In existing implementations, mobile devices may operate in either a stand-alone mode (e.g., connected to a 5G core and/or a next generation core network with a primary connection via a 5G base station, e.g., a gNB) or a non-stand-alone mode (e.g., connected to an enhanced packet core (EPC) network with a primary connection via a 4G base station, e.g., an eNB). In a non-stand-alone mode, a wireless device may have a control plane connection to an eNB and the EPC and a user plane connection allowing data transport through the eNB and a gNB via the EPC. Thus, in non-stand-alone mode, there may be data flow aggregation across an LTE (Long Term Evolution) base station (e.g., the eNB) and a 5G NR (Fifth Generation New Radio) base station (e.g., the gNB) via the EPC. For example, as illustrated by FIGS. 9A-B, a UE, such as UE 940 (which may include an application layer 942, an LTE modem 944, and an NR modem 946) may be connected to both an eNB 904 (e.g., via connection 912) and a gNB 906 (e.g., via connection 922). In non-stand-alone mode, both the eNB 904 and the gNB 906 may be connected to EPC 902 and UE 940 may communicate with the EPC 902 via eNB 904 via communications 932. As shown, eNB 904 may communicate with EPC 902 via connection 910. Connection 910 may support both control signaling (e.g., via a control plane) exchange and data transport (e.g., via a user plane) with the UE 940. In addition, gNB 906 may communication with EPC 902 via connection 920. Connection 920 may support data transport (e.g., via the user plane) with the UE 940. Additionally, connection 930 between eNB 904 and gNB 906 may support both data exchange (e.g., via the user plane) and control signaling (e.g., via the control plane) between the base stations.
