The Environmental Sensing Capability (ESC) is a network of sensors used to detect federal frequency use in the 3550–3650 MHz band in protection zones where U.S. Navy radar systems can operate, primarily along the Pacific, Atlantic and Gulf coasts. The ESC informs the SAS of radar operation and the SAS reacts to ensure there is no interference between CBRS and radar operations. As of now, there are two ESC networks that have been approved. Federated Wireless operates one of them, and CommScope and Google jointly operate the other one.