The Extension And Implementation Of Channel Model For Wireless Underground Sensor Networks On NS2

Wireless underground sensor network is a sensor network which is used wireless as medium,and most of its sensor nodes are located in underground soil,and the soil is used as the communication medium.As a new field of wireless sensor network,wireless underground sensor network has promising application areas,but most research is still the on the theoretical stage,need a large number of experiments.In order to reduce the resources used in the experiment,the network simulation platform is an important research tool.So far,none of the existing network simulation platform is completely corresponding underground channel module.In order to improve the simulation of wireless sensor networks,the upper layer protocol and network system performance are studied,and a simulation platform which is more close to the real underground environment is needed.In this thesis,based on the two-path model and multipath fading effects,consider the all ingredients of electromagnetic transmission signal,the introduction of the direct wave,reflected wave and lateral wave(3W)model,considering the dominant communication in far field communication lateral wave effects on communication,gives a detailed derivation and calculation methods.On this basis,a hybrid topology structure is introduced further.The hybrid topology structure includes the channel models from the underground to aboveground and from the aboveground to underground,the attenuation model is deduced and calculated in detail,implement the communication between aboveground and underground nodes.The model is implemented on the NS2 platform,In the implementation of the simulation platform,research the electromagnetic wave propagation characteristics of the communication channel,analysis the influencing factors of communication in soil.The simulation results are compared with the theoretical calculation values.and analyzes the effects of channel topology and environmental conditions on the wireless underground sensor network performance,verify the feasibility of model used in underground environment simulation,and provides a reference tool for the further study of wireless underground sensor networks.