t us provide more information to elaborate more on type A and type B scheduling. There is a lot of similarity between type A scheduling and LTE scheduling, and DMRS uses slot boundaries. One slot (14 symbols) PDCH (data) Control (PDCCH), eventual data Figure 4.20 - Type A scheduling In Type B scheduling, the transmission can start at any symbol. The length can range from 1 to 13 OFDM symbols. However, it is limited to 2, 4, and 7 OFDM symbols. DMRS is relative to the start of the transmission. PDCH (data) Control (PDCCH), eventual data Figure 4.21 - Type B scheduling The slot-based scheduling assigns a slot to devices. The devices monitor the control channels in each slot and the assignments are always referred to the slot boundaries. 5G Air Interface and Physical Layer Procedures - Part 1 One subframe (1 ms) 15 kHz 30 kHz 60 kHz One slot One "mini-slot" Figure 4.22 - A slot and mini-slot The device monitors control channels in the mini-slot and assignments are referred to in these mini- slot boundaries, which can float within the slot, giving more flexibility in time domain assignments. Mini-slot use cases One of the motivations to have a non-slot-based scheduling scheme is to support low-latency use cases. Low-latency traffic can be sent over mini-slots, since they are not required to be aligned with slot boundaries, as described before. Once the traffic arrives to layer 1, it can start being transmitted almost immediately without us having to wait for the next slot, which reduces the latency in the process. The other motivation is having a finer time domain granularity for scheduling operations. This is very interesting in the case of beamforming and the MM wave for different devices. The gNB can transmit to one device in one mini-slot and move to another device in the next mini-slot. This process can be repeated several times within a slot, since mini-slots are shorter than slots. The third motivation is to support LTE and NR coexistence. When we have LTE and NR in the same RF frequency, it is important for N