Inside the Wi-Fi 8 Standardization Effort: Focus on User Experience, Not Just Speed

As IT technologies evolve, standardization drives generational distinctions. This is especially true in telecommunications, where generation-by-generation divisions are built on standards, as shown by the development of 3G, LTE, and 5G on the basis of international standards. Wi-Fi has also evolved through standards, and since IEEE established the first WLAN standard, 802.11, in 1997, it has continued to develop generation by generation based on 802.11.

Against that backdrop, this article focuses on the field of telecommunications technology standardization working groups and the latest Wi-Fi technology trends. The interview subject is Chan-woo Kim, enterprise networking solutions engineer at Cisco Korea, and the article covers Cisco Korea's participation in the Wi-Fi 8 standardization working group IEEE 802.11bn, along with what led Kim to join IEEE 802.11bn. Kim said he became involved in IEEE 802.11bn after wondering why technologies needed in the field had not been standardized.

Wi-Fi is a wireless communications technology that uses radio waves to provide high-speed Internet and LAN access in areas where APs, shared routers, and other wireless access equipment are installed. The starting point for Wi-Fi was the 1997 release of the first WLAN standard, 802.11, by IEEE.

Kim said the traditional direction of Wi-Fi development across generations had centered on improving speed. He added that the focus of Wi-Fi 8 has shifted toward strengthening network stability and service continuity.

Kim joined Cisco in 2008 and built his career in the U.S. and Singapore. He currently works as a solutions engineer at Cisco Korea, with a primary focus on campus networking. His equipment responsibilities include switches and routers.

A solutions engineer is responsible for localizing headquarters solutions for the Korean market and setting technology strategy, as well as conveying customer requirements to headquarters, directly supporting customers, and training internal and partner engineers. Based on his long career in wireless communications, Kim created the "Wireless Champion Community."

The community was created to share training for engineers interested in wireless and partners, and to provide a venue for sharing the state of field technologies.

Asked what led him to participate in IEEE 802.11bn, he explained that Cisco has engineers in a variety of roles, and that the company headquarters also has engineers and developers dedicated to standardization. He also said Cisco is a company with technology leadership among AP makers, and that an AP is equipment that converts wired networks into wireless signals and is one of the core Wi-Fi devices that supports connectivity for terminals such as smartphones and laptops.

Kim said Cisco operates in an environment that encourages contributing that kind of technology leadership to the standardization process, and as a result field engineers are also given opportunities to participate in IEEE working groups. He said that, based on his long experience in wireless, he wanted to experience the standard-setting process firsthand, and that he also joined because he was curious about why technologies he considered necessary in the field had not been standardized.

IEEE has a Standard Association that is responsible for standardization. Within the Standard Association, there is Working Group 802.11, which establishes Wi-Fi-related standards. Under 802.11, there are subgroups such as bn, bi, and bq.

Among them, IEEE 802.11bn serves as the task group for developing the Wi-Fi 8 (UHR, ultra-high reliability) standard. Anyone can propose a standardization idea. If needed, a Study Group can be formed.

The role of a Study Group is to define the technical need and direction. After going through the Study Group stage, approval from IEEE is obtained via a Project Authorization Request, or PAR, and then it transitions into a Task Group. The prerequisite for moving to a Task Group is completing the Study Group stage.

In the Task Group, participants repeatedly discuss and revise various technical proposals and go through a process of reaching consensus. The goal is to refine the standard. The main decision-making method is majority-based, and the threshold for adoption is 75% or more agreement.

Cisco's past collaboration cases and field experience were cited as grounds for persuading participants during the standardization discussions. Cisco previously worked with Apple to provide more stable QoS features based on "Fast Lane," and it also collaborated with Apple, Samsung, and Intel to jointly develop analytic features to improve device visibility.

Such field experience before standardization was cited as a factor that can strengthen persuasiveness in securing agreement when shared with the standardization working group. At the same time, the difficulty of securing member agreement was also raised.

The article explained that Wi-Fi has focused on performance improvements several times over with each generational shift. Three core factors that determine Wi-Fi speed were presented as channel bandwidth, the number of antennas, and modulation, followed by the explanation that Wi-Fi 7 technology has reached the maximum possible in the existing frequency environment.

