.1109\/IACS.2017.7921981"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Bor-Yaliniz, R.I., El-Keyi, A., and Yanikomeroglu, H. (2016, January 22\u201327). Efficient 3-D placement of an aerial base station in next generation cellular networks. Proceedings of the 2016 IEEE International Conference on Communications (ICC), Kuala Lumpur, Malaysia.","DOI":"10.1109\/ICC.2016.7510820"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Lu, J., Wan, S., Chen, X., and Fan, P. (2017, January 4\u20138). Energy-Efficient 3D UAV-BS Placement versus Mobile Users\u2019 Density and Circuit Power. Proceedings of the 2017 IEEE Globecom Workshops (GC Wkshps), Singapore.","DOI":"10.1109\/GLOCOMW.2017.8269064"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Kalantari, E., Yanikomeroglu, H., and Yongacoglu, A. (2016, January 18\u201321). On the Number and 3D Placement of Drone Base Stations in Wireless Cellular Networks. Proceedings of the 2016 IEEE 84th Vehicular Technology Conference (VTC-Fall), Montreal, QC, Canada.","DOI":"10.1109\/VTCFall.2016.7881122"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"604","DOI":"10.1109\/LCOMM.2016.2633248","article-title":"Placement Optimization of UAV-Mounted Mobile Base Stations","volume":"21","author":"Lyu","year":"2017","journal-title":"IEEE Commun. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1109\/LWC.2017.2752161","article-title":"3-D placement of an unmanned aerial vehicle base station for maximum coverage of users with different QoS requirements","volume":"7","author":"Alzenad","year":"2018","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_19","unstructured":"Azizi, A., Mokari, N., and Javan, M.R. (2017). Joint Radio Resource Allocation, 3D Placement and User Association of Aerial Base Stations in IoT Networks. arXiv."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1109\/TGCN.2017.2767203","article-title":"Resource allocation for energy harvesting-powered D2D communication underlaying UAV-assisted networks","volume":"2","author":"Wang","year":"2018","journal-title":"IEEE Trans. Green Commun. Netw."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Mignardi, S., Buratti, C., Bazzi, A., and Verdone, R. (2019). Trajectories and Resource Management of Flying Base Stations for C-V2X. Sensors, 19.","DOI":"10.3390\/s19040811"},{"key":"ref_22","unstructured":"Huo, Y., Dong, X., Lu, T., Xu, W., and Yuen, M. (2018). Distributed and multi-layer UAV network for the next-generation wireless communication. arXiv."},{"key":"ref_23","first-page":"36","article-title":"When UAV Swarm Meets Edge-Cloud Computing: The QoS Perspective","volume":"33","author":"Chen","year":"2019","journal-title":"IEEE Netw."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Lai, C.C., Chen, C.T., and Wang, L.C. (2019). On-Demand Density-Aware UAV Base Station 3D Placement for Arbitrarily Distributed Users with Guaranteed Data Rates. IEEE Wirel. Commun. Lett.","DOI":"10.1109\/LWC.2019.2899599"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Liu, X., Wang, J., Zhao, N., Chen, Y., Zhang, S., Ding, Z., and Yu, F.R. (2019). Placement and Power Allocation for NOMA-UAV Networks. IEEE Wirel. Commun. Lett.","DOI":"10.1109\/LWC.2019.2904034"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/j.jnca.2017.08.013","article-title":"Energy efficient device discovery for reliable communication in 5G-based IoT and BSNs using unmanned aerial vehicles","volume":"97","author":"Sharma","year":"2017","journal-title":"J. Netw. Comput. Appl."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Motlagh, N.H., Bagaa, M., and Taleb, T. (2016, January 4\u20138). UAV Selection for a UAV-Based Integrative IoT Platform. Proceedings of the 2016 IEEE Global Communications Conference (GLOBECOM), Washington, DC, USA.","DOI":"10.1109\/GLOCOM.2016.7842359"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Al-Hourani, A., Kandeepan, S., and Jamalipour, A. (2014, January 8\u201312). Modeling air-to-ground path loss for low altitude platforms in urban environments. Proceedings of the 2014 IEEE Global Communications Conference, Austin, TX, USA.","DOI":"10.1109\/GLOCOM.2014.7037248"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"590","DOI":"10.1016\/0377-2217(94)90257-7","article-title":"A global approach for general 0\u20131 fractional programming","volume":"73","author":"Li","year":"1994","journal-title":"Eur. J. Oper. Res."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/9\/2157\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:50:35Z","timestamp":1760187035000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/9\/2157"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,5,9]]},"references-count":29,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2019,5]]}},"alternative-id":["s19092157"],"URL":"https:\/\/doi.org\/10.3390\/s19092157","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,5,9]]}}}