Interleaved polling with adaptive cycle time: Difference between revisions

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Interleaved{{Short Polling with Adaptive Cycle Time (IPACT) is an algorithm designed by Glen Kramer and others at the Univ. of California, Davis. IPACT is a dynamicdescription|Dynamic bandwidth allocation algorithm for use in Ethernet Passive Opticalpassive Networksoptical (EPONs).networks}}

'''Interleaved polling with adaptive cycle time''' (IPACT) is an [[algorithm]] designed by Glen Kramer, Biswanath Mukherjee and Gerry Pesavento of the Advanced Technology Lab at the [[University of California, Davis]] in 2002.<ref>{{Cite book |last=Ma |first=Lin |url=https://books.google.com/books?id=WynRyQgFHh0C |title=Current Research Progress of Optical Networks |date=2009-04-16 |publisher=Springer Science & Business Media |isbn=978-1-4020-9889-5 |pages=128 |language=en}}</ref> IPACT is a [[dynamic bandwidth allocation]] algorithm for use in [[Ethernet]] [[passive optical network]]s (EPONs).

IPACT uses the Gate and Report messages provided by the EPON Multi-Point Control Protocol (MPCP) to allocate bandwidth to Optical Network Units (ONUs). If the Optical Line Terminal grants bandwidth to an ONU and waits until it has received that particular ONU's transmission before granting bandwidth to another ONU, then time equivalent to a whole messaging round-trip is wasted during which the upstream may remain idle. IPACT eliminates this idle time by sending downstream grant messages to succeeding ONUs while receiving transmissions from previously granted ONUs. It accomplishes this by calculating the time at which a transmission grant allocated to a previous ONU ends.

IPACT uses the Gate and Report messages provided by the EPON Multi-Point Control Protocol (MPCP) to allocate [[Bandwidth (signal processing)|bandwidth]] to Optical Network Units (ONUs).<ref>{{Cite journal |last1=De Andrade |first1=Marilet |last2=Chen |first2=Jiajia |last3=Skubic |first3=Björn |last4=Ahmed |first4=Jawwad |last5=Wosinska |first5=Lena |date=2013-10-01 |title=Enhanced IPACT: solving the over-granting problem in long-reach EPON |url=https://doi.org/10.1007/s11235-013-9722-1 |journal=Telecommunication Systems |language=en |volume=54 |issue=2 |pages=137–146 |doi=10.1007/s11235-013-9722-1 |s2cid=255099225 |issn=1572-9451|url-access=subscription }}</ref> If the Optical[[optical Lineline Terminalterminal]] grants bandwidth to an ONU and waits until it has received that particular ONU's transmission before granting bandwidth to another ONU, then time equivalent to a whole messaging round-trip is wasted during which the upstream may remain idle. IPACT eliminates this idle time by sending [[downstream (computer science)|downstream]] grant messages to succeeding ONUs while receiving transmissions[[transmission (telecommunications)|transmission]]s from previously granted ONUs. It accomplishes this by calculating the time at which a transmission grant allocated to a previous ONU ends.

== References ==

{{Reflist}}

== External links ==

* [[doi:10.1023/A:1012959023043|Original paper, published January 2002]]

{{DEFAULTSORT:Interleaved Polling With Adaptive Cycle Time}}

[[Category:Network scheduling algorithms]]

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