Low-speed Wireless Sensor Network Design And Implementation

Recently the wireless sensor network has been used widely. Most wireless sensor network use 802.15.4 or the Zigbee as data transfer protocol. In many situations, the sensor in the node is low sampling, which lead to low data transmit rate. Complicate network protocol like 802.15.4, needs powerful controller and additional memory, meaning more expensive and more power consumption.So it has practical meaning to design a simple network protocol for the low sampling speed rate sensors network.In this thesis, requirement of low sampling speeds sensors network has been analyzed carefully. According to this requirement, a appropriate topology is proposed. The model of this protocol is also constructed. The protocol takes 802.15.4 and Zigbee as a reference.This thesis describes the principle of the MAC layer, which is realized in C language.To verify this protocol, some sensor nodes has been designed. These nodes choose some typical sensor to collect data. The protocol runs on these nodes, together with the sensor's hardware driver. These sensor nodes with the data center form a wireless net, and transmit data that they have collected. The data those sensors collected have been verified accurate in the data center.The code size of this node is only 2Kbytes include the protocol part and hardware drivers. The controller of the node selected the MSC9S08, a simple 8bit MCU. The node can work 4 weeks continuance no need change the battery.Our tests show that this protocol is simple, low power consumption but efficient, and robust. The protocol is very suitable for the low sampling speed rate sensors network.