Kim said that physical limits had been reached starting with Wi-Fi 7, and that the main concept of Wi-Fi 8 is not speed but "user service experience." The photo caption also reflected his remarks about the physical limits reached at Wi-Fi 7 and the concept of Wi-Fi 8.

Accordingly, the core of Wi-Fi 8 was presented as "multi-AP coordination." Among the main functions under discussion for Wi-Fi 8 were multi-AP coordination (MAPC: Multi-AP Coordination), non-primary channel access (NPCA: Non-Primary Channel Access), and dynamic bandwidth expansion (DBE: Dynamic Bandwidth Expansion).

Multi-AP coordination is a technology that improves network quality and efficiency based on organic collaboration among multiple APs. In the existing Wi-Fi environment, APs compete to access channels independently, which can create interference and collisions and can, in turn, reduce performance and quality. By contrast, multi-AP coordination jointly adjusts the transmission timing, power, and spatial resources of multiple APs and performs simultaneous or scheduled data transmission. This reduces interference, improves latency, and enhances processing efficiency, ultimately improving overall wireless performance and quality.

Kim then used a highway analogy to explain non-primary channel access and dynamic bandwidth expansion. He said existing Wi-Fi has a limitation in that even if there is a problem in the main channel, or the first lane, the second lane cannot be used. He added that non-primary channel access is a technology that temporarily changes the main channel when a problem occurs in the first lane, making it possible to use the second and third lanes.

Dynamic bandwidth expansion is a technology that flexibly adjusts an AP's channel width when traffic surges or high performance is needed, maximizing throughput.

Kim said the related technologies are expected to be especially effective in high-density environments where wireless quality has often deteriorated due to AP crowding and interference. Examples of such environments included stadiums, large offices, and airports.

In the Q&A, it was raised that the requirements for Wi-Fi could change as generative AI and XR spread. AI services and extended reality, or XR, require ultra-low latency that is far lower than before, and it was noted that this would require even lower latency than Wi-Fi 7.

It was also explained that working group discussions are under way on ways to achieve lower latency. In addition, two expected changes related to AI traffic were mentioned, and the outlook was presented that while existing communication infrastructure has focused on downlink traffic, uplink traffic will become much more important in the future.

Downlink refers to activities such as video playback on YouTube and web browsing. Uplink refers to posting photos on SNS, transmitting camera and voice during video conferences, and streaming live broadcasts in real time.

The speaker identified multi-AP coordination (MAPC) as a core Wi-Fi 8 technology. Five detailed technologies within MAPC were presented: CO-TDMA, CO-SR, CO-BF, CO-CR, and CO-RTWT. Among them, CO-TDMA and CO-BF were singled out as the technologies expected to see the most active use first.

CO-TDMA is a technology that distributes transmissions to prevent overlap in time among multiple APs, and it is a cooperative method in the form of a central control system. CO-BF is a technology that directs signals so that APs do not interfere with one another.

He then explained that through Wi-Fi 7, the existing approach was to terminate the current connection and reconnect when moving between APs. In Wi-Fi 8, by contrast, one AP can use two links based on Seamless Mobility Domain. As a result, he said uninterrupted roaming between APs is possible when users move.

Cisco places importance on device compatibility as a core element of readiness for the Wi-Fi 8 ecosystem. That is because even if products are developed based on the same standard document, differences in interpretation can create compatibility issues.

As a first measure against this, Cisco cites compatibility verification of major functions through the Wi-Fi Alliance certification program. Most major device makers and chipset makers have already obtained that certification.

Cisco is also separately partnering with Samsung, Apple, and Intel to conduct in-depth compatibility verification and joint development. Cisco and Samsung Electronics have worked together for a long time through the standardization and commercialization of Wi-Fi 6E, and Samsung Electronics conducted Wi-Fi performance tests with Cisco Wi-Fi 6E APs before the launch of the Galaxy S21 Ultra. Cisco also has separate partnerships with Intel and Apple, and Cisco said that if compatibility issues arise with Intel or Apple, it operates a rapid communication channel between developers.

Source: IT DAILY · Seong Won-young
Original: https://www.itdaily.kr/news/articleView.html?idxno=240993

References

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