This is the fourth article in a 6-part series featuring articles on Next-Gen Wi-Fi Applications and Solutions. The series focuses on the improvements Wi-Fi 6/6E and its applications bring to enhance the performance of the next-gen wireless networking devices. This series is sponsored by Mouser Electronics. Through the sponsorship, Mouser Electronics shares its passion for technologies that enable smarter and connected applications.
Ever wondered why phones have three radios (LTE/5G, Wi-Fi, and Bluetooth®) while tablets and computers typically have two (Wi-Fi and Bluetooth)? For that matter, why do multiple wireless radio communication technologies like Wi-Fi, Bluetooth, LTE, and 5G even exist? Where do technologies like Zigbee® or Matter fit in?
At the same time that wireless data-communication technology and standards are still in development, new standards and proprietary technologies are clamoring for attention. How to separate the noise from what really matters? Should consumers care about any of this?
This article presents a systematic comparison between the most popular radio communication technologies that exist today. By comparing them on the basis of the most critical performance parameters, we try to form a perspective regarding which technology is suitable for different use cases and where the wireless communication industry is headed. And as is often the case, it can be helpful to remind ourselves how we got to where we are today.
Balancing Range, Data Rate, and Power Consumption
There are only three things of overriding importance in radio technology, and we experience them all in our daily lives. These three things are range, data rate, and power.
We experience the significance of range as our phone is connected to a base station (or not), when our laptop is connected to the router at home, or when our headset is connected to the phone. We all know from experience what happens if a device gets far enough.
We are also quite familiar with data rates, particularly when watching videos, playing video games, or listening to music. Wi-Fi has been the king of data rates until now, but we have been able to receive similar data rates with LTE and 5G – though perhaps at a higher price.
Finally, while we have grown accustomed to regularly recharging our phones and laptops, we are reminded of the importance of power consumption in those annoying moments when we discover that our smaller devices, like headsets or smartwatches, are not charged when we want to use them.
These three items fit together in an interesting way, a sort of fundamental law of physics. Try to improve one, and the two others must give way. Of course, general overall improvements have been made over time on all three, but the relationship between them is still the same. For instance, if you want an increased data rate, then you must either lose range or increase the output power. Wi-Fi today, with its higher speeds (data rate), has less range than in the past and more often needs repeaters. This is one of the motivators for distributed Wi-Fi or mesh Wi-Fi.
This same relationship holds true for Zigbee, also called the “low power Wi-Fi”. It essentially gets the same range as Wi-Fi at a low data rate but with significantly lower power, thereby achieving a very long battery life.
There is a fourth element in this equation that we may be less aware of in our daily lives. That element is frequency. Higher frequencies reduce the range or require higher power to achieve the same range. But higher frequencies have the advantages of more bandwidth and, thus, higher data rates.
This explains the tendency for higher data rates to “look for” higher frequencies. The newest versions of Wi-Fi are in the 60 GHz frequency band, with targets up to 100 Gb/s (IEEE 802.11ay that still struggles to pass through walls).
Figure 1, below, offers a comparison of the variety of wireless technologies that play an important role in our daily lives.
There’s a lot more to be said about this, but to a large extent, the parameters mentioned above are the reasons we have three radios in smartphones.
One radio (LTE) to get the range to connect to the closest telecom base station in the neighborhood; one (Wi-Fi) to get high-performance network connectivity within a room or on a floor at home or in the office; and another one (Bluetooth) to enable very short-range connectivity for small and portable devices like wireless headsets or smartwatches.
Connectivity Standard Alliance (formerly Zigbee Alliance) has been working on Matter, an Internet of Things (IoT) focused networking standard that adds interoperability between different communication protocols. It brings WiFi, Bluetooth, Zigbee, and other popular communication protocols under one umbrella by operating in the application layer. Matter can make IoT product development faster and more affordable.
It is an ambitious project that has the potential to solve the issues related to balancing range, data rates, and power consumption in addition to making different systems interoperable.
But then again, why do laptops and tablets usually only have two radios? There is a logical answer, but before we get to that, let's go through a few historical developments of wireless communication technologies.
