gnb gets an error while we have 15kHz SCS in band n78

[emadrezz]

Issue Description

As what we see in the standard 38.101-1 v17.5 - Table 5.3.5-1 and https://www.sharetechnote.com/html/5G/5G_FR_Bandwidth.html#Spectrum_and_Bandwidth the band n78 supports 15KHz subcarrier spacing as well as 30KHz scs in different bandwidths but srsGNB will run perfectly on 30KHz but gets an error with 15KHz. I've tested this exact configuration but on band n3 with 15KHz and it worked fine screenshot of gnb with band n3 and 15khz scs :

screenshot of gnb with band n78 and 30khz scs : screenshot of gnb with band n78 and 15khz scs :

gnb log for band 78 and 15 khz scs:

Setup Details

I'm using usrp x300 with latest version of uhd and ubuntu 22 and my configuration file goes as below:

Expected Behavior

I supposed that gnb works fine with 15khz scs in band n78 with srate 11.52

Actual Behaviour

I've got the error about SSB SCS must be equal to SCS common jst with 15KHZ scs in band n78

[ismagom]

Hi, band n78 with 15 KHz requires mixed numerology, since SSB is still 30 KHz. Unfortunately mixed numerology is not yet supported.

[emadrezz]

Thanks for quick responce.

[EugeneBogush]

srsGNB will run perfectly on 30KHz

Hello do you have successful connection in b78 with bandwidth 10mhz & scs 30KHz ?

Because my UE (Fibocom FG-150) only has detecting a carrier with a bandwidth of 20Mhz & scs 30KHz in tdd. It does not detect a carrier with a bandwidth of 10Mhz or 15Mhz in any tdd bands.