WiMAX

WiMAX is a family of wireless broadband standards built on the IEEE 802.16 specification that delivers internet connectivity to fixed outdoor antennas or mobile subscriber units across distances of 10 to 50 kilometers, depending on frequency band and environmental conditions. It operates in licensed microwave bands, typically 2.3 GHz, 2.5 GHz, 3.5 GHz, or 5.8 GHz, and uses orthogonal frequency division multiplexing (OFDM) to pack multiple data channels into the same frequency allocation.

Two main variants emerged in practice. Fixed WiMAX (802.16d) locks subscriber antennas to a single tower location and was deployed from the mid-2000s onward in countries where DSL and cable infrastructure was sparse or expensive to roll out. Mobile WiMAX (802.16e) added mobility by allowing clients to hand off between base stations, creating a cellular competitor to 3G and early 4G networks. Theoretical peak throughput reached 70 Mbps per sector in 802.16e, though real-world sustained rates were substantially lower, typically 5 to 15 Mbps downstream under good propagation.

Deployment and decline

WiMAX saw serious investment in the 2000s. Sprint and Clearwire built substantial mobile WiMAX networks in North America; Korean, Japanese, and Eastern European operators deployed it as a bridge technology to 4G. However, the explosive adoption of LTE after 2009 overtook WiMAX in device ecosystem breadth and chipset economies of scale. By 2020, most carriers had deprecated or shut down WiMAX networks. Fixed WiMAX persisted longer in emerging markets where leased copper lines remained unavailable, and some industrial applications continue to use unlicensed WiMAX derivatives for point-to-point campus links.

The technology's strength was its ability to cover long distances with a single base station, reducing the site acquisition burden. The main weakness was higher latency and lower sustained throughput than LTE at comparable spectrum, plus poorer indoor penetration below 3 GHz. Terminal cost and power consumption were also barriers to mass consumer adoption relative to cellular alternatives.

In terminology, WiMAX was a marketing umbrella name coined by the WiMAX Forum industry group; the actual standards lived in IEEE 802.16. This naming convention sometimes confused engineers unfamiliar with the standards body structure. Today, any active WiMAX reference in industrial or telecom contexts usually refers to legacy fixed-point networks serving rural or developing regions, or proprietary wireless systems licensed under 802.16 protocols for enterprise use.