The Ieee 802.15.4 A Time Slot The Csma / Ca Protocol Performance In Wireless Sensor Networks,

Wireless sensor network has potential wide application range as a newly emerging technology. However, the user-oriented characteristics cause the Wireless sensor network has various aspects of requirement on standard protocol, it is difficult to have a common communication standard protocol to meet requirement. But in the domain of wireless personal area network, IEEE 802.15.4 wireless personal area network protocol can be a candidate protocol for wireless sensor network.This thesis is based on background of national science foundation project key issue research on dynamic reconfigurable SOC system architecture and implementation method, and serves as a pre-search study. It first adopts OPNET Modeler simulation tool to model slotted CSMA/CA mechanism of IEEE 802.15.4 in beacon enabled mode, and implements simulation and analysis to the function of beacon order, superframe order, backoff exponent and node number to network performance, and get three important conclusions, i.e.: slotted CSMA/CA backoff algorithm is not flexible enough in large-scale sensor network environment; the optimal range to achieve stand-off between network throughput and average delay is G∈[35%,60%]; the lowersuperframe order will bring additional consumption and affect network throughput. The thesis functions as complementarity to the current Markov chain models on slotted CSMA/CA, and it builds a foundation to comprehensively understand CSMA/CA mechanism in IEEE 802.15.4 and the available application in WSN, and through understanding the limitation in mechanism, it provides reference for study on bring in MAC reconfigurable measures to improve the mechanism.The chapter 1 in the thesis is general for wireless sensor network characteristic and protocol design problem for WSN; the chapter 2 makes general introduction to the three protocols in wireless personal area network and the 802.15 work group, and makes a detailed introduction to the concerned 802.15.4 protocol mechanism; the chapter 3 expatiates the algorithm of Markov chain model in both non-saturation and saturation conditions, and points out the limitations; the chapter 4 expatiates the algothrim adopted in this thesis and the modeling process, including introduction to OPENT simulation tool, and gives the simulation node model, process model, attribute configuration and simulation scenario simulation; the chapter 5 implements valuation and analysis to the model, and gives the performance graph and analysis of model in different network settings; in the end, the thesis makes a summary to the protocol mechanism limits and gives some suggestions on the improvement.