Mantra– 5G NR defines a flexible frame structure that efficiently supports a variety of services and deployment scenarios.
Brief Explanation. Like LTE, a radio frame in NR is 10 ms long and consists of two half frames or 10 subframes. While an LTE subframe has two slots, an NR subframe has one or more variable-length slots. The NR slot consists of 14 OFDM symbols in case of a normal cyclic prefix or 12 OFDM symbols in case of an extended cyclic prefix. In NR, different OFDM numerologies have different subcarrier spacings and hence different OFDM symbol durations, because the OFDM symbol duration is inversely proportional to the subcarrier spacing. Due to different OFDM symbol durations, the slot length is no longer fixed in NR. While the subframe is the basic scheduling interval in LTE, the slot can be viewed as the basic scheduling interval in NR. NR also supports mini-slots (i.e., fewer than 14 or 12 OFDM symbols) and aggregated slots (i.e., same information in multiple consecutive slots) as resource allocation units.