Low-power Multi-hop Ad-hoc Zigbee Transmission System Design Technology

With the advances in wireless communications technology and sensor technology,the development of wireless sensor networks is accelerated,people's needs for high-reliability,low-cost wireless network protocol is more urgent.Traditional wired communications is high-cost.It is inconvenient to overhaul and susceptibly corrosioned.Wireless communication has become the people's choice.Meanwhile,the general common wireless communication protocol does not have the characteristics of multi-hop transmission,it does not support expansion and the self-healing capacity is relatively poor.Zigbee has high fault tolerance and self-healing capabilities.The purpose of this thesis is to design a transmission system based on Zigbee protocol suited for wireless sensor networks in geotechnical engineering monitor,that is an alternative to traditional wired RS485 communication.The transmission system's goal requires that the Zigbee protocol is selected to complete the design.Zigbee protocol can achieve the low-power,self-organization and multi-hop goals.In order to achieve multi-hop transmission of data,use Zigbee own multicast way to achieve.Low-power nodes needs both hardware and software optimization,in order to improve the usefulness of the transmission system,increased the distance prompts.In accordance with the general principles of communication system and embedded system design,descripted in-depth related technologies in the transmission system design process.The good operation of the transmission system cannot do without the appropriate hardware and software platform.Hardware,MAX485 chip is selected as the main chip of the signal conversion circuit.Software,software development work has completed using the Z-Stack protocol stack.Based on a consideration of practical application,the thesis focused on the completion of the design and implementation of the communication protocol and the distance prompts.Finally,actually tested the transmission system,including sensor module,signal conversion circuit module,data transceiver circuit module,and the performance of the transmission system.The results show that the design of the transmission system will be able to convey pc-instruction to the sensor by multiple-hop,and the sensor will accurately upload the data to the host computer.The thesis achieved the design goal.