Research And Implementation Of Real-time Transport Protocol For Wireless Sensor Networks

Wireless sensor networks(WSNs) is an emerging research area in computer science and technology, it converges several top technologies, such as sensor, MEMS (Micro-Electro-Mechanical Systems), embedded technology and wireless communication, and has a wide application future. As data being transmitted from sensing area to the sink, it is required reliability and real-time guarantee in many WSNs applications, reliability and real-time transmission have become the key issues in WSNs.In this paper, the unique characteristics of WSN applications is analyzed, and the key technology of existing transport protocols of WSNs is studied. Based on the previous work on transport protocols for WSNs, the idea of cross-layer consideration is introduced, and a new transport protocol, RCTP (Real-time Collection Tree Protocol), is designed and implemented, which guarantees reliability and provides soft real-time transmission in WSNs. RCTP utilizes a real-time messages differentiated and priority-based scheduling algorithm, and enables the interaction among communication layers.The main works in this paper are listed as follows:â‘ Summarize the key technology of congestion and reliability in WSNs;â‘¡Introduce the idea of cross-layer consideration: the performance of transport protocol is affected significantly by the interaction among layers.â‘¢Propose a real-time tasks differentiated, and priority-based scheduling algorithm.â‘£Design six control experiments, and evaluate the performance of RCTP by rate of receiving packets and transmission delay.The RCTP is implemented on TinyOS, and is simulated by TOSSIM, a simulator provided by TinyOS. As the control experiments shown, the reliability of RCTP approximates to CTP(Collection Tree Protocol), both of them share the receiving rate of more than 90%. In comparison with CTP, RCTP enhances the real-time performance of WSNs by cutting the transmission delay by 17.7% at maximum.