by Akoustis|March 16, 2021

Wireless Carriers Deploying Private & 5G Networks over CBRS

Last week, the FCC authorized full use of the Citizens Broadband Radio Service (CBRS) band for commercial wireless service while lifting the restrictions previously placed to prevent interference with military use of the spectrum. Wireless carriers have already begun to deploy private and 5G networks over the CBRS spectrum, both over the General Authorized Access tier and the Priority Access tier.

The auction for Private Access Licences (PALs) ended last August, with larger carriers spending big in a bid to add capacity in areas where constraints are present. The FCC auctioned seven 10-MHz blocks for each county in the country and a total of more than 20,000 PAL licenses with 10-year terms were purchased. Licenses were limited to a maximum of 40 MHz of band per bigger per county.

What is Citizens Broadband Radio Service?

CBRS is a 150 MHz wide broadcast band ranging from 3.55 GHz to 3.7 GHz that was traditionally used by the US Navy along with commercial fixed satellite stations. In 2012, this band was identified by the FCC as a potential source of advancing more efficient use of radio spectrum by sharing the spectrum for federal and non-federal applications. From early 2021, commercial and general access to the band will commence.

Spectrum sharing will be governed by a three-tiered authorization framework:

  • Incumbent Access provides protection from interference for incumbent users of the spectrum, which includes federal agencies, US Navy radar and fixed satellite stations. Existing users will be able to grandfather in wireless protection zones for up to five years, with the geographical boundaries of protection being outlined by the FCC.
  • Priority Access License (PAL) provides 10 MHz channels of licensed usage to carriers that purchased bands at auction. Licenses are allocated per county for up to three years and limited to four licenses in any given county per carrier.
  • General Authorized Access permits open, flexible access to the band for any non-assigned segment of the 3.55 GHz to 3.7 GHz band in addition to opportunistic usage of any licensed Priority Access channel not currently in use.

Faster and Easier Deployment of Private and 5G Networks

As band usage will not require spectrum licenses, it is expected that the cost of data transmission will drop. Additionally, the removal of the need to deal for or purchase licenses at auction will allow carriers to deploy networks much more quickly over the shared spectrum.

Deployment over the spectrum does require that carriers not interfere with incumbent users already operating over the band in select locations. Similar to Wi-Fi, building owners who have deployed CBRS equipment or end users accessing the band via a server will pay the FCC fees.

Indoor and Outdoor Applications

Carriers expect to deploy networks for PAL and General Authorization access in both indoor and outdoor applications, incorporating primarily small cells but also macros. CBRS is particularly useful for adding capacity at stadiums, arenas and other venues but is well-suited for any dense urban area where capacity constraints exist. 

Many wireless devices already support CBRS and global market intelligence and consulting firm SNS Telecom & IT predicts that approximately 90% of all smartphone shipments in the US will support the CBRS band within just two years.