The Asynchronous Bounded-Cycle Model

  • Peter Robinson
  • Ulrich Schmid
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5340)


This paper shows how synchrony conditions can be added to the purely asynchronous model in a way that avoids any reference to message delays and computing step times, as well as any global constraints on communication patterns and network topology. Our Asynchronous Bounded-Cycle (ABC) model just bounds the ratio of the number of forward- and backward-oriented messages in certain (“relevant”) cycles in the space-time diagram of an asynchronous execution. We show that clock synchronization and lock-step rounds can easily be implemented and proved correct in the ABC model, even in the presence of Byzantine failures. We also prove that any algorithm working correctly in the partially synchronous Θ-Model also works correctly in the ABC model. Finally, we relate our model to the classic partially synchronous model, and discuss aspects of its applicability in real systems.


Fault-tolerant distributed algorithms partially synchronous models clock synchronization 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Peter Robinson
    • 1
  • Ulrich Schmid
    • 1
  1. 1.Embedded Computing Systems Group (E182/2)Technische Universität WienViennaAustria

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