A Prospectus for Mobile Broadcasting Systems

Computer messages are often broadcast over ethernets, and sent point-to-point between them: globally asynchronous, locally synchronous (GALS). This paradigm is captured here by a primitive calculus, MBS (mobile broadcasting systems). MBS processes talk in rooms by local broadcast, and walk between rooms at unspecified speeds. Names are like object names in the π-calculus, but its “get/put b on channel a” becomes in MBS “go to a and hear/say b”. Speakers wait for departing processes, who are grouped by destination, and walkers can enter only silent rooms. These rules, and a primitive to make a room wait for a walker from a given room, seem adequate for programming.