How will smartphones move between private and public networks?

person holding smartphone
Smartphone users will not expect to lose coverage when they move onto private networks. (Getty Images)

CBRS spectrum has the potential to bring enterprises a new option for wireless connectivity, combining the reliability and security of cellular with the economics of Wi-Fi, and transmitting further than Wi-Fi radios can. But if enterprises are truly going to evaluate CBRS as an alternative to Wi-Fi, devices need to move from private CBRS networks to public carrier networks as seamlessly as they move from Wi-Fi to cellular.

Right now, the average smartphone cannot even connect to CBRS. Device manufacturers are starting to bring phones with CBRS chipsets to market, but in the U.S. most carriers have not yet unlocked the 3.55-3.7GHz spectrum, so in most instances these bands are not available for smartphones to use yet.

When the FCC auctioned Priority Access Licenses for CBRS, Verizon, T-Mobile and Dish all acquired some licenses, which suggests that they probably do not intend to lock the spectrum indefinitely.

RELATED: Verizon, Dish & cable top list of CBRS auction winners

Of course many private networks around the world are being deployed in spectrum other than CBRS. But a private network deployed by an operator does not automatically include the ability to connect to other operator networks.

According to Mikaël Schachne, CMO and VP for Mobility and IoT at BICS, there are two hurdles that need to be overcome in order for devices to move freely from private networks to public networks. One is technical and one is commercial, and BICS has experience with both. The company has negotiated agreements to provide roaming capabilities for mobile operators around the world, and Schachne said BICS carries roughly 50% of the world’s data roaming traffic via its global infrastructure and its direct connections to more than 500 mobile operators worldwide.

SIM's role

On the technical side, BICS addresses roaming at the device level through its eSIM, a tiny chip that can be embedded into almost anything a customer wants to connect to cellular networks. The company has trials ongoing with three systems integrators who are building private networks with operators in airports and harbors. The customers want to eventually welcome mobile subscribers from other networks, Schachne said.

“We can provide … roaming capabilities to bridge mobile private networks and mobile public networks,” Schachne said. BICS provides a cloud-based core network capability, as well as SIM cards for connected machinery and employees’ smartphones. “We can provide dedicated instances on our SIM for Things platform to manage the private SIMs that will be used in the private network,” Schachne said.

Within the U.S., there are other approaches to connecting private networks to public networks. FreedomFi, which created an open source wireless network core based on Facebook’s Magma platform, is talking to three of the nationwide operators about integration, and two of those conversations involve roaming to private networks, according to founder Boris Renski.

Renski said FreedomFi is talking to one operator about the integration of Magma with the HSS, OSS and BSS components of the operator’s existing network core, to enable private 5G-as-a-service. He said the operator would potentially use SIM data records in their existing network core, but deploy localized mini-cores based on Magma for private 5G customers. Smartphone users would be able to move seamlessly between the private network and the carrier’s public network, Renski said.

Another approach would use S8 roaming integration to enable phones to move from public networks to private networks. FreedomFi is working on this use case with Facebook, a nationwide carrier, and Access Parks, which has deployed dozens of CBRS networks around the country.