Sudeep Bhattarai, an ECE Ph.D. student advised by Professor Jerry Park, actively contributed in the design, development, and deployment of the first prototype Environmental Sensing Capability (ESC) in San Francisco during his summer research at Google. This deployment is the first step towards enabling shared usage of 150 MHz of the radio spectrum in the 3.5 GHz band, also known as the Citizens Broadband Radio Service (CBRS) band.
The U.S. Federal Communications Commission (FCC) has recently opened the 3.5 GHz band for sharing between the Navy's shipborne radars (incumbent users) and broadband communication systems (CBRS devices). A fundamental requirement for shared use of this band is that a dedicated network of sensors called ESCs must detect incumbent operations and alert the spectrum manager.
The spectrum manager for the CBRS band is called the Spectrum Access System (SAS). SAS maintains orderly use of the band while protecting incumbents and coordinating spectrum use among CBRS devices. Upon receiving an alert from the ESC, the SAS reconfigures CBRS devices under its control to avoid harmful interference to the Navy radar.
Google, among others, has applied to the FCC to operate both a SAS and an ESC, and has been actively developing software and hardware capabilities to detect incumbent radars. The goal is to deploy a network of ESCs along the U.S. coastline and allow CBRS devices to operate in the coastal areas provided that they do not cause harmful interference to the incumbent users.