LoRaWAN Indoor Coverage Test

The Idea:

The idea was simple: Why not use our permanently installed outdoor Gateway on our office roof, which we otherwise use for network coverage and performance tests outdoors, to conduct an indoor coverage test? Said and done ...

Objective:

Besides the question of how the LoRaWAN network behaves from the roof in our office building, we hoped the test would also answer the following questions: Is there a connection between the transmission and reception strength of the Adeunis RF? What impact do the antenna position and its own network propagation have on reception strength?

Test Setup:

The office building at Langestr.2, 76199 Karlsruhe, has a floor area of just under 900m² per floor (20m * 45m) and consists of a total of 4 floors. On the roof is our permanently installed outdoor Gateway & antenna on the northern side of the building. The floor below is our office (2nd floor), the first floor is a completely vacant office floor without walls. On the ground floor, there is a supermarket and below that an underground car park. In total, we distributed 18 measurement points throughout the building, 5 per floor and 3 in the underground car park. Only a few ingredients were needed for the test:

• An outdoor Gateway: the Lorrier LR2, IoT LoRa Gateway 868MHz
• Outdoor Antenna: Barracuda – 868MHz 5dBi Omnidirectional Outdoor Antenna
• Handheld Test Device: Adeunis RF - FIELD TEST DEVICE LORAWAN 868
• Two hours to walk through the measurement points and evaluate the data

Procedure:

We walked through the individual measurement points with the Adeunis and established the connection to the server 10 times at each measurement point at the push of a button. Thus, we created 10 measurements per measurement point within a minute, noted the time period, and repeated this measurement at the remaining measurement points. Using the timestamps and sufficient distance between the measurement points to compensate for the time delay in the communication path, we were able to assign the individual measurements to the respective measurement points. Additionally, we noted the displayed transmission power on the Adeunis to measure possible correlations between the transmission power on the device itself and the reception power at the Gateway.

Results and Conclusion:

The test results show that a consistently satisfactory network penetration is measurable down to the basement, even though the measurement points are directly below the Gateway and no optimization of the antenna position took place. Reflection effects can also be observed, as the measurement values in the basement would be significantly lower purely through the penetration of the floors. A significant decrease in reception strength at measurement points below the antenna location cannot be observed. However, the test setup and procedure were too simple to attribute too much importance to the results now. Long-term indoor and outdoor tests will follow.

Equipment: Lorrier LR2, IoT LoRa Gateway 868MHz Barracuda – 868MHz Omnidirectional Outdoor Antenna Adeunis RF - FIELD TEST DEVICE LORAWAN 868