One of the persistent problems in infantry operations is the location of your own soldiers. In training environments and well-connected headquarters, GPS tracking is standard. But in degraded communications environments — urban canyons, dense forest, underground — where conventional military radios struggle for range or are jammed, commanders lose the real-time position picture of their own forces.
The ideal solution would be a tracking device that every soldier carries, that transmits position updates reliably over several kilometres, that requires no fixed infrastructure, that runs for months on standard batteries, and that costs little enough to be fielded at squad level.
A body of research published between 2017 and 2025 has systematically explored whether LoRa (Long Range) radio technology can meet this requirement. The findings are compelling — and directly relevant to anyone designing low-power tracking or monitoring systems for tactical or defence-adjacent use.
Background: The Case for LoRa in Military Applications
LoRa is a chirp spread-spectrum radio modulation scheme, developed by Semtech and commercialised from around 2013. Its civilian market applications — smart city sensors, utility metering, agriculture monitoring — created a large ecosystem of silicon, modules, and protocols that are now mature, affordable, and well-understood.
The physical properties that make LoRa attractive for civilian IoT translate directly to military edge sensing:
| Property | Value | Military relevance |
|---|---|---|
| Frequency | 433 / 868 / 915 MHz | Sub-GHz penetrates foliage and building materials |
| Range | 2–15 km (terrain dependent) | Covers squad-to-platoon tactical distances |
| Transmit power | 17–22 dBm (50–160 mW) | Low power, low thermal signature |
| Receive current | ~12 mA | Can be duty-cycled to very low average current |
| Sleep current | <1 µA (transceiver only) | Enables multi-month battery operation |
| Modulation | Chirp spread-spectrum | Inherently resistant to narrowband jamming |
| Data rate | 0.3–50 kbps | Adequate for sensor telemetry and position reporting |
The spread-spectrum modulation characteristic is particularly noteworthy. LoRa’s chirp signals spread energy across a wide bandwidth (125–500 kHz), making them:
– Difficult to detect against the noise floor — the signal-to-noise ratio at the receiver can be negative (−20 dB SNR capability at SF12)
– Inherently resistant to narrowband jamming — a narrowband jammer must spread its power across the LoRa signal bandwidth to be effective
– Not providing military COMSEC by themselves, but providing a layer of physical-layer robustness that civilian protocols (Wi-Fi, Bluetooth) lack
The 2017 IEEE Research: U-LoRa for Tactical Troops Tracking
Research context and objectives
The landmark 2017 IEEE paper, “A Long-Range Low-Power Wireless Sensor Network Based on U-LoRa Technology for Tactical Troops Tracking Systems,” addressed the specific need for low-power soldier position reporting in environments where conventional military radios are too expensive, too heavy, or too power-hungry for individual tracker use.
The research team designed a complete end-to-end system: tracker nodes worn by individual soldiers, a mobile gateway (carried by the commander or mounted on a command vehicle), and a command display interface.
Hardware design
Tracker node:
– Microcontroller: ARM Cortex-M0+ based ultra-low-power MCU
– LoRa transceiver: SX1278 operating at 433 MHz (chosen over 868/915 MHz for superior foliage penetration)
– GNSS: u-blox MAX-M8Q GPS/GLONASS module with power control
– Battery: AA lithium primary cells (LiFeS₂ chemistry, −40 °C rated)
– Enclosure: ABS injection-moulded housing with silicone urethane conformal coating on PCB; rated IP65
Power management strategy:
The tracker node implements a three-state duty cycle:
1. GNSS acquisition (active): GPS module powered on, acquires fix in 1–30 seconds. Current draw: 18 mA. Duration: 5–30 seconds per fix interval.
2. LoRa transmission: GPS module powered off. LoRa transmitter powered on, transmits a 20-byte encrypted position packet at 17 dBm. Duration: ~200 ms at SF10. Current draw: 45 mA during TX.
3. Deep sleep: All subsystems powered off except RTC. Current draw: 280 nA. Duration: remaining time between fix intervals.
