By Chen Chang and Alejandro Escobar Calderon
Although each generation in wireless technologies often introduces enhanced capabilities, the broad adoption of any new technology requires both technical and business viability. For 5G, solving for technical challenges such as path loss and radio front-end efficiency has led to massive innovations in network design, semiconductor packaging, and test technology.
When 5G was first introduced, mmWave was the only option for delivering the fastest speeds and highest density for mobile devices. It promised to transform the industry across a wide array of applications, from autonomous driving to smart, connected cities. Even after overcoming the technical challenges associated with making mmWave viable, adoption has been significantly slower than initially anticipated mainly due to the higher cost and challenges of implementation. While the demand for 5G mmWave deployment revolves around increasing network capacity, many carriers have recently turned their focus toward other alternatives.
What carriers are keeping a close eye on
One of the main technical challenges hindering 5G mmWave carrier adoption is the infrastructure CapEx investment needed to make up for its reduced cell tower range. Simply put, mmWave can deliver the network capacity needed in highly dense urban environments but deploying it at a large scale requires a significantly higher number of small cells.
Between 2019 and 2021, new mid-band spectrum opened in the sub-6 GHz space. This recent availability of spectrum in the C-band has made it a more cost-effective option for carriers to adopt. Major US carriers (T-Mobile, AT&T, and Verizon) have shifted their network deployment strategy to mid-band spectrum rather than on the mmWave spectrum, with real-world throughput reaching hundreds of megabits per second range over wider area coverage across both urban and suburban deployments.
So, does that mean mmWave is dead? The short answer is no. That said, there are a few considerations for carriers moving into 2024 and beyond. Each frequency bands in low/mid/high ranges have pros and cons and unique applications where they can deliver unique value. As wireless carriers continue adapting to consumer and business demands, network deployment relies on a constant tradeoff between capacity, coverage, density, quality of service, and cost of implementation. To add complexity to this equation, the arrival of Wi-Fi 7’s expected mmWave-like speed creates an additional choice for end users. To better understand the top contenders in the wireless space, let’s break down 5G mmWave, 5G mid-band, and Wi-Fi 7.
A closer look at 5G mmWave (24~52GHz)
mmWave (22.5GHz – 72 GHz) offers one of the highest throughput and user density options in wireless network deployment, which makes it optimal for servicing high-traffic areas, like stadiums and large city centers. However, some of the challenges associated with 5G mmWave lie in its shorter signal propagation distance and higher power consumption. As stated earlier, the shorter the propagation distance, the more cells are needed to be built. For moderately dense suburban areas, the business case for mmWave is not viable. However, for fixed wireless access applications to deliver high-throughput data in the last mile to end users, mmWave has proven to be a great cost-effective alternative to traditional fiber or cable base solutions.
Understanding 5G mid-band (1~6GHz)
While lacking in peak throughput when compared to 5G mmWave, 5G mid-bands (i.e., 2.5GHz, 3.5GHz C-band) offers 5X to 10X in terms of coverage area. In the past two years, even the US carriers who are the first movers in deploying mmWave bands have shifted their volume network deployment to mid-bands. For them, mid-band is the “sweet spot” when it comes to finding a balance between throughput, capacity, and range. Because of this, it is best positioned for city and greater metro area coverage. However, the mid-band spectrum in the US has become available fairly recently, and the competition for C-band has greatly increased its value. This highly competitive landscape means that bandwidth shortages are to be expected in the short-to-mid-term future.
How does Wi-Fi 7 come into play?
There is a wide range of connected devices that do not have 5G connectivity. Laptops, tablets, smart home devices, and speakers are perfect examples. Being hosted by a private administrator-controlled LAN allows for high throughput and ubiquitous connectivity. In this way, Wi-Fi-compatible devices act as a supplement to cellular connections and help ease network capacity issues. While cellular speeds are approaching Wi-Fi and offer a longer signal range, Wi-Fi 7 brings with it major innovations. Wi-Fi 7 (802.11be) now meets the extremely high throughput of >30Gbps. Additionally, Wi-Fi 7’s low latency, enhanced OFDMA, PHY optimization, and channel sounding capabilities have the potential to transform the wireless experience.
The bottom line: Wireless will continue to change
Wireless has always been and will continue to be an ever-changing space. Even as alternative bands like FR3 (7~24GHz) are being explored (being deemed as the “best of both worlds” due to its higher throughput than mid-band with less complexity than mmWave), the adoption of 5G mid-band, 5G mmWave, Wi-Fi 7, and even FR3 will not be absolute.
The reality is that all these standards will coexist (not compete) with one another, which is why it’s important to set up engineering teams with flexible solutions that can meet current and future test requirements. NI offers a wide range of hardware and software solutions that help automate tests and maximize high-performance instrument reuse. NI is committed to helping engineers test the new, complex technologies that will enable the interconnected, reliable, and accessible wireless communications of the future.
To learn more about how to streamline RFIC validation & test visit www.ni.com/semiconductor
Alejandro Escobar Calderon is a product marketing engineer at National Instruments.
Chen Chang is senior director of strategic sales development for semiconductor validation at National Instruments.