Kutyłowski M., Loryś K., Oesterdiekhoff B. (1996) Periodic merging networks. In: Asano T., Igarashi Y., Nagamochi H., Miyano S., Suri S. (eds) Algorithms and Computation. ISAAC 1996. Lecture Notes in Computer Science, vol 1178. Springer, Berlin, Heidelberg
We consider the problem of merging two sorted sequences on constant degree networks using comparators only. The classical solution to the problem are the networks based on Batcher's Odd-Even Merge and Bitonic Merge running in log(2n) time. Due to the obvious log n lower bound for the runtime, this is time-optimal.
We present new merging networks that have a novel property of being periodic: for some (small) constant k, each processing unit of the network performs the same operations at steps t and t+tk (as long as t+k does not exceed the runtime.) The only operations executed are compare-exchange operations, just like in the case of the Batcher's networks. The architecture of the networks is very simple, easy to be laid out. The runtimes achieved are c · log n, for a small constant c.