Deployment of wireless sensor and actuator networks for precision agriculture

• Main Author: Sivertsen, Kyle N.
• Language: English
• Published: University of British Columbia 2013
• Online Access: http://hdl.handle.net/2429/45041

Wireless sensor and actuator networks (WSAN) are emerging as a key enabling technology for precision agriculture, a technique for maximizing crop yield and quality through targeted application of resources such as water, fertilizer and pest control agents by exploiting temporal and spatial variability in crop and soil conditions. In this thesis, we make three contributions to the field. First, we assess the state of the art in deployment and configuration of wireless sensor and actuator networks for precision agriculture, including the relevance and suitability of existing propagation models, lessons learned from previous demonstrations and field trials, and the potential for improving network performance through suitable deployment strategies, and physical, medium access control (MAC) and network layer design. We reveal an urgent need to assess airlink design of such networks to account for the unique nature of the wireless propagation environment and to consolidate proposed improvements to and best practices for WSAN design in the form of an industry standard. Second, we show that the conventional practice of employing wireless transceivers that operate at 800 MHz or above incurs significant penalties for achievable range and/or power consumption and propose that low-power short-range wireless devices intended for use as sensor nodes in precision agriculture be allowed to share the 433 MHz sub-band currently authorized for use by active radio frequency identification (RFID) devices at cargo terminals, port facilities and warehouses so that they may experience less path loss and achieve greater range and reliability while consuming less power. Finally, we analyze 2450 MHz channel impulse responses that we measured in a high-density apple orchard and consider the implications of both their form and scale for the design and deployment of WSANs and our understanding of the propagation environment. Of particular note is the vastly reduced delay spread compared to that observed in traditional residential, commercial and industrial environments