Ofcom mulls sharing 6 GHz band between 5G and Wi-Fi

With vested interests fighting for every scrap of spectrum going, Ofcom wants to know if it’s possible to please everyone.

The UK telco regulator this week launched a new consultation about sharing the upper 6 GHz band between Wi-Fi and mobile.

It aims to identify what it calls ‘hybrid sharing’ mechanisms to facilitate coexistence; encourage tech-based sharing solutions like managed databases and dynamic sensing; and lobby for international harmonisation of hybrid sharing at upper 6 GHz to drive economies of scale for equipment makers.

Ofcom has a couple of ideas for how sharing might be implemented.

One of them, called indoor outdoor split, would see 6 GHz used for Wi-Fi indoors and mobile outdoors, since Wi-Fi routers tend to be indoors and mobile sites are usually located outdoors. Of course, that isn’t always the case – and it is safe to assume Ofcom is aware of this too – which is presumably where some sort of dynamic sensing, managed database or prioritisation mechanism would come in handy.

Another possible approach is geographical sharing. In this case, the frequencies would be reserved for mobile use in specific high-traffic locations and used for Wi-Fi elsewhere. The logic here is that mobile data traffic tends to be concentrated in a relatively small proportion of sites.

Spectrum being the finite resource that it is, Ofcom’s consultation is bound to attract keen interest from both the Wi-Fi and mobile industries.

With the ITU’s next World Radio Communication Conference (WRC-23) coming up in November, mobile operators, backed by the GSMA, have been making the case for as much spectrum as possible to be allocated for licensed cellular services. In January, the GSMA argued that deployment of 5G in the upper 6 GHz band “is crucial” if countries want to maximise the socio-economic benefits delivered by 6 GHz.

However, there is already strong momentum behind Wi-Fi at 6 GHz. Ofcom’s US counterpart, the Federal Communications Commission (FCC), allocated the 6 GHz band for Wi-Fi in 2020, paving the way for the commercialisation of Wi-Fi 6E, an even faster version of Wi-Fi 6.

According to the Wi-Fi Alliance, many other major markets have freed up some or all of the 6 GHz band for Wi-Fi, including Japan, South Korea, the EU and Canada, among others.

This gives certainty to OEMs that there is a big enough addressable market to mass produce Wi-Fi access points and terminals that connect at 6 GHz. The same cannot be said of the cellular side of the device ecosystem.

Therefore, even if Ofcom’s consultation does leave the door open for 5G at upper 6 GHz, chances are, Wi-Fi 6E smartphones will arrive on the market before smartphones that support 5G at 6 GHz.

Meanwhile, Ofcom also has to consider the needs of industries that are already using the upper 6 GHz band right now.

They include fixed links, fixed satellite services, programme making and special events (PMSE), and short-range devices. Space sciences, including Earth exploration satellite services (EESS) and radio astronomy, also use 6-GHz spectrum. Ergo, Ofcom’s consultation also seeks feedback on the potential coexistence challenges these user might face should hybrid sharing be introduced.

With all these factors to consider, it is little wonder that Ofcom’s position for WRC-23 regarding the upper 6 GHz band is for no change to be made to its current designation. At the same time though, in trying to please everyone, Ofcom might leave all of them feeling a little short-changed.

The consultation is open until 15 September.

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