Revitalization of 60 GHz WLAN Ecosystem Required to Address the Untapped Potential of 60 GHz WLAN

Following a decade of slow traction for the 60 Gigahertz (GHz)-orientated WiGig standard (802.11ad/ay) and the collapse of Meta’s overhyped Terragraph project last year, many in the industry had viewed the inclusion of 60 GHz in the prospective Wi-Fi 8 standard (802.11bn) as the last hope for Millimeter Wave’s (mmWave) future in Wireless Local Access Networks (WLANs). These hopes were quashed though by the 802.11bn working group’s June vote to exclude 60 GHz from Wi-Fi 8’s pre-draft planning. The future of 60 GHz WLAN is now resting on the shoulders of the recently established Integrated Millimeter Wave (IMMW) Study Group, which aims to rejuvenate 60 GHz WLAN by moving beyond the approach of developing a separate 802.11 standard based on 60 GHz, and to instead extend existing mainstream 802.11 standards into 60 GHz. Does this renewed attempt at 60 GHz WLAN have the potential to succeed where previous attempts have failed?

For guidance on how to approach the development of the latest iteration of 60 GHz WLAN, members of the IMMW Study Group would do well to reflect on the history of the technology up until now. 60 GHz WLAN’s origins date back to 2009, when the Wireless Gigabit Alliance (WiGig Alliance) was established by a consortium of major chipset manufacturers and technology leaders, including Marvell, NEC, Intel, Broadcom, Samsung, Nokia, and Microsoft. The WiGig Alliance initially envisioned WiGig as a solution for high-throughput, low-latency wireless connectivity over short distances, and successfully convinced the Wi-Fi Alliance to accept its approach to 60 GHz networking in 2013, beating the competing WirelessHD consortium. That same year the two alliances merged and launched a WiGig certification program. Buzz for the technology drove a wave of acquisitions (Qualcomm acquired  WiGig pioneer Wilocity in 2014; Lattice Semiconductor purchased SiBEAM in 2015) and new entrants spurred the market (Peraso released its first WiGig chipset in December 2015), but the technology ultimately failed in go-to-market because for the short-range applications it was targeting, cable remained more cost-efficient and performed better due to WiGig’s Line-of-Sight (LOS) requirements. An uncommitted ecosystem, with early pioneers Broadcom and Intel dropping out of the market early, was the nail in the coffin.

Subsequently, WiGig found a second life in the form of long-range, high-gigabit Point-to-Point (PtP) and Point-to-Multi-Point (PtMP) Fixed Wireless (FW). Aside from offering rapid, low-cost deployment, WiGig benefits from being highly scalable and versatile, as networks can be expanded, downsized, or reorganized at any time. This makes the technology ideal for time- or cost-sensitive deployments, or those with dynamic demands. Today, the technology is being applied for two key applications. The first is as an alternative broadband access technology for customers not connected by cable, Digital Subscriber Line (DSL), or fiber. The second is in enterprise for building-to-building connectivity, for fiber backup, or for the connecting of remote outdoor spaces, such as stadiums or parking lots. These two use-cases have seen some degree of success - there are 9 million Americans connected by FW according to the Wireless Internet Service Providers Association (WISPA), and enterprise PtP WiGig has been leveraged in a range of campus networks globally, including in the campus network at Cisco’s headquarters.

Momentum for FW 60 GHz accelerated in 2016 with Meta’s launch of the open-source Terragraph project. Terragraph promised to further lower deployment costs and improve performance by augmenting WiGig with additional technologies, including Time Division Duplex (TDD)/Time Division Multiple Access (TDMA) for spectrum efficiency, an Open/R-based mesh architecture that allowed all nodes to interact with each other, and an advanced Artificial Intelligence (AI) engine that would dynamically allocate paths for traffic in real time. The silicon for Terragraph was supplied by Qualcomm, the modules from Murata and Samsung, the software package from Meta itself, and the infrastructure from numerous vendors, including Ubiquiti, Siklu, MikroTik, Edgecore, Radwin, and Cambium Networks. While promising, Terragraph could not fulfill its low-cost pledge due to the high density of power-hungry nodes required for the functioning of its AI engine and to compensate for distorting oxygen attenuation over long-range transmissions. Ultimately, Terragraph was unable to progress from the proof-of-concept phase, and Meta disbanded the project in 2022. Murata and Samsung have also signaled that their modules are reaching the end of life. The failure of Terragraph to deliver on its promises severely shook the industry’s confidence in the technology and left many businesses feeling burnt.

Now we come to the latest stage of 60 GHz WLAN—the newly established IMMW Study Group. The group’s current proposal is that instead of creating a separate and distinct technology as was done for 802.11ad/ay or Terragraph, it would be easier to gain widespread market adoption for the 60 GHz WLAN if the lower band Wi-Fi PHY design from the core Wi-Fi standards (e.g., 802.11ax and 802.11be) was reused and scaled up to support mmWave frequency bands. Building upon the lower band PHY designs will enable mmWave to use channel bandwidths as narrow as 160 Megahertz (MHz), which would allow for the creation of considerably more non-overlapping channels compared to wider channels, reducing congestion, increasing capacity, and resulting in lower latencies with greater reliability. Alongside improving WLAN performance and increasing capacity, it is also assumed that the extension of mainstream 802.11 standards into mmWave will reduce complexity, ease integration, and accelerate the innovation cycle because advanced 802.11 features (like Multi-Link Operation (MLO)) can be transferred over, and design and validation tasks will not need to be repeated. This, in turn, will ensure that 60 GHz WLAN remains competitive with cellular mmWave, and help prevent the reallocation of the 60 GHz band for licensed.

