LPWAN range under ideal conditions

LPWAN companies often advertises with extreme ranges. In this article we bring the marketing teams in the unlicensed band back on the ground. In the unlicensed band, hot-air balloons are often used for propaganda about ranges. Hot air balloons are filled with hot air. Claims of range are in this case only hot air. The propagation of radio waves must follow physical laws. The molecules in the air already form a attenuation for the radio wave. The surface of the earth, the condition of the surface and/or structure of the surface form likewise a attenuation of the radio waves. In addition, there are buildings or trees.

In order to hide the topography in this observation, we have placed the antenna mast with a height of 25 m in the North Sea near the island of Helgoland. In the simulation, the water of the North Sea forms a planar surface, including the terrestrial curvature. The surface of water has a lower attenuation than, for example, the moor or the meadows in the Neustadt am Rübenberge area. This means that the range we have achieved in the North Sea is an extreme that we cannot achieve in the real area of Neustadt. The region around Neustadt is very flat, but also no salt desert. From the approx. 21 km in the North Sea under ideal conditions, becomes in reality in Neustadt approx. 7.5 km range. For the 21 and 7.5 km, 8 dB attenuation for fading and 20 dB for the first wall of a building were considered. Areas with possible indoor coverage are marked in green. As soon as the maximum attenuation of 28 dB is exceeded, the software marks the area with the color red. East of the 25 m high antenna mast in the North Sea is the island of Helgoland. The island forms a radio shadow and leads to the fact that behind the island no more reception is possible. The wave propagation in the simulation is based on the Okumura Hata model.

Furthermore, the program calculates the refraction of radio waves at the tops of hills and mountains. Thus, the reception behind the hills and mountains is also visible. The cliffs of the island Helgoland show this clearly. A part of the island, already marked red, is only reached by refraction.

In the south of the antenna mast are the Frisian islands. The minimal increase of the islands leads to the fact that a reception is still possible in the outside area on the island. A few kilometres before the islands, the radio link departs through the earth's curvature and the high points of the islands are just reached in this way.

Something similar happens on the mainland. There are no islands in the path, but the area around Neustadt am Rübenberge has a few hills. This leads to the limitation of the range by the topography. But also the opposite can be seen well. The moor west of Neustadt is a very flat environment without buildings only covered with low trees and shrubs. This leads to the fact that the radio wave covers the complete Steinhuder Meer (large inland sea). A similar result can be achieved by using Cellmapper to evaluate the mobile base station of the network operators. The base station in the city of Neustadt reaches the lake and as far as Mardorf.

Inquiries to LPWAN - make or buy, consultation to the economy of LPWAN and very inexpensive SIM cards are welcome to harald.nauman (at) lte-modem.com

Note to the bean counters. Possibly a module has one dB more or less sensitivity. The two dB antenna gain hopefully covers the concerns of the bean counters. If a bean counter feels skipped, then I do the simulation again. Just send me the desired parameters.