Knowledge Base
HOME » KNOWLEDGE BASE » FORUM

LoRa Gateway Throughput Question

Hi all,

I have a question on the throughput of the multi-channel gateway.

Here is my configuration:
* using Lorix One gateway, 8 channels enabled in AS928
* proprietary LoRa end device running on proprietary LoRa protocol (not LoRaWAN)
* fixed SF9/125
* each proprietary LoRa packet is large, max can be 244 bytes

Here is the issue I see:
* If send max size packet on each channel at the same time, only 3 out of 8 packets received by pkt_fwd, other 6 packets dropped
* if send max size packet with 450ms stagger delay time, all packets received by pkt_fwd, no packets dropped. see the picture attached for a better explanation.

It looks like a throughput issue. I do not know where is the bottleneck, however. my questions are:
1. bottleneck in Semtech sx1301? 1024 bytes buffer in SX1301?
2. bottleneck in Packet Forwarder?
3. Lorix One ARM Cortex A5?

Is there any way to improve, maybe:
* change the value of LGW_DATABUFF_SIZE in loragw_hal.h?
* something else?

Thanks a lot!

Cheers,
Paul



Image Attachments
throughput.png
Avatar
Hi Paul,

What you observe is expected. The buffer is 1024 bytes in length. Each packet received is appended with 18 bytes of macro data. So in your case, only 3 packets can be received, the other ones will be dropped.

Hope this helps.
Can I ask how much buffer does SX1302 has?

Thanks for your explanation.
Avatar
It will be 4KB at least