Deployment of wireless sensor network (WSN) in agricultural environment in northen Malaysia

Abstract

The advent of Wireless Sensor Networks (WSN) has been fuelled mainly by the advancement in miniaturization of electronic devices and the rise of high volume manufacturing that has been the key supporting factor for the advancement economically. Recent food crises happening over various parts of the world triggered the consciousness over food security and food production capability. For the modern food production to be successful, a thorough understanding and awareness of temporal and spatial crops behaviour is super critical. Thus the use of sensor and wireless sensor networks and proper deployment planning to support modern precision farming is the key to optimum coverage establishment in the farmland. This thesis was written based on the following objectives; assessment energy consumption in WSN nodes as a function of data transmission interval and transmission power level setting; configure a system for short to mid-range link measurement for the study in agricultural environment. The thesis also evaluates existing signal path loss models, identifies or develops new path loss models for WSN system in agricultural environment. Additionally, the thesis also design and model a wide area WSN in agricultural environment. To meet the objectives, propagation path loss measurements were conducted in multiple types of agricultural environments which cover assessment in mixed crop plantation, aquaculture ponds, green houses and mono crop plantations. Path loss models were evaluated and or developed and results were used in WSN simulation. Concurrently, WSN nodes energy consumption assessment was carried out and results used in the WSN simulation. Output from these study and measurements are energy consumption assessment in WSN nodes, path loss models and results from WSN simulation in agricultural environment. Measurement results acquired from the studies show that Log-distance model is the best fit model for measurement in mixed crop plantation while 2-ray model is sufficient to describe the propagation in aquaculture environment. Signal variation in aquaculture is influenced by changes in temperature, humidity and thus refractive index of the medium. Studies in mango greenhouse shows that signal fluctuation varies with vegetation density and Non Zero Gradient model can describe the overall signal propagation while Modified Exponential Decay is more appropriate for lower antenna height. Non Zero Gradient model with specific parameters can be used to describe overhead trellis type grape in greenhouse. For mono-crop plantation, Non Zero Gradient is suitable to describe ISM (Industrial, Scientific and Medical) band frequencies while Modified Exponential Decay is more suitable for frequency 800 MHz to 4.2 GHz in rubber plantation. Modified Exponential Decay is best describe the propagation at branch level while Non Zero Gradient at canopy level. For palm plantation, Modified Exponential Decay best describe signal propagation at trunk while Maximum Attenuation is at canopy level. A deployment model simulation was done at the end of the thesis illustrating the potential coverage based on power consumption in various signal behavior in mixed crop plantation.