Online Packet Scheduling with Bounded Delay and Lookahead

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F16%3A10331740" target="_blank" >RIV/00216208:11320/16:10331740 - isvavai.cz</a>

Výsledek na webu

<a href="http://drops.dagstuhl.de/opus/volltexte/2016/6790/" target="_blank" >http://drops.dagstuhl.de/opus/volltexte/2016/6790/</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4230/LIPIcs.ISAAC.2016.21" target="_blank" >10.4230/LIPIcs.ISAAC.2016.21</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Online Packet Scheduling with Bounded Delay and Lookahead

Popis výsledku v původním jazyce

We study the online bounded-delay packet scheduling problem (PacketScheduling), where packets of unit size arrive at a router over time and need to be transmitted over a network link. Each packet has two attributes: a non-negative weight and a deadline for its transmission. The objective is to maximize the total weight of the transmitted packets. This problem has been well studied in the literature, yet its optimal competitive ratio remains unknown: the best upper bound is 1.828 [Englert and Westermann, SODA 2007], still quite far from the best lower bound of phi, approx. 1.618 [Hajek, CISS 2001; Andelman et al, SODA 2003; Chin and Fung, Algorithmica, 2003]. In the variant of PacketScheduling with s-bounded instances, each packet can be scheduled in at most s consecutive slots, starting at its release time. The lower bound of phi applies even to the special case of 2-bounded instances, and a phi-competitive algorithm for 3-bounded instances was given in [Chin et al, JDA, 2006]. Improving that result, and addressing a question posed by Goldwasser [SIGACT News, 2010], we present a phi-competitive algorithm for 4-bounded instances. We also study a variant of PacketScheduling where an online algorithm has the additional power of 1-lookahead, knowing at time t which packets will arrive at time t+1. For PacketScheduling with 1-lookahead restricted to 2-bounded instances, we present an online algorithm with competitive ratio (sqrt(13) - 1)/2 approx. 1.303 and we prove a nearly tight lower bound of (1 + sqrt(17))/4 approx. 1.281.

Název v anglickém jazyce

Online Packet Scheduling with Bounded Delay and Lookahead

Popis výsledku anglicky

We study the online bounded-delay packet scheduling problem (PacketScheduling), where packets of unit size arrive at a router over time and need to be transmitted over a network link. Each packet has two attributes: a non-negative weight and a deadline for its transmission. The objective is to maximize the total weight of the transmitted packets. This problem has been well studied in the literature, yet its optimal competitive ratio remains unknown: the best upper bound is 1.828 [Englert and Westermann, SODA 2007], still quite far from the best lower bound of phi, approx. 1.618 [Hajek, CISS 2001; Andelman et al, SODA 2003; Chin and Fung, Algorithmica, 2003]. In the variant of PacketScheduling with s-bounded instances, each packet can be scheduled in at most s consecutive slots, starting at its release time. The lower bound of phi applies even to the special case of 2-bounded instances, and a phi-competitive algorithm for 3-bounded instances was given in [Chin et al, JDA, 2006]. Improving that result, and addressing a question posed by Goldwasser [SIGACT News, 2010], we present a phi-competitive algorithm for 4-bounded instances. We also study a variant of PacketScheduling where an online algorithm has the additional power of 1-lookahead, knowing at time t which packets will arrive at time t+1. For PacketScheduling with 1-lookahead restricted to 2-bounded instances, we present an online algorithm with competitive ratio (sqrt(13) - 1)/2 approx. 1.303 and we prove a nearly tight lower bound of (1 + sqrt(17))/4 approx. 1.281.

Druh

D - Stať ve sborníku

CEP obor

IN - Informatika

OECD FORD obor

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Projekt

<a href="/cs/project/GA14-10003S" target="_blank" >GA14-10003S: Omezené typy výpočtů: algoritmy, modely, složitost</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

27th International Symposium on Algorithms and Computation (ISAAC 2016)

ISBN

978-3-95977-026-2

ISSN

1868-8969

e-ISSN

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Počet stran výsledku

13

Strana od-do

1-13

Název nakladatele

Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik

Místo vydání

Dagstuhl, Německo

Místo konání akce

Sydney

Datum konání akce

12. 12. 2016

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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