5G TTI

A resource block (RB ) is the smallest unit of resources that can be allocated to a user . The resource block is 180 kHz. wide in frequency and 1 slot long in time.

5G NR physical layer uses time-frequency resource (physical resource block) for transmission. A resource grid consists of N size,μgrid,x subcarriers and N subframe,μ symb number of OFDM symbols (Table 2 and 3).22 Şub 2022

The E-UTRA uses the concept of VRB (Virtual Resource Block) when allocating resources . It defines two types: LVRB (Local Virtual Resource Block) – this is the same as the PRBs; DVRB (Distributed Virtual Resource Block) – this identifies a distribution of the resources required over a number of PRBs.

In 5G, One NR Resource Block (RB) contains 12 sub-carriers in frequency domain similar to LTE . In LTE resource block bandwidth is fixed to 180 KHz but in NR it is not fixed and depend on sub-carrier spacing.24 Nis 2019

In 5G NR, similar to 4G the resource allocation is done in Time domain and frequency domain . Time domain resource allocation defines which symbols are allocated to UE and frequency domain allocation defines which RBs are allocated to the UE.