TY - GEN

T1 - A fluid analysis of utility-based wireless scheduling policies

AU - Liu, Peijuan

AU - Berry, Randall

AU - Honig, Michael L.

PY - 2004

Y1 - 2004

N2 - We consider packet scheduling for the downlink in a wireless network, where each packet's service preferences are captured by a utility function that depends on the packet's delay. The goal is to schedule packet transmissions to maximize the total utility. We examine a simple gradient-based scheduling algorithm, the U̇R-rule, which is a type of generalized cμ-rule (Gcμ) that takes into account both a user's channel condition and derived utility. We study the performance of this scheduling rule for a draining problem. We formulate a "large system" fluid model for this draining problem where the number of packets increases while the packet-size decreases to zero, and give a complete characterization of the behavior of the U̇R scheduling rule in this limiting regime. We then give an optimal control formulation for finding the optimal scheduling policy for the fluid draining model. Using Pontryagin's minimum principle, we show that, when the user rates are chosen from a TDM-type of capacity region, the U̇R rule is in fact optimal in many cases. Finally, we consider non-TDM capacity regions and show that here the U̇R rule is optimal only in special cases.

AB - We consider packet scheduling for the downlink in a wireless network, where each packet's service preferences are captured by a utility function that depends on the packet's delay. The goal is to schedule packet transmissions to maximize the total utility. We examine a simple gradient-based scheduling algorithm, the U̇R-rule, which is a type of generalized cμ-rule (Gcμ) that takes into account both a user's channel condition and derived utility. We study the performance of this scheduling rule for a draining problem. We formulate a "large system" fluid model for this draining problem where the number of packets increases while the packet-size decreases to zero, and give a complete characterization of the behavior of the U̇R scheduling rule in this limiting regime. We then give an optimal control formulation for finding the optimal scheduling policy for the fluid draining model. Using Pontryagin's minimum principle, we show that, when the user rates are chosen from a TDM-type of capacity region, the U̇R rule is in fact optimal in many cases. Finally, we consider non-TDM capacity regions and show that here the U̇R rule is optimal only in special cases.

UR - http://www.scopus.com/inward/record.url?scp=14244265629&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=14244265629&partnerID=8YFLogxK

U2 - 10.1109/CDC.2004.1428984

DO - 10.1109/CDC.2004.1428984

M3 - Conference contribution

AN - SCOPUS:14244265629

SN - 0780386825

T3 - Proceedings of the IEEE Conference on Decision and Control

SP - 3283

EP - 3288

BT - 2004 43rd IEEE Conference on Decision and Control (CDC)

PB - Institute of Electrical and Electronics Engineers Inc.

T2 - 2004 43rd IEEE Conference on Decision and Control (CDC)

Y2 - 14 December 2004 through 17 December 2004

ER -