Through-the-Earth Magnetic Induction Communication and Networking: A Comprehensive Survey

TL;DR

This survey establishes a comprehensive view of through-the-earth MIC within SAGUI networks, highlighting MI fast fading as a foundational challenge that disrupts the conventional quasi-static MIC assumption. It introduces a fine-grained decomposition of channel power gain into circuit, space, eddy, and polarization gains, and proposes a universal antenna-variation-based model to study MI fast fading. The work maps MI network design across the OSI stack, reviews relay and CMIC techniques, and proposes a Linux- and TCP/IP-enabled MIC framework to enable runnable MIC prototypes and deployments. It also identifies critical gaps in TCP/IP support, TTE-specific channel models, and upper-layer protocols, offering future directions including MCNSI, massive MI MIMO, and deep JSCC for MIC within SAGUI. The practical impact is a structured pathway to integrate MI-based underground communications with existing mobile networks, enabling resilient, scalable SAGUI-enabled systems.

Abstract

Magnetic induction (MI) communication (MIC) has emerged as a promising candidate for underground communication networks due to its excellent penetration capabilities. Integration with Space-Air-Ground-Underground (SAGUI) networks in next-generation mobile communication systems requires a well-defined network architecture. A recent discovery in MIC research, MI fast fading, remains in its early stages and presents unique challenges. This paper provides a comprehensive survey on through-the-earth (TTE) MIC, covering MI applications, channel modeling, point-to-point MIC design, relay techniques, network frameworks, and emerging technologies. We compare various MIC applications to highlight TTE-specific challenges and review the principles of channel modeling, addressing both MI slow fading and MI fast fading, along with its potential impact on existing MIC theories. We conduct a fine-grained decomposition of MI channel power gain into four distinct physical parameters, and propose a novel geometric model to analyze MI fast fading. We also summarize MI relay techniques, examine crosstalk effects in relay and high-density networks, and explore key research tasks within the OSI framework for a holistic MI network protocol in SAGUI. To bridge the gaps identified, we propose a MIC framework that supports TCP/IP and Linux, enabling full implementation of existing and emerging MIC solutions. This framework empowers researchers to leverage Linux resources and deep learning platforms for accelerated development of MIC in SAGUI networks. Remaining research challenges, open issues, and promising novel techniques are further identified to advance MIC research.

Figures (33)

• Figure 1: Comparison of the penetration abilities of communication approaches. Green and red texts indicate the advantages and disadvantages, respectively. Performance and deployment comparisons are presented in Table \ref{['tbl_cmpcommperf']}.
• Figure 2: The structure of this survey, where we perform fine-grained decomposition of the MI power channel gain and novel antenna vibration model for MI fast fading in Section \ref{['sect_sub2channel']}, MI crosstalk effect in Section \ref{['sect_cmi']}, and MI network framework with TCP/IP & Linux support in Section \ref{['sect_linux']}.
• Figure 3: P2P TTE MI communication model in polar coordinates. Here, $\hat{e}_{\mathrm{D}}$ and $\hat{e}_{\theta_{\mathrm{S}}}$ are the radial and angular unit axial vectors, respectively; $\mathbf{n}_{\mathrm{S}}$ and $\mathbf{n}_{\mathrm{D}}$ are the normal vectors of the dipole and sensor, respectively.
• Figure 4: FEM simulation of magnetic flux density in multilayer materials with different conductivities. Here, the conductivities of air, soil and seawater are 0, 0.01, and 4.8 S/m, respectively. The current of coil $I_{\mathrm{S}}$$=$$15\cos(2\pi\times 10^4 t)$ (A). The coil radius is 6 m.
• Figure 5: Relationship among circuit, eddy, space, and polarization gains. The normal fonts with gray background represent the primary parameters.