Research On File System And Reprogramming Techonology Based On Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are bringing about a revolution on informationperception on account of the advantages of low-cost, low-power, distributed andself-organizing. As the increasing complexity of application on sensor nodes, operatingsystems is desperately needed for multi-task management and the booming ofElectronic information technology makes it possible. Even so, sensor nodes are stillresource-constrained, compared with PC even embedded system, which requires thateach part of WSNs operating system is well-designedFile system and reprogramming are significant components of WSNs operatingsystem and its design will directly affect the performance of entire system. Since thereprogramming is closely linked with file system, this research refines both of them forglobal optimum based on consideration of their correlation. The main contents of thisstudy are as follows:(i)Analyze Contiki operating system deeply. This research selects Contikioperating system as the object of study. However, the references of Contiki are verylimited. As a result, analyzing the source code of Contiki deeply is needed to understandits technical details, including Contiki kernel, file system, dynamic loading and Rimestack, which lays a solid foundation for the following research.(ii)Refine Coffee file system. After in-depth analysis of Coffee, several bugs arefixed and some code styles are improved to enhance the robustness of Coffee. Inaddition, the Coffee file sytem is improved in various aspects, considering the featuresof reprogramming which include Coffee format, adapting to the type of FLASH, thecharacteristics of collected data and file metadata.(iii)Refine the reprogramming of Contiki. Three WSNs operating system (TinyOS,SOS and MantisOS) are analyzed for a better understanding of typical implementationson reprogramming. After then, the ELF file format is redesigned and the ELF file istailored to improve the reprogramming of Contiki.(iv)Build development platform and test. In order to enhance the abilities ofdebugging, the development platform of Contiki is ported from GCC to IAR+J-Link, including setting up the development environment and porting Contiki operating system.The function of revised file system and reprogramming is tested on this platform.Furthermore, the way, using network simulator COOJA, is introduced to test itsperformance.This study analyzes Contiki kernel, Coffee file system, reprogramming technologyand Rime stack by getting into its source code deeply and refines Coffee andreprogramming of Contiki, which has a realistic significance.