5G • Services
IMS
IP Multimedia Subsystem
Architectural framework delivering IP-based multimedia telephony, video calling, and SMS over 5G.
Technical Explanation
The IMS core handles call session control, SIP signaling, subscriber registration, and media routing. Over 5G, IMS connects to the 5G Core UPF via the N6 interface over a dedicated IMS PDU session (5QI 5 for SIP signaling and 5QI 1 for RTP voice media).
Key Functions
- Provides standardized IP telecommunication services (voice, video, RCS, SMS)
- Operates over dedicated IMS PDU Session with high priority 5QI 5 signaling
- Interconnects mobile cellular voice to global Public Switched Telephone Networks (PSTN)
Specifications
3GPP TS 23.228, TS 24.229
Interfaces
N6GmRx
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