Ham radios provide push-to-talk, real-time voice communication over long distances for radio hobbyists to collaborate, coordinate action, and share information or alerts, especially during emergencies and natural disasters when cell networks and power grids are down. Also known as amateur radios, they operate on Amateur Radio Service (ARS) in a subset of frequencies called the ham bands. ARS frequencies are shared by all operators for personal use. Ham radios typically have greater range and crisper transmission than CB radios. They require an amateur operator license from the Federal Communications Commission (FCC).