MUX (Multiplexer)

A multiplexer combines multiple input signals onto a single transmission medium, allowing efficient use of capacity. Telecom uses several techniques: frequency-division (FDM/OFDM), time-division (TDM), wavelength-division (WDM/DWDM in optical networks), and code-division (CDMA). Demultiplexers reverse the process at the receiving end.

Categories: Radio Access NetworkSignalingInternet and Routing

MUX 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 MUX in the wider telecom-security picture, review Carrier Aggregation, MGCF, OFDMA, CAPEX, Fixed Wireless Access (FWA) and Mediation System.

Related terms

Related topic hubs

  • SS7 Security SS7/MAP/CAP/SCCP attacks and defenses across 2G/3G interconnect.
  • Signaling Firewall Unified SS7/Diameter/GTP/SMS signaling firewall framework.

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.