Metaswitch, AT&T, Celona discuss the elements of a CBRS network: Special Report

In order to build an LTE or 5G private wireless network in the United States, the first requirement is spectrum. Fortunately, that’s been handled by the FCC. It recently awarded a bunch of CBRS priority access licenses (PALs) at auction to operators and other organizations for their use. In addition, the FCC has set up a unique spectrum sharing arrangement to ensure that CBRS spectrum that is not being used doesn’t sit fallow. And organizations can also access the general authorized access (GAA) band of free CBRS spectrum. So, one way or the other, organizations that don’t own PAL licenses can still access CBRS spectrum.

Beyond spectrum, there are a variety of elements necessary for a private wireless network. And the topic will be discussed next Monday, October 19, at FierceWireless’ CBRS Week Fall, which is a free, virtual event.

The elements of a CBRS network have also been amusingly explained in a presentation put together by Boris Renski of Freedom Fi. Renski is a well-known figure in the OpenStack community via his former company Mirantis. Currently, Renski is getting his new company Freedom Fi off the ground: this company will provide software for CBRS private wireless networks.

RELATED: Enterprises could tap CBRS, leave carriers in the dust

Renski is keynoting at the Open Infrastructure Summit next week, where he'll explain in more detail how to build a private LTE network using open source. He shared a snippet of his presentation here.

Speaking with Fierce, Renski explained that, after spectrum, the next requirement for a private wireless network is small cells that are designed to work with CBRS. These are called Citizens Broadband Radio Devices (CBSDs). And since most small cells do not come with an antenna, those will have to be bought separately.

Next, the private network radios will need to connect to an LTE or 5G core. The core software includes a database of subscribers and SIM card management. The core also provides other functions such as traffic shaping, quality of service rules, billing and data plan rules, and parameters related to monitoring the network itself.

Finally, the network will require SIM cards that are properly programmed to connect to the private network.


One company doing private wireless networks is Celona, whose mission is to bring cellular technology into enterprises. Celona’s Co-Founder and CTO Mehmet Yavuz will be presenting at next week’s FierceWireless CBRS event.

RELATED: Farmers use private LTE in CBRS spectrum to increase yields

Yavuz was at Qualcomm when the CBRS Alliance was formed in 2016. At the time, he was looking at ways to bring small cell technology to indoor spaces, “but it was always confined to the traditional deployment model by the operators,” he said. “At Celona we are enabling the model where enterprises can have their own private 5G network in their enterprise in addition to Wi-Fi.”

Yavuz said, “It took a while to get FCC certifications in place, and commercial deployments started officially at the end of 2019. We kind of timed the company with the commercialization of the CBRS.”

RELATED: FCC approves initial commercial deployments in CBRS

Celona’s private wireless system includes the core, the necessary radio access network (RAN) elements, orchestration software, and spectrum management within the enterprise.

“It’s somewhat similar to a Wi-Fi solution from Cisco, Aruba or whatever,” said Yavuz. “We bring the same type of end-to-end solution but with LTE and 5G.”

Celona gets its radio hardware from third parties, but it loads its own radio software. The company also integrates its technology with the enterprise’s existing IT infrastructure whether that is on-premises or in the cloud.


Metaswitch was recently bought by Microsoft, although it hasn’t yet been integrated into the cloud giant. Shubh Agarwal, SVP of 5G Solutions at Metaswitch, said the U.K.-based company had been looking at different market segments to sell its 5G core, even before it was purchased by Microsoft.

“We have been working with several partners to bring the advantages of our platform into the private enterprise market,” said Agarwal. “The enterprise market is now showing up on many people’s radar.”

But with Microsoft, “we now see a bigger vision around how this product will evolve,” said Agarwal. That vision blends Metaswitch’s 5G core with Microsoft’s Azure Stack Edge. Azure’s edge will bring the value of Azure applications to the enterprise, and it can also run the 5G core software.

RELATED: Microsoft works with Rogers, Vodafone on private LTE/5G

“Our focus is specifically on the edge deployments,” Agarwal said. “We believe a lot of enterprise use cases can be served by deploying the core network on the enterprise premise.”


AT&T is thinking along the same lines with its new private wireless offering. This week AT&T said it was teaming with Ericsson to set up private wireless networks for enterprises. The service, called AT&T Private Cellular Networks, will initially use LTE technology, but AT&T plans to offer 5G private wireless soon.

RELATED: AT&T teams with Ericsson for private wireless networks on CBRS spectrum

AT&T will also offer its on-premises edge technology — AT&T Multi-Access Edge Computing (MEC) — as part of its private wireless portfolio. AT&T considers both AT&T MEC and AT&T Private Cellular Networks as private network solutions.

AT&T Business VP of Mobility Robert Boyanovsky will participate in next week's FierceWireless panel.

CBRS vs. Wi-Fi

One topic that perpetually comes up in CBRS discussions is: Will CBRS compete with Wi-Fi?

Metaswitch’s Agarwal said that Wi-Fi has been more focused on enterprises, and a whole ecosystem has developed around Wi-Fi. In comparison, LTE and 5G have been about nationwide mobility.  But the availability of CBRS spectrum and the new possibilities of LTE and 5G for the enterprise will spawn a similar ecosystem where chipset makers, radio and core vendors and device makers will come together to create a combination of solutions that enterprises can deploy. 

Celona’s Yavuz said, “Our position is each technology is great at certain things.” He said Wi-Fi provides a lot of capacity and bandwidth but not always with high quality and predictability. LTE and 5G have much higher transmit power from the radio devices with long-range coverage.

“At this point our focus is 5G,” said Yavuz. "It’s not only a new technology, it’s also a new [CBRS] spectrum. Pretty much any enterprise likes this new spectrum.”