g system information. The RLC sub- layer also provides sequential delivery of SDUs to the upper layers and eliminates duplicate packets from being delivered to the upper layers. It may also segment the SDUs. The RLC configuration is defined per logical channel with no dependency on numerologies and/or TTI durations, and ARQ can operate with any of the numerologies and/or TTI durations for which the logical channel is configured. For SRBO, paging and broadcast system informa- tion, RLC TM mode is used. For other SRBs, RLC AM mode is used. For DRBs, either RLC UM or AM mode is used. The services and functions provided by the PDCP sublayer in the user plane include header compression/decompression of IP packets; transfer of user data between NAS and RLC sublayer; sequential delivery of upper layer PDUs and duplicate detection of lower layer SDUs following a handover in RLC acknowledged mode; retransmission of PDCP SDUs following a handover in RLC acknowledged mode; and ciphering/deciphering and integrity protection. The services and functions provided by the PDCP for the control plane include ciphering and integrity protection and transfer of control-plane data where PDCP receives PDCP SDUs from RRC and forwards them to the RLC sublayer and vice versa. The main services and functions provided by SDAP sublayer include mapping between a QoS flow and a DRB and marking QoS flow IDs in downlink and uplink packets. A single instantiation of SDAP protocol is configured for each individual PDU session, with the exception of dual-connectivity mode, where two entities can be configured. The RRC sublayer in the gNB makes handover decisions based on neighbor cell mea- surements reported by the UE; performs paging of the users over the air-interface; broadcasts system information; controls UE measurement and reporting functions such as the periodicity of channel quality indicator reports; and further allocates cell-level temporary identifiers to the active users. It also executes transfer of UE context from the serving gNB to th