 for the uplink and reduces latency. In this mode, the mobile cannot transmit on the two uplink bands simultaneously (TDD and SUL or FDD and SUL). The three transmission modes TDD, FDD and SUL are supported in the frequency range FR1. The FR2 frequency range only supports the TDD mode. The bandwidth capacity of the mobile is not necessarily as wide as the base station's radio bandwidth. The bandwidth can be adjusted at any time. 4.1.3. NR frame structure OFDM modulation has been implemented on the LTE (Long-Term Evolution) radio interface. In the case of LTE, the spacing Af between the subcarriers (SCS) has a single value equal to 15 kHz. The symbols at the input of the OFDM modulator are distributed by a serial/parallel converter and transmitted to the DSP (Digital Signal Processor), which performs the operation of the IFFT (Inverse Fast Fourier Transform). For the LTE interface, the size of the IFFT inverse Fourier transform is 2048 subcarriers, but only a maximum of 1200 subcarriers are modulated (except for the case of NB-IoT in the guard band). The duration of an OFDM symbol is inversely proportional to the spacing between subcarriers; the choice of 15 kHz results in a sample rate of 30.72 MHz. This value guarantees clock compatibility with 3G (3.84 MHz) and 2G (200 kHz). For the NR interface, the spacing between the subcarriers Af takes several values depending on the parameter , according to the formula Af = 2"X15 [kHz]. The spacing between the subcarriers with the frequency bandwidth defines the IFFT size (Table 4.3). The size of the 5G-NR IFFT is variable between 512, 1024, 2048 or 4096, with a limitation to 3300 subcarriers: - u = {0, 1}: these values are reserved for the FR1 frequency range; - = {2}: this value is used for the FR1 and FR2 frequency ranges; - u = {3, 4}: these values are reserved for the FR2 frequency range. NG-RAN and 5G-NR 5G-NR-Numerology - SCS\BW 20 MHz 50 MHz 100 MHz 200 MHZ 400 MHZ 15 kHz 2048 IFFT 4096 IFFT 30 kHz 1024 IFFT 2048 IFFT 4096 IFFT 60 kHz 512 IFFT 1024 IFFT 2048 IFFT 