What is the definition of Resource Block in 5G

My friend: Do you know the answer of this question?

Me: Yes, it is 12 consecutive subcarriers in the frequency domain.

My friend: But, this is wrong as you didn’t mention the time domain allocation.

Me: Actually, this is the definition as per 3GPP 38.211(see below) and it is the main difference between RB in 4G and 5G as in 4G, RB is a 12 consecutive subcarriers allocated in 7 symbols and so it is a fixed unit in frequency and time, but 5G is more flexible as only frequency domain is determined and time domain can change based on the need, so for example if your activity needs high throughput, it can be scheduled for multiple symbols and if it requires low latency, so a few symbols will be allocated. So, when we made resource allocations in 5G, we should mention both no. of RBs and no. of symbols.

My friend: OK. Thank you, I got it now.

The above discussion happened between me and one of my friends during last week and I am highlighting it here as 5G has many definitions that are similar to 4G, but concept can be different, so take care about that.

Please find below our and share this information to spread it and make sure it is clear for everyone.

Source: Ibrahim Sayed

Linkedin Profile: https://www.linkedin.com/in/ibrahim-sayed-88a7747-5g/