Frutos Escrig, David DeMarroquín Alonso, OlgaRosa Velardo, FernandoGervasi, Osvaldo2023-06-202023-06-202005Frutos Escrig, D., Marroquín Alonso, O. & Rosa Velardo, F. «Ubiquitous Systems and Petri Nets». Computational Science and Its Applications – ICCSA 2005, editado por Osvaldo Gervasi et al., vol. 3481, Springer Berlin Heidelberg, 2005, pp. 1156-66. DOI.org (Crossref), https://doi.org/10.1007/11424826_123.978-3-540-25861-210.1007/11424826_123https://hdl.handle.net/20.500.14352/53226Several years before the popularization of the Internet, Mark Weiser proposed the concept of ubiquitous computing with the purpose of enhancing the use of computers by making many computers available throughout the physical environment, but making them effectively invisible to the user. Nowadays, such idea affects all areas of computing science, including both hardware and software. In this paper, a formal model for ubiquitous systems based on Petri nets is introduced and motivated with examples and applications. This simple model allows the definition of two-level ubiquitous systems, composed of a collection of processor nets providing services, and a collection of process nets requesting those services. The modeled systems abstract from middleware details, such as service discovery protocols, and security infrastructures, such as PKI’s or trust policies, but not from mobility or component compatibility.engbook parthttps//doi.org/10.1007/11424826_123http://link.springer.com/content/pdf/10.1007%2F11424826_123open access004Informática (Informática)1203.17 Informática