Cyber-Physical Networking Lab

Supported by NSF CNS #1619285

Description

Extending the communication ranges and increasing data rates in wireless UG communications faces unique challenges because of the interactions between soil and communication components: (1) Antenna properties depend on soil type and vary with changes in soil parameters such as temperature and moisture. (2) Channel characteristics, such as delay spread and coherence bandwidth, are time-variant functions of the soil parameters. (3) The soil-air interface results in fluctuations in both antenna performance and EM wave propagation, which should be considered in system design. To address these challenges, the project captures the impulse response of the wireless UG channel through extensive experiments throughout the state of Nebraska, which is one of the most diverse states in terms of soil textural properties, climatic gradients, and land use. Based on this analysis, advanced modulation schemes are developed. Moreover, based on UG antenna analysis, long-range communication techniques are developed. Two distinct applications from agriculture and transportation are considered to evaluate the developed solutions in a crop field and a crash test site.

Goals

This project aims to increase the communication ranges and data rates of buried radios by leveraging expertise in the nexus of computer science and engineering and biological systems engineering. The goals of this project are to characterize the underground channel; develop environment-adaptive solutions to achieve high data rate, long-range communications; and illustrate applications to agriculture and transportation. The emerging use of wireless underground sensor networks (WUSNs) in many areas, including precision agriculture, transportation, environment and infrastructure monitoring, and border patrol, underscores the importance of wireless underground (UG) communications. Yet, existing limitations in terms of communication ranges and data rates prohibit widespread adoption. The novel approaches developed in the project broaden the scope of existing and novel applications, leading to economically viable solutions. The results and the insight from this project have the potential to enable a wide array of novel solutions from saving water resources for more food production to saving lives on the roadways. 

Personnel 

PI: Mehmet Can Vuran

PI: Suat Irmak

Outcomes

2019-2020

Intellectual Merit Outcomes

Theoretical and Empirical Evaluations of LoRa for Wireless Underground Communication: LoRa provides a long-range, low data-rate solution for rural connectivity. Comparing to existing IOUT utilizes communication schemes used in unlicensed bands, including Bluetooth, ZigBee, Wi-Fi, and Dash7, LoRa has a larger link budget to potentially increase the communication ranges in UG communication scenario. Hence, with the help of long-range communication schemes such as LoRa, the IOUT architecture and field deployment can be improved.Wireless Underground Channel Modeling: Channel models are the basics to characterize the performance and reliability of wireless communications. Wireless underground channel models are necessary to capture the impairments caused by the nature of soil and their dependence on the environment. Our previous investigation is conducted under the assumption of a homogeneous soil environment. During this investigation period, we conducted measurements using our newly deployed testbed to facilitate investigation on the inhomogeneities in wireless UG channels. The antenna return loss and channel power delay profile are measured for dipole and wideband micropatch antennas using our new testbed design.

Experiment Infrastructure Development for Wireless Underground Communication Evaluations: Wireless UG communication technologies are driven by the practical needs of providing wireless connectivity and telemetry capabilities to remote and inaccessible underground environments. Evaluations of proposed solutions in realistic environments are critical to understanding the performance of the techniques under dynamic environmental factors and soil conditions. We continued our efforts in building state-of-the-art UG communication testbeds to perform evaluations of our solutions through in-field experiments. We deployed a new testbed at the Irmak Research Laboratory (IRL) at the South Central Agricultural Laboratory (SCAL), and expanded our indoor and outdoor testbeds at UNL east campus, with the addition of various types of buried antenna and deployment scale. The diversity of our UG testbeds provides capabilities for evaluating our solutions in both rural and urban settings for agricultural and horticultural soil monitoring applications.

LoRa-based IOUT Development: We have continued our in-field research of wireless underground sensor networks and IOUT at the field research facilities at IRL-SCAL. We updated our existing UG radio system design and architecture with the latest commercial LoRa IoT radios and developed software-defined radio-based UG communication research platform. The developed systems will enable reconfigurable, remotely accessible, and flexible UG communication research and IOUT based precision irrigation research. However, the in-field deployment and test were postponed in the spring due to the COVID-19 pandemic.

Outreach

K-12 Outreach: We actively participate in the organization of local outreach events to share our research and education experience with students and teachers. In this investigation period, we presented our research activities at Science Connectors showcases with Lincoln Public Schools (LPS) on August 7th, 2019 through easy-to-understand demonstrations. The main goal of these events is to inform the public-school teachers about state-of-the-art scientific research at the University of Nebraska and enable teachers to engage in building creative K-12 curricula. Co-coordinated by the LPS science curriculum specialist, this annual event shares STEM activities with over 150 science teachers at UNL. See pictures from outreach events at Science Connector Event, August 2019.

To increase broader participation in Agricultural IoT solutions, the PI organized a virtual Agricultural IoT panel as a part of the 6th World Forum on Internet of Things (WF-IoT). This was the fourth Ag-IoT day that the PI organized as a part of WF-IoT. The agricultural panel featured speakers from academia and industry to an interdisciplinary audience of researchers in IoT.

Resources

Please see the resource page.