# 5G basic understanding for RB, PRB, RE

Hi 5G Experts,
Please check below basic understanding for RB, PRB, RE and correct or not for 5G…

1 RB = 12 Subcarrier * 1 OFDM Symbol
1 PRB = 12 subcarrier * 14 OFDM Symbol
1 RE = 1 subcarrier * 1 OFDM Symbol

UE will be scheduled per slot basis as of now i.e. PRB allocated to UE ●●●1 UE can be scheduled per slot.

1 RB = 12 Subcarrier * 1 OFDM Symbol… Any reference for this?
Remaining are correct as my understanding, only above point need to be confirmed.

1 RB = 12 Subcarrier.
And that’s all.

The 5G resource block is in one dimension only yes.

Ok guys… I read that in one PPT and would like to confirm.

No more multiplying with time dimension that is symbol.

Frequency domain only.

This is correct.
In NR, RB is not defined in time domain.
It’s depends upon numerology.

I think all of them are defined just in frequency domain without time domain.
Although basic scheduling unit is slot in 5G there can be minislot scheduling like 2,5 or 7 symbols scheduling only for URLLC.

+ in FR2 it can be used for eMBB also.

Ok, but then how to differentiate between RB and PRB?
Without symbol, how user will be allocated resource?

Do concept of PRB even exist in NR?

Yes, exist.

In LTE, RB is for 0.5 ms and PRB is for 1 ms.
I didn’t read get PRB in NR.
Any reference?

I read RB definition in Nokia.

Ok, but that’s Nokia definition, not reflecting 3GPP spec.
The RB is defined in only one domain: frequency only.

I think we need to consider symbols then only we need to difference between RB and PRB.

In NR, PRB word is only use to differentiate CRB and RB (PRB).
There is no difference between RB and PRB in time domain.

Then please tell, without symbol how can we differetiate between RB and PRB? Only question left…
User will allocate RB or PRB.

As i know both are same in NR.
Please someone correct me if I am wrong…