Difference between "Usage preference" "voice-centric" or "data-centric"?

[Martin Maurer]

Hello,

when using this command:

# qmicli -p -d /dev/cdc-wdm0 --nas-get-system-selection-preference
[/dev/cdc-wdm0] Successfully got system selection preference
         Emergency mode: 'no'
         Mode preference: '5gnr'
         Disabled modes: 'none'
         Band preference: 'wcdma-2100, wcdma-pcs-1900, wcdma-1700-us, 
wcdma-850-us, wcdma-900, wcdma-850-japan'
         LTE band preference: '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, 43'
         LTE band preference (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, 43, 
46, 48, 66, 71'
         NR5G SA band preference: '1, 2, 3, 5, 7, 8, 12, 13, 14, 18, 20, 
25, 26, 28, 29, 30, 38, 40, 41, 48, 66, 70, 71, 75, 76, 77, 78, 79'
         NR5G NSA band preference: '1, 2, 3, 5, 7, 8, 12, 13, 14, 18, 
20, 25, 26, 28, 29, 30, 38, 40, 41, 48, 66, 70, 71, 75, 76, 77, 78, 79'
         TD-SCDMA band preference: 'a, b, c, d, e, f'
         Roaming preference: 'any'
         Network selection preference: 'automatic'
         Service domain preference: 'cs-ps'
         GSM/WCDMA acquisition order preference: 'automatic'
         Usage preference: 'data-centric'
         Voice domain preference: 'ps-preferred'
         Registration restriction: 'unrestricted'
         Acquisition order preference: '5gnr, lte, umts'
#

there is "Usage preference", which can be "voice-centric" or "data-centric".

In Quectel RM520N-GL there is an AT command, where I can choose between 
the two modes.

What is the difference between them?

What does the module do different when choosing the one or the other?

Could it be (with voice centric) that it builds up a connection to 
somewhere, for voice calls,
which could influence my data calls (especially when choosing APN/IP-Type)?

Best regards,

Martin