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A speculative transmission scheme for scheduling‐latency reduction
Author(s) -
Iliadis Ilias,
Minkenberg Cyriel
Publication year - 2007
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.200700153
Subject(s) - latency (audio) , computer science , scheduling (production processes) , critical path method , crossbar switch , computer network , distributed computing , engineering , telecommunications , operations management , systems engineering
Low latency is a critical requirement in some switching applications, specifically in parallel computer interconnection networks. The minimum latency in switches with centralized scheduling comprises two components, namely, the control‐path latency and the data‐path latency, which in a practical high‐capacity, distributed switch implementation can be far greater than the cell duration. We introduce a speculative transmission scheme to significantly reduce the average control‐path latency by allowing cells to proceed without waiting for a grant, under certain conditions. It operates in conjunction with any centralized matching algorithm to achieve a high maximum utilization and incorporates a reliable delivery mechanism to deal with failed speculations. The speculative transmission scheme is employed in a non‐blocking N × N R input‐queued crossbar switch with R receivers per output. The control‐path latency can be almost entirely eliminated for loads up to 50%. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)