Historical Developments in Cellular Networks and Wireless Local Area Networks (WLANs)
In a relatively short period of time, we have seen three new technologies develop and converge. As technology progresses, the differences between phones, TVs, laptops, and tablets are slowly disappearing. In a way, they are all becoming “networked computers”, but each still has its history of wireless communication standards as each experienced its own transition from wired to wireless technology.
Phones and computers had a more dynamic path, but because TVs are largely static (non-mobile) devices, the cable/satellite industry mostly stayed in its wired world. As phones became more computer-like (i.e., smartphones), and computers began supporting all kinds of video and phone-like communication capabilities, it should come as no surprise that the variety of networking technologies that have developed in the past and present are sometimes at odds.
Differences in Design Philosophies and Methodologies
The standardization body for wireless phone communication today is the 3rd Generation Partnership Project (3GPP); for wireless computer data communication, it is IEEE 802.11. The roots of 3GPP are with the telephone operators and their governmental sponsors since operators were initially governmental bodies in most countries. On the other hand, IEEE 802.11 is rooted in the computer industry. In addition to academia and regulators, IEEE 802.11 has a large engineers’ membership, most of whom are sponsored by their companies.
The IEEE 802.11 and the 3GPP had another fundamental difference. The government-sponsored 3GPP worked on licensed spectrums that could be acquired for a certain amount of time to provide communication services. The government, as the licensor of the spectrum, is responsible for making sure that the spectrum can only be used by the licensee.
But that’s not how IEEE 802.11 worked. This standardization body has developed standards specifically in the “unlicensed” bands that have been set aside by the government for “free usage”, based on a set of rules with limited power so that the interference range for realistic applications stays local. These bands are called ISM (Industrial, Scientific, and Medical) bands and can be around the frequencies of 2 GHz, 5 GHz, and 60 GHz bands.
The companies that sponsored their engineers to develop IEEE 802.11 then needed to enforce compliance to the IEEE 802.11 standard definitions as IEEE itself does not regulate compliance. So, the Wi-Fi Alliance was founded by these interested companies to enforce and promote the IEEE 802.11 standard under the Wi-Fi brand, which without exaggeration, is one of the most valuable brands today.
3GPP, on the other hand, never really focused on a cohesive brand strategy aimed at consumers. This makes sense because 3GPP was the interest group of operators who always had a certain market control. They never had to win the hearts and minds of the consumers as Wi-Fi and Bluetooth did. So instead of bothering with brand consistency issues, whole sets of ever-improving standards migrated from GSM/GPRS to 3G, Edge, 4G, LTE and now 5G, which will likely involve a new set of implementations.
The Battles and Successes of Wireless Technologies
When Wi-Fi was emerging in the late 1990s, the general tendency in “3GPP-land” was to ask: Why do you need Wi-Fi? At that time, the standardization of 3G was progressing well and promising high data rates, and 3G modems connected to or integrated with laptops would provide ubiquitous connectivity. So, why bother with Wi-Fi? The general opinion was that this “unlicensed technology” would disappear, probably sooner than later, because in the unlicensed bands, the lack of oversight would bring the performance spiraling down quickly.
Of course, we know today that things turned out rather differently. Wi-Fi has found a way to properly operate in the unlicensed ISM bands and satisfy the needs for wireless connectivity indoor, in-home or in-building, where 3G was not able to penetrate well. Also, Wi-Fi rapidly increased its data rate and expanded its capabilities by moving from the 2.4 GHz band into the 5 GHz band and further into the 6 GHz band. Range extender technologies and, more recently, the concept of distributed Wi-Fi (“Wi-Fi Mesh”) have also supported Wi-Fi’s success to date.
A significant part of the reason that Wi-Fi was successful was the fact that data communications via 3G required a paid subscription from telephone operators and a data plan that initially led to quite hefty bills, not to mention roaming charges. By comparison, Wi-Fi was free, or at least, the incremental cost for Wi-Fi via a fixed telephone, Integrated Services Digital Network (ISDN), and later with Asymmetric Digital Subscriber Line (ADSL), was limited.
