Connecting to 5G

Fri Jun 4 18:40:04 UTC 2021

Hi Paul,

I’m assuming you are trying to connect to an NSA (non-standalone) 5G network. In that case it is up to the network to decide if it adds you the secondary, 5G data radio bearer. Based on signal strength/quality measurement reports sent by your device to the network the decision is made.
While scanning you would not see a 5G network, since it is non-standalone, so it only provides a secondary, optional and faster data radio bearer. However SIB2 iirc shall contain a single bit indicating your LTE master node has a 5G node connected to it, allowing you to potentially get the 5G bearer. However I am unsure if this information is exposed in any way in libqmi. On Android e.g. you could see it with a 5G logo at the top without being filled with white color. If it is filled you have an active 5G DRB working. If it is just the contours it means you are in the coverage area potentially, but the bearer is not active.

I hope this helps.
Of course if you are going for a standalone 5G network things are different, because then even during idle you shall be fully connected to 5G.

Kind regards,
Domi

> 04.06.2021 dátummal, 12:25 időpontban Paul Gildea <gildeap at tcd.ie> írta:
> 
> 
> Hi, 
> 
> I am currently trying to connect some 5G modems to a 5G network, Telit F980m and Cinterion MV31-W with libqmi 1.28.4. They are failing to connect. Perhaps the 5G signal is not great as a phone with the same sim can connect sometimes and not others (pr [perhaps it is that it is idling in LTE), but I'd like to make sure the modems are looking ok. I notice some irregularities in the output of commands, for the former modem I get:
> 
>> Mode preference: umts, lte 
>> Acquisition order preference: umts, lte, 5gnr
> 
> For the Cinterion I get the opposite:
> 
>> Mode preference: umts, lte, 5gnr
>> Acquisition order preference: lte, umts
> 
> In each case 5gnr is missing from one of the outputs, is this usual?
> Output for Cinterion bands:
> 
>> qmicli -p -d /dev/cdc-wdm2 --dms-get-band-capabilities
>> [/dev/cdc-wdm2] Device band capabilities retrieved:
>>         Bands: 'wcdma-2100, wcdma-pcs-1900, wcdma-dcs-1800, wcdma-1700-us, wcdma
>> -850-us, wcdma-800, wcdma-900, wcdma-1700-japan, wcdma-850-japan'
>>         LTE bands: '1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 17, 18, 19, 20, 25, 26, 28,
>>  29, 30, 32, 34, 38, 39, 40, 41, 42'
>>         LTE bands (extended): '1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 17, 18, 19, 20,
>> 25, 26, 28, 29, 30, 32, 34, 38, 39, 40, 41, 42, 46, 48, 66, 71'
> 
> Are there any other debugging/commands that will be useful when I am attempting to connect? 
> For instance a network scan should show 5g networks, not just LTE?
> 
> Thanks,
> 
> --
> Paul
> 
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