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In sensor networks, analyzing power consumption before actual deployment is crucial for maximizing service lifetime. This paper proposes an instruction‐level power estimator (IPEN) for sensor networks. IPEN is an accurate and fine grain power estimation tool, using an instruction‐level simulator. It is independent of the operating system, so many different kinds of sensor node software can be simulated for estimation. We have developed the power model of a Micaz‐compatible mote. The power consumption of the ATmega128L microcontroller is modeled with the base energy cost and the instruction overheads. The CC2420 communication component and other peripherals are modeled according to their operation states. The energy consumption estimation module profiles peripheral accesses and function calls while an application is running. IPEN has shown excellent power estimation accuracy, with less than 5% estimation error compared to real sensor network implementation. With IPEN's high precision instruction‐level energy prediction, users can accurately estimate a sensor network's energy consumption and achieve fine‐grained optimization of their software.

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Recentlypartitioning and virtualization techniques for Integrated Modular Avionics (IMA) of aeronautics sector are proposed as the candidate architecture for safety-critical space applications. However, spacecraft software has subtle difference from aeronautic applications. Radiation particles in space environment cause various faults on the spacecraft computer. Requirement for autonomous operation with constrained resources is more stringent in space missions. Once it is launched, no way to refurbish the spacecraft without tremendous cost. These extra properties on top of those of regular aeronautic systems cause large software development cost in spacecraft projects. Summing up, spacecraft software should have real-time property, fault tolerance and efficient resource usage.In this paper, we introduce a hypervisor for spacecraft computer to improve reusability of inherited flight software from previous missions without redevelopment cycle. Fault tolerance is designed into the hypervisor to provide autonomous operation in space. We designed a prototype which is Type-II full virtualized hypervisor with kernel-level ARINC 653 partitioning on a dual-core LEON4based flight computer for spacecraft. As the guest system, RTEMS-based flight software running on ERC32 flight computer is chosen because it has been used for many recent space missions and its flight software is likely to be reused when multicore LEON4 becomes widely available.

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