So now we had wired operators directly competing with the wireless operators, which ultimately stimulated worldwide acceptance of Wi-Fi. The wireless operators helped this along by initially discouraging the use of 3G for data (and therefore encouraging the use of Wi-Fi) due to concern for a voice service collapse if 3G was “overused” for data. By marketing 3G as having a data element, even though it really was designed for voice, the 3G folks didn’t help themselves in this regard.
This answers the question of why most computers and tablets have only two radios. 3G-licensed radios (and their successors) were rarely integrated with computers or tablets because Wi-Fi offered a cost-effective and versatile internet connection. An integrated 3G radio was just too expensive by comparison. When a mobile solution was needed, users turned to devices like 3G dongles or, more commonly today, using their mobile phone as a hotspot.
Wi-Fi vs. Bluetooth (now Zigbee and Matter)
At the same time the battle between Wi-Fi and 3G unfolded, another battle emerged. Several companies that were suppliers to the telephone industry (notably Ericsson and Nokia) saw another usage for ISM bands to improve phone connectivity when connecting to a hotspot for information downloads and when connecting wireless headsets and other devices to the phone.
To create a standard for the type of phone connectivity, the Bluetooth SIG (Special Interest Group) was formed, with companies as members (as opposed to the engineer members of IEEE 802.11). Fairly soon, the Bluetooth SIG echoed 3GPP in declaring Wi-Fi redundant and telling the market Wi-Fi would soon disappear.
After a few years, it became clear that Wi-Fi and Bluetooth had separate, defined application domains–Wi-Fi for “high-speed networking” and Bluetooth for “peripheral connectivity”.
Since then, many devices have emerged with both Wi-Fi and Bluetooth. For a while, there was an effort to make Bluetooth part of IEEE, but their organizational and membership differences drove them apart.
Interestingly, there is a sequel to this battle in the works today. Zigbee, the low-power variant of Wi-Fi (based on IEEE 802.15.4), is under threat from Bluetooth Low Energy (BLE), the low-power variant of Bluetooth. The Bluetooth SIG is developing a networking variant (Bluetooth Mesh) that is supposed to compete with Zigbee.
Looking at the early proposals, however, it seems that considerable complexity would need to be added to BLE to achieve what is already available with Zigbee.
Again, Matter has emerged as an attractive option with a lot of potential to aggregate all the protocols under a single application layer and improve the overall user experience. The collaboration between Apple, Amazon, Google, Nordic Semiconductor, Samsung, and other notable organizations, and developments in Matter, in customer’s perception, would make everything ‘WiFi-connected’.
We will just have to wait and see how everything plays out.
Telecom operators complementing their services with Wi-Fi
One would think that after 3G and Wi-Fi fought their battles, the demarcations between the two technologies would be clear–Wi-Fi (and going forward Matter) for private and localized areas (home, office) and cellular networks everywhere else. But initially, the telephone operators in 3GPP were naturally quite suspicious about the development of hotspots at public places where people could get access to high-speed internet without the need for a subscription.
Fortunately for the telephone operators, it turned out that running a large number of hotspots was not a trivial effort, in particular for large retail and hotel chains, cities, trains, etc. Public hotspot companies have been slowly absorbed by the telephone operators, who started to further embrace Wi-Fi and learned that “unlicensed” was not as bad as it initially sounded. Operators even developed strategies to use public hotspots along with private routers to “off-load” the traffic. In other words, use Wi-Fi-connected hotspots for traditional phone services.
At the same time, consumers and companies are learning that running Wi-Fi networks is becoming more complex, and telephone operators (and more recently, also cable operators) are finding out that private Wi-Fi networks are business opportunities, helping consumers and smaller companies run their Wi-Fi networks.
And finally, with the further rapid growth of data traffic, primarily via video streaming services like YouTube and Netflix, the operators needed an increased capacity. But getting more frequency bands was not easy. A faster way of getting this capacity, next to leveraging Wi-Fi, was realizing the successor of 3G, 4G, or LTE technology.
