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WRC-23 and the unresolved battle for 6 GHz

Arguments over the 6 GHz spectrum band risk missing valuable opportunities for sharing. VAL JERVIS, TIM MILLER and RICHARD RUDD explain why getting agreement at the 2023 World Radiocommunication Conference proved so difficult

A hot topic at WRC-23 (which took place in Dubai between 20 November and 15 December 2023) was the identification of further bands for international mobile telecommunications (IMT) under agenda item 1.2.1 Discussions and negotiation resulted in identification for IMT through a footnote to the radio regulations of the band 6425-7025 MHz in region 1, and 7025-7125 MHz in region 3.2 Both of these identifications exist alongside wireless access systems (WAS).3 It remains to be seen what the outcome of this decision will be in practice: for the upper 6 (U6) GHz (6425-7125 MHz) band – will sharing between the two services (IMT and Wi-Fi) be feasible within a country? Or will it be necessary to segment the band or identify a single technology? Will there be a split between countries, with some supporting the introduction of IMT and other Wi-Fi 6 technologies, requiring the need for coordination at country borders?

Prior to the latest World Radiocommunication Conference, Article 5 of the radio regulations (edition 2020) identified the allocations for the 5925-7145 MHz bands as follows:

Frequencies (MHz)Allocation in Regions 1, 2 and 3
5925-6700FIXED 5.457
FIXED SATELLITE (E-s) 5.457A, 5.457B
5.149, 5.440, 5.458
FIXED SATELLITE (E-s)(s-E) 5.441
5.458, 5.458A, 5.458B
5.458, 5.459

While there were primary mobile allocations in all the bands listed above, the main use was for fixed point-to-point links, which are extensive in some countries, and fixed satellite service.

At WRC-23 there was a mix of views regarding the U6 GHz (6425-7125 MHz) band – for example China, Russia and France were in favour of IMT having exclusive use of the band. The outcome was that through footnote 5.6A12, 6425-7125 MHz in region 1 and 7025-7125 MHz in region 3 were identified for the terrestrial component of IMT. The frequency bands are also identified for WAS including radio local area networks.

In Cambodia, Lao PDR and the Maldives, 6425-7025 MHz is also identified for IMT (footnote 5.6B12) and in Brazil and Mexico for IMT subject to agreement with neighbouring countries, as well as WAS (footnote 5.6C12). Only in region 1 has the whole U6 GHz band been identified for both IMT and WAS.

IMT or WAS (Wi-Fi)

It is important to consider the competing demands for this spectrum.  As data traffic demand increases, the need for high bandwidths requires users to move to higher frequencies, in turn reducing the effective distance that signals can travel.  In the past, mobile services tended to use spectrum at 2.1 GHz or below, and Wi-Fi used the 2.4 GHz band, as these had favourable propagation.  However, as demand for higher speeds rose, mobile services started to move to the 2.6 GHz and 3.5 GHz bands, while Wi-Fi increasingly used 5 GHz. 

The 6 GHz band, with shorter wavelengths, means antenna elements are small and it allows MIMO (multiple input, multiple output antennae) or massive MIMO to be implemented much more easily, which makes the band attractive. This in conjunction with the available bandwidth makes it ideally suited to provide the necessary capacity and coverage needed to support 5G and 6G high power terrestrial mobile networks.  While higher than the current 3.5 GHz allocations, 6 GHz is still considered as part of the mobile ‘mid-band’ spectrum, being significantly lower frequency than millimetric wave bands.

The GSMA has argued that the 6 GHz band is needed to provide sufficient mid-band spectrum capacity.4 ‘Constrained mid-band spectrum risks network densification, higher carbon emissions, increased capex and higher consumer tariffs. Without access to 6 GHz capacity, 5G networks will be slower and more expensive – consumers will pay more while commerce that relies on Industry 4.0 capabilities of 5G will be less competitive. The benefits for the global economy and tax revenue that governments will receive from 5G will be lower.’ GSMA’s studies assert that ‘by 2030, 5G can be responsible for 0.68% of global GDP’ but ‘without enough mid-band spectrum, the 2030 GDP impact will be reduced to 0.42% of global GDP’.

