Ieee 802.15.4 Protocol Realization

IEEE802.15.4 is an emerging standard specified the physical layer and medium access control layer and designed as a basic technology for low-cost, low-power and low- rate wireless communications. ZigBee and 6LoWPAN is builded on this standard, it is also provides the widely accepted solution for wireless monitoring and wireless control about battery-powered devices, therefore become one of the technologies for wireless sensor network (WSN) application research.This paper encapsulates the development, application, characteristics and current research status of IEEE802.15.4 protocol at first, then deeply analyse the framework, device type, network topology, main functions and frame structure of PHY layer and MAC layer. Specially on networking process and the value of some parameters, we give a analysis as a foundation for the realization of networking.Energy is a scarce resource in LR-WPAN. On the basis of a thorough understanding of IEEE 802.15.4 protocol, we find that the major energy consumption is idle listening for devices usually are idle. Focusing on its beacon-enable mode for a star-topology network, we give a study on duty cycle. It is well known that periodically putting nodes into sleep can effectively save energy in PAN, but at the cost of increased communication delays. During deployment an appropriate duty cycle to adjust the trade-off between energy consumption and transmission delay has to be found. This study is based on key features such as the superframe which provides beacon order (BO) and superframe order (SO) decide the duty cycle. Our study gives the proper range BO and SO developed for the simulation framework NS2.According to the result of duty cycle, this paper developed a low-power, low-latency and self-organizate LR-WPAN platform on the AT86RF212 and implemented the most functions of physical layer and MAC layer protocol. This platform scanning the channel at first, then establish a Personal Area Network (PAN), after these the network node associated with the PAN. Finally, implementing a wireless sensor network system for temperature and humidity monitoring, this system operate properly. All of this verify the realizable and self-orgnization of the LR-WPAN platform, at the same time demonstrates how to use this platform for applications.