Research And Implementation Of Wireless Sensor Networks Communication Protocol Stack

As one of the most important technologies in the 21 st century, wireless sensor networks(WSN) has a very wide application in many fields. WSN is composed of a large number of nodes and a PC. Acquisition nodes collect the information of perceived objects in the monitoring area, using multi-hop ad hoc networks to communicate with the sink node. The PC obtains the data of the monitoring region from the sink node, so as to acquire the information of the physical world. WSN communication protocol stack is the main way of communication in the network, and it plays a vital role in the data transmission and network management.WSN communication protocol stack includes physical layer, MAC layer, network layer and application layer. This paper presents a design, simulation and implementation of the WSN communication protocol stack based on the IEEE802.15.4 standard and the ZigBee technologies. The MAC layer design supports the channel scanning, association and data requesting. The network layer supports formatting the network, joining the network and leaving the network and it also supports network data unicast and broadcast services. The network layer is responsible for routing discovery and maintenance, its routing strategy supports tree routing, minimum routing cost routing and energy balance routing. The application layer is designed for environmental monitoring. It has the functions concerning sending sleep command, collecting data and achieving network addresses, routing tables, neighbor tables. This protocol stack is designed with high portability, energy balance routing strategy and good programming interface that can reduce the difficulty of WSN application development and provide a solid foundation for developers to optimize the protocol stack based on the actual application scenario.In this paper, NS2 is used as the network simulation platform to simulate and analyze the performance of the protocol stack, especially for the minimum routing cost strategy and the energy balance routing strategy. On the hardware platform built by RF chip CC2531 as core, this paper do some functional tests of the protocol stack. The test process focuses on testing the functions of network, broadcast and routing. The protocol stack is modified and improved based on test results.