Europe Looks to Open Up 6GHz Band for Wi-Fi

Article By : John Walko

European regulators are being pressured to open up the 6-GHz band for Wi-Fi and its successor, Wi-Fi 6E...

European regulators have been coming under increasing pressure regarding the slow pace at which the necessary lower 6-GHz band for Wi-Fi and its successor, Wi-Fi 6E, has been made available in the region.

At the same time, standards setters at the IEEE 802.1 committee have been making good progress in finalizing specifications for the next stage in wireless LANs. A working group has recently released detailed technical criteria for what is now referred to as 802.11be, but which is widely expected to be  designated Wi-Fi 7 when the technology becomes a reality, now expected to be late 2024.

Let’s focus on the positive first. The technologists and standards setters working to define 802.11be [or Extremely High Throughput (EHT)] have set themselves hugely ambitious goals so as to meet the ever-increasing connectivity demands as well as ensuring the sector makes even more efficient use of the spectrum.

Wi-Fi roadmap
The Wi-Fi standards roadmap (click on the image for a larger view).

The developing standard targets higher data rates, lower latency, better power (and cost) efficiency, improved interference mitigation and higher capacity density — achieving all of these incremental improvements together is going to be tough. As is the ability to meet the mid-2024 target date set by the Committee for publishing the 802.11 be amendment,  so that certification and interoperability tests can commence under the auspices of the Wi-Fi Alliance by the end of that year.

Of course as with previous iterations of the WLAN,  pre-certified end-user gear is likely to appear before late 2024, as is happening now with Wi-Fi 6 and will soon with the next generation to follow — Wi-Fi 6E.

And backward compatibility with previous generations of the WLAN will need to be ensured for a smooth transition to the next generation.

The standards for 802.11be (let’s call it Wi-Fi 7) will still be based on OFDMA, but some key advances are expected that should allow the option to deploy 4096-QAM.

An improved MU-MIMO is being specified (to date referred to as “cooperative” CMU-MIMO), designed to support the defined 16 spatial streams, double that being used in Wi-Fi 6. This is expected increase throughput by 20%, but as noted, this will be offered as an option, and lower modulation schemes will continue to be supported.

Wi-FiThe standards setters suggest that making this work could turn out to be perhaps the biggest design challenge for Wi-Fi 7.

The maximum channel size being targeted is 320MHz, also double that used in Wi-Fi 6, such that Wi-Fi 7 will be targeted for deployment in the 6GHz band, the most recent part of the spectrum added  for unlicensed use  (at least in some countries — see later) and supported by Wi-Fi 6E. Doubling the maximum channel should also double the throughput for Wi-Fi 7. In addition, the specifications will also support 160+160MHz, 240+180 MHz and 160+80 MHz channels so as to combine non-adjacent spectrum blocks.

Multi-link operation is also expected to be mandated for Wi-Fi 7. This will allow devices to simultaneously receive and/or transmit data across different channels or bands, with separation of data and control planes. This is what will give Wi-Fi 7 the ability to significantly increase the throughput to multiple devices, lower the latency and thus offer higher reliability.

These advances are expected to lead to the anticipated much higher maximum data rates to a theoretical 46 Gbps. A more realistic data rate anticipated by the standards setters will peg this back to about 30 Gbps, for real-world deployment shared across numerous devices.

Of course by the time all this is commercialized, the 6 GHz band will already be widely used for other wireless services, not least 5G cellular. It is anticipated that the Automated Frequency Co-ordinator (AFC) under development will be a work-around for this and will ensure efficient spectrum sharing.

And a recent technology brief from Monica Paolini, founder of networking consultancy Senza Fili , and supported by Intel, noted that “Wi-Fi 7 brings more flexibility and capabilities to enterprises,” extending the reach of wireless LANs.

She stresses the two networking technologies will need to work together “to introduce edge computing, distributed and cloud architectures, virtualization and digitalization in the emerging private wireless networks” as well.

Paolini notes that Wi-Fi 7 will also play a major role in supporting applications that require deterministic latency, high reliability and improved QoS.

Still on the impact on enterprises, the improved Wi-Fi should also offer even greater opportunities in IoT and IIoT applications such as industrial automation, surveillance, remote control, AV/VR and other video-based applications.

