Resumen: We propose a modeling framework composed of a Markov chain and the related coupling equations to evaluate the performance of unslotted IEEE 802.15.4 wireless sensor networks based on CSMA/CA Medium Access Control. Different from the related literature, the proposed model is able to capture heterogeneous classes of nodes with class-specific traffic generation rate and includes a more refined calculation of the probability of finding the channel busy during the carrier sensing process. The proposed model is used to derive class-specific performance figures including the probability of a successful transmission and the average delay for a successful/unsuccessful transmission. Idioma: Inglés DOI: 10.1109/LWC.2018.2873347 Año: 2018 Publicado en: IEEE Wireless Communications Letters 8, 2 (2018), 380-383 ISSN: 2162-2337 Factor impacto JCR: 3.546 (2018) Categ. JCR: COMPUTER SCIENCE, INFORMATION SYSTEMS rank: 33 / 154 = 0.214 (2018) - Q1 - T1 Categ. JCR: ENGINEERING, ELECTRICAL & ELECTRONIC rank: 66 / 265 = 0.249 (2018) - Q1 - T1 Categ. JCR: TELECOMMUNICATIONS rank: 24 / 88 = 0.273 (2018) - Q2 - T1 Factor impacto SCIMAGO: 0.923 - Control and Systems Engineering (Q1) - Physics and Astronomy (miscellaneous) (Q1) - Electrical and Electronic Engineering (Q1)