As demonstrated by the history of 60 GHz WLAN, there are several key potential pitfalls that the industry needs to avoid in order for the next approach to 60 GHz WLAN to be a success. These include:

• Identify Technology’s Killer App: The single biggest challenge that 60 GHz WLAN has faced to date is a lack of compelling use-cases, as there has often been alternatives which were lower-cost and performed better for the applications for which the technology was implemented. Therefore, the ecosystem needs to identify use-cases which demand the unique attributes of 60 GHz. One example is mobile secure communications, where there is a need to rapidly transfer large amounts of data between mobile objects (such as a vehicle) and a stationary network. Only 60 GHz WLAN could provide the requisite strong levels of security and high throughputs for this task. Another potential is for emerging high-throughput, low-latency demanding applications (such as VR) that the 2.4/5/6GHz spectrums are unable to support.
• Develop a Committed Ecosystem: As highlighted by the failure of short-range WiGig and Terragraph, without a broad ecosystem of supporting vendors, it will be challenging for the next version of 60 GHz WLAN to move beyond the proof-of-concept phase. Strong partnerships between complementary vendors, ensuring that each player has a stake in the technology’s success, and direction by industry bodies, such as the Wireless Broadband Alliance (WBA), are all steps that can help establish an engaged ecosystem.
• Simplify adoption: One of WiGig’s initial barriers was that no vendor brought an integrated solution to market, meaning it was necessary for client vendors to integrate the components (silicon, module, etc.) themselves. This added complexity further dissuaded WiGig adoption. To streamline the adoption of the next phase of 60 GHz WLAN, the ecosystem should collaborate to develop an integrated solution, or a vendor looking to spearhead the technology’s development could produce one themselves.
• Educate the Market: Following reputational damage from Terragraph’s failure to deliver on its promise, the 60 GHz WLAN ecosystem needs to collaborate to re-educate the market on the key advantages of the technology over the alternatives, and to convince industry to adopt 60 GHz WLAN for the use cases it is best positioned to serve. One method to achieve this goal is by conducting industry trials to demonstrate the technology’s capabilities using 60 GHz.

While 60 GHz WLAN has many innate abilities, further increasing the value proposition of 60 GHz WLAN infrastructure, vendors could consider some of the following approaches:

• Realize the Full Potential of Wi-Fi 7/Wi-Fi 8: The additional spectrum of 60 GHz can compensate for the lack of 6 GHz in some markets, and support up to 43 non-overlapping 320 MHz channels (assuming the full 14 GHz is used), compared to just 3 channels for 6 GHz. This will allow the core capabilities of Wi-Fi 7, and Wi-Fi 8 in the future, to be pushed to their limits, leading to significant Quality of Service (QoS) improvements and the enablement of next-generation use cases, such as 8K Virtual Reality (VR).
• Converged mmWave/sub-7 GHz Infrastructure: Infrastructure that can leverage both 60 GHz and the 2.4/5/6 GHz spectrums will be able to switch between the different bands depending on performance requirements, and fall back on the sub-7 GHz bands when 60 GHz faces high levels of interference or attenuation, which previously was a major issue with WiGig. Converged mmWave and sub-7 GHz could also help reduce power consumption through discovery and scheduling in the lower bands.
• Enable Enhanced Wi-Fi Sensing: The lower frequencies of the 2.4/5/6 GHz bands restrict Wi-Fi sensing’s functionality to just approximate positioning, but the higher precision of 60 GHz could help unlock advanced applications, such as gesture recognition, vital signs monitoring, and people identification. The prospect of the additional revenue opportunities from these applications will help accelerate adoption of 60 GHz WLAN. Furthermore, the superior sensing capabilities of 60 GHz will also likely be pivotal toward realizing Integrated Sensing and Communication (ISAC).

Vendors eager to stimulate 60 GHz WLAN’s development and to maintain a market leading position should consider some of the following steps:

• Influence Standardization: By becoming an active participant of the IMMW Study Group and helping to direct the future trajectory of 60 GHz WLAN, vendors can position themselves at the forefront of the technology’s development.
• Highlight Cost-efficiency vis-à-vis 5G: Industry hype for 5G began soon after Terragraph’s introduction, and as a consequence the unproven Terragraph found it hard to gain the attention of businesses. Whilst successful in the carrier market, 5G for enterprise has since struggled to go-to-market, and many of its features have now been revealed to have been over-hyped. The 60 GHz WLAN ecosystem should take advantage of this opportunity to convince businesses that it is capable of delivering on many of 5G’s promises in enterprise, such as for remote connectivity, at a much more favorable price point.
• National Promotional Councils: In Japan, the proactive “802.11ah Promotion Council” (AHPC) has been highly successful in increasing adoption of 802.11ah (Wi-Fi HaLow) throughout industry and in convincing regulators of the need for expanded spectrum access and higher power levels. Similar councils should be established for 60 GHz WLAN by ecosystem vendors active in each country.