They are included along with my own. Stan Barber's Notes Altavista says there about 1000 responses to a search for wireless networking . Some countries don't license things in 915Mhz. WaveNet provides bridged access to a wired network.
Access points announce themselves to mobile stations and to other mobile stations.
However, without the beacon key, the network ID can't be decrypted. A Mobile station listens to multicast announcements from the various access points. Roaming may not be required and doesn't have to be used. There are risks. Unwanted access to your network can happen.