3GPP Compliance¶

Ella Core implements 3GPP-standard interfaces for signalling.

Note

Open an enhancement proposal if you notice a 3GPP-compliance gap or require a new capability for a production deployment.

Supported¶

Interface	Transport
Cx	Diameter over SCTP or TCP
N1	NAS, over N2
N2	NGAP over SCTP
N3	GTP-U over UDP (IPv4 and IPv6)
N6	IP
Rx	Diameter over SCTP or TCP
S1-MME	S1AP over SCTP
S1-U	GTP-U over UDP (IPv4 and IPv6)
S6c	Diameter over SCTP; over SCTP or TCP with the IMS
SGd	Diameter over SCTP; over SCTP or TCP with the IMS
Sh	Diameter over SCTP or TCP
SGi	IP

Ella Core is a single binary and does not expose internal 3GPP interfaces. See Architecture.

Registration. 4G: attach, detach, and normal and periodic tracking area update. 5G: initial, mobility, and periodic registration, and UE- and network-initiated deregistration.
Service request. An idle UE returns to connected mode to resume its session.
Paging. Ella Core pages an idle UE when downlink data arrives for it.
Handover. 4G: S1 handover, and X2 handover via the Path Switch procedure. 5G: Xn handover, and N2 handover between radios served by Ella Core.
4G/5G interworking. A device moving between 4G and 5G keeps its IP address and its session.

Ella Core carries IP data sessions for 4G and 5G subscribers.

Session management. 4G PDN connectivity and 5G PDU sessions: establishment, modification, and release, including network-requested procedures.
Session types. IPv4, IPv6, and IPv4v6.
QoS. A default QoS flow (5G) or default bearer (4G) per session, with the 5QI/QCI, ARP priority level, and pre-emption capability and vulnerability of the session's policy.
Dynamic PCC rules. GBR and non-GBR rules from the PCRF/PCF. A rule with the 5QI/QCI and ARP of the default QoS flow or bearer is carried on it; other rules get dedicated QoS flows (5G) or dedicated bearers (4G), up to 4 per session. A change of a rule's ARP modifies its QoS flow or bearer in place. The Subscribers API lists each session's QoS flows or bearers.

Procedures. Identity, authentication, and security mode control.
Authentication. EPS-AKA on 4G, 5G-AKA on 5G.
Subscriber identity concealment. SUCI with the null scheme, Profile A, and Profile B, on 5G.
Ciphering and integrity. The null, SNOW 3G, and AES algorithms: EEA0/1/2 and EIA0/1/2 on 4G, NEA0/1/2 and NIA0/1/2 on 5G.

SMS over NAS. 4G (SMS in MME) and 5G.
Mobile-originated and mobile-terminated SMS. Relayed to and from external SMSCs over SGd.
HSS for the SMSC. Send Routing Info for SM, Report SM Delivery Status, and Alert Service Centre over S6c.
HSS for the IP-SM-GW. IP-SM-GW registration by Sh-Update of SMS registration info. Send Routing Info for SM proxied to the registered IP-SM-GW over S6c.

IMS voice and video. VoLTE on 4G and VoNR on 5G, with an external IMS. EPS fallback from 5G to 4G.
MCPTT. On-network MCPTT on 4G and 5G, with an external IMS and MCPTT server. QCI/5QI 69 for signalling, 65 for calls, and the Rx MCPTT priority feature.
HSS for the IMS. User authorization, server assignment, location info, multimedia authentication, registration termination, and push profile over Cx.
User profile. Initial filter criteria per profile, and distinct and wildcarded Public Service Identities per application server.
PCRF for the IMS. AA, re-auth, session termination, and abort session over Rx, with GBR QoS for voice, video, and MCPTT.

Cell identity and E-CID positioning: LPPa on 4G, NRPPa on 5G. GNSS positioning in standalone mode: LPP on 4G and 5G. See the Location API.

No emergency services. Emergency sessions and emergency service requests are rejected.
No roaming. Ella Core does not support roaming between networks.