LoRa Speed Suspiciously Slow

LPWAN Developer Gateways / Concentrators
#1

Hello, we are using a RAK7268 LoRa Gateway and trying to transmit data from RAK arduino with a LoRa chip (RAK4630) and antennae. All products are RAK. We are able to send data form the arduino to the Gateway, but the fastest we have been able to send packets is roughly every 1.5 seconds. On the documentation we read the data rates are between 0.3 and 50 kbps - but due to the infrequent packets we are not even hitting 0.3kbps. I have experimented with the available data rates in our region and nothing seems to improve speeds. Looking at the LoRa gateway logs it is consistent and we are usually around 30-40 packets per minute. Additionally the breathing LED on the Gateway has been flashing red but appears to be functioning correctly.

How can we increase our data rate? Can we send packets faster than every 1.5 seconds? Any help would be greatly appreciated. Thanks, and please let me know if I can provide any additional information.

-Blaine

#2

Welcome to the forum @bayotte

In LoRaWAN a data transmission includes the TX cycle (length is depending on the size of the packet and datarate) followed by 2 RX windows with an delay of 1 second and 2 seconds (default defined by LoRaWAN regional specifications).

Knowing this, sending every 1.5 seconds is difficult to achieve.

The data rates are for a single packet only, not a generic data rate that you can achieve when sending LoRaWAN packets.

1 Like
#3

Thanks for such a fast reply!

Mhmm that is interesting. So it sounds like we are probably getting the advertised data rates for the actual LoRaWAN packet. BUT because of some overhead packets we cannot control, the overall data rate appears to be much slower. Essentially, LoRa packets are just not able to send in such rapid succession.

Is there any way to remove the delays between LoRa packets? Perhaps a different mode to operate in? I am guessing that is not possible but it never hurts to ask.

Thanks again, I really appreciate it!

#4

You could use LoRa P2P mode, that has no protocol defined. But in that mode you cannot send data to a LoRaWAN gateway/LoRaWAN server. You can only send/receive packets between multiple LoRa Nodes.

It will still limit the packet size to 255 bytes (reserved buffer for RX in the LoRa Transceiver) and you might be hunted down by government and angry LoRaWAN users, because you are blocking a frequency from usage by other devices. ISM bands are free to use, but abuse of the bandwidth of a frequency is a really bad thing.

If you need to transmit a lot of data with a high bitrate you will need a different communication method like WiFi, BLE or cellular connections. LoRaWAN / LoRa is not made for such kind of transmissions.

#5

Thank you for all of the good information - it has been very helpful. I think the last thing we want to do is anger other users and/or be hunted down by the government!

Based on this I think we will pursue LTE options such as the RAK5860.

#6

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