The FCC issued a Public Notice last week seeking comment on a two-pronged approach to define the Wireless Protection Zone around grandfathered 3650-3700 MHz base stations.  Under the FCC’s 3.5 Order, grandfathered 3650-3700 MHz base stations are entitled to protection from harmful interference from Citizens Broadband Radio Service users for a fixed period (Vol. XII, Issue 17).  For base stations with unregistered Customer Premises Equipment (CPE), the FCC proposed a 4.4 km radius around each registered grandfathered base station.  For base stations with registered CPE, the FCC proposed a protection zone based on the azimuth and beamwidth of grandfathered base stations in relation to the furthest CPE unit registered in ULS.  As an added measure of protection, the Commission also proposed requiring Citizens Broadband stations to limit field strength at the boundary of Grandfathered Wireless Protection Zones.