Magnetic Communication Principle
The "Chosen One" for Underwater/Underground Environments
水下/地下环境的"天选之子"
Transmitting coil carries alternating current → Generates quasi-static alternating magnetic field
发射线圈通交变电流 → 产生准静态交变磁场
Receiving coil induces electrical signal through magnetic coupling → Demodulation
接收线圈通过磁耦合感应出电信号 → 解调
One-sentence principle: Use near-field magnetic induction to transmit information, not electromagnetic waves.
一句话原理：用近场磁感应传递信息，而非电磁波。
Why are Underwater/Underground Environments So Friendly to Magnetic Fields?
为什么水下/地下对磁场如此友好？
- Biological tissues, water, non-magnetic metals, concrete and other materials have magnetic permeability close to vacuum (μ ≈ μ₀)
生物组织、水、非磁性金属、混凝土等物质的磁导率均接近真空（μ ≈ μ₀）
- Magnetic fields do not propagate as electromagnetic waves in water, avoiding severe attenuation caused by medium conductivity
磁场在水中不以电磁波方式传播，不承受由介质电导率带来的剧烈衰减
- Low-frequency magnetic fields attenuate minimally in seawater; magnetic field lines penetrate seawater as easily as air
低频磁场在海水中衰减极小，磁力线穿透海水犹如穿透空气
- Magnetic fields naturally form closed loops with extremely low side lobes, combining confidentiality and anti-interference
磁场天然形成封闭回路，旁瓣极低，保密性与抗干扰性兼具
Key Formula:
Received end induced voltage attenuation ∝ 1/d³
关键公式：接收端感应电压衰减 ∝ 1/d³（d 为线圈间距）
Reference: IEEE - Near-Field Magnetic Induction Communication
Core Advantages of Magnetic Communication Underwater
磁场通信在水下的核心优势
环境绝对鲁棒
无论清澈/浑浊海水、淡水、含沙量、温差层、气泡群，传输特性几乎不变，全天候可靠
Unaffected by clear/turbid seawater, freshwater, sand content, temperature layers, or air bubbles. Transmission characteristics remain stable in all weather conditions.
零延迟体验
磁场传播无惯性，时延由电路决定，支持实时语音、视频和控制指令
Magnetic field propagation has no inertia. Latency is determined by circuit design, supporting real-time voice, video, and control commands.
跨介质无缝连接
可轻松穿透船壳、管道、人体、水-空气界面，实现无穿孔密封通信
Easily penetrates hulls, pipelines, human bodies, and water-air interfaces, achieving non-penetrating sealed communication.
隐藏与无干扰
近场边界锐利，不易被远场探测，且不干扰声学、光学等传感器工作
Sharp near-field boundary makes it difficult to detect from afar, without interfering with acoustic, optical, or other sensor operations.
极简硬件
无需笨重换能器或精密光学对准，空心线圈可柔性共形安装
No bulky transducers or precision optical alignment required. Hollow coils can be flexibly co-mounted.
Core Comparison of Four Communication Methods
四大通信手段核心指标对比
| Metric指标维度 | Acoustic声学通信 | Optical光学通信 | RF射频通信 | Magnetic磁场通信 |
|---|---|---|---|---|
Transmission Range 传输距离 | Tens of km 数十公里 | Several m - 100+ m 几米~百余米 | Near zero in seawater 海水几乎为0 | Within 100m near-field 近场100米内 |
Communication Rate 通信速率 | Tens of bps 几十bps | Several Mbps-Gbps 数Mbps-Gbps | Extremely low bps 极低bps | Tens of kbps-mbps 几十kbps-mbps |
Physical Latency 物理时延 | Seconds 秒级 | Microseconds 微秒级 | Extremely low 极低 | Milliseconds 毫秒级 |
Water Quality Impact 水质影响 | Significant impact 影响极大 | Extremely sensitive 极其敏感 | Freshwater only 仅淡水可用 | Almost no impact 几乎无影响 |
Penetration (Water/Air/Metal) 穿透水空/金属 | Very poor 极差 | Very poor 极差 | Poor 较差 | Excellent 极好 |
The only underwater/underground wireless communication technology that simultaneously satisfies "strong penetration + low latency + environmental robustness"
唯一能同时满足「穿透性强 + 低时延 + 环境鲁棒性」的水下地下无线通信技术
The only reliable communication method in extreme scenarios such as underground collapses
地下塌方等极端场景下的唯一可靠通信手段
Learn more about magnetic induction communication technology:
了解更多磁感应通信技术：