Section: 5.8.12 DFN derivation from GNSS
Content: When the UE selects GNSS as the synchronization reference source, the DFN, the subframe number within a frame and slot number within a frame used for NR sidelink communication/discovery are derived from the current UTC time, by the following formulae: DFN= Floor (0.1*(Tcurrent –Tref–OffsetDFN)) mod 1024 SubframeNumber= Floor (Tcurrent –Tref–OffsetDFN) mod 10 SlotNumber= Floor ((Tcurrent –Tref–OffsetDFN)*2μ) mod (10*2μ) Where: Tcurrent is the current UTC time obtained from GNSS. This value is expressed in milliseconds; Tref is the reference UTC time 00:00:00 on Gregorian calendar date 1 January, 1900 (midnight between Thursday, December 31, 1899 and Friday, January 1, 1900). This value is expressed in milliseconds; OffsetDFN is the value sl-OffsetDFN if configured, otherwise it is zero. This value is expressed in milliseconds. μ=0/1/2/3 corresponding to the 15/30/60/120 kHz of SCS for SL, respectively. NOTE 1: In case of leap second change event, how UE obtains the scheduled time of leap second change to adjust Tcurrent correspondingly is left to UE implementation. How UE handles to avoid the sudden discontinuity of DFN is left to UE implementation. NOTE 2: Void.