When the hang time expires, another low speed disconnect tone is transmitted by the central controller on the voice channel, releasing all radios to return to the control channel and await further instruction. Simultaneously, the controller adds the request to a queue, and will signal the radio with a talk permit tone when a repeater is free. Large users, such as public-safety agencies, may need more than 16 subfleets. Multiple independent systems can be installed and programmed into user radios. In addition, a SmartNet radio affiliates with the system on power on and before processing data from the control channel.
Affiliation also occurs whenever a user changes talkgroups.
De-affiliation occurs when the radio is powered off. System administrators can disable individual radios as needed by setting the controller to refuse affiliation. A non-affiliated radio can not process information from the controller, and will not transmit or receive. A Type II system can have up to 4,000 talkgroups, and the controller must manage all of the talkgroups to avoid overloading the system. Because each discrete talkgroup will occupy a system repeater, talkgroups only become active when two or more radios have affiliated with it.