Industry association Wireless Innovation Forum (WinnForum) has approved support for the 5G NR air interface in the citizens broadband radio service (CBRS) band, paving the way for mobile 5G deployments in that band. Announcement of the approval came from WinnForum and another industry association, the CBRS Alliance.
The two organizations have been working closely to divvy up the work required to develop CBRS standards. The CBRS Alliance previously said it would support 5G NR in its Release 3 specifications, which are slated for completion before the end of the year.
Mobile 5G CBRS
The CBRS band includes mid-band spectrum between 3550 and 3700 MHz. Some wireless internet service providers already use a portion of the band on an unlicensed basis to provide fixed wireless service. The FCC paved the way for mobile deployments in the band when it adopted a plan to auction a portion of the band based on large license areas and long license terms — rules some said favored large mobile providers.
Mobile operators may be particularly interested in the band because it is mid-band spectrum, which many industry observers believe to be important for 5G deployments. AT&T and Verizon initially deployed 5G in high-frequency millimeter wave spectrum, which supports the highest speeds but over relatively short distances. The trade-off to using that spectrum is that operators must undertake a more extensive buildout compared with deploying 5G in lower-frequency bands.
Another consideration, as the CBRS Alliance and WinnForum note, is that other countries also are planning to make spectrum in the 3.5 GHz band available for 5G. And that potentially could enable substantial economies of scale.
Initial 5G standards called for fixed use, but the subsequent 5G -NR standard addresses mobile service.
According to the CBRS Alliance WinnForum announcement, 5G deployments based on their 5G-NR standards could begin as early as the first half of 2020. Initial deployments are likely to be in the unlicensed portion of the band, however, as one FCC commissioner has said he doesn’t expect the CBRS band auction to occur before that time. And there would undoubtedly be a lag time before license winners would be able to deploy service.
The full unlicensed portion of the CBRS band, including the portion already in use by WISPs as well as some additional frequencies, is expected to be available soon for commercial use.