1. 3GPP TS 23.003(2019).Numbering addressing and identification.
2. 3GPP TS 23.214(2019).Architecture enhancements for control and user plane separation of EPC nodes.
3. 3GPP TS 23.401(2019).General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E‐UTRAN) access; Stage 2.
4. 3GPP TS 23.501(2019).System architecture for the 5G System (5GS); Stage 2.
5. 3GPP TS 23.502(2019).Procedures for the 5G System (5GS); Stage 2.