Client-centered energy savings for concurrent HTTP connections

In mobile devices, the wireless network interface card (WNIC) consumes a significant portion of overall system energy. One way to reduce energy consumed by a WNIC is to transition it to a lower-power sleep mode when data is not being received or transmitted.This paper investigates client-centered techniques for saving energy during web browsing. The basic idea is that the client predicts when packets will arrive, keeping the WNIC in high-power mode only when necessary. This is challenging because web browsing generally results in concurrent HTTP connections. To handle this, we maintain the state of each open connection on the client and then transition the WNIC to sleep mode when no connection is receiving data. Our technique is compatible with standard TCP and does not rely on any assistance from the server, a proxy, or IEEE 802.11b power-saving mode (PSM). Our technique combines the performance of regular TCP with nearly all the energy-saving of PSM during web downloads, and we save more energy than PSM during client think times. Results show that over an entire web browsing session (downloads and think times), our scheme saves up to 21% energy compared to PSM and incurs less than a 1% increase in transmission time compared to regular TCP.

[1]  Paul J.M. Havinga,et al.  Mobile Multimedia Systems , 2002 .

[2]  Jason Flinn,et al.  Self-Tuning Wireless Network Power Management , 2003, MobiCom '03.

[3]  Hari Balakrishnan,et al.  Minimizing Energy for Wireless Web Access with Bounded Slowdown , 2002, MobiCom '02.

[4]  Amin Vahdat,et al.  ECOSystem: managing energy as a first class operating system resource , 2002, ASPLOS X.

[5]  Thomas D. Burd,et al.  The simulation and evaluation of dynamic voltage scaling algorithms , 1998, Proceedings. 1998 International Symposium on Low Power Electronics and Design (IEEE Cat. No.98TH8379).

[6]  Victor Yodaiken,et al.  A Real-Time Linux , 2000 .

[7]  Amin Vahdat,et al.  Application-specific Network Management for Energy-Aware Streaming of Popular Multimedia Formats , 2002, USENIX Annual Technical Conference, General Track.

[8]  Luigi Rizzo,et al.  Dummynet: a simple approach to the evaluation of network protocols , 1997, CCRV.

[9]  Surendar Chandra,et al.  Wireless network interface energy consumption implications of popular streaming formats , 2001, IS&T/SPIE Electronic Imaging.

[10]  James Gettys,et al.  The WebMUX Protocol , 1998 .

[11]  Jason Flinn,et al.  Energy-aware adaptation for mobile applications , 1999, SOSP.

[12]  David Kotz,et al.  Analysis of a Campus-Wide Wireless Network , 2002, MobiCom '02.

[13]  Karsten Schwan,et al.  Power-aware communication for mobile computers , 1999, 1999 IEEE International Workshop on Mobile Multimedia Communications (MoMuC'99) (Cat. No.99EX384).

[14]  Virgílio A. F. Almeida,et al.  Characterizing reference locality in the WWW , 1996, Fourth International Conference on Parallel and Distributed Information Systems.

[15]  Fred Douglis,et al.  Adaptive Disk Spin-Down Policies for Mobile Computers , 1995, Comput. Syst..

[16]  Scott Shenker,et al.  Scheduling for reduced CPU energy , 1994, OSDI '94.

[17]  Prashant Shenoy,et al.  Proxy-Assisted Power-Friendly Streaming to Mobile Devices , 2003, IS&T/SPIE Electronic Imaging.

[18]  Hari Balakrishnan,et al.  Minimizing Energy for Wireless Web Access with Bounded Slowdown , 2005, Wirel. Networks.

[19]  Xing Li,et al.  On the correspondency between TCP acknowledgment packet and data packet , 2003, IMC '03.

[20]  Alvin R. Lebeck,et al.  Power aware page allocation , 2000, SIGP.