Section: 5.27.1.2.1 Distribution of 5G internal system clock
Content: The 5G internal system clock shall be made available to all user plane nodes in the 5G system. The UPF and NW-TT may get the 5G internal system clock via the underlying PTP compatible transport network with mechanisms outside the scope of 3GPP. The 5G internal system clock shall be made available to UE with signalling of time information related to absolute timing of radio frames as described in TS 38.331[ NR; Radio Resource Control (RRC); Protocol specification ]  [28]. The 5G internal system clock shall be made available to DS-TT by the UE.