Development Of A WSN Gateway For Perimeter Protection System

Perimeter protection serves an important role in country safety and public guard.However, with the great progresses of technology approaching Wireless SensorNetworks (WSN), this new technology is employed into perimeter protection is a newtechnological trend, which also returns progresses to WSN technology, including WSNnode, gateway, and related software. WSN gateway is a special network component,which is a interface between WSN and core network. That is, the gateway has a strictrequirement on reliability. To a WSN gateway for perimeter protection, the ability ofreal-time response is another requirement. In this thesis, depend on a project Real-timePositioning Intelligent Intrusion Protection System from company, we discuss how totransplant Operation System (OS) core, μC/OS-Ⅱ, into ARM7platform based chip,AT91SAM7S256of Atmel, and then, we discuss how to transplant LwIP network stackinto the chip in μC/OS-Ⅱ OS in order to support TCP/IP communication. With these,our work can meet the requirements of the project.The WSN gateway employs μC/OS-Ⅱ, the most famous real-time OS, as itsoperation software. Even though μC/OS-Ⅱ provides real-time task scheduling andinterrupts management, it doesn’t offer any supports to outside interface andcomponents. Furthermore, it hasn’t networking stack. Therefore, we adopt μC/OS-ⅡOS and free network stack, LwIP to implement the WSN gateway by transplantingLwIP into μC/OS-Ⅱ OS on ARM7platform of Atmel AT91SAM7S256. In this thesis,we first introduce μC/OS-Ⅱ OS in sequence of kernel architecture, task scheduling andinterrupt management. In order to get a deep view into μC/OS-Ⅱ, we analyze taskscheduling and interrupt management at source code level. Following by this, weintroduce LwIP network stack from aspects of architecture, implementation, process,memory management and application interface. And then, the thesis details how totransplant μC/OS-Ⅱ into AT91SAM7S256chip and how to transplant LwIP intoμC/OS-Ⅱ on AT91SAM7S256platform, and we provides the source code. With these,we have a simple test on the transplanted codes. The results show that the transplants ofμC/OS-Ⅱ OS and LwIP network stack into AT91SAM7S256platform are successful, and then the WSN gateway can meet the requirements of the project.