This realization gave rise to the concept of LTE-LAA, LTE with Licensed Assisted Access. The 3GPP specifications allow both Wi-Fi and LTE-LAA to be used in the same 5 GHz spectrum. The first installations of LTE-LAA are being planned now, but we will have to wait and see if LTE-LAA is a step in the right direction.
Advancing to the next generation of wireless connectivity
Armed with this understanding of history, we can see a new battle looming. The IEEE 802.11 has been working diligently on higher-speed versions–.11n, .11ac, and the recently developed .11ax. At the same time, the 3GPP is moving on from 4G/LTE and is investing heavily in 5G. The Wi-Fi Alliance is doing a great marketing job by calling everything higher-speed Wi-Fi, while 3GPP continues to be technology-driven, making the different generations explicit and creating disruptions that are detrimental to a smooth migration.
In any case, it should now not come as a surprise that the talk is (again) about which technology is going to win: 5G or IEEE 802.11ax?
Both will have high data rates (Gbps), and be power-intensive to get a good range, and both are trying to infringe on each other’s territory. 5G claims it will have “way better indoor penetration”, and IEEE 802.11ax has a clear path worked out, although, with the increased data rate, the range is definitely reducing.
Interestingly, Wi-Fi has turned this disadvantage into an advantage by focusing this new IEEE 802.11ax standard on distributed Wi-Fi (Wi-Fi Mesh) and enabling the usage of multiple channels at the same time to connect multiple access points in different rooms to the main router. The focus of IEEE 802.11ax is on full indoor coverage to provide the same high data rate, creating an experience that will not be easily replaceable with 5G.
5G, on the other hand, is facing its own quite serious challenges. 5G’s higher data rates create a penalty on its range, too, and for cellular base stations, coverage goes “by the square”. The range for 5G decreased by less than half, forcing the number of base stations to more than quadruple. In dense urban areas, where finding real estate to place base stations is expensive, this meant that rolling out 5G infrastructure was at significant expense, while many operators are still recovering from their 4G investments.
Although it varies a bit by country and the financial structure of the telephone operators, a generalized belief is that higher data rates will be needed to sustain the consumer and business appetites, particularly in dense population settings, where the usage of the licensed spectrum can be better controlled than unlicensed.
So, who wins the battle? Honestly, there shouldn’t even be a battle. Both 5G and Wi-Fi have very particular characteristics that will be beneficial for connecting “computers”, including all the devices that can now be classified under this term, to the internet. So, the operator that can exploit both technologies to its advantage and execute a strategy that leverages them both will become the winner.
Standards like Matter that aim to unify different communication protocols and make devices from different vendors compatible with each other will play a prominent role in the future. From this perspective, the winner of these technology battles will be the end-user.
This article was initially published by Mouser and Qorvo in an e-magazine. It has been substantially edited by the Wevolver team and Electrical Engineer Ravi Y Rao. It's the fourth article from the Next-Gen Wi-Fi Applications and Solutions Series. Future articles will introduce readers to some more interesting applications of the technology in various industries.
- The introductory article provided an overview of wireless communication and the subsequent articles of the series.
- The first article explored the origins and the evolution of WiFi to showcase how the wireless local area networking standard improved over time.
- The second article was focused on recent trends and the design philosophy behind WiFi 6/6E. The article explains why even with a marginal improvement in raw data rates, WiFi 6/6E is the biggest upgrade yet.
- The third article dives into the technicalities of WiFi 6/6E. It explains the 6 enabling technologies of WiFi 6/6E including OFDMA, BSS Coloring, TWT, Beamforming, 8X8 MU-MIMO, and 1024-QAM.
- The fourth article is a comparison between WiFi and 5G based on some of the key performance parameters. It tries to form a perspective regarding which technology is suitable for different use cases.
About the sponsor: Mouser Electronics
Mouser Electronics is a worldwide leading authorized distributor of semiconductors and electronic components for over 1,100 manufacturer brands. They specialize in the rapid introduction of new products and technologies for design engineers and buyers. Their extensive product offering includes semiconductors, interconnects, passives, and electromechanical components.