The CBRS Alliance started development of technical specifications which will clear the path for deployment of 5G services in the US’ shared 3.5GHz band.

The new specs are aimed at complementing rather than supplanting the 5G standards set by the 3rd Generation Partnership Project (3GPP).

In a statement to Mobile World Live, Gary Boudreau, chair of the CBRS Alliance’s Technical Working Group, explained: “Just as we had to work on specifications to customise 3GPP specifications to optimise [4G] LTE operation in a shared spectrum environment over 3GPP Band 48 and 49, we similarly need to work on 3GPP specifications to ensure operation of 5G NR in the [3.5GHz] CBRS band.”

He added the standards will address “coexistence requirements to ensure seamless interoperability between LTE and 5G NR in and out of Band 48, as well as 5G NR network architecture for deploying a private network in a shared spectrum environment.” Additionally, he said the specifications group is exploring “certificate-based authentication in CBRS band, a key feature to support private networks enabled by shared spectrum”.

Completion of the Alliance’s so-called Release 3 specifications is expected in Q4 2019, setting the stage for 5G service availability in the 3.5GHz band in 2020.

Delays
Though the CBRS Alliance is already preparing for 5G, long-awaited LTE deployments in the 3.5GHz band have been delayed while government agencies continue their evaluation of key systems which will allow commercial wireless deployments to coexist with federal incumbents.

Launches were originally expected in 2018, though that timeline was subsequently pushed back to Q1 2019. A US government shutdown early in the year delayed expectations even further, and initial commercial deployments are now expected in Q2 2019.