 a TTI. For example, if the subcarrier spacing (SCS) is increased from 15 kHz (NR numerology 0) to 60 kHz (NR numerology 2), the TTI length decreases from 1 ms to 250 us. Therefore, the transmission timing of the UE has to be adjusted over the borders of indi- vidual TTIs in NTN applications, causing a high number of NR TA update commands (3GPP R1-1904225, 3GPP TS 38.213). To mitigate this effect, in LEO scenarios a UE should be enabled to perform the compensation of the predictable delay variation by itself. The delay variation for satellite networks is quite predictable. Depending on the available information, the prediction of the delay variation can be done in the terminal for different time durations, resulting in a significant reduction of the required control plane overhead for TA adjustments. Two options were considered: The longest prediction of the fast timing drift is possible, where the UE knows its position (e.g. by GNSS) and the satellite ephemeris. Therefore, the UE is able to calculate the exact TA and apply it for uplink transmissions. For UEs with fewer capabilities (e.g. for MTC use cases), not knowing the position and ephemeris, the delay drift prediction can still be done for a smaller time window. Different solutions are possible, when the UE has been enabled for timing prediction, e.g. based on the last TA commands and their updated values, or based on the observed downlink tim- ing drift via SSB tracking. Supporting information by the gNB to the UE is also possible, e.g. provisioning of timing drift rates. 5 NG-RAN Evolution 5.3.5.4 Physical Layer Control Loops A UE operating in GEO satellite access networks can experience a one-way propagation time of up to 270 ms (3GPP TR 38.811). Using a LEO satellite access network at 600 km altitude, the one-way propagation delay can range between 2 and 7 ms. The slow reaction time caused by this delay has a performance impact on physical layer procedures, particu- larly on those with closed loops such as power control and adaptive modulation and codi