Rounds in Communication Complexity Revisited

The k-round two-party communication complexity was studied in the deterministic model by [14] and [4] and in the probabilistic model by [20] and [6]. We present new lower bounds that give (1) randomization is more powerful than determinism in k-round protocols, and (2) an explicit function which exhibits an exponential gap between its k and (k − 1)-round randomized complexity. We also study the three party communication model, and exhibit an exponential gap in 3-round protocols that differ in the starting player. Finally, we show new connections of these questions to circuit complexity, that motivate further work in this direction.

• Type: Conference
• Year: 1991
• Where: STOC
• Authors: Noam Nisan, Avi Wigderson
• Keywords: 1)-round Randomized Complexity, Algorithms, Exponential Gap, STOC 1991, Two-party Communication Complexity