At the same time, the Wi-Fi community has been lobbying for further spectrum, noting the lack of new frequencies beyond the 2.4 and 5 GHz bands over a significant time and the increase in traffic, as shown below.

Figure 1. Global data traffic (Cisco VNI, 2017-2022)

A recent report from the Wi-Fi Alliance states: ‘Without Wi-Fi access to 6.425 to 7.125 GHz — the frequency range that 5G/IMT proponents are targeting — consumers and enterprises will not realise the full benefits of Wi-Fi 6E, Wi-Fi 7, and future generations of Wi-Fi technologies. Access to less than the entire 6 GHz band (i.e. 5.925 to 6.425 GHz and 6.425 to 7.125 GHz) would substantively increase Wi-Fi latency and reduce data throughput. Importantly, there are no alternative frequency bands that adequately address expanding Wi-Fi spectrum requirements.’5 Limiting the available spectrum to the lower 6 GHz (500 MHz in total), as currently in Europe, makes it less likely that the larger channel bandwidths will be utilised. As shown in Figure 2 below the full 6 GHz band can support an increased number of larger bandwidth channels.

Figure 2. Comparison of channels and bandwidth

Given these competing demands and the existing use of the spectrum in various countries for fixed links or satellite communications, it is worth considering whether there is a possibility of the band being shared.

It will also be important to consider the anticipated demand for Wi-Fi and IMT and whether, for example, the U6 GHz band is required to meet user requirements in dense urban areas or to meet universal gigabit connectivity to homes.

Potential for sharing the U6 GHz band

There are two key sharing considerations relating to the U6 GHz band:

  • In those countries where there is significant use of fixed links how can sharing be achieved with IMT or Wi-Fi?
  • Is it feasible for IMT and Wi-Fi to share?

To deal with the first situation here, would sharing such as implemented for the Citizens Broadband Radio Service in the United States be feasible? In this instance the incumbents would be the fixed satellite service (FSS) and fixed service (FS) for which  the locations of the transceivers are known, so there can be a separation by frequency and geography from priority access users.

Figure 3. Tiered access

For IMT, a spectrum access system could combine all sources of information and take into account the necessary protection requirements and margins to enable sharing between IMT and incumbents. A major concern is that the protection needed by large numbers of fixed links will provide limited opportunity for sharing with outdoor IMT macro cells. This could require fixed links to be migrated from the band.

For Wi-Fi, mitigation may be challenging, as device locations are generally unknown and devices are already available that cover the whole 6 GHz band. In the US for the 6 GHz band, to facilitate sharing, two different types of Wi-Fi access points (APs) are supported in different parts of the spectrum: low power for indoor use, and standard power. Automated frequency coordination (AFC) is used for standard power APs to protect fixed links. The AFC system provides to the AP a list of channels that it may use for a range of different powers.6

The next consideration is whether it is possible to facilitate sharing between IMT and Wi-Fi. There have been proposals that low-power licence exempt use could be authorised indoors and medium- to high-power licensed mobile networks used outdoors, with necessary rules to protect the indoor use. This would allow for mobile network offload to Wi-Fi but not the need for mobile coverage indoors (around 70 per cent of mobile traffic is generated indoors and often served by outdoor base stations, although this is less likely in the 6 GHz band due to building propagation losses). It is therefore unlikely that geographic sharing will be a viable solution.

The WRC outcome is currently the worst of all worlds, with no clear direction on what should be prioritised.

There are a number of unanswered questions over potential solutions and whether sharing will be feasible or whether it will be necessary either to use the U6 GHz band for IMT, or Wi-Fi, or to segment the band. The identification of the U6 GHz band for both IMT and WLANs at WRC-23 might be considered premature but it does bring the focus within the International Telecommunication Union to consider the technical options to facilitate sharing. Studies will need to be undertaken to address the different sharing options such as those already underway in the Electronic Communications Committee (ECC) in Europe. Industry will have an important input in developing innovative ideas such as the adoption or adjustments of access protocols to allow sharing. Where database sharing is implemented, this requires agreement of the necessary rules for who can use the spectrum.

