ersa. 5.7.1 5G QoS Control and Rules Regarding QoS control in 5G, one should note that QFI can be equal to 5QI in some cases, but also these two parameters can have different values. Why? The parameter QFI is defined (in 3GPP Release 15) with 6 bits, which gives possible values in the range between 1 and 64 (because 26 = 64). So, 5QI values that do not belong to this range can- not become values for QFI. The approach is the following: for non-GBR flows when the 5QI parameters are used, the value of the 5QI can be used (when it is in the range 1-64) as the value of the QFI for the given flow. When a non-GBR flow goes over a non-3GPP network (e.g. fixed network, WiFi), a default ARP value should be preconfigured in the access network, while in the case of 5G access networks the ARP and QFI are sent to RAN via PDU session establishment/modification mechanisms. In all other cases (including both GBR and non-GBR flows) dynamically assigned QFI values are used, while 5QI values can be the standardized ones, preconfigured (except for roaming sce- narios) or dynamically assigned to the flow. However, the QoS profile and the corre- sponding QFI for the given QoS flow are also provided via 5G RAN using the PDU session establishment/modification mechanisms. 5.7.2 5G QoS Flow Mapping The classification and marking of the user data traffic in the uplink direction (that is association of uplink traffic to QoS flows) is done by the user equipment (i.e. mobile terminal), based on QoS rules which may be explicitly provided to the user terminal (via PDU session establishment or modification), preconfigured, or implicitly derived by using the reflective QoS (i.e. deriving the QoS rules from the downlink direction and applying them in the uplink). The QoS flow mapping in 5G is shown in Figure 5.12. In 5G networks from 3GPP the function responsible for service flow detection, authorized QoS, charging, traffic reporting, etc. is SMF. The SMF performs also the binding of SDFs to QoS flows by interacting with the mobile terminal (i.e. u