Remote Meter Reading: Migrate from 2G/3G GPRS to LTE Without Changing Your Billing System
2G GPRS networks are being phased out across Europe. Orange shut down its 2G network in France at the end of 2024. SFR and Bouygues will follow suit. If your remote meter reading devices use 2G or 3G, migrating to LTE is urgent—and easier than it seems.
The State of Emergency in 2G Remote Meter Reading
According to RTE and the distribution network operators’ unions, more than 2.3 million metering points in France still use 2G/3G communication for remote meter reading. These installations include:
- Modbus electricity meters in industrial settings
- Gas and water submeters
- Solar inverters (inverters under 5 kWp)
- Pumping stations
- Generation meters (solar, wind)
The phase-out of 2G/3G networks is causing data collection outages that have already been observed in several regions. The lack of remote meter reading is disrupting billing, energy reports, and alerts for abnormal consumption.
Why LTE Is a Game-Changer
LTE Cat-M1 and Cat-NB1 (NB-IoT) were specifically designed for low-data-rate IoT applications such as remote meter reading:
| Criterion | GPRS 2G | LTE Cat-M1 | LTE Cat-NB1 |
|---|---|---|---|
| Download Speed | 85 kbps | 1 Mbps | 250 kbps |
| Indoor Coverage | Average | Better (+15 dB) | Excellent (+23 dB) |
| Power consumption | High | Very low | Minimal |
| Latency | ~500 ms | ~15 ms | ~1500 ms |
| Network availability | Ending soon | 2035+ | 2035+ |
For industrial remote meter reading (Modbus meters, polling every 15 minutes), LTE Cat-M1 with the Eziwan Gateway router offers the best balance of data rate, coverage, and cost.
Migration Without Replacing the Billing System
The main obstacle to migration is the fear of having to replace the billing system (energy CRM, IT services provider, ERP) that uses meter data.
Good news: Eziwan uses exactly the same data interface as your current system.
Scenario 1: Modbus RTU Meters → MQTT
Your meters communicate via Modbus RTU over RS-485. Your billing system uses MQTT.
The only difference for your billing system: the MQTT topic still exists, and the values arrive with the same structure. If you replace the field device, your backend won't notice a thing.
Scenario 2: Meters with Modbus TCP IP Output
# Eziwan Configuration for Modbus TCP → MQTT Polling
modbus_tcp:
host: "192.168.10.10"
port: 502
unit_id: 1
polling_interval: 900s # 15 minutes
registers:
- address: 0x0000
name: "energy_kwh_import"
type: uint32
scale: 0.001
- address: 0x0002
name: "energy_kwh_export"
type: uint32
scale: 0.001
- address: 0x0100
name: "power_kw"
type: int16
scale: 0.1
mqtt:
broker: "mqtt.eziwan.com"
topic_prefix: "site/usine-01/energie"
qos: 1
Scenario 3: Chassis-to-chassis replacement
If you have a fleet of standardized GPRS modems (Wavecom, Sierra, Lantronix, etc.), Eziwan can provide an identical configuration on the Eziwan Gateway with mass ZTP deployment.
Migration Process:
- Export a CSV file of your device fleet (ID, site, associated meters)
- Import into Eziwan → generate ZTP tokens
- Ship the preconfigured routers
- Physically replace the field devices (5 minutes per site)
- Automatically verify data collection in the dashboard
We recommend migrating in waves of 20–50 sites. The first wave allows you to validate the integration with your billing system before scaling up.
Return on Investment from the Migration
For a fleet of 200 meters:
| Item | Annual 2G GPRS Cost | Annual LTE Eziwan Cost |
|---|---|---|
| SIM subscription | €24/year × 200 = €4,800 | Included in the plan |
| Device maintenance | €15/device × 200 = €3,000 | Support included |
| Service calls for collection outages | ~40 hours × 80 €/hour = 3,200 € | < 500 € (99.7% uptime) |
| Total | ~11,000 €/year | ~6,500 €/year |
Not to mention the cost of compliance if your collection falls below the regulatory thresholds.
