Energy-Conscious Co-scheduling of Tasks and Packets in Wireless Real-Time Environments

Exclusive access to the wireless medium, e.g., as provided by bandwidth-reservation mechanisms, limits contention and therefore is capable of providing effective real-time support to periodic communications. Furthermore, to preserve energy, wireless cards can be powered down between periodic accesses without loss of data. However, packet schedulers must be aware of the limited communication opportunities to ensure that packets are transmitted before their deadlines, CPU schedulers must execute jobs such that the packets generated by these jobs are available for transmission in time, and DVS algorithms must choose processor speeds such that job execution and therefore packet generation are not unduly delayed. This paper proposes a co-scheduling approach to integrate CPU, network, and energy management for wireless real-time systems that rely on bandwidth reservations. Both simulation and experimentation indicate significant improvements in meeting packet deadlines (up to 40%) with only small increases in overall energy consumption (less than 10%) compared to the state of the art.

[1]  Hussein M. Alnuweiri,et al.  Hybrid polling and contention access scheduling in IEEE 802.11e WLANs , 2007, J. Parallel Distributed Comput..

[2]  Luca Benini,et al.  A survey of design techniques for system-level dynamic power management , 2000, IEEE Trans. Very Large Scale Integr. Syst..

[3]  Christian Poellabauer,et al.  Energy-aware traffic shaping for wireless real-time applications , 2004, Proceedings. RTAS 2004. 10th IEEE Real-Time and Embedded Technology and Applications Symposium, 2004..

[4]  Kang G. Shin,et al.  MiSer: an optimal low-energy transmission strategy for IEEE 802.11a/h , 2003, MobiCom '03.

[5]  Yang Xiao,et al.  A Survey of Energy-Efficient Scheduling Mechanisms in Sensor Networks , 2006, Mob. Networks Appl..

[6]  X. Hu,et al.  Energy efficient fixed-priority scheduling for real-time systems on variable voltage processors , 2001, Proceedings of the 38th Design Automation Conference (IEEE Cat. No.01CH37232).

[7]  Kang G. Shin,et al.  Real-time dynamic voltage scaling for low-power embedded operating systems , 2001, SOSP.

[8]  G. Manimaran,et al.  Energy-Aware Scheduling of Real-Time Tasks in Wireless Networked Embedded Systems , 2007, 28th IEEE International Real-Time Systems Symposium (RTSS 2007).

[9]  Vinay Devadas,et al.  Real-Time Dynamic Power Management through Device Forbidden Regions , 2008, 2008 IEEE Real-Time and Embedded Technology and Applications Symposium.

[10]  Christian Poellabauer,et al.  Wireless channel access reservation for embedded real-time systems , 2008, EMSOFT '08.

[11]  Tei-Wei Kuo,et al.  Leakage-Aware Energy-Efficient Scheduling of Real-Time Tasks in Multiprocessor Systems , 2006, 12th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS'06).

[12]  Christian Poellabauer,et al.  Network-Aware Dynamic Voltage and Frequency Scaling , 2007, 13th IEEE Real Time and Embedded Technology and Applications Symposium (RTAS'07).

[13]  Seongsoo Hong,et al.  An engineering approach to decomposing end-to-end delays on a distributed real-time system , 1996, Proceedings of the 4th International Workshop on Parallel and Distributed Real-Time Systems.

[14]  Israel Koren,et al.  System-level power-aware design techniques in real-time systems , 2003, Proc. IEEE.

[15]  Yuting Zhang,et al.  End-to-end Window-Constrained Scheduling for Real-Time Communication , 2004 .