The CBRS Alliance, which advocates for using the 3.5 GHz Citizens Broadband Radio Service (CBRS) spectrum to expand wireless indoor and outdoor coverage, quietly announced last week that it has two more operator members: T-Mobile US and Sprint and a new vendor member: Samsung.

This news is significant in that the group’s membership now includes Google; all four major U.S. wireless operators AT&T, Verizon, Sprint, and T-Mobile US; and cable heavyweights Comcast and Charter. Additional members include equipment firms Nokia, Qualcomm, Intel, and Brocade’s Ruckus Wireless Division. It also includes newcomers like Federated Wireless, which is one of the companies making the spectrum access system (SAS) that will enable these service providers to use the 3.5 GHz band without creating interference with the military and satellite incumbents that have primary use of the band. Using a SAS will let the incumbents use the 3.5 GHz band when needed, but then frees the spectrum for commercial use at all other times.

Paul Challoner, vice president of network product solutions at Ericsson, and a member of the CBRS Alliance, said that this is the first time he can recall when major competing telecom operators and Google have come together to advocate for the same thing —unlicensed spectrum. “This [spectrum] gets you affordable spectrum and a model you can deploy,” Challoner said.

In the past, service providers would have cringed at the idea of sharing spectrum. But today, with 5G on its way and vast amounts of spectrum needed to make 5G possible, the idea of sharing spectrum is not so farfetched.

The number of powerful players behind the CBRS ecosystem is moving this initiative forward quickly. On the chip front, Qualcomm announced in February that its Snapdragon X20 modem will support the CBRS spectrum. And Qualcomm Vice President of Engineering John Smee noted that the company is working with Nokia and GE on a private LTE trial using CBRS spectrum for an industrial Internet of Things (IoT) network.

The trial is happening at GE Digital’s San Ramon, California, headquarters and is using Nokia’s digital automation cloud to run the network. GE Digital is integrating the CBRS connectivity into its Predix platform.

Progress is also being made on the SAS front. Late last month Ericsson announced that it has successfully tested Federated Wireless’ SAS and demonstrated that Federated’s cloud-based spectrum controller can manage and optimize spectrum.

But Federated isn’t the only game in town. Google announced in February that it had trialled its Access SAS system with members of its trusted tester program. Those members include Nokia, Juni, ZTE, Sercomm, Ericsson, and Ruckus Wireless. In a blog post from Google’s Product Lead for Mobility Mathew Varghese, he said that SAS certification is expected to happen this year.

And at Mobile World Congress last week, Brocade’s Ruckus Wireless Division (which is being acquired by Arris) debuted its OpenG small cell product that is intended for the 3.5 GHz CBRS band. The small cells offer neutral host capabilities (meaning that multiple service providers can use them) to offer in-building cellular coverage. Ruckus said the OpenG small cells are currently being used in trials and will be generally available in the third quarter.

Although the current vision for 3.5 GHz CBRS spectrum involves in-building coverage for LTE networks or private LTE networks for enterprises, in the long-term many of the CBRS Alliance members are eyeing this spectrum for its 5G potential.

Qualcomm’s Smee said there is no reason that this spectrum won’t also be used for 5G. “5G could be shared,” he said. “The 3GPP is having discussions about addressing unlicensed spectrum and spectrum sharing.”