 group, the maximum number of configured component carriers for a UE is 16 for downlink and 16 for uplink. A gNB may configure the same physical cell IDs (PCIs) for several NR cells that it serves. To avoid PCI confusion for MR-DC, the NR PCIs may be allocated in a way that an NR cell is uniquely identifiable by a PCell ID. This PCell is in the coverage area of an NR cell included in the MR-DC operation. In addition, the NR PCIs may only be reused in NR cells on the same SSB frequency sufficiently apart from each other. An X2-C/ Xn-C signaling can be used to help identify NR PCIs by including the cell global identifier (CGI) of the PCell in the respective X2AP/XnAP messages and by providing neighbor cell relationship via non-UE-associated signaling [4]. In MR-DC, the UE is configured with two MAC entities: one MAC entity for the MCG and one MAC entity for the SCG. In MR-DC, SPS resources can be configured on both PCell and PSCell. In MR-DC, the BSR configuration, triggering, and reporting are independently performed per cell group. For split bearers, the PDCP data is considered in BSR in the cell group(s) configured by RRC signaling. In EN-DC, separate DRX configurations are pro- vided for MCG and SCG. Both RLC-AM and RLC-UM can be configured in MR-DC for all bearer types (i.e., MCG, SCG, and split bearers). In EN-DC, packet duplication can be applied to carrier-aggregation in the MN and in the SN; however, MCG bearer carrier- aggregation packet duplication can be configured only in combination with LTE PDCP; and MCG DRB carrier-aggregation duplication can be configured only if dual-connectivity packet duplication is not configured for any split DRB. In NGEN-DC, carrier-aggregation packet duplication can only be configured for SCG bearer. In NE-DC, carrier-aggregation packet duplication can only be configured for MCG bearer. In NR-DC, carrier-aggregation packet duplication can be configured for both MCG and SCG bearers. In EN-DC, ROHC can be con- figured for all bearer types. In MR-DC with 5GC, the network may ho