A new optional parallelism operator in CSP for wireless sensor networks

Simulation from formal specification is an important topic in Wireless Sensor Network (WSN) research. Classical Communicating Sequential Processes (CSP) are often used to write these specifications, but their concurrency operators are either too restrictive, or too lenient, to directly describe real-world WSN scenarios. In this paper we introduce a new optional parallel operator, based on previous work, that allows a process to 'opt out' of the all-synchronisation, as it would happen in real WSN scenarios where some node may run out of resources whilst other nodes continue to function. For its formal semantics, a translation of optional parallelism into classical CSP has been defined. This work also resulted in a notion of directional multi-way synchronisation, enabling various interesting broadcasting properties. Our evaluation of various WSN topology scenarios showed success in terms of deadlock freedom and trace refinement.