{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T15:49:08Z","timestamp":1774540148028,"version":"3.50.1"},"reference-count":49,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2019,12,19]],"date-time":"2019-12-19T00:00:00Z","timestamp":1576713600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Vehicular ad hoc networks (VANETs) are the key enabling technology for intelligent transportation systems. Carrier-sense multiple access with collision avoidance (CSMA\/CA) is the de facto media access standard for inter-vehicular communications, but its performance degrades in high-density networks. Time-division multiple access (TDMA)-based protocols fill this gap to a certain extent, but encounter inefficient clock synchronization and lack of prioritized message delivery. Therefore, we propose a priority-based direction-aware media access control (PDMAC) as a novel protocol for intra-cluster and inter-cluster clock synchronization. Furthermore, PDMAC pioneers a three-tier priority assignment technique to enhance warning messages delivery by taking into account the direction component, message type, and severity level on each tier. Analytical and simulation results validate the improved performance of PDMAC in terms of clock synchronization, channel utilization, message loss rate, end-to-end delays, and network throughput, as compared with eminent VANET MAC protocols.<\/jats:p>","DOI":"10.3390\/s20010045","type":"journal-article","created":{"date-parts":[[2019,12,23]],"date-time":"2019-12-23T03:15:01Z","timestamp":1577070901000},"page":"45","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":36,"title":["PDMAC: A Priority-Based Enhanced TDMA Protocol for Warning Message Dissemination in VANETs"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3836-1373","authenticated-orcid":false,"given":"Ghulam","family":"Abbas","sequence":"first","affiliation":[{"name":"Faculty of Computer Science and Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640, Pakistan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ziaul Haq","family":"Abbas","sequence":"additional","affiliation":[{"name":"Faculty of Electrical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640, Pakistan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shahab","family":"Haider","sequence":"additional","affiliation":[{"name":"Telecommunications and Networking (TeleCoN) Research Lab, GIK Institute of Engineering Sciences and Technology, Topi 23640, Pakistan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5166-4873","authenticated-orcid":false,"given":"Thar","family":"Baker","sequence":"additional","affiliation":[{"name":"Department of Computer Science, Faculty of Engineering and Technology, Liverpool John Moores University, Liverpool L3 3AF, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Saadi","family":"Boudjit","sequence":"additional","affiliation":[{"name":"Laboratoire de Traitement et Transport de l\u2019Information Lab (L2TI), Institut Galil\u00e9e, University of Paris 13, 99 Av J-Baptiste Cl\u00e9ment, 93430 Villetaneuse, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0405-0083","authenticated-orcid":false,"given":"Fazal","family":"Muhammad","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, City University of Science and Information Technology, Peshawar 25000, Pakistan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,12,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"657","DOI":"10.1109\/COMST.2016.2611524","article-title":"A comparative survey of VANET clustering techniques","volume":"19","author":"Cooper","year":"2016","journal-title":"IEEE Commun. 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