IEEE Transactions on Very Large Scale Integration (VLSI) Systems
A predictive system shutdown method for energy saving of event-driven computation
ICCAD '97 Proceedings of the 1997 IEEE/ACM international conference on Computer-aided design
System-level power estimation and optimization
ISLPED '98 Proceedings of the 1998 international symposium on Low power electronics and design
Stochastic dynamic programming and the control of queueing systems
Stochastic dynamic programming and the control of queueing systems
Dynamic power management for non-stationary service requests
DATE '99 Proceedings of the conference on Design, automation and test in Europe
Dynamic power management based on continuous-time Markov decision processes
Proceedings of the 36th annual ACM/IEEE Design Automation Conference
Dynamic power management of complex systems using generalized stochastic Petri nets
Proceedings of the 37th Annual Design Automation Conference
Dynamic power management using adaptive learning tree
ICCAD '99 Proceedings of the 1999 IEEE/ACM international conference on Computer-aided design
System level online power management algorithms
DATE '00 Proceedings of the conference on Design, automation and test in Europe
Energy efficient design of portable wireless systems
ISLPED '00 Proceedings of the 2000 international symposium on Low power electronics and design
Proceedings of the 7th annual international conference on Mobile computing and networking
Dynamic Programming and Stochastic Control
Dynamic Programming and Stochastic Control
PowerPC 603, A Microprocessor for Portable Computers
IEEE Design & Test
Adaptive Disk Spin-down Policies for Mobile Computers
MLICS '95 Proceedings of the 2nd Symposium on Mobile and Location-Independent Computing
The Pentium processor-90/100, microarchitecture and low power circuit design
VLSID '95 Proceedings of the 8th International Conference on VLSI Design
Event-Driven Power Management of Portable Systems
Proceedings of the 12th international symposium on System synthesis
Energy efficient system design and utilization
Energy efficient system design and utilization
Policy optimization for dynamic power management
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Towards minimum delay broadcasting and multicasting in multihop wireless networks
COCOA'11 Proceedings of the 5th international conference on Combinatorial optimization and applications
Minimum delay routing in multihop wireless networks
WASA'11 Proceedings of the 6th international conference on Wireless algorithms, systems, and applications
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Energy efficient operation is of paramount importance for battery-powered wireless nodes. In an effort to conserve energy, standard protocols for WLANs have the provision for wireless nodes to ''sleep'' periodically. In this paper we first consider the problem of optimizing the timing and duration of the sleep state of a single wireless node (or user) with the objective of minimizing power consumption with respect to a QoS constraint. The QoS parameter that we have focused on is average packet delay. Using a Dynamic Programming formulation, coupled with a duality argument, we solve the optimization problem numerically. Using a branching process analysis, we were able to derive closed form expressions for the optimal sleep duration, as well as the associated minimal rate of power consumption. We show that the optimal power cost derived from the one-user Dynamic Programming (DP) formulation provides a lower bound to the average power consumption for the multiple user case. To gain better insight into the optimal sleep policy we also formulate and solve a two-user optimization problem, similar to the one user case. Although the complexity of the DP approach grows very quickly with the number of users, the insights gained from the DP approach led us to design a simple, centralized, adaptive algorithm for assigning the sleep duration of an arbitrary number of wireless nodes operating in an infrastructure mode served by a single Access Point (AP). Our algorithm adapts dynamically to the packet arrival rate and statistics, as well as the tolerable average packet delay. We describe two different service policies - the Round Robin scheme and the Shortest Sleep First (SSF) scheme. The Round Robin scheme is the preferred service policy when all wireless nodes in the system have the same packet arrival statistics and the same tolerable average delay. The SSF Scheme is designed mainly for a system where nodes are heterogeneous with different tolerable average packet delay. Simulation results show that the power efficiency of our algorithm is comparable to the bound on performance that is obtained from the one-user dynamic programming formulation.