Paolini also organized and moderated a webinar late last week, in collaboration with the Wi-Fi Alliance, focusing on progress of allocating Wi-Fi spectrum in Europe.

Andreas Geiss

Andreas Geiss, Head of Unit for Radio Spectrum Policy in GD CONNECT of the European Commission, a “special guest” during the webinar, was put on the spot. Host Alex Roytblat, VP of Worldwide Regulatory Affairs at the Wi-Fi Alliance, referenced the landmark ruling of the US FCC to release about 1200 MHz of the 6GHz bands for Wi-Fi 6 and the follow-up Wi-Fi 6E, as well as other more recent moves in the same direction by authorities in South Korea and the UK, and urged Geiss to clarify progress in Europe in this area.

Geiss noted that the process was “very convoluted” as the discussions involve not just the 27 countries in the European Union (soon to be 26 with the imminent departure of the UK) but all the other of the 48 countries within the CEPT (Conference of European Posts and Telecommunications  — the regulatory body representing all European countries in all matters relating to telecommunications.

Geiss also stressed that “being limited to on-line meetings over the past months rather than the much easier route of face-to-face meetings has not helped in trying to reach consensus.”

But he then revealed that European regulators are targeting April 2021 as the date for releasing 500 MHz (between 5945 MHz and 6425 MHz) for Wi-Fi use. “We hope to finalize our proposals by the end of November,” said Geiss.

He stressed that after this these proposals “will need to be looked at by other harmonization bodies, including, importantly, the European Radio Spectrum Committee (RSC) that I also chair. It is very important that we get this harmonization effort right.”

Here, it might be apposite to precis the continent-wide rules for making such important decisions as the release of the 6GHz band.

The CEPT’s Electronic Communications Committee (ECC) is, according to Geiss, expected to approve the draft of the Working Group’s proposals for 6GHz regulation very shortly. This will then have to be rubber-stamped by the wider ECC plenary planned for mid- November.

The proposals are then passed up to the European Commission   to organize approval by all the countries of the European Union, with input from specialist groups such as the RSC.

If there is broad agreement, the group should then review and adopt the proposals by December, which will then have to be approved by all member states by, as Geiss suggests, next April.

One of the most contentious issues during the discussions within the ECCapparently relates to protection of the so-called CBTC (Communications Based Train Control) signalling regulations that are used by many European train operators.

But stay with us as there is yet another twist in the process. Current rules in the EU oblige all member states to transfer the approved rules into national regulation within six months after adoption. But the wider CEPT rules state countries can take up to two years to fully implement the rules. The expectation, though, is that all countries will in fact nod the new rules through within the six months.

And both groups are expected to adopt harmonized Low Power Indoor (LPI) and Very Low Power (VLP) versions of the 6GHz regulations.

The differences between the two categories of equipment will be transmission power and portability. LPI gear will only be allowed to be deployed inside buildings and have access to the full 480 MHz, while VLP equipment will be sanctioned for both indoor and outdoor use. The spectrum for that will be divided into two categories — 400 MHz and 80 MHz.

Most installations are expected to come under the LPI umbrella, while the newly devised VLP version will focus on consumer applications such as VR/AR glasses and other applications that can be connected to smartphones.

Chris Szymanski

Another of the panel speakers, Chris Szymanski, director of product marketing and government affairs at Broadcom, was keen to get an insight of when the upper part of the 6 GHz band would become available for use.

“We  are open to studying this aspect next, but we do need to make more studies into this area, notably regarding connectivity interference issues — notably with 5G operations,” noted Geiss.

“Sharing that spectrum in the correct way is one of the key issues for achieving the European target for a ‘gigabit society’, said Geiss. “But for now, member states want to focus on ensuring they can make best use of the lower 6GHz region, and ensuring there are no mitigation issues.”

Szymanski welcomed the progress in regulation which he said “is set to offer a huge opportunity for companies like ours who are readying the components and end-user equipment at pace Wi-Fi 6 and soon Wi-Fi 6E.

“Yes, at times it has been challenging and frustrating, but we are getting there.”

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