E911 (Enhanced 911)

Enhanced 911 is the US emergency-services capability that automatically delivers the caller's location and callback number to the dispatcher answering a 911 call. E911 imposes specific obligations on wireless and VoIP carriers (Phase I and Phase II location accuracy, handling of nomadic VoIP) enforced by the FCC, and is the model for similar services worldwide such as E112 in the EU.

Categories: Radio Access NetworkSignalingIdentity and Subscriber

E911 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.

Signaling protocols carry the control-plane instructions that set up calls, register subscribers, hand over sessions and route SMS. SS7, Diameter, GTP-C and SIP are the four dominant families, and interconnect exposure of any of them is treated by GSMA FS.11 / FS.19 / FS.20 as a top-tier telecom risk.

To place E911 in the wider telecom-security picture, review UMTS, BTS Impersonation (Fake BTS), Cleartext (Plain Text), OFCS, Rogue Base Station (Fake BTS) and SMS Pumping.

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