Energy Efficient Data Restoring after Power-Downs for Wireless Sensor Networks Nodes with Energy Scavenging

The article focuses on the new problem, which became topical for Wireless Sensor Networks (WSN) with energy harvesting possibility and which is in the realization of system and user data restoring for nodes after unexpected power-downs due to the temporal unavailability of harvested energy. Different possibilities for the creation of the restore point and data restoring after power-downs are described and evaluated in the article, which include the usage of microcontroller internal RAM and Flash memory, the usage of external EEPROM and NVRAM chips or the radio interface with joint node data storing. The evaluations for the article were made using presented Restorable Event-Based Operation System (REBOS) which is intended to solve the problem of OS and user application automatic restoring point creation and restoring after power-downs. The evaluation of energy consumption for different restoring methods is included.