3 Technology Components UE close to BTS Figure 3.22 Transmission and reception timing with long propagation delay. BTS transmission UE reception UE transmission BTS reception UE 300 km from BTS BTS transmission UE reception UE transmission BTS reception 2 ms later from the far-way UE. The UE is not aware of the propagation delay during the preamble transmission. Therefore, the propagation delay must be considered in the uplink reception window. The uplink reception in 5G is synchronous, which requires that the transmissions from distant UEs must start earlier than those from close UEs in order to simultaneous uplink reception in the base station. The uplink transmission timing is adjusted with a timing advance, and the range of the signaling is large enough to accommodate a 300 km cell range. Network Slicing 5G networks are designed to support very diverse and extreme requirements for latency, throughput, capacity, and availability. Network slicing offers a solution to meet the requirements of all use cases in a common network infrastructure. The concept of network slicing is illustrated in Figure 3.23. The same network infrastructure can support, for example, smartphones, tablets, virtual reality connections, personal health devices, critical remote control, or automotive connectivity. LTE supports Quality of Service (QoS) differentiation, but we need more in 5G. Network slicing is described in more detail in Chapter 5. 3.6 Dual Connectivity with LTE 5G is the first radio solution which is closely integrated with the legacy radio network for a smooth rollout and seamless experience. The solution is called dual connectiv- ity, where a 5G UE can have simultaneous connections to a 5G radio network and an LTE radio network. The first version of 5G in 3GPP supports the non-standalone (NSA) architecture with dual connectivity. Both 5G base stations (gNodeB) and LTE base sta- tions (eNodeB) are connected to Evolved Packet Core (EPC). The control plane goes 3.6 Dual Connectivity with LTE Smart- Network phones Orchestrat