Networked cybernetic and physical systems of the Internet of Things (IoT) immerse civilian and industrial infrastructures into an interconnected and dynamic web of hybrid and mobile devices. The key feature of such systems is the hybrid and tight coupling of mobile and pervasive discrete communications in a continuously evolving environment (discrete computations with predominant continuous dynamics). In the aim of ensuring the correctness and reliability of such heterogeneous infrastructures, we introduce the hybrid π -calculus ( H p C ), to formally capture both mobility, pervasiveness and hybridisation in infrastructures where the network topology and its communicating entities evolve continuously in the physical world. The π -calculus proposed by Robin Milner et al. is a process calculus that can model mobile communications and computations in a very elegant manner. The H p C we propose is a conservative extension of the classical π -calculus, i.e., the extension is “minimal”, and yet describes mobility, time and physics of systems, while allowing to lift all theoretical results (e.g. bisimulation) to the context of that extension. We showcase the H p C by considering a realistic handover protocol among mobile devices.

@article{paperbot3153,
  title = {HpC: A Calculus for Hybrid and Mobile Systems},
  author = {Xiong Xu and Jean-Pierre Talpin and Shuling Wang and Hao Wu and Bohua Zhan and Xinxin Liu and Naijun Zhan},
  journal = {Proceedings of the ACM on Programming Languages},
  volume = {9},
  number = {OOPSLA1},
  year = {2025},
  doi = {10.1145/3720478}
}