 is flexible (either up or down). 4.2.1. Static configuration per cell The cell-specific configuration is defined by one or two profiles (patterns) transmitted to the mobile via an RRC message. 5G-NR Radio Interface - The Physical Layer The RRC message is either broadcasted in the cell by the SIB1 message or transmitted to the mobile during a dedicated RRC message. The first profile (pattern 1) is mandatory, the second (pattern 2) is optional. In the time domain, the tdd-UL-DLConfigurationCommon configuration is characterized by: - the period P of the TDD UL/DL duplexing scheme (0.5 ms, 0.625 ms, 1 ms, 1.25 ms, 2.5 ms, 5 ms, 10 ms); - the number of DL dslots slots (between 0 and 320); - the number of dsym symbols in DL (between 0 and 13); - the number of UL uslot slots (between 0 and 320); - the number of usym symbols in UL (between 0 and 13). Over one period P, the frame is configured with the following information (Figure 4.4): - number of symbols in DL: dslots slots in DL, followed by dsym symbols in DL; - number of symbols in UL: usym symbols in UL, followed by uslots slots in UL. The total number of slots (DL and UL) of the profile depends on the numerology and the period of the multiplexing scheme according to the formula P*2", which must be an integer value (thus the value of 0.625 ms is only valid for the numerology u = 3). One frame = 10 ms One_sub-frame = 1 ms P=5ms usym= 2 uslot= 1 dslot= 3 dsym= 6 Flexible UL slot= 1 DL slot= 2 DL slot= 3 - DL slot= 4- DL/UÉ slot= 5-UL Figure 4.4. TDD configuration example If the two profiles (patterns 1 and 2) are configured, then the mobile configures the direction of the symbols on the first period according to pattern 1 and the second period according to pattern 2. NG-RAN and 5G-NR 4.2.2. Specific TDD configuration The base station imposes the cell configuration of the slot format, according to the direction of uplink, downlink or flexible transmission. In the case where a symbol is configured as flexible, it can be uplink or downlink. The configuration profile td