A Hybrid Embedded Real-Time Operating System for Wireless Sensor Networks

Traditional operating systems for Wireless Sensor Networks (WSN) are based on either event-driven or multitask concept. Instead, this paper presents an embedded real-time operating system, named HEROS 'Hybrid Embedded Real-time Operating System', which is configurable to run in different modes: event-driven, multitask or hybrid to adapt to diverse domains of WSN applications. HEROS adopts a modular and hierarchical architecture: action (system operation), thread (component) and event (etask) and provides a predictable and deterministic scheduling mechanism: 'Non pre-emption Priority Based' scheduling for events and 'Pre-emptive Priority Based' scheduling for threads.