The idea was simple: Why don't we use our permanently installed Outdoor Gateway on our office roof, which we normally use for network coverage and performance testing outdoors, and use it to carry out an indoor coverage test? No sooner said than done ...
In addition to the question of how the LoRaWAN network behaves from the roof of our office building, we hoped the test would provide further answers to the following questions: Is there a connection between the transmit and receive strength of the Ardeunis RF? What effects do the position of the antenna and its own network propagation have on the reception strength?
The office building in Langestr.2, 76199 Karlsruhe, has a floor space of almost 900m² per floor (20m * 45m) and consists of a total of 4 floors. Our permanently installed outdoor gateway & antenna is located on the roof on the northern side of the building. The floor below is our office (2nd floor), the first floor is a completely empty office floor without walls. On the ground floor there is a supermarket and below that an underground car park. In total we have 18 measuring points distributed 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 time to run the measuring points and evaluate the data
We ran through the individual measuring points with Adeunis and at the push of a button at each measuring point we established 10 connections to the server. Thus, we created 10 measurements per measurement point within one minute, noted the time period and repeated this measurement at the remaining measurement points. Using the time stamps and sufficient distance between the measuring points to compensate for the time offset in the communication line, we were able to assign the individual measurements to the respective measuring points. In addition, we noted the displayed transmit power on the Adeunis to measure possible correlations between transmit power on the device itself and receive power on the gateway.
Results and conclusion:
The test results show that a consistently satisfactory network penetration down to the basement level can be measured, although the measuring points are located directly under the gateway and no optimization of the antenna position took place. Reflection effects can also be detected, since the measured values in the basement would be significantly lower purely by means of the penetration of the floors. A significant decrease in the reception strength at measurement points below the antenna location cannot be detected. However, the test setup and the test procedure were too simple to give the results too much importance now. Long term indoor and outdoor tests will follow.
Lorrier LR2, IoT LoRa Gateway 868MHz
Barracuda - 868MHz Omnidirectional Outdoor Antenna
Adeunis RF - FIELD TEST DEVICE LORAWAN 868