CDMA (Code Division Multiple Access)

Code Division Multiple Access is the air-interface technique used by 2G IS-95 (cdmaOne) and 3G CDMA2000/EV-DO networks, originally championed in North America. Multiple users share the same frequency by being separated through orthogonal pseudo-random code sequences. CDMA networks have largely been migrated to LTE and 5G, and the technology is operationally retired in most markets, though the underlying CDMA principle survives in WCDMA and 5G NR control-channel coding.

Categories: Radio Access NetworkInternet and RoutingEncryption and Cryptography

CDMA in context

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

Telecom networks depend on Internet-style routing (BGP, DNS, MPLS) for interconnect. Route hijacks and DNS abuse can degrade or intercept signaling, which is why RPKI and DNSSEC are now standard hardening for carrier networks.

To place CDMA in the wider telecom-security picture, review Broadband, Noise, OFDMA, SHR, TDMA and A5/2 — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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