5G vs Wi-Fi: Expectations vs. Reality

In recent years, the future of Wi-Fi networks has been a hot topic, especially with the anticipated widespread rollout of fifth-generation (5G) cellular networks. Many wonder: why do we need Wi-Fi in a world where cellular networks provide billions of people with high-speed internet access? Will Wi-Fi standards stop evolving with the arrival of 5G? Will the technology disappear, having fulfilled its “historical mission”? This article is dedicated to everyone who answered “yes” to these questions—and to those who are interested in network technologies in general.

Despite the apparent logic, the debate over Wi-Fi vs. 5G is based on an artificial rivalry between related but fundamentally different technologies. Most claims about Wi-Fi’s impending obsolescence come from cellular operators, and we’ll explain why at the end of this article. For now, let’s debunk two common myths: “5G is much faster than Wi-Fi” and “Wi-Fi will soon die out.” But first, let’s clarify what 5G and Wi-Fi actually are.

The Frequency Crunch

5G refers to the new generation of cellular standards, which many believe will revolutionize telecommunications. However, a similar claim was more justified for 4G, which brought a tenfold increase in data speeds, a new radio interface, a new core network architecture, and many new features for operators and users alike.

5G also brings many changes, some quite radical. But here’s a key fact: 5G standards will be used to build three different types of cellular networks:

• 5G networks for traditional cellular use in the 1–6 GHz range
• Networks for wide-area coverage and the Internet of Things (IoT) below 1 GHz
• Millimeter-wave networks (above 24 GHz)

Only the first type will be widely available to regular mobile users in the near future. The other two have specialized use cases, which we’ll discuss later.

Superfast Speeds? Not So Fast

For mass-market users, 5G networks will operate in the familiar 1–6 GHz bands. At higher frequencies, it’s nearly impossible to provide continuous coverage with a limited number of powerful base stations. Unfortunately, there’s a global shortage of free spectrum below 6 GHz. The industry has already gone through spectrum conversions, moving users to new bands and refarming frequencies from older standards to newer ones. There’s no magical new source of spectrum for 5G in these bands. Many 5G innovations are aimed at mitigating this frequency shortage, with the goal of increasing network capacity and speed without significantly raising costs.

Wi-Fi to the Rescue

To boost network capacity and speed, new frequencies would help—but as discussed, they’re scarce. Cellular networks are now trying to use bands already allocated to other technologies, especially Wi-Fi. Globally, Wi-Fi has access to hundreds of MHz in the 1–6 GHz range, and cellular operators have long eyed these frequencies.

But they can’t simply take these frequencies from public Wi-Fi networks. Instead, new technologies are being developed to allow simultaneous use of these bands by both Wi-Fi and cellular networks, without significantly harming Wi-Fi quality. This trend has evolved from simple, poorly coordinated LTE-U (which interfered with Wi-Fi) to LAA (Listen Before Talk), and now to LWA and eLAA, which enable direct coordination between Wi-Fi and cellular radio subsystems. The key trend here is coordination and cooperation between cellular and Wi-Fi networks.

Will these technologies boost cellular network speed and capacity? Yes, but don’t expect a revolution.

The Limits of 5G Growth

If there’s not enough spectrum, the next step is to increase spectral efficiency—transmitting more data in the same channel. 5G is better than 4G in this regard, thanks to improved modulation and coding, but the gains are incremental. Most modern modulation schemes are already near physical limits. The jump in efficiency from 3G to 4G was greater than what’s expected from 4G to 5G.

Significant potential for increased efficiency remains, but it comes from more complex methods: dynamic spectrum allocation, better division between uplink and downlink, network self-organization, resource recombination, improved carrier aggregation, and so on. Most of these are already present and evolving in 4G.

Another approach is to increase frequency reuse—serving more users in the same band by isolating channels to avoid interference. This has always been a key driver of cellular capacity growth, far more than spectrum expansion or spectral efficiency alone.

By some estimates, since the dawn of cellular, capacity has increased 3–4x due to more spectrum, 5–6x due to better spectral efficiency, and 40–60x due to improved frequency reuse.

But There’s a Catch: Investment

All these improvements can significantly boost 5G network capacity in standard frequency bands compared to 4G, but they won’t deliver a breakthrough in per-user speeds. Capacity and speed are related but not identical: serving more users without quality loss doesn’t mean each user gets much faster speeds in real-world conditions.

To realize these gains, operators will need to deploy more base stations, connect them with higher-capacity backhaul, use more complex and expensive antenna systems, and acquire more spectrum. In short, it will require massive investment—and operators only invest where there’s a clear business case. For now, it’s unclear why operators would pour huge sums into mass-market 5G networks with blanket coverage and high capacity.

