Silent SMS
A silent SMS (Type 0 SMS) is a message that is delivered to the handset and acknowledged on the network but never displayed to the user. Law enforcement and intelligence services use it to trigger paging and confirm a target's presence and approximate location through the resulting signalling. Silent SMS is detectable by some end-user privacy tools and is regulated in some jurisdictions.
Categories: Regulation and Compliance
Silent SMS in context
Telecom regulation is fragmenting: NIS2 and the CER Directive in the EU, the Telecoms Security Act in the UK, sector rules in the US, GCC and APAC, plus horizontal frameworks like GDPR and DORA. Operators need control-level mappings between technical baselines (GSMA FS.11/FS.19) and each jurisdictional obligation.
To place Silent SMS in the wider telecom-security picture, review X2 (LI), Network Exposure Function (NEF), OCSP, Paging Attacks, SMS Home Routing and SMSC.
Related terms
Equipment
Messaging (SMSC, SMS router, MMSC, IP-SM-GW, SMSF, RCS)
Related topic hubs
- Silent SMS Type-0 SMS location tracking and detection.
- SMS Firewall SMS spam, phishing, A2P bypass and MAP-layer SMS filtering.
- Signaling Firewall Unified SS7/Diameter/GTP/SMS signaling firewall framework.
- Telecom Security Audit Structured MNO/MVNO security audit methodology.
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.