End nodes transmit intermittently to TTN

End Devices (Nodes) Dragino
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Hi everyone :wave:

I am doing some tests trying to send pressure and flow data from two points within a plot. Each point has two dragino sensors (PS-LB and SW3L-LB) that are below ground but the antennas of these are about 20 and 40 cm above ground. These points are 30 and 40 meters in a straight line to the antenna but with trees and bushes in between. The sensors are connected via OTAA.
The Dragino gateway (LG308) is under the eaves of the house roof and is connected via wifi to the network while the antenna next to the gateway is a directional antenna pointing towards the sensors.

The problem is that by default these sensors transmit every 20 minutes, but the data do not arrive in that time but are intermittent and can take several hours. As far as I know, there are no other end nodes or other gateways nearby.

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While a directional antenna seems a good idea, it usually isn’t. Have you checked how the system behaves with the default dipole?

Given the position of the antennas is above ground while the sensors are below I assume you are using coax between the units and the antennas? What kind of antennas are being used? And what kind of antenna cable?

Another point of concern is bushes in the line of sight. Are those leafy ones with a lot of leaves (still) on the bush? Because of the water content leaves are RF shields and a number of them between the antennas will severely impact signal levels.