Research And Implementation Of QoS Measurement For Wireless Sensor Network Based On Primary-Vice Agent

Wireless sensor network (WSN), integrated with the wireless communication technology, sensors and computer network technology, is a distributed network system consists of a large number of self-organization sensors which are randomly distributed in the monitored area, and it has become a research hotspot in recent years. With the wide spread of various WSN applications, the research on quality of service (QoS) of WSN has received more attentions. Though the research on WSN measurement goes for a short time and gets few achievements, according to the existing measurement-related research documents, traditional measurement models and methods for IP network don't suit sensor network anymore, due to the special features of sensor network, such as limited node energy and variant network topology, and this make the sensor network performance measurement facing many challenges. Therefore, it has become more and more important to explore new measurement modules and methods that can apply to sensor network.With some studies on measurement-related supporting technology:route protocols and data aggregation, this thesis focus upon QoS measurement models and methods for WSN. It makes a further prospect for the future work on WSN measurement. The main work and innovation of the study are given as follows:First, an energy-efficient data collection protocol for WSN based on tree is proposed (EEDCP-TB) to compensate for the shortcomings of the available data collection protocol, such as, shorter network lifetime, higher energy consumption, and so on. This protocol constructs data collection tree through the method of flooding avoidance and uses the cascading timing scheme to allocate aggregation time in order to save node's energy. Furthermore, it introduces the node energy state parameters to meet energy balance to a certain extent when we choose forwarding nodes. Finally, compared with TBDCS protocol and Flooding protocol, simulations show that this protocol requires less transmission and receiving, saves more nodes'energy and prolongs network lifetime.Second, a measurement model for WSN based on primary-vice agent is designed. This model obtains average measurement results by the cooperator of Sink, primary agent and vice agent. And it enhances measurement accuracy by computing the average value of several measurements. In the end, we carry out simulation experiment on the proposed model and methods through OMNeT++ software, and the simulation results show that the measurement dates obtained by this model and corresponding method are quite accurate, and it can provide reliable scientific evidences for network control center to take some measures to improve performance for the whole sensor network by analyzing the measurement results, for example, reconstruction of the network topology.