Use Amarisoft CLI to debug Radio Quality
Using Amarisoft CLI can help troubleshoot bad radio quality. First follow this tutorial to learn how to use Amarisoft CLI on your gNB or eNB service: How To Use eNB / gNB Websocket (Amarisoft GUI and API)
We advise starting a speedtest while debugging, please follow this tutorial to learn how to do this (we don't advise using websites like speedtest.net, it is much better to do a local speedtest between core network and UE) : rapidspace-HowTo.Test.4G.5G.Signal.With.Android
Then, once you have opened the Amarisoft CLI (by clicking the terminal / monitor icon), type in "t" command
You should get an output similar to this:
----DL----------------------- ----UL----------------------------------------------------
UE_ID CL RNTI C cqi ri mcs retx txok brate C snr puc1 nl mcs rxko rxok brate #its phr pl ta
1 020 4601 1 15 2 26.9 0 3000 302M 1 22.6 - 1.0 23.0 22 239 729k 1/2.7/5 24 49 0.4
1 020 4601 1 15 2 26.9 0 3000 302M 1 26.7 - 1.0 23.0 20 244 740k 1/2.7/5 32 50 0.4
1 020 4601 1 15 2 26.9 0 3000 302M 1 23.5 - 1.0 23.1 22 245 742k 1/2.8/5 36 49 0.5
If you don't get these values it means either:
- no UE is connected (or all UE's are in idle mode, this shouldn't be the case if you are doing a speedtest)
- you need to disable xlog in the gNB / eNB parameters (this will disable Wendelin statistics, so please enable it again after you have finished debugging)
Checking all the values displayed in the columns will help you debug the radio quality. Please check this page to get an explanation of all the parameters: https://tech-academy.amarisoft.com/userguide_callbox_pro.doc#cbfb46c29922c7c539623f29f26391e1-7
Here are our tips for what you should check to debug radio quality
- UE_ID: UE RAN ID of your UE. You may cross reference this with the UE ID displayed in Core Network CLI to check the IMSI of UE. UE_ID may change frequently, for instance it will change if UE goes idle or disconnects / reconnects
- cqi: This should be equal to 15 all the time, if not then there is a radio quality issue
- mcs: This will determine how many bits of QAM modulation will be used, if it drops too low then you will see a big drop in throughput, because for instance QAM might go from 256QAM to 64QAM. You can try adjusting TX and RX gain to improve this value
- ri: This corresponds to the number of antenna being using in downlink, if it is lower than your configured value it is either because of UE support issue or because it is not able to distinguish each antenna. UE may not be able to distinguish all antennas if antennas are too close together, or if there are not enough reflections of the signal (in an open environment there will be less reflections and path taken by all antenna will be too similar for MIMO to be effective)
- phr: This value should not be negative, if it is then you may want to consider changing TX Power Offset. It should be high if the UE is close to the antenna (high value means UE is not emitting at high power, which is expected if UE is close)