3, 3a, and 3x in addition to option 4 and option 7. In the introduction, we took the example of a deployment option known as option 3x. Let us further discuss the main features of this deployment option in detail: All control plane signaling is handled by the eNB. The eNB is connected to a 4G core for data and signaling. There is data plane connectivity between both the gNB and EPC and the eNB and EPC. In this case, both the master nodeB and the EPC are capable of splitting the data traffic between the eNB and gNB. Types of NSA networks The other two options of the same flavor are options 3 and 3a, as shown in the following diagrams: EPC (5G-enabled) Option (3) Figure 10.2 - NSA network option 3 The features of option 3 are as follows: All control plane signaling is handled by the master eNB. The eNB is connected to the EPC for data and signaling. The signaling for gNB is sent from the master eNB via the X2-C interface. The gNB is only connected to the eNB (master), and the Packet Data Convergence Protocol (PDCP) sublayer of the eNB splits the traffic SO that some traffic is sent to the gNB via the X2-U interface. Next, we will go over the aspects of option 3a: EPC (5G-enabled) Option (3a) Figure 10.3 - NSA option 3a The features of option 3a are as follows: All control plane signaling is handled by the master eNB. The eNB is connected to the EPC for data and signaling. The signaling for gNB is sent from the master eNB via the X2-C interface. The gNB is connected to the SGW via S1-U. In this option, the EPC splits the traffic. 5G Non-Standalone Networks The last item in the preceding list brings us to another new concept of split bearers, which answers the question of how data is split to go to the gNB and eNB. This brings us to the introduction of a few new terms: 5G - EN-DC Bearers Bearer Splitting The Master eNB can split the data between itself and secondary (191) MCG Bearer Master MCG Split Bearer SCG Bearer SCG Split Bearer Network (191) Secondary EN-gNB Bearer Splitting The secondary EN-gNB can also split 