Your browser is not supported. Please update it.

13 November 2019

Cloud giants bring their lobbying power to bear on 6 GHz future in USA

One way in which the cloud giants have influenced wireless markets behind the scenes, especially in their native USA, has been through relentless lobbying over spectrum.

A combination of webscale and IT players helped to drive the opening up of many bands of spectrum for unlicensed, shared and flexible usage. Examples include:

  • Increased unlicensed capacity for WiFi in 5 GHz
  • Spectrum access systems for sharing with incumbents in TV white spaces, CBRS and potentially 12 GHz (see separate item below)
  • Unlicensed use of 60 GHz (WiGig)
  • Unlicensed and lightly licensed use of millimeter wave bands from 70 GHz to 90 GHz for fixed access and ‘wireless fiber’

Google even threatened to buy the single nationwide licence in the 700 MHz band when that was auctioned, not because it wanted to build a 4G network, but to pressurize the FCC to impose an open access condition (this happened, and Verizon bought the license, though the open mandate has had far less impact than Google had hoped).

The latest coalition of IT and cloud companies to bring pressure to bear on the traditional wireless industry structure brings together Apple, Broadcom, Cisco, Facebook, Hewlett-Packard Enterprise (HPE), Microsoft and Ruckus Networks, among others. They are opposing a bid, spearheaded by Ericsson and Huawei, to have the 6 GHz band earmarked for licensed cellular by having it included in an ITU study, which defines official IMT (International Mobile Telecommunications) bands.

In a letter to the FCC, the companies leverage the current wave of ‘America-first’ sentiment that is impacting trade relationships. They note that they are all US-based firms and that the US leads in WiFi technology, while Ericsson’s move would harm this industry and its operators by restricting or delaying the deployment of the latest WiFi standard, WiFi 6. The submission claims that unlicensed technologies like WiFi contribute $2 trillion to the global economy and will contribute nearly $1 trillion to the US economy by 2023.

The Apple-led group also argues that the ITU study will take at least four years to complete and will prevent WiFi 6 from being adopted by other regions of the world, limiting global economies of scale. It wants the FCC to release 6 GHz for unlicensed technologies while protecting incumbents in the band. Ericsson has suggested that 500 MHz in the lower portion of the 6 GHz band should be set aside for unlicensed use immediately, to support changes like WiFi 6, while the rest should be the focus of the ITU study.

Assuming the FCC does approve a spectrum sharing proposal – somewhat like that in CBRS – for 6 GHz next year, it will not be an outright victory for the cloud industry. The regulator still faces a clash with the energy sector over the plans. Utilities, with the backing of the US Department of Energy, claim that WiFi could disrupt communications supporting critical energy use cases.

The utilities are belatedly stepping up their opposition in light of new evidence apparently showing interference to critical applications. Specifically, they say that 6 GHz spectrum is “used for critical situational awareness, to underpin safety functions, and to enable crews to safely repair and restore services after storms”. Utilities groups also argue that the new rules risk interference relating to “the greater deployment of distributed energy resources such as solar or battery storage, smart meters, and other technologies to enable grid modernization”.

Broadcom led the response to this, pointing out that the FCC proposal would allow only devices supporting the latest WiFi 6 standard (802.11ax) to operate in 6 GHz, therefore removing any potential disruption from legacy devices operating in 802.11ac/n/g/a/b.

The chip giant argues that the abundance of 160 MHz-wide channels in the 6 GHz slice will more than double throughput compared to using the 80 MHz channels found in 5 GHz spectrum. Wide channels will help reduce congestion and interference, while greatly improving range and latency.

The arrival of WiFi 6 is being heralded as the most important step forward in WiFi since its inception. The new standard includes latency-reducing techniques like OFDMA, while Multiuser-MIMO increases capacity when serving a small number of high bandwidth clients.

The FCC recently underscored its intent to release the full 1.2 MHz of spectrum in the 6 GHz band to WiFi and other unlicensed use cases. Chairman Ajit Pai stated: “This band is currently populated by microwave services that are used to support utilities, public safety, and wireless backhaul. But studies have shown that sharing this band with unlicensed operations is feasible – and can put massive amounts of new spectrum into the hands of consumers.”

The WiFi Alliance,  meanwhile, has been lobbying for additional unlicensed spectrum for WiFi in the 5 GHz and 6 GHz bands, with members developing a certification program for WiFi devices operating in 6 GHz.

“As the full 6 GHz band is made available for unlicensed use – with multiple 160 MHz-wide channels – the WiFi 6 consumer experience will be turbocharged for the gigabit home and AR/VR,” Vijay Nagarajan, VP of wireless at Broadcom, said recently.

Assuming the FCC’s proposal is ratified, it will be important for WiFi vendors to be able to support all three of the standard’s bands, 2.4 GHz, 5GHz and 6 GHz, in a single unit. An interesting development is a chipset from full duplex radio technology developer Kumu, promising to suppress the self-interference that could occur in such devices, especially because there will be only a narrow guard band between the two higher frequencies.

That guard band is insufficient for a conventional RF filter to handle, according to Joel Brand, Kumu’s VP of product management. The company’s chip can be used to enhance the performance of those filters, or replace them completely.