Average current calculation (5-minute position update rate):
– GNSS acquisition (10 s average): 18 mA × 10 s = 180 mAs
– LoRa transmission: 45 mA × 0.2 s = 9 mAs
– Deep sleep (290 s): 0.00028 mA × 290 s = 0.08 mAs
– Total per 5-minute cycle: ~189 mAs ÷ 300 s ≈ 0.63 mA average
At 0.63 mA average current draw from a pair of AA lithium cells (~3,500 mAh total at −20 °C), the projected operational lifetime is approximately 230 days — well over six months of continuous operation at one position update every five minutes.
Range performance
Tests were conducted in three terrain types:
| Environment | Range achieved | Notes |
|---|---|---|
| Open field / low vegetation | 5.2 km | 100% packet delivery at SF10, 125 kHz BW |
| Mixed woodland | 2.1 km | Significant foliage attenuation at 433 MHz |
| Dense forest | 1.4 km | Urban deployment equivalent |
| Simulated urban | 800 m | Building penetration demonstrated |
At SF12 (maximum spreading factor, lowest data rate), range extended to 7.8 km in open field at the cost of a higher time-on-air and proportionally higher average current draw.
Cost per node
At prototype production quantities, the complete tracker node BOM was assessed at under $15 USD — making it feasible to equip every individual soldier in a unit rather than just squad leaders.
The 2018 Research: Evaluating LoRaWAN for Tactical Military Use
A 2018 study (“Evaluating LoRaWAN-based IoT devices for the tactical military environment”) applied a more rigorous operational evaluation framework, assessing LoRaWAN’s suitability across multiple tactical scenarios:
Scenario 1: Logistics tracking — GPS trackers on vehicles, equipment pallets, and supply containers reporting position and status via LoRaWAN. Assessment: suitable. Duty cycles and data rates are adequate; encryption requirements can be met with application-layer AES-256.
Scenario 2: Environmental monitoring — Sensors reporting temperature, humidity, and chemical indicators from dispersed positions. Assessment: suitable. Very low data rates are adequate; long battery life is achievable.
Scenario 3: Real-time situational awareness — Sub-second latency position reporting for fast-moving tactical scenarios. Assessment: not suitable with standard LoRaWAN. LoRaWAN’s Class A protocol imposes latency constraints (downlink only after uplink) and duty cycle limits (1% in EU 868 MHz band) that make real-time tracking problematic.
Key finding: LoRaWAN as a civilian protocol stack is not directly usable for all military applications. However, custom LoRa physical-layer implementations — using the Semtech SX1276/SX1278 transceiver in point-to-point or star mode with a custom MAC layer — can eliminate the duty cycle constraints and latency limitations of LoRaWAN while retaining all the physical-layer advantages of LoRa modulation.
This finding is directly reflected in ThingsLog’s custom Open LoRa Protocol, which operates on the LoRa physical layer with a custom MAC designed for the specific requirements of long-duration, low-power, high-reliability monitoring deployments.
The 2019 Research: Cyber Security Analysis
“Investigating LoRa for the Internet of Battlefield Things: A Cyber Perspective” (2019) shifted focus from performance to security — a critical consideration for any military communications technology.
Key findings:
Detection resistance: LoRa’s chirp spread-spectrum modulation reduces the peak spectral density of the transmitted signal compared to narrowband alternatives. At SF12, the signal can be received at −20 dB below the thermal noise floor — meaning a passive intercept receiver at the same range as the gateway would see the signal at 20 dB below the noise floor, making it difficult to detect without prior knowledge of the LoRa symbol rate and bandwidth.
Jamming resistance: LoRa is inherently resilient to narrowband jamming. A narrowband jammer (tone or narrowband noise) must spread its power across the 125–500 kHz LoRa signal bandwidth to degrade the link; a jammer operating at equivalent power but narrowband will have reduced effectiveness against LoRa compared to a narrowband FSK or GFSK radio.
Confidentiality: LoRa/LoRaWAN’s standard AES-128 encryption (network session key + application session key) provides adequate confidentiality for low-classification sensor data. Military CONFIDENTIAL and above data requires application-layer AES-256 or beyond, combined with key management infrastructure not present in standard LoRaWAN.
Physical security vulnerability: A captured LoRa node could reveal its keys if not protected by a secure element (hardware key storage). Military implementations should use hardware secure elements (e.g., Microchip ATECC608B or equivalent) for key storage.
Conclusion: LoRa provides meaningful physical-layer security advantages over conventional IoT radios, but does not provide military-grade COMSEC without additional cryptographic and key management measures. For unclassified IoBT sensor reporting and logistics tracking, LoRa with application-layer encryption is viable.
