The CBRS Alliance is marking yet another milestone, publishing of the Network and Coexistence Baseline Specifications that will enable deployment and coexistence of LTE in the 3.5 GHz Citizens Broadband Radio Service (CBRS) band.
“The networking and coexistence specifications are the critical foundation the industry needs to ensure seamless interoperability between CBRS Alliance-certified Citizens Broadband Radio Service Devices (CBSDs) when operating in CBRS,” said Dave Wright, president of the CBRS Alliance and director, regulatory affairs & network standards at Ruckus Networks, in a press release. “2018 is expected to be a marquee year for CBRS, and we are particularly proud to kick it off with this significant technical achievement.”
The technical specifications for coexistence align with WInnForum Baseline specifications. Such alignment not only ensures CBSDs will be compatible and coexist—it also guarantees adherence to FCC requirements (part 96). The coexistence technical specs also address cell phase synchronization, TDD configurations for LTE-TDD CBSDs, GAA channelization and SAS-CBSD protocol extensions, the alliance said.
The network specifications define how to deploy an LTE private network, LTE neutral host network, or a hybrid (private and neutral hosted network) using 3GPP standard LTE technology. They also include the use cases, requirements, architecture and LTE protocol configuration to support these network deployments.
“These are key specifications to enable commercial deployment of LTE systems in the CBRS Band. The coexistence specification ensures LTE systems in adjacent channels within the band can operate without the need for guard bands, making use of the spectrum much more efficient,” said Al Jette, chair of the Technical Working Group for the CBRS Alliance and head of North American Standards at Nokia.
The CBRS Alliance was formed less than two years ago to develop an ecosystem around a new approach to spectrum management and includes a diverse set of more than 80 companies, including Google, Qualcomm and the nation’s largest mobile carriers. They’ve all collaborated on a set of detailed specifications to enable the CBRS architecture and ensure interoperability.
The FCC is currently reviewing the rules for CBRS and is expected by this summer to finalize them.
The CBRS band will use a unique tiered sharing model that hasn’t been done previously. Spectrum Access System (SAS) administrators are being set up to dynamically prioritize traffic within the FCC’s sharing framework.
Wireless operators like Verizon and T-Mobile have said they will likely use the unlicensed General Authorized Access (GAA) portion of the band as well as the Priority Access License (PALs) part when that becomes available.
Verizon has said it expects to have 3.5 GHz CBRS-capable devices, including smartphones, entering its lineup by the end of this year.