If Wi-Fi were to use the U6 GHz band it would be reasonable to expect that this would be on a licence exempt basis, as for the 2.4 and 5 GHz bands. This makes it difficult to refarm the band at a later date for other services, due to the widespread presence of unlicensed devices at unknown locations. This may have implications for some national administrations as well as the loss of potential revenue from licence fees were it to be licence exempt.

European developments

Work has started in ECC project team 1 (PT1) looking at the feasibility of shared use in the 6425-7125 MHz band. Document ECC PT1 (24)036 rev 1 provides more information including the sharing scenarios being considered:7

  • Indoor and outdoor sharing: mobile/fixed communications networks (MFCN) restricted to outdoor and Wi-Fi indoor only
  • Geographical sharing: either MFCN or Wi-Fi prioritised in a particular area (e.g. towns and cities)
  • Temporal splits: where MFCN or Wi-Fi could be prioritised in a location for the duration of particular events or parts of the day.

It then identifies some potential interference management mechanisms:

  • Wi-Fi sensing of a MFCN base station
  • MFCN handset sensing of Wi-Fi
  • Database control.
Licensing to date

A number of countries have already decided on the authorisation of the 5925-7125 GHz band. In the US all the band has been allocated for unlicensed use –‘it will deliver higher speeds, low latency and service levels that are equivalent to 5G networks and be able to support the widespread, low-cost use of advanced business, industrial and consumer applications’.8

When Saudi Arabia issued new regulations in March 2021 to release the full 6 GHz band for Wi-Fi for licence exempt technologies, it was reported that South Korea, Chile, Guatemala, Honduras and Brazil had adopted a similar approach. Canada has also released the full 6 GHz band.

Other countries, such as Australia, Hong Kong and Japan, have only released the lower 6 GHz band (5925-6425 MHz) on an unlicensed basis.

In the UK an Ofcom consultation on access to the upper 6 GHz band  indicated they were exploring options that would enable the introduction of both Wi-Fi and licensed mobile use of the band in relatively close proximity – referred to as ‘hybrid sharing’.9

The different approaches to licensing the U6 GHz band raise another problem, as Wi-Fi devices will be made which use the whole band. Countries which decide to implement IMT will need to prevent the use of these devices to avoid interference. The only way of preventing this would be to ban imports of electronics without certification of what bands they use. This is why licence exempt spectrum is best defined globally.


There are large economic benefits from all potential uses of the 6 GHz band – including the incumbent fixed links and satellite. National governments need to investigate their own demands and carry out sharing studies. Use will differ from country to country, which will lead to inefficiencies from an ecosystem point of view but there may be opportunities to harmonise the technical framework(s).

The WRC outcome is currently the worst of all worlds, with no clear direction on what should be prioritised. It will be interesting to see how the licensing of the upper 6 GHz band progresses and whether sharing options are developed to allow both IMT and Wi-Fi to have access to the same spectrum.

Val Jervis

Val Jervis is a director at Plum Consulting. She previously held senior roles in the telecommunication industry and at Ofcom. She is a chartered engineer and a member of the Institute of Engineering and Technology.

Tim Miller

Tim Miller is a partner at Plum Consulting and a specialist in the application of economic theory to telecommunications issues.

Richard Rudd

Richard Rudd is a director at Plum Consulting and a specialist in modelling and measuring radiowave propagation. He is a chartered engineer.

1 See ITU (2022). World Radiocommunication Conference 2023 (WRC-23): Agenda and relevant resolutions.

2 Footnote 5.6A12.

3 The expectation is that Wi-Fi 6 will be the deployed wireless access system.

4 GSMA (2022). 6 GHz in the 5G Era, July.

5 Wi-Fi Alliance(2022). 6 GHz Wi-Fi®: Connecting to the future, October.

6 Schelstraete S (2020). New regulations for unlicensed 6 GHz operation – explained. 5G Technology World, 15 May.

7 CEPT/ECC (2023). Status of CEPT preparation for WRC-23 / RA-23, 10 February.

8 Bicheno S (2020). FCC unanimously votes to make 6 GHz band available for unlicensed use., 24 April.

9 Ofcom (2023). Hybrid sharing: enabling both licensed mobile and Wi-Fi users to access the upper 6 GHz band – Consultation, 6 July.