EPC / 5GC
Definition
Evolved Packet Core (LTE) and 5G Core (5G NR), the all-IP packet cores that replaced the circuit-switched GSM core. 5GC is service-based, with discrete network functions like AMF, SMF and UPF.
- EPC
- Evolved Packet Core, used by LTE
- 5GC
- 5G Core, used by 5G NR
- Architecture
- 5GC is service-based (AMF, SMF, UPF functions)
- Replaces
- The circuit-switched GSM core network
Common questions
Why does the shift from a circuit-switched core to EPC/5GC matter for lawful interception?+
An all-IP packet core routes voice, data, and signalling as IP traffic rather than dedicated circuits, which changes how interception and call-record extraction points are architected compared to legacy GSM circuit-switched networks.
What distinguishes 5GC's architecture from EPC's?+
5GC decomposes the core into discrete, independently scalable network functions such as AMF for access and mobility, SMF for session management, and UPF for user-plane traffic, replacing EPC's more monolithic gateway-based design.
Related terms
- ICCID
- Integrated Circuit Card Identifier. The serial number of the physical SIM card itself, stored in EF_ICCID. It identifies the card as a...
- IMEI
- International Mobile Equipment Identity, a 15-digit identifier of the handset hardware. Format is 8-digit TAC + 6-digit serial + 1-digit Luhn check....
- IMSI
- International Mobile Subscriber Identity. A 15-digit number stored in EF_IMSI on the SIM that uniquely identifies the subscriber account on the mobile...
- Ki
- The 128-bit secret authentication key stored on the SIM and in the operator's Authentication Centre (AuC). Never leaves either party in cleartext...
- MSC
- Mobile Switching Centre, the GSM core node that routes calls and SMS between the cellular network and the PSTN, and queries the...