registrations, and initial access using an FR2 link. To enable all legacy services like 911, voice, or messaging and also roaming and operation in low-coverage areas, an FR1 link is needed to provide link robustness and ubiquity of the baseline services. This will first be provided by using an LTE anchor in the EN-DC configuration, but once refarmed to NR, using an FR1 NR band in an NN-DC combination. As for EN-DC in FR1, this will imply concurrent UL operation in FR1 and FR2. At the early stages of NR specifications, in 3GPP, in-device (UE) coexistence between FR1 and FR2 was discussed to understand if some requirements or exceptions like MSD and MPR/A-MPR would be required. With FR1 finishing at 7.125 GHz (in fact, with the current specified bands at 5 GHz) and FR2 starting at 24.25 GHz, there is not only a large gap in frequency but also the antennas are separate and use very different technologies and radiation patterns, with FR1 being omnidirectional and FR2 being beamformed. This guarantees that there is large antenna large isolation and that the filter, matchings, and DC coupling imple- mented in both frequency range paths also provide significant attenuation for interfering signals transmitted by the other side. For this reason: IMDs resulting from both ULs are negligible as the signal coming from the one fre- quency range is largely attenuated before it mixes with the other side; even so, the generated IMD products are also at a very large offset and will see further attenuation before they reach any victim band. Harmonics from FR1 overlapping with FR2 are above 3rd order (5th order for band n79, which is the highest band today) and will experience significant attenuation and large antenna isolation before it reaches any FR2 receiver. Similarly, harmonic mixing is of 5th order (only odd orders are of concern), and the FR2 UL signal is very significantly attenuated before it reaches any FR1 receiver. For all these reasons, it was decided that no specific coexistence study will be con- ducted for combinati