How far can a LoRa sensor transmit
in a basement or cellar?

cell_tower 1. What is LoRa Technology?

LoRa (Long Range) is a radio communication technology specifically designed for Internet of Things (IoT). It allows the transmission of small amounts of data over very long distances with minimal energy consumption.

Unlike WiFi, which prioritises data rate, LoRa prioritises range and obstacle penetration. A LoRa sensor can emit through several concrete walls, making it ideal for underground applications.

Key features of LoRa

• Range in open field: up to 15 km (theoretic), 5 km in real conditions.
• Barrier penetration: through several reinforced concrete walls.
• Low power consumption: A battery can last more than 3 years.
• Frequency: 868 MHz in Europe (free and regulated ISM band).
• Flow: low (max. 50 kbps), but sufficient for sensor data.

The 868 MHz frequency is a strategic choice: it penetrates obstacles far better than the 2.4 GHz frequency used by WiFi. It is the same band used by alarm systems and gate remotes.

distance 2. Theoretical range of a LoRa sensor

The numbers announced by LoRa module manufacturers are impressive: up to 15 km in open field. In real-life conditions, with urban or industrial obstacles, the range is usually 2 to 5 km.

Note that in the case of a tankio installation, the gateway is usually located in the same house the sensor. The distance to be covered is therefore 5 to 30 meters max, which is very much in the capacities of LoRa, even through several floors.

tune 3. Factors influencing the actual range

The actual range of a LoRa sensor depends on several factors that it is important to understand to optimize your installation.

Physical Barriers

• Reinforced concrete: 20-30 dB reduction per wall. A concrete floor with steel reinforcement is the most difficult obstacle.
• Bricks and concrete blocks: 5-15 dB attenuation per wall. Easier to cross than reinforced concrete.
• Metal: Very high attenuation. A steel tank can act as a shield if the sensor is placed against it.
• Land (buried): attenuation of 10-20 dB per metre of wet soil.
• Insulation with metal vapour barrier: can significantly weaken the signal.

Interference

The band 868 MHz is shared with other devices: alarms, remote controls, weather sensors. Interferences may reduce the range, but LoRa uses a mechanism of spread spectrum which allows it to "pass under" the ambient noise. That is one of its major advantages.

basement 4. Performance in basement and cellar

Specifically, what can be expected from a LoRa tankio sensor installed in a typical Belgian cellar?

Current configuration: tank in the cellar

The tank is in the basement, the gateway is on the ground floor or on the first floor. There is usually 1 or 2 concrete floors to cross, possibly with metal pipes.

In this configuration, more than 95% of tankio installations work perfectly without any particular configuration. The gateway receives the signal even with 2 concrete floors and 15 meters distance.

Difficult configuration: tank buried in the garden

If your tank is buried in the garden and the house is 20-30 meters away, the signal must cross the earth and then the foundations. In this case, the signal is weaker but can generally still be received if the gateway is placed on the side of the house nearest to the tank.

"My tank is buried 15 meters from the house, under a concrete slab. I had no problem with reception. The gateway sits on the windowsill facing the garden." — Sophie, tankio user in Charleroi.

compare_arrows 5. LoRa vs WiFi for transmission from a cellar

Some level sensors use WiFi rather than the LoRa. Let's compare the two technologies for underground use.

WiFi is very powerful for video streaming and large files, but its high frequency (2.4 GHz) makes it not suitable for transmission from a basement. LoRa, with its lower frequency and exceptional radio sensitivity, is clearly superior for this application. Moreover, our connected level sensor uses LoRa exclusively to ensure reliability.

settings_input_antenna 6. How the tankio gateway manages weak signals

The bridge tankio is not a standard LoRa receiver. It was designed and optimized by our engineers to maximize reception in Belgian conditions.

Tankio-specific optimizations

• High sensitivity antenna: our gateway uses an external antenna with a gain of 3 dBi, compared to 0-1 dBi for standard modules.
• Signal processing: filtering algorithm that extracts the useful signal even with a very low signal-to-noise ratio.
• Repetition of frames: The probe repeats each measurement 3 times at short intervals to ensure the reception of at least one frame.
• Low data-rate mode: In difficult environments, the probe automatically switches to low data-rate mode which improves reception sensitivity by 6 dB.

These optimizations allow the tankio gateway to capture signals up to 20 dB lower a standard LoRa receiver. That's what makes the difference in the most difficult cellars.

tips_and_updates 7. Solutions if the range is insufficient

In very rare cases (less than 2% of installations), the signal may be too low. Existing solutions include:

Move the gateway

The simplest solution. Try to place the gateway closer to the tank, ideally in the room above the cellar, or near a window on the tank side. Sometimes a 2 metre shift is enough to pass over an obstacle.

Use a relay gateway

For large properties or very distant tanks, a second gateway can be installed as a relay. The two gateways communicate with each other to route data to the Internet.

Position antenna

The tankio bridge comes with an external antenna that can be positioned separately. Placing the antenna higher or in a different position can significantly improve reception. An antenna placed 1 metre from the ground captures 2 to 3 times better than an antenna placed on the ground.

Need personalized tips for your installation? Consult our installation FAQ or contact our team.