doi:10.1109/JIOT.2025.3539786engOrtín, JorgeGállego, José RamónCanales, MaríaModeling the Coexistence of LECIM ALOHA PCA and CSMA/CA in Unslotted IEEE 802.15.4 NetworksART-2025-143065Wireless sensor networks are pivotal in critical infrastructure monitoring due to their cost-effectiveness and real-time data processing capabilities. The IEEE 802.15.4 standard, especially the Low Energy Critical Infrastructure Monitoring (LECIM) portions, plays a crucial role in enhancing monitoring efficiency of critical infrastructure. LECIM introduces Priority Channel Access (PCA) for traffic prioritization, particularly beneficial for critical information transmission. This paper investigates the coexistence of CSMA/CA-based nodes transmitting non-priority data and LECIM ALOHA PCA nodes handling critical information in unslotted IEEE 802.15.4 networks. We propose a novel theoretical framework to evaluate the performance of a heterogeneous LECIM network, where some nodes use the CSMA/CA channel access method while others use LECIM ALOHA PCA. The performance is measured in terms of reliability, delay and power consumption. Validation of the theoretical framework is conducted using a system-level simulator.2025http://zaguan.unizar.es/record/15136910.1109/JIOT.2025.3539786http://zaguan.unizar.es/record/151369oai:zaguan.unizar.es:151369info:eu-repo/grantAgreement/ES/DGA/T31-20Rinfo:eu-repo/grantAgreement/ES/MCINN/PID2022-136476OB-I00IEEE INTERNET OF THINGS JOURNAL (2025), [18 pp.]byhttps://creativecommons.org/licenses/by/4.0/deed.esinfo:eu-repo/semantics/openAccess