School bells systems have as a primary purpose promoting the transit of a whole student body from one class to one more as effectively and efficiently as possible. School bell systems maintain all timekeeping mechanisms in sync, consisting of all clocks, all bells, and other linked gadgets such as tone generators; moreover, they work over both wireless and hardwired channels. The principal network tool is the master clock, itself integrated with an atomic or network clock, setting the moment for all other tools and issuing interactions to them as the demand develops.