gNB will use the concept of beam sweeping to transmit both the synchronization signals and the system information, containing the minimum configuration for a device that needs to access the network. Eventually, one of these beams or spatial directions is detected by the device, which provides random access using the same beam direction to the gNB if channel reciprocity exists; if not, it performs beam sweeping as well. Once the initial communication has been established between the device and the gNB, the rest of the required system information is sent to the device on a dedicated beam, as shown in the following figure: TRxP-Wide Coverage Beam-sweeping Synchronization Signals transmission Beam-sweeping System Information transmission Basic information for all UEs Beam-sweeping Random Access Channel reception Random Access Response and System Single-beam or UE-specific Information Beam-sweeping selected beam UE-Specific Coverage Required only for UEs after random access UE-specific Data and control channels beamforming Figure 5.1 - The initial access procedure Initial access and beam management This is the basic procedure by which communication shifts from a wide coverage scenario into a beam- sweeping scenario. The beams to be used are further narrowed down once the data transmission is done through beam refinement procedures. Here, we have introduced the concept of channel reciprocity. This implies the channel conditions measured in one link direction can be assumed to be equivalent in the other one, the reciprocal one. For instance, if the device sees that the gNB downlink transmission is in one spatial direction, it will assume that the transmitted uplink in the same direction will also be received by the gNB. Note that this is only true in Time Division Duplex (TDD) systems where the same frequency is used for the downlink and uplink transmissions. Beam-sweeping and initial access As we described during the initial access section, a network will transmit synchronization signals and basic broadcast information