o enable or disable HARQ, for example, the UE QoS, memory size, round-trip time, network type, or transport block size, 1 Refers to HARQ RV configuration, as defined in 3GPP TS 38.312. 5 NG-RAN Evolution etc. Hence, it is important to study the impact of disabling HARQ on NR (e.g. impacts on the TBS, MCS, etc.). It is also important to consider the following HARQ reliability mechanisms to support HARQ disabling: HARQ-less operation and redundancy transmission. Transmission Time Interval (TTI) bundling and HARQ-less repetition as specified in LTE Release-15 can be used to completely avoid retransmissions, thus avoiding a large number of required HARQ processes and excessive HARQ feedbacks. In NR Release-15 a similar mechanism was also agreed for uplink, the k-repetition. Those k repetitions can be similar to the initial transmission or following a certain RV sequence. Currently, NR supports only bundling and repetition in the time domain. Therefore, the impact on repetition value k, rate reduction (i.e. 1/k), and the TBS/MCS tables needs to be studied. In order to mitigate longer delays between scheduling the grant and uplink transmis- sions, grant-free retransmissions can be used and should be studied in the case of varying channel conditions. Utilizing terrestrial dual connectivity. In the case of deactivated HARQ, when it is required to guarantee a certain QoS, the HARQ operation can still be resumed with reduced latency, utilizing a dual connec- tivity with a ground station (gNB) in a terrestrial network-offloading scenario (3GPP R1-1904650). The ground gNB might be backhauled using a satellite reliable link or lossless connection to the network. Once a UE is in the coverage of a terrestrial and a non-terrestrial node, the initial transmission can be sent over the NTN link, while HARQ retransmissions (other RVs) and HARQ acknowledgement/negative acknowledgement (ACK/NACK) feedbacks can simply flow over the terrestrial link (i.e. rather than the longer delay NTN link) as illustrated in Figure 5.3.9. Here, the g