What Is WiMax And How Does It Compare To WiFi And 3G/4G?

WiMAX (Worldwide Interoperability for Microwave Access) is a wireless broadband technology based on the IEEE 802.16 standard and certified by the WiMAX Forum. It uses licensed spectrum (typically 2.3, 2.5, or 3.5 GHz) to deliver non-line-of-sight links from a base station to subscribers within a 3 to 10 km (1.9 to 6.2 mi) cell radius, at speeds up to 40 Mbps. Once a leading 4G contender, WiMAX has been largely superseded by LTE and 5G.

In the late 2000s, two wireless technologies battled for the 4G (fourth generation) crown. One was LTE, the cellular industry's evolution of 3G; the other, championed by the PC and chip industries, was WiMAX. WiMax stands for Worldwide Interoperability for Microwave Access, and was designed to deliver high broadband data speed, robust security, and easy mobility. LTE eventually won the standards war, but WiMAX still found its niches in fixed wireless access and aviation. In this article, we will take a deeper look into WiMax and its certifying body, the WiMax Forum, compare it with WiFi and the cellular networks of its era, and see how it brought rural broadband to parts of Africa and Australia before being eclipsed by LTE and 5G.

What Is WiMax?

WiMax is an IP-based (just like your WiFi) wireless technology built on the IEEE 802.16 family of standards, designed to accommodate fixed, nomadic, and mobile usage models. Interoperability between vendors is certified by an industry body called the WiMax Forum. The Forum was established to help deliver wireless broadband services anytime, anywhere, regardless of which equipment maker built the gear.

WiMax delivers non-line-of-sight (non-LoS) connectivity between a subscriber station and a base station, with a typical cell radius of 3 to 10 km (1.9 to 6.2 mi). For the uninitiated, non-LoS is a technique for maintaining communication between the radio transmitter and the receiver even when they are not in direct visual line of sight, by routing the signal through multiple reflected paths. WiMax Forum certification calls for systems to deliver up to 40 Mbps of capacity per channel, which is large enough to serve both commercial and residential users for high-speed Internet access. The Forum also requires mobile WiMax (IEEE 802.16e) network deployments to sustain about 15 Mbps within a typical cell radius of up to 3 km (1.9 mi). In its heyday, WiMax modems were embedded in laptops and netbooks (most famously, certain Intel Centrino models) so that users could roam onto carrier networks the moment they walked out of WiFi range.

Why WiMax?

A key selling point for WiMax is the interoperability of WiMax Forum Certified equipment. This interoperability paves the way to mass production and the economies of scale that benefit end users. It also reassures service providers that gear bought from different vendors will actually work together. Other important advantages of WiMax include better coverage, larger channel capacity, and tighter standardization for both fixed and mobile wireless networks. Compared with the cellular technologies of its era, WiMax considerably raised the data rates available for bandwidth-hungry applications like video streaming and HD video conferencing.

The WiMax Forum

There is an enormous amount of complexity involved in licensing spectrum for mobile networks. On top of that, rules and standards differ from region to region, which makes running a wireless internet business tough and makes interoperability across regions (or between gear from different vendors) a real challenge. That is why the WiMax Forum was set up in June 2001: to eliminate the ambiguity of competing terminologies and to harmonize how the new generation of wireless broadband technology, WiMax, would be built. The Forum is a not-for-profit industry body whose members include network operators, chip and component vendors, equipment makers, systems integrators, and regulators, all working to promote broadband wireless products based on the harmonized IEEE 802.16 standard. At its commercial peak around 2008-2011, membership swelled past 500 companies, with hundreds of operators worldwide; today the membership is considerably smaller and increasingly focused on niche applications like aviation and smart utility grids.

The Forum works in tandem with service providers, hardware manufacturers, certification labs, and application providers to ensure that WiMax systems meet customer and government requirements. It also runs the WiMax Forum Certified program, under which independently tested products are deemed interoperable and able to support the full range of usage models that broadband wireless service providers deploy.

WiMax Vs The Rest

Now, let’s have a face-off of WiMax with the other contemporary internet technologies.

WiMax Vs WiFi

WiMax, like WiFi, is an IP-based wireless technology. Both are designed to deliver high-speed internet wirelessly. That is the similarity, but now it’s time for the differences.

