Section: 5.2.3.2.1 NORMAL-SERVICE
Content: The UE: a) shall initiate the mobility or the periodic registration update procedure (according to conditions given in subclause 5.5.1.3.2), except that the periodic registration update procedure shall not be initiated over non-3GPP access; b) shall initiate the service request procedure (according to conditions given in subclause 5.6.1); c) shall respond to paging; NOTE 1: Paging is not supported over non-3GPP access. NOTE 2: As an implementation option, the MUSIM UE is allowed to not respond to paging based on the information available in the paging message, e.g. voice service indication. d) if configured for eCall only mode as specified in 3GPP TS 31.102[ Characteristics of the Universal Subscriber Identity Module (USIM) application ]  [22], shall perform the eCall inactivity procedure at expiry of timer T3444 or timer T3445 (see subclause 5.5.3); and e) shall initiate a registration procedure for mobility and periodic registration update on the expiry of timer T3511; and f) if acting as a 5G ProSe UE-to-network relay UE as specified in 3GPP 24.554 [19E], shall initiate the authentication and key agreement procedure (according to the conditions given in subclause 5.5.4).