Journal ArticleDOI
Synchronization of fault-tolerant clocks in the presence of malicious failures
N. Vasanthavada,P. N. Marinos +1 more
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TLDR
A solution to the problem of achieving global clock synchronization in fault-tolerant clocks by preventing so-called multiple cliques in the presence of malicious clock failures, referred to as the averaging rule, is developed, and its use is analytically justified using the notions of clock partitions and generalized clock partitions.Abstract:
The problem of achieving global clock synchronization in fault-tolerant clocks by preventing so-called multiple cliques in the presence of malicious clock failures (i.e. clock failures that are perceived differently by different nonfaulty clocks) is addressed. A solution to the problem, referred to as the averaging rule, is developed, and its use is analytically justified using the notions of clock partitions and generalized clock partitions. Experimental characterization of the multiple cliques problem has been undertaken, and certain conditions that induce their occurrence in practical hardware implementation are identified. The effects of clock-receiver triggering variations and phase-detector operating range on the instantaneous frequencies of the clock modules are investigated. The efficacy of the averaging rule is established not only by analysis but also by means of simulations and experimentation with hardware clock implementations. >read more
Citations
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Journal ArticleDOI
Reaching approximate agreement with mixed-mode faults
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Proceedings ArticleDOI
Improved algorithms for synchronizing computer network clocks
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References
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Journal ArticleDOI
Synchronizing clocks in the presence of faults
TL;DR: Three algorithms for maintaining clock synchrony in a distributed multiprocess system where each process has its own clock work in the presence of arbitrary clock or process failures, including “two-faced clocks” that present different values to different processes.
Journal ArticleDOI
Clock Synchronization of a Large Multiprocessor System in the Presence of Malicious Faults
TL;DR: A new method is proposed that requires little time overhead by using phase-locked clock synchronization, needs a clock network very similar to the processor network, and uses only 20-30 percent of the total number of interconnections required by a fully connected network for almost no loss in the synchronizing capabilities.
Journal ArticleDOI
Ensuring Fault Tolerance of Phase-Locked Clocks
TL;DR: Processors within a real-time multiprocessor system must be synchronized with as little overhead as possible, and phase-locked clocks are most attractive due to their small overheads.
Journal ArticleDOI
Two Designs of a Fault-Tolerant Clocking System
TL;DR: Two designs of a fault-tolerant clocking system are described: a time-discrete design based on autonomous oscillators and a time/time-continuous designbased on voltage-controlled oscillators.