PRB19 PRB20 PRB21 PRB22 PRB23 PRB24 Length Starting position Figure 3.54 Illustration of frequency-domain type 0 and type 1 resource allocations [15,39]. is a need to reduce the bitmap size while maintaining the allocation flexibility. This can be achieved by addressing a group of contiguous resource blocks as opposed to individual PRBs. The size of the resource block group (RBG) is determined by the size of the BWP (see Table 3.16). Resource allocation type 1 indicates the allocated resources to the UE by means of a starting position and the length of the resource block allocation, thus only supporting contiguous allocations in frequency domain. In order to further reduce the sig- naling overhead, resource allocation type 1 combines the starting position and the length of resource allocation values into a single value referred to as resource indication value [15]. The two resource allocation types are illustrated in Fig. 3.54 (example). The resource allocation scheme is configured using a bit in the DCI. Both resource allocation types refer to virtual resource blocks. For resource allocation type 0, a non-interleaved mapping from virtual to physical resource blocks is used, thus the virtual resource blocks are directly mapped to the corresponding physical resource blocks. For resource allocation type 1, both interleaved and non-interleaved mapping is supported. The VRB-to-PRB mapping bit, if pres- ent, indicates whether the allocation is based on interleaved or non-interleaved mapping. In downlink resource allocation type 0, the resource block assignment information includes a bitmap representing the RBGs that are allocated to the scheduled UE where RBG is a set of consecutive physical resource blocks defined by a higher layer parameter and the size of the carrier BWP. The total number of RBGs NRBG defined for a downlink carrier BWP of 402 Chapter size BWis o/whe = the size of the first RBG is the size of last RBG is BGwn= if modP 0 and P otherwise. The size of all other RBGs is P [15]. The nominal values of P a