access rights (say, for w units of time) once during every cycle (say, of length c). Hence with TDMA, the minimum worst-case delay is at least c. In general, the worst-case delay is some multiple of c depending on whether the information from a subtask to its successor is transferable in time w. In any case, such delays are computable and used in the construction of communication graphs. The scheduling of the (multiple-access) network is also not too much more complicated than the simple scheme: A TDMA gives the impression of each site possessing an exclusive communication channel (where each can be used between specific time intervals onlydepending on the phasing of the sites). In deterministic protocols using dynamic token passing schemes [12] [7] the maximum communication delays can be determined and can be used in the the construction of communication graphs. However, in this case, the algorithm will not be involved in scheduling communication subtasks. REFERENCES J. A.