WiFi was originally meant to provide indoor wireless connectivity, typically over a very short distance. WiFi is suitable for home networks or in a smaller public space, like a coffee shop. There have been attempts to “mesh” the technology and use for a citywide application as a whole. However, to materialize that, there would be a need to deploy hundreds of radios for city coverage of just a few kilometers. This dramatically raises the project cost and makes it a financially less viable option. Another major differentiator between WiMax and WiFi lies in the usage of the radio spectrum. This might sound surprising, but WiFi uses an unlicensed spectrum. However, WiMax uses licensed spectrum, with the most widely deployed bands being 2.3 GHz, 2.5 GHz, and 3.5 GHz.

Interestingly, WiMax is often referred to as ‘WiFi on steroids’. Networking academic experts like Scott Shamp opine that WiMax is an interesting mix of cellular and WiFi networks. WiMax gives you the high-speed internet like WiFi, along with much wider network coverage, like a typical cellular network. Also, since WiMax is designed to be a carrier-grade technology, there is much more reliability and quality of service built in, as compared to a typical WiFi system.

WiMax Vs 3G

3G is a third-generation cellular service. Like WiMax, 3G transmits data over long distances. Like WiMax, these services are also modeled around licensed spectrums. 3G networks are roughly three times slower than WiMax. That’s because the 3G network was fundamentally designed for voice traffic, with data as a value-added service. On the contrary, WiMax is specifically designed to provide high-speed portable data.

WiMax Vs LTE

For networking purists, I should clarify the heading: WiMax and LTE were the two technologies marketed as 4G, so comparing them is really an intra-4G face-off. WiMax (specifically Mobile WiMax, IEEE 802.16e) was actually the first to reach commercial deployment, while LTE, developed by the 3GPP standards body as an upgrade path from 3G GSM/UMTS, arrived a year or two later and ultimately won the global market.

They actually have more similarities than differences. Like WiFi, both are IP-based. At their core, they are designed for data, with voice carried as just another packet stream. (You might have noticed I keep coming back to that ‘IP-based’ phrase. The full story of what IP-based really means deserves its own article.) For simplicity, being IP-based means WiMax and LTE both deliver a true mobile broadband experience on portable devices like smartphones and tablets. Unlike the 2G/3G era, where GSM and CDMA were bitter rivals, in the 4G era WiMax and LTE were more like siblings sharing a common parent: both use OFDM on the downlink. OFDM stands for orthogonal frequency division multiplexing, a digital encoding and modulation scheme. The trick OFDM pulls off is achieving a high data rate and better spectral efficiency by splitting the signal across many narrow, overlapping but mathematically orthogonal subcarriers, rather than cramming everything onto one wide carrier.

Thanks to the early push from technologies like WiMax, the prices of wireless internet equipment and broadband access fell sharply, to the point where fixed wireless can compete with cable and fiber in the right markets. WiMax found particular traction in places where laying cable was uneconomic. In parts of rural Australia, iiNet and Adam Internet ran WiMax services in South Australia until the National Broadband Network and 4G/5G fixed wireless took over. In several African countries, including Nigeria, Kenya, Uganda, and South Africa, operators used WiMax to connect homes and businesses that the wired network never reached.

So where does WiMax stand today? The honest answer is: largely retired from consumer use. Sprint and Clearwire, which built the largest mobile WiMax network in the United States on 2.5 GHz spectrum, began shutting it down on November 6, 2015, with the last cities going dark on March 31, 2016, and migrated the spectrum to LTE. The IEEE 802.16 working group has been disbanded, no new chips are being designed for mainstream phones, and the 5G fixed wireless access services from carriers like T-Mobile, Verizon, and AT&T now deliver the home broadband experience WiMax pioneered. The WiMax Forum, however, is still alive, but its focus has shifted to specialized industrial deployments, most notably AeroMACS (Aeronautical Mobile Airport Communication System), which uses a WiMax-based protocol on aviation spectrum at airports worldwide, and WiGRID, used by electric utilities for smart-grid communications. So while you are not likely to buy a WiMax dongle for your laptop in 2026, the standard quietly lives on in the towers of busy airports and the substations of power utilities.