{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T18:22:46Z","timestamp":1776882166799,"version":"3.51.2"},"reference-count":43,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2023,5,23]],"date-time":"2023-05-23T00:00:00Z","timestamp":1684800000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China (NSFC)","award":["62001269"],"award-info":[{"award-number":["62001269"]}]},{"name":"National Natural Science Foundation of China (NSFC)","award":["RCS2022K009"],"award-info":[{"award-number":["RCS2022K009"]}]},{"name":"State Key Laboratory of Rail Traffic Control and Safety","award":["62001269"],"award-info":[{"award-number":["62001269"]}]},{"name":"State Key Laboratory of Rail Traffic Control and Safety","award":["RCS2022K009"],"award-info":[{"award-number":["RCS2022K009"]}]},{"name":"Beijing Jiaotong University","award":["62001269"],"award-info":[{"award-number":["62001269"]}]},{"name":"Beijing Jiaotong University","award":["RCS2022K009"],"award-info":[{"award-number":["RCS2022K009"]}]},{"name":"Future Plan Program for Young Scholars of Shandong University","award":["62001269"],"award-info":[{"award-number":["62001269"]}]},{"name":"Future Plan Program for Young Scholars of Shandong University","award":["RCS2022K009"],"award-info":[{"award-number":["RCS2022K009"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Regarding the new demands and challenges of sixth-generation (6G) mobile communications, wireless networks are undergoing a significant shift from traditional terrestrial networks to space-air-ground-sea-integrated networks. Unmanned aerial vehicle (UAV) communications in complicated mountainous scenarios are typical applications and have practical implications, especially in emergency communications. In this paper, the ray-tracing (RT) method was applied to reconstruct the propagation scenario and then acquire the wireless channel data. Channel measurements are also conducted in real mountainous scenarios for verification. By setting different flight positions, trajectories, and altitudes, channel data in the millimeter wave (mmWave) band was obtained. Important statistical properties, such as the power delay profile (PDP), Rician K-factor, path loss (PL), root mean square (RMS) delay spread (DS), RMS angular spreads (ASs), and channel capacity were compared and analyzed. The effects of different frequency bands on channel characteristics at 3.5 GHz, 4.9 GHz, 28 GHz, and 38 GHz bands in mountainous scenarios were considered. Furthermore, the effects of extreme weather, especially different precipitation, on the channel characteristics were analyzed. The related results can provide fundamental support for the design and performance evaluation of future 6G UAV-assisted sensor networks in complicated mountainous scenarios.<\/jats:p>","DOI":"10.3390\/s23114998","type":"journal-article","created":{"date-parts":[[2023,5,23]],"date-time":"2023-05-23T07:00:02Z","timestamp":1684825202000},"page":"4998","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":25,"title":["Channel Characterization and Modeling for 6G UAV-Assisted Emergency Communications in Complicated Mountainous Scenarios"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-2561-707X","authenticated-orcid":false,"given":"Zhaolei","family":"Zhang","sequence":"first","affiliation":[{"name":"School of Microelectronics, Shandong University, Jinan 250101, China"}]},{"given":"Yu","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Microelectronics, Shandong University, Jinan 250101, China"},{"name":"The State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing 100044, China"}]},{"given":"Jie","family":"Huang","sequence":"additional","affiliation":[{"name":"The National Mobile Communications Research Laboratory, School of Information Science and Engineering, Southeast University, Nanjing 210096, China"},{"name":"The Purple Mountain Laboratories, Nanjing 211111, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0425-0704","authenticated-orcid":false,"given":"Jingfan","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Microelectronics, Shandong University, Jinan 250101, China"}]},{"given":"Jingquan","family":"Li","sequence":"additional","affiliation":[{"name":"School of Microelectronics, Shandong University, Jinan 250101, China"}]},{"given":"Ruisi","family":"He","sequence":"additional","affiliation":[{"name":"The State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing 100044, China"}]}],"member":"1968","published-online":{"date-parts":[[2023,5,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Wang, C.X., You, X., Gao, X., Zhu, X., Li, Z., Zhang, C., Wang, H., Huang, Y., Chen, Y., and Haas, H. (2023). On the road to 6G: Visions, requirements, key technologies and testbeds. IEEE Commun. Surv. Tutor.","DOI":"10.1109\/COMST.2023.3249835"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"6345","DOI":"10.1109\/TCOMM.2021.3088898","article-title":"Secrecy-energy efficient hybrid beamforming for satellite-terrestrial integrated networks","volume":"69","author":"Lin","year":"2021","journal-title":"IEEE Trans. Commun."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"3717","DOI":"10.1109\/TAES.2022.3155711","article-title":"Refracting RIS-aided hybrid satellite-terrestrial relay networks: Joint beamforming design and optimization","volume":"58","author":"Lin","year":"2022","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1109\/MCOM.2016.7470933","article-title":"Wireless communications with unmanned aerial vehicles: Opportunities and challenges","volume":"54","author":"Zeng","year":"2016","journal-title":"IEEE Commun. Mag."