CBRS Explained: The 3.5 GHz Shared Band Behind Private LTE and 5G

The Citizens Broadband Radio Service (CBRS) is 150 MHz of spectrum between 3550 and 3700 MHz that the FCC opened for shared use in the United States. It lets businesses, schools, utilities and cities run their own private LTE or 5G network with carrier-grade radios, without buying an exclusive spectrum license.

Three tiers of access

Incumbent access covers the existing users of the band, mainly federal radar and certain satellite earth stations. They always have priority.

Priority Access Licenses (PAL) were sold at auction by county and cover part of the band. A PAL holder has protection from General Authorized Access users in its area.

General Authorized Access (GAA) is open to anyone using certified equipment, with no license fee. Most private networks run on GAA.

The Spectrum Access System

A CBRS radio, called a CBSD, registers with a Spectrum Access System (SAS) before it transmits. The SAS assigns channels and power levels and moves users when a higher tier needs the spectrum. SAS service is purchased as a subscription from an FCC-approved provider.

Device categories

Category A devices transmit at up to 30 dBm per 10 MHz and suit indoor and low-height outdoor use. Category B devices transmit at up to 47 dBm per 10 MHz for wider outdoor coverage and require registration by a Certified Professional Installer.

What a CBRS network needs

• Radio access: small cells such as the Sercomm SCE4255W indoors or the Baicells Nova 430.
• A core network (EPC for LTE, 5G core for 5G), run on premises or as a service.
• SAS registration for every radio.
• SIM cards for the devices.
• Client devices: phones, routers, cameras, or CPE such as the MultiTech CBRS Wi-Fi AP, which serves Wi-Fi to laptops and tablets over the CBRS link.

Where CBRS and LoRaWAN meet

CBRS carries high-bandwidth traffic such as video, voice and laptops. LoRaWAN carries low-power sensor data. Many private networks run both, with LoRaWAN gateways using the CBRS network as their backhaul.

Browse the 5G - CBRS and Private Networks collections for volume pricing.