BC660K - Not receiving UDP messages during eDRX

IoT Modules LPWA Module
1

With the UDP Service running I receive UDP messages without a problem.

When I enable PSM:

I receive all UDP messages once the module wakes up, but only the first time it wakes up. If I send more UDP messages during the next sleep cycle, the messages are not delivered via QUIRC when the module wakes up again.

When I enable eDRX:

I never receive UDP messages that I send.

How does the UDP Service work? Is the service running during eDRX at all?

2

What are your application requirements? Do you need to send UDP data to the module at any time through the server?

3

@herbert.pan-Q If possible, yes.

  • The BC66 is connected to a microcontroller via the main RX/TX.
  • To save power, the microcontroller is put to sleep and the BC66 is placed in eDRX mode.
  • The module is connected to a private APN so we can address it on a static IP.

I need to wake up the microcontroller by sending a message to the BC66 during eDRX. What is the best way to do this?

4

In terms of your UDP test results and issues, it’s actually a complex issue, related to the UDP server, core network, and eDRX cycle; For your needs, I suggest：
1）mcu actively wakes up and sends data to BC660K to the server. The server determines whether to send command’s data according to the reported data;
2)If your device is battery powered, I recommend using the PSM feature

5

@herbert.pan-Q I need to be able to wake the system ASAP (remotely) when required. I have eDRX configured to page every 20 seconds, for 10 seconds. As I understand eDRX, packets are buffered on the network and delivered to the module during the paging cycle. I am not seeing this behaviour. Am I correct in assuming that the UDP service gets suspended during eDRX and never “wakes up” to interpret messages during the paging cycle?

If not for periodically checking for incoming data, what is the use of eDRX?

My system is battery-powered and eDRX is a lot more efficient that PSM.
PSM: 42.34mC per cycle
eDRX: 6.8mC per cycle

6

Your description has mentioned the key point, the network or core network may hold your UDP data for a very short time, if the module is in eDRX sleep state, your data will be discarded

7

@herbert.pan-Q I will follow up with the mobile network on this. If that is the case, what is the purpose of eDRX?

I have in the meantime run some tests using PSM, and while incoming URC messages always cause the ring-indicator to activate, it does not always cause a QUIRC message on the UART. Sometime I get ring-indicator + QIURC output, other times I get the ring-indicator, but no QIURC output. What would the reason for this be?

8

Yes, this is the problem with the network. In some cases, the network will drop the packet, but it will trigger paging to the module within PTW. In this case, the RI will respond, but no data will be received