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2624","DOI":"10.1109\/COMST.2016.2560343","article-title":"Survey on unmanned aerial vehicle networks for civil applications: A communications viewpoint","volume":"18","author":"Hayat","year":"2016","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1109\/MWC.2018.1800160","article-title":"UAV-assisted emergency networks in disasters","volume":"26","author":"Zhao","year":"2019","journal-title":"IEEE Wireless Commun."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"657","DOI":"10.1109\/JSTSP.2019.2899731","article-title":"Joint beamforming and power allocation for satellite-terrestrial integrated networks with non-orthogonal multiple access","volume":"13","author":"Lin","year":"2019","journal-title":"IEEE J. Sel. Top. Signal Process."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"11123","DOI":"10.1109\/JIOT.2021.3051603","article-title":"Supporting IoT with rate-splitting multiple access in satellite and aerial-integrated networks","volume":"8","author":"Lin","year":"2021","journal-title":"IEEE Int. Things J."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3142","DOI":"10.1109\/COMST.2018.2862141","article-title":"A survey of 5G channel measurements and models","volume":"20","author":"Wang","year":"2018","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"9159","DOI":"10.1109\/TVT.2022.3179695","article-title":"Pervasive wireless channel modeling theory and applications to 6G GBSMs for all frequency bands and all scenarios","volume":"71","author":"Wang","year":"2022","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1109\/TITS.2017.2681112","article-title":"Measurements and analysis of angular characteristics and spatial correlation for high-speed railway channels","volume":"19","author":"Zhou","year":"2017","journal-title":"IEEE Trans. Intell. Transp. Syst."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1140","DOI":"10.1109\/TVT.2018.2886961","article-title":"An empirical air-to-ground channel model based on passive measurements in LTE","volume":"68","author":"Cai","year":"2018","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"7691","DOI":"10.1109\/JIOT.2022.3195512","article-title":"Radio channel measurements and characterization in substation scenarios for power grid Internet of Things","volume":"10","author":"Zhou","year":"2023","journal-title":"IEEE Int. Things J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3303","DOI":"10.1049\/iet-com.2020.0531","article-title":"Vehicular communication channel measurement, modelling, and application for beyond 5G and 6G","volume":"14","author":"Cheng","year":"2020","journal-title":"IET Commun."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"32","DOI":"10.23919\/JCC.2022.11.003","article-title":"AG channel measurements and characteristics analysis in hilly scenarios for 6G UAV communications","volume":"19","author":"Yu","year":"2022","journal-title":"China Commun."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Cui, Z., Briso-Rodr\u00edguez, C., Guan, K., and Zhong, Z. (2020, January 7\u201311). Ultra-wideband air-to-ground channel measurements and modeling in hilly environment. Proceedings of the ICC 2020\u20142020 IEEE International Conference on Communications (ICC), Dublin, Ireland.","DOI":"10.1109\/ICC40277.2020.9148768"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1913","DOI":"10.1109\/TVT.2016.2585504","article-title":"Air\u2013ground channel characterization for unmanned aircraft systems part II: Hilly and mountainous settings","volume":"66","author":"Sun","year":"2016","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"6607","DOI":"10.1109\/TVT.2017.2659651","article-title":"Air\u2013ground channel characterization for unmanned aircraft systems\u2014Part III: The suburban and near-urban environments","volume":"66","author":"Matolak","year":"2017","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Geise, R., Weiss, A., and Neubauer, B. (2018, January 3\u20136). Modulating features of field measurements with a UAV at millimeter wave frequencies. Proceedings of the 2018 IEEE Conference on Antenna Measurements & Applications (CAMA), Vasteras, Sweden.","DOI":"10.1109\/CAMA.2018.8530475"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Khawaja, W., Ozdemir, O., and Guvenc, I. (2017, January 24\u201327). UAV air-to-ground channel characterization for mmWave systems. Proceedings of the 2017 IEEE 86th Vehicular Technology Conference (VTC-Fall), Toronto, ON, Canada.","DOI":"10.1109\/VTCFall.2017.8288376"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Calvo-Ram\u00edrez, C., Cui, Z., Briso, C., Guan, K., and Matolak, D.W. (2018, January 16\u201318). UAV air-ground channel ray tracing simulation validation. Proceedings of the 2018 IEEE\/CIC International Conference on Communications in China (ICCC Workshops), Beijing, China.","DOI":"10.1109\/ICCChinaW.2018.8674482"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"5784","DOI":"10.1109\/TAP.2022.3161277","article-title":"Geometry-Based stochastic line-of-sight probability model for A2G channels under urban scenarios","volume":"70","author":"Zhu","year":"2022","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"17592","DOI":"10.1109\/JIOT.2022.3155773","article-title":"Machine-learning-based 3-D channel modeling for U2V mmWave communications","volume":"9","author":"Mao","year":"2022","journal-title":"IEEE Int. Things J."