E2SM (E2 Service Model)

Also known as: E2 Service Model, E2SM-KPM, E2SM-RC

An E2SM is an O-RAN specification that defines the semantics of RAN functions exposed to xApps over E2: what measurements can be reported, what control actions can be issued, and how they are encoded. Standardised E2SMs include KPM (Key Performance Measurement), RC (RAN Control), NI (Network Interface) and CCC (Cell Configuration and Control). E2SM support determines what an xApp can actually do to a given gNB.

Categories: Radio Access NetworkProtocols and Standards

E2SM in context

The radio access network is the layer where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations, downgrade attacks and jamming, and defenses hinge on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

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 E2SM in the wider telecom-security picture, review E2AP, Open Fronthaul, EAP, TSC, TCP/IP and ETSI ISG MEC.

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