Note that in various embodiments, one or more of the above described network entities may be configured to perform methods to improve security checks in a 5G NR network, including mechanisms for intra-UE co-existence between non-stand-alone (NSA) and stand-alone (SA) mode, e.g., as further described herein.

FIG. 8 illustrates an example of a baseband processor architecture for a UE (e.g., such as UE 106), according to some embodiments. The baseband processor architecture 800 described in FIG. 8 may be implemented on one or more radios (e.g., radios 329 and/or 330 described above) or modems (e.g., modems 510 and/or 520) as described above. As shown, the non-access stratum (NAS) 810 may include a 5G NAS 820 and a legacy NAS 850. The legacy NAS 850 may include a communication connection with a legacy access stratum (AS) 870. The 5G NAS 820 may include communication connections with both a 5G AS 840 and a non-3GPP AS 830 and Wi-Fi AS 832. The 5G NAS 820 may include functional entities associated with both access stratums. Thus, the 5G NAS 820 may include multiple 5G MM entities 826 and 828 and 5G session management (SM) entities 822 and 824. The legacy NAS 850 may include functional entities such as short message service (SMS) entity 852, evolved packet system (EPS) session management (ESM) entity 854, session management (SM) entity 856, EPS mobility management (EMM) entity 858, and mobility management (MM)/GPRS mobility management (GMM) entity 860. In addition, the legacy AS 870 may include functional entities such as LTE AS 872, UMTS AS 874, and/or GSM/GPRS AS 876.