 the normal cyclic prefix and six OFDM symbols for the extended cyclic prefix. For the NR interface, the slot includes 14 OFDM symbols for the normal cyclic prefix and 12 OFDM symbols for the extended cyclic prefix. of = 2. . 15 [kHz] Cyclic prefix Normal Normal Normal, Extended Normal Normal Table 4.5. Prefix cyclic per numerology NG-RAN and 5G-NR 4.2. TDD mode configurations For the TDD mode, the elementary resource allocated to the downlink or uplink is different between LTE and NR interfaces: - for the LTE interface, the elementary resource corresponds to a subframe and seven configurations are defined at the subframe level; - for the NR interface, the elementary resource corresponds to an OFDM symbol and several configurations (patterns) are defined; - for the NR interface, the number of symbols per subframe depends on the numerology (Table 4.4). The 5G-NR TDD frame provides flexibility in the direction of radio resources per slot: OFDM symbols in a slot can be up (uplink), down (downlink) or flexible. A flexible symbol corresponds to an ascending or descending direction. The format of a slot represents the directivity of the symbols in the slot. The format configuration of a slot can be defined semi-statically or dynamically. The dynamic configuration corresponds to the sequencing of the transmission of the mobile based on the control signal DCI (Downlink Control Information). It is also possible to configure an SFI (Slot Format Indicator) slot format for a group of mobiles. The semi-static configuration is transmitted to the mobile by an RRC control message through two Information Elements (IE): - IE tdd-UL-DL-ConfigurationCommon is transmitted in the SIB1 (System Information Block) message and defines the cell-specific configuration model; - IE tdd-UL-DL-ConfigurationDedicated is transmitted to the mobile when configuring the radio channel and defines the mobile-specific configuration template. If the symbol direction of a slot is not configured, the mobile considers that the symbol transmission direction