The whole country has these repeaters. You can listen to one on a radio scanner. When a ham is traveling he or she can find a repeater to use. One can carry on a nice static-free FM radio conversation via a radio that fits in the shirt pocket or in a purse. Linked repeaters allow fun, wireless communication across an entire state.
Repeaters use common transmit and receive frequency pairs.
The frequency pairs in use are informally assigned by groups of hams so that any Frequency pair in use is far enough from another repeater so as not to cause unwanted interference. Amateur radio satellites are a cutting-edge use of technology in amateur radio. Radio amateurs use their hand-held radio to communicate through an amateur radio satellite, when the satellite is overhead. If you ask different hams you would get many different answers. Some would say that it is a contest, others would say it is a emergency prepardness exercise, still others would say it is a party and yet others would say it is a public relations exercise.