RV50X - LTE CA not working

AirLink Routers AirLink routers
1

Hello forum dwellers!

I have RV50X NA/EMEA model that I’m testing. I’ve updated to the latest software and radio module firmware but can’t get LTE CA working. In ACEmanager “Carrier Aggregation Indicator” is “invalid” and in the log it says:

err ALEOS_CELL_RadioTask: AL_getRFCaInfo Return Code: 1074 - Information unavailable at this time

I also noticed it didn’t recognize the phone number on the SIM. How should I debug this and what could cause this? I’m in europe and the operator is using CA with bands 3 and 20. MC7455 should support this, right?

2

Hello,

MC7455 does support bands 3 and 20 for carrier aggregation. What is the RSSI signal that you are seeing for the device? Is it getting an LTE signal?

Thanks,
Gordie

3

Yes, it’s selecting LTE band 3.

Here are the readings from ACEmanager:
RSSI: -49
RSRP: -83
RSRQ: -9
SINR: 6.6

I have a USB-stick modem that I can lock to band 20 and there RSSI is -53 dBm.

Thanks for your help!

4

It seems that RV50X doesn’t allow custom bands, AT commands to define and switch to non-standard band definitions are ignored. So I can’t test if it works with band 20 because it only allows automatic selection and always selects band 3.

It’s strange to me that this sort of professional level device doesn’t allow custom band selection?

5

Hi pmaa80,

I just wanted to add that there is an issue with the way AceManager presents the LTE CA status, and it’s very misleading. When it shows “Invalid” it doesn’t necessarily mean that CA is not enabled. Assuming that your band combination is part of the supported list (provided below), there is no reason for CA not to work. You can confirm that it’s working by going into Admin > Advanced > Radio Module Debug Information > Refresh. The output will show LTE CA STATE under AT!GSTATUS?. If the CA state is ACTIVE then you’re fine. I wouldn’t use the CA status in AceManager. We’re working on trying to get this fixed.

MC7455 Carrier Aggregation Combinations
1 + 8
2+ 2/5/12/13/29
3 + 7/20
4 + 4/5/12/13/29
5 + 2/4
7 + 3/7/20
8 + 1
12 + 2/4
13 + 2/4
20 + 3/7
41 + 41

6

Thanks for that! It seems that the problem is on the network side. The operator hadn’t enabled CA on the closest tower, even though they advertise CA to be available in the area. Trying with a different provider I see CA being activated once there’s some traffic on the line, it isn’t activated by default.

Could you explain how to read the Carrier Aggregation Combination chart? I assume 1 + 8 means bands 1 and 8 combo is supported for CA, but how does the numbers after the “/” change the situation? Is the first number the primary band and numbers after the “+” are possible secondary bands? What about three band CA?

7

Hi pmaa80,

Sorry for the late reply! I hope you found the answer you were looking for. If not, then I can shed some light :slight_smile:

Basically, the chart is read like this:

1 + 8 = means “Primary Band is 1 and Secondary Band is 8”

The slashes mean that the Secondary Band can be “one of”:

2+ 2/5/12/13/29 = means “Primary Band is 2 and Secondary Band is either 2 OR 5 OR 12 OR 13 OR 29”

Regards,
Nick

8

Thanks, that explains it!