ble to limit the usage of a particular grant, cell, or numerology to a subset of logical channels. The three main benefits are as follows: (1) with LCP restrictions, a logical channel can be linked to the physical properties of the resources used for uplink transmission; for instance, the numerology with the largest subcarrier spacing and/or shortest PUSCH transmission duration can be reserved for URLLC services; (2) with LCP restrictions, possible collisions on contention-based resources (configured grant type 1; see Section 7.6.4) can be minimized by restricting their usage to services which really need them, for instance, URLLC services; and (3) with LCP restrictions, duplicates are guaranteed to be sent in different transport blocks (see Section 7.4.6). 7.6.7 A BSR signals the amount of data awaiting transmission in the UE buffers. The reporting is done per Logical Channel Group (LCG), and RRC configures the mapping between the logical channels and an LCG. An LCG can contain one or several logical channels, and not all LCGs need to be configured. With BSR, the gNB can assess how many bits the UE has to transmit. The same types of BSR as in LTE are used in 5G: regular BSR, which triggers a scheduling request procedure if there are no uplink resources to transmit them; periodic BSR, which is only sent if there is an available grant in the uplink (and does not trigger a scheduling request procedure if there is none), and padding BSR, which replaces padding. Typically, when new data becomes available for transmission, a regular BSR is triggered, which in turns triggers a scheduling request to signal the gNB that an uplink grant is needed for the UE to send something (CP signaling or UP data). Once the data exchange between the UE and the gNB has started, periodic BSRs can be used to update the gNB on a regular basis, while padding BSRs can be used to determine when the transmission buffers are empty or identify which LCG cannot be transmitted due to LCP restrictions (see Section 7.6.6) without increasing the over