Worked there many years ago. Security had their own channel. Everyone else monitored one knob position unless it got busy, like festivals, concerts, theater events etc. At that point, the stage department and event service staff would move comms to another channel. Various departments employed Nextel equipment for interdepartmental comms as well. We never used the allotted limit of channels. It may be different now, but that's what I remember. Kind of like marine VHF channel 16, channel 1 was for calling, longer conversations were taken to open channels.