5G for IoT and Enhanced 4G

Another key 5G use case is IoT (Internet of Things). Here, 5G offers major advantages over previous generations: much lower latency (an order of magnitude less than 4G) and the ability to serve huge numbers of devices per cell. 5G standards include LPWA (Low Power Wide Area) protocols for low-speed, low-intensity connections with minimal modem power consumption. This enables not just sensor networks, but also reliable control systems for vehicles, drones, and robots. IoT 5G networks will mainly use sub-1 GHz frequencies, which cover much larger areas per cell. High-speed 5G for regular users in these bands is unlikely due to spectrum scarcity and antenna size limitations.

The third type of 5G network is for ultra-high-speed connections—peak speeds up to tens of gigabits per second—in millimeter-wave bands (wavelengths under 1 cm). These bands offer vast unused spectrum, but signals require line-of-sight and have very low allowed power. In cities, providing continuous coverage would require a 500–1000x increase in the number of cells compared to standard bands, and even then, coverage would be spotty. There’s also no suitable user equipment for these frequencies in typical smartphones and tablets yet. In the medium term, these networks will mainly serve fixed locations (homes, trains, vehicles) and hotspots, not regular mobile users.

In summary, over the next 5–7 years, 5G won’t bring a revolutionary user experience. It will be seen as an improved 4G, with higher and more stable speeds—peak speeds of 200–300 Mbps and average speeds of 30–80 Mbps, compared to today’s LTE peaks of 100–150 Mbps and averages of 10–40 Mbps.

5G Indoors

Most mobile traffic is consumed indoors, so operators need to provide high-quality coverage and capacity inside buildings. The most likely 5G bands (around 3–4 GHz) are heavily attenuated by walls, so indoor 5G will require small cells and antenna systems similar to those used for 4G today. As a result, indoor 5G speeds below 6 GHz will be similar to what’s available in current indoor 4G networks.

Currently, most smartphone and tablet traffic is carried over Wi-Fi, not cellular. For example, in Russia, 78% of mobile device traffic goes through Wi-Fi, and only 22% through cellular (Mediascope). This traffic is mostly consumed indoors. For 5G to change this, operators would need to invest massively in indoor networks, including in residential buildings.

Why Wi-Fi Isn’t Inferior to 5G

So, how does Wi-Fi differ from 4G/5G, and is it really worse? Many people judge Wi-Fi by their experience with basic public networks, but modern Wi-Fi can do almost everything cellular networks can. Wi-Fi fully supports mobility, continuous coverage, moving users, service classes, automatic network authorization, advanced data protection, and automatic roaming between different operators’ Wi-Fi networks. Both 3GPP (cellular) and IEEE (Wi-Fi) standards provide for extensive cooperation and coordination between Wi-Fi and 4/5G, including LAA/LWA, Wi-Fi Calling, and seamless roaming.

In terms of data transmission, Wi-Fi is very similar to 4G/5G, using OFDM and, in modern versions, OFDMA modulation—almost identical to what’s used in cellular. The available modulation and coding levels, and thus spectral efficiency, are also similar.

Wi-Fi evolves in parallel with cellular, but always leads in supported data rates over short distances. Over the past decade, Wi-Fi has undergone a major generational shift: 802.11ac has replaced 802.11n. Unlike cellular, where new standards require costly infrastructure overhauls, Wi-Fi upgrades are much smoother and backward compatible.

802.11ac (the current de facto standard) supports Multi User MIMO and peak PHY rates of 2.34 Gbps (three spatial streams, 160 MHz channel). Real-world peak data rates can reach about 1.5 Gbps. 802.11ac Wave 1 offered up to 1.3/0.8 Gbps (channel/real), and 802.11n up to 450/300 Mbps (three streams, 40 MHz). The upcoming 802.11ax (expected in 2019) will add about 40% more spectral efficiency per channel and quadruple overall efficiency. 802.11ad, like millimeter-wave 5G, is designed for ultra-high-speed connections at 60 GHz, with peak channel rates of 7 Gbps and beamforming support. The next standard, 802.11ay, will offer up to 44 Gbps per stream and up to 176 Gbps with four streams and full channel width, plus much longer range. For IoT, 802.11ah (Wi-Fi HaLow) operates at 900 MHz, with low latency and power consumption—just like 5G IoT features.

Looking at these numbers, why do people say “5G is faster”? Theoretically, maximum data rates in 5G and Wi-Fi are comparable. In fact, new Wi-Fi standards for 5 GHz can offer higher peak speeds than standard 5G bands, and much higher in millimeter-wave bands. But speed isn’t the main difference—the real distinction is in usage models.

