Fundamentals of Efficient Communication in Wireless Underground Sensors Networks

摘要无线地下传感器网络（WUSN）是一个很有前途的领域，它将实现当前有线地下监测技术无法实现的各种新应用。与现有有线地下传感器网络相比，WUSN具有隐蔽性、易部署性、数据及时性、可靠性和覆盖密度等显著优点。尽管具有潜在的优势，但WUSN的实现具有挑战性。该领域的主要挑战是实现高效可靠的地下链路，以建立多跳点并有效传播数据，实现无缝运行。此外，电磁波在土壤中的传播特性阻碍了对地下无线信道的直接表征。因此，需要先进的传播和多路径模型来研究土壤在地下通信中的影响。该研究提供了先进的模型和技术，以全面表征地下无线信道，并为在这种环境下高效通信奠定了基础。该模型旨在通过考虑多径、土壤成分、含水量和埋深来表征电磁波在土壤中的传播。基于土壤中通信的这些特点，提出了一个优化框架来表征土壤网络中跨层通信的特性。该框架以跨层的方式联合建模各种协议层上的问题，如介质访问控制、路由和传输。此外，研究了一个跨层框架来分析各种错误控制技术的影响，并确定WUSNs中的最佳数据包大小。该优化框架基于能耗、吞吐量和资源利用率方面的三个主要优化函数。因此，有效的通信协议可以基于本研究中开发的信道模型的基础和由该框架确定的最有效的错误控制技术来开发。

Fundamentals of Efficient Communication in Wireless Underground Sensor Networks AbstractWireless Underground Sensor Networks (WUSN) is a promising field that will enable a wide variety of novel applications that were not possible with current wired underground monitoring techniques. Compared to the current wired underground sensor networks, WUSN have several remarkable merits, such as concealment, ease of deployment, timeliness of data, reliability and coverage density. Despite its potential advantages, the realization of WUSN is challenging. The main challenge in this area is the realization of efficient and reliable underground links to establish multiple hops and efficiently disseminate data for seamless operation. Furthermore, the propagation characteristics of electromagnetic (EM) waves in soil prevent a straightforward characterization of underground wireless channel. Hence, advanced propagation and multi-path models are required to investigate the effects of soil in underground communication. This research provides advanced models and techniques to completely characterize the underground wireless channel and lay out the foundations for efficient communication in this environment. This model aims to characterize the propagation of EM wave in soil by considering multipath, soil composition, water content, and burial depth. Based on these peculiarities of communication in soil, an optimization framework is developed to characterize cross-layer communication aspects in WUSN. This framework jointly models problems at various protocol layers such as medium access control, routing, and transport in a cross-layer fashion. Moreover, a cross-layer framework is investigated to analyze the effects of various error control techniques and determine the optimal packet size in WUSNs. This optimization framework is based on three main optimization functions in terms of energy consumption, throughput, and resource utilization. Consequently, efficient communication protocols can be developed based on the foundations of the channel model developed in this research and the most efficient error control techniques determined by this framework.