a communication system is provided for communication between network nodes and a communication controller that provides for request timeslot management . in the network , when an individual node has data to transmit , the node transmits a request signal to the communication controller over an assigned timeslot . the timeslots are assigned to individual ones of the nodes , and the timeslots assigned recur in a repeating fashion . if a timeslot is unused for a predetermined period of time , such as when a node is turned off or simply has no data to transmit , the timeslot is either eliminated or reassigned . eliminated timeslots reduce unnecessary time delay before request timeslots recur .