Ofcom shares plan for hybrid sharing of upper 6 GHz band

It has settled on two possible approaches that could form part of a sharing framework for mobile and wifi providers.

The first is called variable spectrum split, which would allow both mobile and wifi to use any part of the band where the other is not being used. There would, however, be sections of the band that prioritise either mobile or wifi. Ofcom said this could be achieved by each technology transmitting a specific signal to avoid interference.

The other idea is indoor/outdoor split. It is based on the idea that wifi is predominantly used indoors and mobile outdoors. This principle could be used to prioritise one type of traffic over the other in these respective environments.

Ofcom plans to flesh out these ideas and consult on them next year.

In an earlier consultation last July, Ofcom sought industry feedback to help it identify so-called 'hybrid' sharing mechanisms for the spectrum that would appeal to both the wifi and mobile industries.

It received 41 submissions, with respondents ranging from mobile operators, chipset makers and equipment vendors, to big tech, academia and industry groups.

The majority argued in favour of using the frequencies for wifi to the exclusion – either in whole or part – of mobile. This group included Apple, Amazon, Meta, HPE, Cisco and Broadcom. The BBC and Sky, as well as the Wi-Fi Alliance, were also on this side of the fence.

Unsurprisingly, the UK's mobile operators – EE, Three, Virgin Media O2 (VMO2) and Vodafone – along with Nokia, Ericsson, Huawei and the GSMA, lobbied for the opposite. They want to use as much of that spectrum as possible in their mobile networks.

A fairly small group, comprising Qualcomm and TalkTalk, came out in favour of hybrid use, while Samsung and trade association TechUK called for the feasibility of sharing to be fully understood before proceeding to implementation.

Those who argued against hybrid sharing fell into one of two camps. They either claimed that hybrid is not needed because the need for mobile spectrum is much greater than the need for wifi spectrum or – vice versa depending on which industry they represent. Or, they aired concerns about the feasibility of sharing mechanisms.

The only thing everyone could agree on was the value that the upper 6 GHz band could bring to wireless broadband services for consumers and industry, and that any hybrid mechanisms need to be developed collaboratively and with international harmonisation.

On that note, Ofcom said it is working with industry on a hybrid sharing framework and coexistence solutions. It is also partnering with European counterparts on a technical report, due to be published next year.

Ofcom also highlighted that Department for Science, Innovation and Technology (DSIT) is currently funding some spectrum sharing trials until next March, which could turn up something useful.

With strong vested interests on either side of the wifi vs cellular debate, all this work is bound to attract a lot of scrutiny.

Meanwhile, Ofcom's predicament has been exacerbated by the ITU's piecemeal approach to the upper 6 GHz band.

Until recently, the spectrum was given over to flexible or licence-exempt use. That changed, albeit slightly, at last December's World Radiocommunication Conference (WRC-23), when the ITU agreed to harmonise the 6.425 GHz-7.125 GHz bands for International Mobile Technology (IMT) use, but only in Europe, the Middle East, Africa, Mexico, Brazil and a few other countries.

However, WRC-23 also recognised the importance of 6 GHz to the wifi industry, and it's important to bear in mind that a bunch of other countries, including the US and Korea, have already opened up the band for licence-exempt use.

Indeed, when it comes to network products that run on 6 GHz, the wifi industry is streets ahead of cellular. The Wi-Fi Alliance expects shipments of 6-GHz wifi kit will reach 807.5 million this year. In contrast, the process for allocating 6-GHz for cellular use, launching equipment and handsets, and then deploying networks, will take years.

It's clear from the consultation responses and the varying status of 6 GHz in different markets that Ofcom has its work cut out trying to please everyone. By pushing on with hybrid sharing – despite concerns about feasibility – it might end up pleasing no one, and this valuable chunk of spectrum might not deliver on its full potential.