EG25 test procedure

Technical Subjects Hardware RF/Antenna
1

Hi,

We are building devices that use EG-25 for providing internet connectivity. We wanted to streamline our test plan before we go for large scale production. If have seen quite some variability with regards to internet connectivity where the signal strength (using CSQ command) fluctuated quite a lot with each test. We wanted to have a better test plan that could be repeatable.

I’m suspecting our design, the SMA connectors, or even the Quectel modules for the inconsistent behaviour of our devices but unable to pinpoint the root cause. Devices have been tested in over 30 countries by our clients with quite a few telecommunication operators.

Can someone point me to the right direction please? Look forward to hearing from the community.

Best regards,
MM

2

Please use the signal reference RSRP/SINR

AT+QENG=“servingcell”

3

Thanks, Herbert.

I receive the following in the response to

AT+QENG=“servingcell”
+QENG: "servingcell","NOCONN","LTE","FDD",525,03,2328A06,206,3050,7,5,5,AC4B,-97,-13,-64,4,30
  1. The following being the RSRP and SINR values. Is there a way to conclude the performance of the devices
  2. Also, I notice from the data sheet that the fields differ for WCDMA, LTE, TD-SCDMA, etc. Not all have rsvp/sinr.
  3. Finally, would these values vary depending on the nearest tower and make the tests inconsistent?
<state> NOCONN
"LTE" "LTE"
<is_tdd> "FDD"
<mcc> 525
<m nc> 03
<cellID> 2328A06
<pcid> 206
<earfcn> 3050
<freq_band_ind> 7
<ul_band width> 5
<dl_bandwidth> 5
<tac> AC4B
<rsrp> -97
<rsrq> -13
<rssi> -64
<sin r> 4
<srxlev> 30
4

1.RSRP indicates the signal strength of the terminal to receive the base station cell, and SINR indicates the interference degree of the terminal to receive the signal. For details, please refer to 3GPP
2.WCDMA, TD-SCDMA corresponding signal receiving intensity indicator is RSCP,SINR is consistent
3.Yes, RSRP reflects the strength of the signal received by the terminal and is strongly related to the distance of the base station

5

Hi,

Given that the above test is also dependent on the quality of the signal from the neighboring cellular tower, it leaves a room for variable outcomes. Sometimes, the signal might be weak and the test might fail.

Is there something more repeatable? Configure the module to transmit in a certain band with certain power and measure using an equipment if the measured readings are the same as the set configuration.

I hope to find some such test procedure that we can automate at the production facility.

6

When you test on a real network, it’s normal for the signal to fluctuate. The variation of RSRP and SINR depends on the position of terminal antenna and the distance between the terminal and the base station. If a stable test environment is needed, generally the terminal needs to be tested through conduction mode, such as CMW500

7

Thanks. I think the manufacturing facility can provide us that. If so, what would be the process to test using the conduction mode?

Does quectel provide any test instructions. Or it would be great if you could share from your experience.

Your help is much appreciated!

8

Sorry, I don’t have such experience, so I can’t provide such service. Please contact the laboratory or factory with CMW500 to solve the problem