DocumentCode :
3074559
Title :
Real-Time Scheduling over Markovian Channels: When Partial Observability Meets Hard Deadlines
Author :
Yang, Lei ; Murugesan, Sugumar ; Zhang, Junshan
Author_Institution :
Sch. of ECEE, Arizona State Univ., Tempe, AZ, USA
fYear :
2011
fDate :
5-9 Dec. 2011
Firstpage :
1
Lastpage :
5
Abstract :
In this study, downlink scheduling of multiuser traffic with hard deadlines and packet-level priorities is cast as a partially observable Markov decision process. User channels are modeled as Markovian and the base station can learn only the channel condition of the currently scheduled user. The optimization of joint channel learning and scheduling presents the combined challenges incurred by the strict deadline constraint of real-time traffic and the partial observability of multiuser channels. In particular, we show that idling adds a new dimension to the action space; and that, through a case study of heterogeneous multiuser networks, idling is indeed the optimal action under certain system states. This somewhat surprising result reveals the existence of the fundamental tradeoffs between exploitation and exploration/idling, going beyond the classic `exploitation vs exploration´. We find that, due to hard deadlines and packet priorities, idling is intimately related to the tradeoff between the successful transmission of backlogged packets and that of future arrivals. In contrast, for the special case with a symmetric two-user system, we show that the scheduling problem exhibits unique structures, rendering a non-idling greedy policy optimal.
Keywords :
Markov processes; decision theory; multi-access systems; radio links; telecommunication traffic; wireless channels; Markovian channel; backlogged packet transmission; base station; downlink scheduling; hard deadlines; heterogeneous multiuser network; joint channel learning optimization; multiuser channel; multiuser traffic; nonidling greedy policy optimal; packet-level priority; partial observability; partially observable Markov decision process; real-time scheduling; real-time traffic; Base stations; Downlink; Markov processes; Optimal scheduling; Real time systems; Scheduling; Wireless communication;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Global Telecommunications Conference (GLOBECOM 2011), 2011 IEEE
Conference_Location :
Houston, TX, USA
ISSN :
1930-529X
Print_ISBN :
978-1-4244-9266-4
Electronic_ISBN :
1930-529X
Type :
conf
DOI :
10.1109/GLOCOM.2011.6133855
Filename :
6133855
Link To Document :
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