OFDMA (Orthogonal Frequency Division Multiple Access)

Orthogonal Frequency Division Multiple Access extends OFDM by assigning subsets of subcarriers to different users at different times, allowing fine-grained scheduling and efficient sharing of the radio resource. OFDMA is used in LTE downlink, 5G NR (both up and downlink), and Wi-Fi 6/6E (802.11ax), where it significantly improves multi-user efficiency.

Categories: Radio Access NetworkInternet and RoutingEncryption and Cryptography

OFDMA 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 networks depend on Internet-style routing (BGP, DNS, MPLS) for interconnect, transport and application delivery. Route hijacks and DNS abuse can degrade or intercept signaling as easily as any application-layer attack, which is why RPKI and DNSSEC are now standard hardening for carrier networks.

To place OFDMA in the wider telecom-security picture, review CDMA, TDMA, OFDM, Broadband, Noise and SHR.

Related terms

Related topic hubs

  • Diameter Security 4G/LTE Diameter threats across IPX/roaming and DEA defenses.
  • Diameter Attacks S6a IDR/PUR/CLR abuse, subscriber tracking, LTE signaling attacks.
  • 5G Security 5G SBA, SEPP, SUCI, 5G-AKA, N32 and service-based interface security.
  • 5G NEF Security Network Exposure Function security in the 5G core.

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