Underground Meter Reading:
4G LTE vs Wi-Fi HaLow for the NE101

The Real Problem: Why Standard Wi-Fi Fails Underground

Standard 2.4 GHz Wi-Fi loses roughly 20–30 dB of signal strength passing through a single reinforced concrete floor — enough to drop a usable –60 dBm signal to below the –90 dBm noise floor. Add a cast-iron pit cover, a steel meter cabinet, and 0.5–1.5 m of earth fill, and you’re dealing with combined attenuation that makes 2.4 GHz Wi-Fi functionally unusable in the majority of underground meter installations.

This isn’t an edge case. A significant share of commercial water and gas metering infrastructure — sub-metering in basements, district heating meters in plant rooms, industrial flow meters in concrete trenches — sits in exactly this environment. The two connectivity options that physically work here are cellular (4G LTE Cat.1) and sub-GHz Wi-Fi (Wi-Fi HaLow, 802.11ah). Both are available as plug-in communication modules for the NeoEyes NE101 camera. Which one you pick has real consequences for power consumption, recurring cost, and infrastructure complexity.

NE101 Communication Modules: What You Are Actually Getting

Both modules slot into the same physical header on the NE101 mainboard — no soldering, no firmware changes, driver-free recognition on insertion. Swapping protocols in the field means opening the enclosure, removing screws, and exchanging the module. That’s the hardware reality to keep in mind when reading the comparison below.

LTE Cat.1 Module

The LTE Cat.1 module uses a Quectel EG912 Series chipset. It supports LTE FDD/TDD and GSM fallback. Two regional variants are available: global version (NE101-L01GL) for Europe, Asia, South America, and Oceania, and North America version (NE101-L01NA) for NA markets. Same 60 mm × 60 mm form factor. Requires a nano-SIM card inserted into the slot behind the front cover.

Wi-Fi HaLow Module

The Wi-Fi HaLow module uses a Quectel FGH100M chipset, compliant with IEEE 802.11ah. It operates in the sub-GHz ISM band: 868 MHz for Europe, 915 MHz for North America. Same 60 mm × 60 mm form factor. No SIM card — it connects to a private Wi-Fi HaLow access point (AP) on your local network. Two SKUs are available: 868 MHz and 915 MHz.

Head-to-Head Comparison

The table below covers the dimensions that matter most for underground meter deployments. “Winner” calls are contextual — there is no universally superior option; the right choice depends on your specific constraints.

Decision Matrix: How to Choose

The two questions that determine the right choice in almost every deployment:
(1) Is there cellular coverage at the installation site?
(2) How many meters are on the same site?

Step-by-Step Configuration

Both modules are configured via the NE101’s built-in Web UI. After installing the module and powering on, access the Web UI at 192.168.1.1 by connecting to the NE101’s Wi-Fi AP (SSID: NE101_XXXXXX, no password).

Configuring LTE Cat.1

Configuring Wi-Fi HaLow

MQTT Payload Reference

Once connected — via either LTE or HaLow — the NE101 publishes an identical JSON payload after each capture event. The payload includes device identity, battery state, capture type, and the Base64-encoded JPEG image. Your OCR pipeline, SCADA system, or data broker subscribes to the configured topic and receives this message directly, with no intermediary cloud service required.

{
  "ts": 1740640441620,           // Unix timestamp, milliseconds
  "values": {
    "devName":     "NE101 Sensing Camera",
    "devMac":      "D8:3B:DA:4E:10:88",
    "devSn":       "458658825555",
    "hwVersion":   "V1.0",
    "fwVersion":   "NE_101.1.0.3",
    "battery":     84,              // Remaining battery %
    "batteryVoltage": 4200,         // mV
    "snapType":    "Scheduled",     // Button | Scheduled | PIR | Alarm
    "localtime":   "2026-04-22 08:30:00",
    "imageSize":   74371,           // bytes
    "image":       "data:image/jpeg;base64,..."
  }
}

The snapType field tells your downstream system what triggered the capture: Scheduled for time-based reads, PIR for motion-triggered events, Button for manual test captures. For meter reading workflows, Scheduled is the typical operating mode — configure a read interval in the Capture Settings section of the Web UI (up to 8 scheduled times per day, or interval-based in minutes/hours/days).

Battery Life Impact

The NE101’s deep sleep current is dominated by the ESP32-S3 in low-power mode — not the communication module. In sleep, the device draws ≤1 W standby regardless of which radio module is fitted. The difference between LTE and HaLow appears during the active transmission window of 5–15 seconds per capture event.

LTE Cat.1 has a higher peak TX current than HaLow, particularly on weak-signal sites where the modem boosts transmit power to maintain the cellular link. In underground pits with marginal LTE signal, this can meaningfully reduce battery life compared to a HaLow deployment with a nearby AP. On strong-signal LTE sites (–80 dBm or better), the practical difference is small.

The CamThink Battery Life Calculator lets you model expected battery life for your specific capture frequency and radio configuration before purchasing. For a 4× capture per day schedule in Wi-Fi mode, the NE101 achieves 3+ years on 4× AA batteries. LTE at the same frequency on a good signal site is in the 1.5–2.5 year range depending on transmission time per event.

Summary: One Deployment, One Decision

If you leave with one rule: use LTE for scattered remote sites; use HaLow for dense concentrated deployments. Both modules are physically interchangeable on the NE101, so you can re-evaluate without replacing hardware — just swap the module and update the Web UI configuration. For large-scale projects, a staged pilot comparing both protocols on representative sites is worth the investment before committing to a module SKU for the full deployment.

Frequently Asked Questions