Why-Fi? The Real Differences

Cellular networks are designed to serve massive numbers of users, providing a unified experience, supporting all standards and bands everywhere, indoors and outdoors. 5G, for the first time, is moving away from this “one-size-fits-all” approach, architecturally enabling different types of networks where needed.

Wi-Fi, by contrast, is built around a single core service—data transmission—mainly for areas with many relatively stationary users, mostly indoors. Wi-Fi’s additional services differ greatly from cellular, largely because there’s no need for contracts or SIM cards. Wi-Fi enables things like advertising on connection, hyperlocal analytics, instant paid access for tourists, and more. Thanks to its neutrality, Wi-Fi allows offloading, Wi-Fi Calling, and international roaming for all cellular and Wi-Fi operators.

Typical Wi-Fi equipment is limited in power and designed for short-range use. Wi-Fi is inherently a niche technology, which makes its architecture much simpler than cellular. The biggest simplification is the lack of a centralized core network—each Wi-Fi segment can be built independently, with local traffic processing and routing, yet still managed centrally. The Internet itself serves as the backbone. Wi-Fi bands are unlicensed or lightly licensed, making them much cheaper per user than cellular. No matter how cellular evolves, Wi-Fi will always be fundamentally cheaper to deploy for a given area and service level.

On the other hand, trying to use Wi-Fi for blanket coverage, large numbers of outdoor users, and centralized subscriber management will yield worse results than cellular, which is more efficient and higher quality outdoors. Wi-Fi frequencies are also less protected, making interference more likely—less of an issue indoors, but a big problem outdoors.

Cooperation, Not Competition

Cellular operators aren’t worried about Wi-Fi because of quality, convenience, or security—they’re worried because Wi-Fi is free. Since operators still make most of their money from traffic, a free alternative is unacceptable. The market has long offered an alternative to this rivalry: offloading cellular traffic to Wi-Fi networks automatically and transparently. The user may not even know which network they’re using, as all services (voice, data, messaging) work seamlessly. There are many types of Wi-Fi offload and advanced cooperation between cellular and Wi-Fi networks, and these are increasingly used worldwide. As high-quality Wi-Fi segments appear, they become a natural alternative to building or expanding cellular infrastructure, or allow operators to limit investments by building lower-capacity cellular networks.

In Russia, cooperation between cellular and Wi-Fi is lagging, mainly due to a lack of high-quality, standards-compliant, well-managed Wi-Fi networks. It’s a chicken-and-egg problem: building quality Wi-Fi in high-traffic areas requires significant investment (though still much less than cellular), but to invest, you need a business case. Few know how to monetize public free Wi-Fi, so most networks are built for non-commercial reasons (convenience, security, etc.), with minimal spending and little regard for cellular operators’ needs. This has led to the stereotype of Wi-Fi as a low-quality technology. In reality, with proper design, construction, and operation, Wi-Fi can deliver a user experience as good as 4G or 5G, but at lower cost and only where it makes sense.

Wi-Fi in the Subway: A Special Case

Let’s address Wi-Fi in subways. MaximaTelecom operates such networks in the Moscow and St. Petersburg metros, serving about 1.5 million unique users daily. People often ask how we view the prospect of full cellular coverage in subway tunnels, especially 5G, and whether this will cause a mass shift to cellular.

First, 5G’s advantages rely heavily on MIMO technology, which doesn’t work well in subway tunnels for physical reasons. So, 5G won’t offer much higher speeds or capacity than 4G (or even 3G) in tunnels. Available speed and capacity will depend mainly on the spectrum operators can use, not the standard. Thus, we don’t expect the arrival of 5G in the subway to affect our user base. The mere fact of having quality cellular coverage in tunnels (if it ever happens) will be more important than whether it’s 5G.

Convenience and security are also important. Some say mandatory user identification (required by law in Russia) is a barrier to public Wi-Fi use, but our experience shows that a one-time ID check is not a problem for most users. Far more people are bothered by the ads we show on login. MaximaTelecom builds and maintains these networks at its own expense, paying the metro for the right to install infrastructure. The cost is high, as it includes not just Wi-Fi and data networks, but also a transport radio network (Track Side Network, TSN) connecting moving trains and base stations in tunnels. This is the most expensive part and the foundation for our unique service. Our business model, unlike cellular operators, is based on advertising and services, not data charges. We must show a certain amount of ads to keep the service free. Each user chooses between seamless but paid cellular access (with lower quality in the subway) and ad-supported, free, unlimited Wi-Fi. If high-quality cellular appears in Moscow trains (currently only MTS, with our help, provides reliable 3G voice), some users—especially those who value instant access—may prefer it. We’re not worried, as we can always provide higher quality Wi-Fi in subway cars (speed, stability, availability) than cellular operators, and at much lower investment. Whether or not they have 5G is irrelevant.