e PDN connection with non-IP PDN type corresponds to PDU session type of Ethernet or unstructured, respectively. This is to ensure that the appropriate PDU session type will be used if the UE transfers back to the 5GS. 162 Chapter 1 1.4.2 5G Deployments Scenarios and Architecture Options This section describes 5G network architecture deployment options supporting stand-alone and non-stand-alone mode of operation. These deployment options were extensively dis- cussed in 3GPP and have been prioritized based on their viability and practicality. Each option provides NR access to sufficiently capable UEs either through direct access to gNB/ 5GC or indirectly via LTE interworking. 3GPP defined both stand-alone and non-stand- alone deployment configurations for NR in 3GPP Rel-15. A stand-alone NR deployment would not require an associated LTE network. The NR-capable UE could use random access to directly establish a radio link with a gNB and attach to the 5GC in order to use network services. The stand-alone NR deployment required a complete set of specifications from 3GPP for all entities and interfaces in the network, which was subsequently defined in 3GPP Rel-15 specifications. In stand-alone operation (shown as option 2 in Fig. 1.80), the network access procedures closely follow the LTE counterparts. The additional requirements mainly include broadcast of NR system information, which includes a minimum set of parameters and extended set of parameters where the former is periodically broadcast and comprises basic information required for initial access and the scheduling information for other system information; and the latter encompasses other system information that are not transmitted via the broadcast channel, which may either be broadcast or provisioned in a dedicated manner which can be triggered by the network configuration or upon request from the UE. In comparison to LTE system information broadcasting scheme, on-demand broadcasting is a new mechanism introduced in NR to deliver other system information by U