RC7611 Performance Issue


We are looking for a simple TCP/IP to serial port embedded gateway solution for our applications. I was testing the RC7611 LTE module as it looks suitable for such use.

I configured the module as a TCP server according to the examples in the AT Commands Reference Guide and was able to get the TCP/IP to serial port tunnel session working. But when performing a load test, I ran into the issue of the low bandwidth of this setup. Although the module’s serial port is running at 460800bps, I haven’t seen more than 5kBytes per second of actual system throughput performance which is much lower than the port rate limit.

Theoretically, I expect a system throughput data rate to be close to the serial port rate, but in fact, I see that it’s much below. The declared over-the-air data rate for this module is very high, and I have a perfect signal and the RSSI value. There are also no limitations from the internet provider’s side.

Has anyone else experienced this bandwidth issue when using RC7611 or similar modules in TCP server mode? Is there anything I should pay attention to at the first turn when troubleshooting my setup?

PS. It’s also worth noting that on the initial firmware that was on the RC7611 modules when I received them, the TCP to serial gateway didn’t work at all at any baud rate above 115200. Updating to the latest Firmware Release 9 (SWI9X07H_00.08.24.02) fixed this. But I wonder if there is still some bandwidth limitation even if the port is running at a higher rate?

Please advise. Thank you.

have you tried with USB interface to isolate uart issue?
Have you tried with FTP client download to see if problem only exists in TCP server?
You can also establish data channel for a PC through USB port and see if problem exists in TCP server setup in PC.

Thanks for your reply.
No, I haven’t tried the USB interface, I don’t have a chance to test this quickly. All we need for our application is to bridge TCP/IP to UART. I haven’t tried the FTP client either. I have only tried TCP client and server according to the examples in the documentation. I’m not looking for very high data rates, a bandwidth of the order of tens of kilobytes per second would be sufficient, but I can’t achieve this with RC7611. Can you recommend anything else?

I think recommendation might be done after your test.
e.g. FTP client, USB interface, etc