is TEeRE/RE is 20 ns (as per Table 10-18), the TET-TSC for case 1.1 is 60 as per ITU-T G.8273.2 Class B T-TSC that includes the budget of cTE and dTE values. To calculate the maximum relative TE, max TER for case 1.2, TEeRE/RE at the input of the eRE/RE is 20 ns (as per Table 10-18) and TET-TSC for case 1.2 is 15 ns. In case 2, the T-TSC is integrated into the radio equipment and TEeRE/RE at the input of the eRE/RE is 30ns (as per Table 10-18). To help achieve these stringent requirements on the network between a common master clock and the end application, the ITU-T has also defined a new Class C clock performance level for T-BC, T- TC, and T-TSC clocks in the G.8273.2 recommendation. This is mainly to reduce the 60-ns TE that results from the previous Class B performance in the T-TSC down to 15 ns. In addition, the ITU-T introduced a new level of performance for the PRTC in the ITU-T G.8272 standard, and introduced the enhanced PRTC in ITU-T G.8272.1. SyncE performance was also en- hanced in the ITU-T G.8262.1 recommendation to ensure that the network clock distribution has an improved physical layer frequency signal to assist the PTP timing signal distribution. These changed were made principally to improve the timing performance in the front-haul network. Once again, do not forget that in spite of all the discussion about relative time error, there is still the absolute time requirement, which remains at +1.1 us from the PRTC to the handover point to the radio equipment-and depicted as Category C in Table 10-17. 10.5.1 Network Time Error Budget Analysis With the functional split in the RAN and then deploying the BBU as virtualized DU and CU func- tions, the timing synchronization design aspects for 5G xHaul architecture require extra attention and care. For 5G services, knowing when and how to apply the relative timing budget requirements (alongside the absolute one) within the network architecture is important to ensure the successful deployment of the services. Within the virtualized 5G RAN architecture, th