The 2025 Research: Complete Tactical Communication System
The most recent publication in this series, “Design and Implementation of a LoRa-Based Tactical Communication System Using Low-Power Sensors” (IEEE, 2025, DOI: 10.1109/11041237), presents a complete implementation of a tactical sensor and communications network based on LoRa, validated in field trials.
The system architecture includes:
– Low-power sensor nodes — environmental, motion, acoustic, and position sensors with LoRa uplinks
– Mobile gateway — vehicle-mounted or man-portable LoRa gateway with encrypted satellite/LTE backhaul to command
– Command display — real-time dashboard displaying sensor readings, node positions, and detection alerts
– Encrypted messaging — bidirectional command messaging from headquarters to field nodes
– Degraded communications mode — system continues to operate and buffer data when the backhaul link is unavailable, uploading stored data when connectivity is restored
The store-and-forward degraded communications capability is a direct parallel to the architecture used in ThingsLog’s Antarctic deployment — buffering 24 hours of sensor data locally and uploading when the communication window opens, rather than requiring continuous connectivity.
Design Lessons for Military-Adjacent LPWAN Systems
1. Choose the right frequency for the terrain
433 MHz penetrates foliage and building materials better than 868/915 MHz but has worse antenna efficiency at the node (requiring a physically larger antenna). For dismounted infantry in forests or urban environments, 433 MHz is typically preferable. For open terrain or UAV uplinks, 868/915 MHz gives better antenna compactness with acceptable range.
2. Size the GNSS power separately from the LoRa power
In a tracking node, GNSS acquisition typically dominates the power budget. Choosing a GNSS chipset with a hot-start capability (where recent ephemeris data is retained in SRAM or battery-backed SRAM) reduces average acquisition time from 30 seconds to 1–2 seconds, cutting average GNSS current draw by 15–30×.
3. Use a custom MAC layer for military use
Standard LoRaWAN’s duty cycle restrictions and Class A latency model are incompatible with many military use cases. A custom MAC operating on the LoRa physical layer — as used in ThingsLog’s Open LoRa Protocol — provides the flexibility to define duty cycles, retransmission logic, and downlink timing appropriate to the specific operational requirement.
4. Add a hardware secure element
Military tracker nodes should store LoRa session keys and device credentials in a hardware secure element, not in microcontroller flash. This prevents key extraction from a captured node and enables remote revocation if a node is compromised.
5. Plan for the denied communications scenario
A tracker that transmits position continuously is tactically obvious — its transmissions can be used to locate the soldier. Consider architectures that buffer position data locally and transmit in short, infrequent bursts, or only when the soldier reaches a designated reporting point. This reduces the RF signature of the individual soldier while maintaining the position record at the command post.
What ThingsLog Brings
ThingsLog’s LPMDL-series devices have been designed from the ground up for the challenges visible in this research body: ultra-low-power LoRa communication, local data buffering, scheduled transmission windows, and multi-year battery operation in extreme environments.
The Open LoRa Protocol, developed by ThingsLog, provides the custom MAC flexibility that military and defence-adjacent applications require — operating outside the constraints of civilian LoRaWAN while retaining full compatibility with the LoRa physical layer and its unique range and power characteristics.
For defence-adjacent monitoring requirements — from logistics tracking and environmental sensing to perimeter surveillance and critical infrastructure protection — contact ThingsLog to discuss how our LPWAN platform can be adapted to your operational requirements.
Sources
- IEEE: U-LoRa Tactical Troops Tracking (2017)
- ResearchGate: Evaluating LoRaWAN for Tactical Military (2018)
- ResearchGate: Investigating LoRa for IoBT — Cyber Perspective (2019)
- IEEE: LoRa-Based Tactical Communication System (2025)
Series Navigation
- Why Low Power Matters in Military Operations
- Key Application Domains
- How Military Low-Power Electronics Are Built
- Protective Coatings for Military Electronics
- Military Electronics Standards
- IP Ratings and Ingress Protection
- Case Study: DARPA N-ZERO
- Case Study: LoRa Tactical Troop Tracking
- Case Study: ThingsLog LPMDL in Antarctica
- Case Study : Army CombatConnect