Meter Protocols: Modbus RTU, M-Bus, and Wireless M-Bus
Industrial meter parks rarely use a single protocol. A typical industrial facility may have the following simultaneously:
- Electricity meters: Modbus RTU over RS-485 (de facto industry standard)
- Industrial gas meters: M-Bus (Meter Bus, EN 13757-2) over twisted-pair cable
- Cold/hot water meters: Wireless M-Bus (wM-Bus, EN 13757-4) at 868 MHz
- Heating/cooling meters: Wired M-Bus or DLMS/COSEM, depending on the model
- Solar meters: Modbus RTU or SunSpec (standardized Modbus profile for inverters)
The Eziwan Gateway natively supports Modbus RTU over RS-485 and can integrate industrial M-Bus concentrators via the RS-232 serial interface. For Wireless M-Bus meters (868 MHz), a USB or serial receiver module connects to the gateway.
| Protocol | Physical medium | Max. range | No. of devices/bus | Typical use |
|---|---|---|---|---|
| Modbus RTU | RS-485 | 1,200 m | 247 | Industrial electricity meters |
| Wired M-Bus | Twisted-pair cable | 1,000 m | 250 | Gas, water, heat |
| Wireless M-Bus | 868 MHz radio | 100 m indoors | 100–500 | Smart water/gas meters |
| DLMS/COSEM | RS-485 or TCP | Variable | Variable | High-voltage meters, Linky |
| SunSpec (Modbus) | RS-485 or TCP | Standard | ~32 per bus | Photovoltaic inverters |
A single Eziwan Gateway can aggregate Modbus RTU and M-Bus meters simultaneously using its two serial interfaces. Each protocol is configured independently in the YAML file—data from all meters is sent to the same MQTT topic with the tags energy_type: electricity/gas/water.
NB-IoT vs. LTE Cat-M1 for Industrial Remote Meter Reading
The phase-out of 2G makes it necessary to choose a replacement technology. Two low-power LTE options dominate the market:
NB-IoT (Narrowband IoT) — adopted by Enedis for the Linky meter (NB-IoT module integrated into Linky meters since 2022). NB-IoT offers exceptional indoor coverage thanks to frame repetition (+23 dB vs. 2G), but with high latencies (1–10 seconds) and a limited data rate (250 kbps). Suitable for meters that transmit small amounts of data at very low frequencies (daily or hourly readings).
LTE Cat-M1 — offers higher data rates (1 Mbps), lower latency (<100 ms), and support for VPN tunnels. Recommended for industrial applications that transmit data in near real time (every 30–900 seconds) with a SCADA system that queries the meters on demand.
| Criterion | NB-IoT | LTE Cat-M1 | 2G GPRS (reference) |
|---|---|---|---|
| Downlink speed | 250 kbps | 1 Mbps | 85 kbps |
| Typical latency | 1–10 s | 50–150 ms | 300–500 ms |
| Indoor coverage | +23 dB (excellent) | +15 dB (very good) | Reference |
| Standby power consumption (PSM) | <1 µA | ~5 µA | 1–10 mA |
| Real-time VPN tunnel | ❌ Incompatible latency | ✅ Compatible | ✅ Compatible |
| International roaming | Limited | Good availability | Extensive |
| Recommended use | Hourly/daily meter readings | Industrial Modbus remote meter reading | - |
For industrial Modbus remote data collection (polling every 1–15 minutes, remote VPN access), LTE Cat-M1 is the recommended choice. NB-IoT latency makes standard Modbus timeouts and interactive VPN sessions impractical.
Schedule for the Phase-Out of 2G/3G Networks by Carrier in France (2024–2026)
| Carrier | 2G Shutdown | 3G Shutdown | Status at the End of 2025 |
|---|---|---|---|
| Bouygues Telecom | End of 2024 | End of 2023 | ✅ 2G and 3G completed |
| SFR | End of 2024 | Phased out 2025–2026 | ✅ 2G completed, 3G in progress |
| Orange | Phased out 2025–2026 | Phased out 2025–2026 | ⚠️ In progress — varies by region |
| Free Mobile | Depends on Orange (MVNO) | Depends on Orange (MVNO) | ⚠️ Follows Orange’s schedule |
Priority Areas for Shutdown: Orange is prioritizing the shutdown of densely populated urban areas where 4G coverage is complete. Rural areas sometimes retain 2G service longer as a safety net, but these extensions are unpredictable. Do not count on 2G service continuing in rural areas after the end of 2026.
