ATSSS (Access Traffic Steering, Switching and Splitting)

Also known as: Access Traffic Steering Switching Splitting

ATSSS is the 3GPP Release 16 feature that lets a UE simultaneously use 3GPP and non-3GPP accesses (for example 5G NR and Wi-Fi) for a single PDU session, with the network steering, switching or splitting flows based on policy. It uses MP-TCP and MP-QUIC proxies at the UPF and dedicated PCF policy control, and underpins tightly integrated Wi-Fi and 5G convergence.

Categories: Identity and SubscriberProtocols and StandardsInternet and Routing

ATSSS in context

Subscriber identifiers (IMSI, SUPI, MSISDN, IMEI) are the anchor for authentication, charging, lawful interception and fraud analytics. Any protocol or interface that leaks a permanent identifier is treated as a serious privacy defect, which is why 5G introduced SUCI concealment on the air interface.

Telecom security is written into standards from 3GPP, GSMA, ETSI, IETF and ITU-T. Understanding which body owns which specification, and how the specs interlock (for example 3GPP TS 33.501 with GSMA FS.34 for 5G SBA security), is essential for both design and audit work.

To place ATSSS in the wider telecom-security picture, review OCS, LEO, LTE-Advanced (LTE-A), Subnet, WEP and URSP.

Related terms

Related topic hubs

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.