 
Summary: Performance Evaluation 00 (2010) 122
Performance
Evaluation
A Modeling Framework for Optimizing the
FlowLevel Scheduling with TimeVarying Channels
Urtzi Ayestaa,b
, Martin Erausquinc
, Peter Jackoa,
aBCAM  Basque Center for Applied Mathematics, 48170 Bilbao, Spain
bIKERBASQUE  Basque Foundation for Science, 48011 Bilbao, Spain
cUPV/EHU  University of the Basque Country, Bilbao, Spain
Abstract
We introduce a comprehensive modeling framework for the problem of scheduling a finite
number of finitelength jobs where the available service rate is timevarying. The main motiva
tion comes from wireless data networks where the service rate of each user varies randomly due
to fading. We employ recent advances on the restless bandit problem that allow to obtain an op
portunistic scheduling rule for the system without arrivals. When the objective is to minimize the
mean number of users in the system or to minimize the mean waiting time, we obtain a priority
based policy which we call the "Potential Improvement" (PI) rule, since the priority index equals
to the ratio between the current available service rate and the expected potential improvement of
