The timeline for commercialization of the 3.5 GHz band has been pushed back more than once, and while initial deployments over LTE are expected this year, the CBRS Alliance announced it has already started work on specifications to support 5G deployments using spectrum in the shared CBRS band.

The alliance indicated that the technical specification, dubbed CBRS Alliance Release 3, is meant to complement 3GPP’s 5G NR air interface. The latest 3GPP 5G NR release is expected to include support for CBRS (Citizens Broadband Radio Service), also known as Band 48.

“Utilizing the CBRS band can be a key enabler for making 5G deployments possible. The Alliance is hard at work developing technical specifications to ensure that OnGo supports 5G applications as seamlessly as traditional LTE services,” said Gary Boudreau, Chair of the CBRS Alliance’s Technical Working Group, in a statement. “The specifications in development include addressing coexistence requirements to ensure seamless interoperability between LTE and 5G NR in and out of Band 48, certificate-based authentication, and more.”

The FCC last October finalized rules governing the 3.5 GHz band and rollouts were initially expected in 2018, but were first delayed until the first quarter of 2019 as agencies continue to test elements that enable the band’s unique spectrum-sharing model. A partial U.S. government shutdown early in 2019 did not help matters, and now initial commercial deployments using 3.5 GHz over LTE are, at the earliest, expected to happen during the second quarter.

CBRS Alliance anticipates development of its Release 3 will conclude at the end of 2019, with 5G service availability by 2020.

Players continue to make progress toward commercialization, including Ruckus, Federated Wireless and Syniverse, which partnered together last month to launch a private LTE network using CBRS at Syniverse’s Innovation Lab for enterprise use.