affic, it can just skip decoding the affected code blocks and save power and processing time. 5G Air Interface and Physical Layer Procedures - Part 3 eMBB DL Agent eMBB data URLLC data Pre-emption indication A pre-emption indication is not used to Opt. 1: In current slot enable data re-decoding due to insufficient eMBB slot Opt. 2: In subsequent slot processing time for UE N,: Minimum UE processing time HARQ-ACK timing Figure 6.5 - A downlink PI There is a minimum processing time called N1, which defines the minimum processing time in the device to send the Hybrid Automatic Repeat Request (HARQ) feedback. The device notifies the gNB about N1 time and the PI is given afterward. Now, let's move to the next downlink physical signal, the CSI-RS. CSI-RS and CSI reports A CSI-RS is used for two main purposes: CSI acquisition and beam management. For CSI acquisition, they are used to measure the channel characteristics and to report that information back to the gNB. Thus, it can be taken into account when scheduling downlink data. For beam management, it provides a way for the device to measure different downlink beams and report the measurements back to the gNB. So, the CSI-RS is used by the device for channel and beam measurements and to report the CSI feedback to the gNB. This feedback can be of two different types - normal or enhanced. The normal feedback is similar to that of LTE. The channel matrix is reported using a set of Precoding Matrix Indicators (PMIs) with normal spatial resolution. The enhanced CSI feedback type allows for higher resolution or explicit channel matrix reporting. This latter feedback type is crucial. Better CSI feedback means better channel estimation for the gNB, which results in efficient downlink scheduling. NR and LTE, under the same conditions, for instance, with 15 kHz subcarrier spacing and 20 MHz bandwidth at the same frequency band, will perform similarly with normal CSI feedback. However, enhanced CSI feedback allows NR to outperform LTE under the same conditions. Downlink physica