Existing sensor network simulators are not appropriate for indoor sensor network systems. We present RealSSim, the sensor network simulator especially developed for indoor sensor networks. RealSSim considers the structure of buildings and the quality of construction materials for accurate radio propagation analysis. It also supports an attractive visualization of the level as commercial products. In our demonstration, we show the whole process of simulation for two indoor sensor network systems.

Domain analysis is the process of analyzing related software systems in a domain to find their common and variable parts. In the case of device drivers, they are highly suitable for domain analysis because device drivers of the same domain are implemented similarly for each device and each system that they support. Considering this characteristic, this paper introduces a new approach to the domain analysis of device drivers. Our method uses a code clone detection technique to extract similarity among device drivers of the same domain. To examine the applicability of our method, we investigated whole device drivers of a Linux source. Results showed that many reusable similar codes can be discerned by the code clone detection method.

Application launching times in embedded systems are more crucial than in general-purpose systems since the response times of embedded applications are significantly affected by the launching times. As general-purpose operating systems are increasingly used in embedded systems, reducing appli-cation launching times are one of the most influential factors for performance improvement. In order to reduce the application launching times, three factors should be considered at the same time: relocation time, symbol resolution time, and binary loading time. In this paper, we propose a new application execution model using a combination of prelinking and preloading to reduce the relocation, symbol resolution, and binary load overheads at the same time. Such application execution model is realized using fork and dlopen execution model instead of traditional fork and exec execution model. We evaluate the performance effect of the proposed fork and dlopen application execution model on a Linux-based embedded system using XScale processor. By applying the proposed application execution model using both prelinking and preloading, the application launching times are reduced up to 71% and relocation counts are reduced up to 91% in the benchmark programs we used.