Choose the 8 or 16 channel model for UG87

[Introduction]

Ursalink offers LoRaWAN gateway for outdoor scenarios, which is UG87. And it supports 8 channels and 16 channels for customers, the higher model owns double performance than the default one. This document is used to guide whether to choose the right model.

The channels here are the concurrent channels that used to receive and decode the data uplinked by the sensors and end nodes connected to this gateway, so more data, more channels are needed. The number of data is related to the number of sensors and the time period they uplink the data, so more sensors and a shorter period to report, more channels are needed.

[How to calculate to get the extract data in theory]

The formula S=N F 0.184/ t0

S：The max sensors and end nodes support.

N: The channel number of this gateway, the value is 8 or 16.

F：The time period to uplink the data, eg 3600s.

t0: The full time used to transmit the data in the air, it's related to the data size, bandwidth, Spreading Factor and Code Rate. More info, you can calculate it through this Tool.

0.184: This is the constant value of Lora channel usage.

For example, SF=7, BW=125KHz, CR=0.8 ( 4/(1+4) ), the payload is 51 byte, we can calculate the t0 through this Tool, which is t0=0.103s

If SF=12, the t0 = 2.466s

N=8, F = 3600s So the max number S (SF=7) = 8 3600 0.184 / 0.103 = 51448, this is the value in theory. While the max number S (SF=12) = 8 3600 0.184 / 2.466 = 2418, this is the value in theory as well.

[Recommendation]

In the real installation scenario, it's much complicated, including some data are uplinked at the same time, the uplink speed is shorter, the uplink data size is bigger, the RF jamming, etc, so If sensor number is no more than 1000, you choose the 8 channel model. If you have more sensors, or you want to keep enough capacity, it's better to choose the 16 channel model instead.

More info, try to click here Ursalink UG87 .