Broadcasting in Time

In the calculus of broadcasting systems (CBS), speech is autonomous, but hearing takes place only when the environment speaks. This paper develops a timed CBS (TCBS) where no time may pass if there is speech pending. A process wishing to speak can be forced, by attaching a time-out to it, to first listen for a specified length of time. TCBS subsumes CBS with priorities, and has an expansion theorem even if time is dense. A delay prefix operator can be derived up to weak bisimulation. TCBS casts light on issues in handshake communication: time abstracted bisimulation, and the relations between time and priority, between expansion theorems and density of time, and between delays and time-outs