Warning sign to watch for: If your GPRS devices are experiencing increasing disconnections, repeated failures to reconnect to the network, or frequent handoffs between cell towers, 2G coverage is being phased out in your area. This is an urgent signal to speed up the migration—typically 2 to 6 weeks before the final shutdown.
Take inventory of your 2G devices and their SIM providers. If the provider is not Orange in rural areas, consider migrating as a matter of urgency. Your M2M SIM provider can provide you with a report of active 2G/3G SIMs still in service.
Multi-utility: electricity, gas, and water on the same gateway
One of the lesser-known benefits of migrating to LTE is the ability to consolidate multiple remote meter reading streams onto a single gateway. Whereas GPRS limitations often required one modem per energy type (due to insufficient bandwidth for multiplexing), LTE Cat-M1 allows for the simultaneous management of 3 to 5 types of meters.
Typical architecture at an industrial site:
Gateway Eziwan
├── RS-485 (Modbus RTU) → 4 medium-voltage electricity meters (Socomec DIRIS)
├── RS-232 → concentrateur M-Bus → 8 compteurs gaz (Elster, Itron)
├── USB → 868 MHz wM-Bus module → 12 cold water meters (wireless)
└── LTE Cat-M1 → broker MQTT Eziwan
├── topic: site-01/energie/electricite/{id}
├── topic: site-01/energie/gaz/{id}
└── topic: site-01/energie/eau/{id}
Operational Benefits: a single SIM subscription, a single piece of equipment to manage, and a single monitoring interface for the site’s entire energy balance. The ISO 50001 report is generated from a single data source.
FAQ
My GPRS remote meter reading service is still working—should I switch now? The 2G GPRS network has already been shut down by Bouygues (2024) and SFR (2024). If your meters are still working, your area is covered by an Orange 2G network that is still active, but Orange is gradually shutting down its 2G/3G towers by the end of 2026. The risk of a sudden service interruption increases every month. Migrating proactively will help you avoid an operational emergency.
Do the meters need to be replaced when switching from GPRS to 4G? In the vast majority of cases, no. Industrial meters (Modbus RTU, M-Bus) remain in place—only the communication module (GPRS modem) is replaced by a 4G gateway. The existing RS-485 or M-Bus is reused as-is.
Can 4G data be integrated into existing billing software? Yes. The Eziwan platform exposes data via REST APIs or webhooks. Most water and energy billing software (Berger-Levrault, Omega, etc.) supports automatic imports from an external API. Integration can typically be completed in a few days.
Further Reading
- Blog: 4G Water and Wastewater Monitoring — 300 Stations
- Blog: Zero-Touch Provisioning — Deploy 50 Routers in 2 Hours
- Blog: Industrial 4G LTE Router — Migrating from ADSL Before the End of Copper
- Blog: Modbus TCP vs. RTU — Which Protocol Should You Choose?
Next Steps
If you manage a fleet of GPRS-enabled remote-reading meters:
- Audit: Identify the 2G/3G devices in your fleet
- Test: Request an Eziwan pilot at 5–10 representative sites
- Validation: Verify integration with your billing system
- Migration: Deploy in phases using mass ZTP
Plan a migration → · View the technical documentation →
Additional Resources
- Remote Meter Reading — comprehensive 4G remote meter reading solution for water, gas, and electricity meters
- Wireless M-Bus Meter Reading — Wireless M-Bus protocol for radio-based meter reading
- M-Bus to Cloud — connect your M-Bus meters to a cloud-based monitoring platform
- Modbus Meters — remote meter reading for industrial meters via the Modbus protocol
- Industrial Connectivity — 4G/LTE connectivity solutions for remote meter reading and the IoT