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Jiang, H., Xiong, B., Zhang, H., and Basar, E. (2023). Physics-based 3D end-to-end modeling for double-RIS assisted non-stationary UAV-to-ground communication channels. IEEE Trans. Commun.","DOI":"10.1109\/TCOMM.2023.3266832"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2992","DOI":"10.1109\/JSAC.2021.3088664","article-title":"A novel non-stationary 6G UAV channel model for maritime communications","volume":"39","author":"Liu","year":"2021","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"70719","DOI":"10.1109\/ACCESS.2019.2919790","article-title":"A 3D non-stationary wideband GBSM for low-altitude UAV-to-ground V2V MIMO channels","volume":"7","author":"Chang","year":"2019","journal-title":"IEEE Access"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"9865","DOI":"10.1109\/JIOT.2020.3018479","article-title":"A novel nonstationary 6G UAV-to-ground wireless channel model with 3-D arbitrary trajectory changes","volume":"8","author":"Chang","year":"2020","journal-title":"IEEE Int. Things J."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Mao, K., Zhu, Q., Song, M., Hua, B., Zhong, W., and Ye, X. (2020). A geometry-based beamforming channel model for UAV mmWave communications. Sensors, 20.","DOI":"10.3390\/s20236957"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"7232","DOI":"10.1109\/TCOMM.2020.3011716","article-title":"A Novel 3D UAV Channel Model for A2G Communication Environments Using AoD and AoA Estimation Algorithms","volume":"68","author":"Jiang","year":"2020","journal-title":"IEEE Trans. Commun."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"7055","DOI":"10.1109\/TCOMM.2022.3204032","article-title":"A mixed-bouncing based non-stationary model for 6G massive MIMO mmWave UAV channels","volume":"70","author":"Bai","year":"2022","journal-title":"IEEE Trans. Commun."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2048","DOI":"10.1109\/TWC.2022.3208635","article-title":"A non-stationary model with time-space consistency for 6G massive MIMO mmWave UAV channels","volume":"22","author":"Bai","year":"2023","journal-title":"IEEE Trans. Wireless Commun."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3103","DOI":"10.1109\/TCOMM.2023.3255900","article-title":"Channel modeling for UAV-to-ground communications with posture variation and fuselage scattering effect","volume":"71","author":"Hua","year":"2023","journal-title":"IEEE Trans. Commun."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Cui, Z., Guan, K., He, D., Ai, B., and Zhong, Z. (2019, January 20\u201324). Propagation modeling for UAV air-to-ground channel over the simple mountain terrain. Proceedings of the 2019 IEEE International Conference on Communications Workshops (ICC Workshops), Shanghai, China.","DOI":"10.1109\/ICCW.2019.8756679"},{"key":"ref_34","unstructured":"3GPP (2017). Study on Enhanced LTE Support for Aerial Vehicles (Release 15), 3GPP Mobile Competence Centre. 3GPP, Technical Report."},{"key":"ref_35","unstructured":"Remcom (2023, January 01). Wireless InSite. Available online: https:\/\/www.remcom.com\/wireless-insite-em-propagation-software."},{"key":"ref_36","unstructured":"USGS (2022, November 01). Global Land Cover Characteristics, Available online: https:\/\/www.usgs.gov\/media\/images\/global-land-cover-characteristics-data-base-version-20."},{"key":"ref_37","unstructured":"Electronic Publication ITU-R (2021). P. 2040-2. Effects of Building Materials and Structures on Radiowave Propagation above about 100 MHz, Electronic Publication. ITU Recommendations, Technical Report."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Zhang, C., Sun, J., Liu, Y., Zhang, W., and Wang, C.X. (2020, January 9\u201311). Channel characteristics analysis of 60 GHz wireless communications in staircase environments. Proceedings of the 2020 IEEE\/CIC International Conference on Communications in China (ICCC Workshops), Chongqing, China.","DOI":"10.1109\/ICCCWorkshops49972.2020.9209915"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Zhang, G., Cai, X., Fan, W., and Pedersen, G.F. (2020, January 15\u201320). A USRP-based channel sounder for UAV communications. Proceedings of the 2020 14th European Conference on Antennas and Propagation (EuCAP), Copenhagen, Denmark.","DOI":"10.23919\/EuCAP48036.2020.9135251"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1080\/01621459.1956.10501314","article-title":"Table of Percentage Points of Kolmogorov Statistics","volume":"51","author":"Miller","year":"1956","journal-title":"J. Am. Stat. Assoc."},{"key":"ref_41","unstructured":"Electronic Publication ITU-R (2005). P. 838-3. Specific Attenuation Model for Rain for Use in Prediction Methods, Electronic Publication. ITU Recommendations, Technical Report."},{"key":"ref_42","unstructured":"Electronic Publication ITU-R (2017). P. 530-17. Propagation Data and Prediction Methods Required for the Design of Terrestrial Line-of-Sight Systems, Electronic Publication. ITU Recommendations, Technical Report."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"4065","DOI":"10.1109\/TVT.2021.3071242","article-title":"Channel characterization and capacity analysis for THz communication enabled smart rail mobility","volume":"70","author":"Guan","year":"2021","journal-title":"IEEE Trans. Veh. Technol."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/11\/4998\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:40:16Z","timestamp":1760125216000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/11\/4998"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,5,23]]},"references-count":43,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2023,6]]}},"alternative-id":["s23114998"],"URL":"https:\/\/doi.org\/10.3390\/s23114998","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,5,23]]}}}