1 / 12

Energy-Saving Buffering Approach for Video Sensors

This study explores an innovative buffering approach to save both CPU and NIC energy in video sensors by avoiding all CPU slack and putting idle NIC to sleep. By encoding one frame per period and buffering frames in bursts, significant energy savings were achieved. Results show up to 83% CPU energy savings and 44% NIC energy savings with minimal delay. The cross-layer adaptation methodology offers promising results for energy-efficient sensor operation.

amelia-shelton
Download Presentation

Energy-Saving Buffering Approach for Video Sensors

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. BUFFERING APPROACH FOR ENERGY SAVING IN VIDEO SENSORS Wanghong Yuan, Klara Nahrstedt Department of Computer Science University of Illinois at Urbana-Champaign {wyuan1, klara}@cs.uiuc.edu

  2. Motivation Video sensors become popular • Capture images • Encode to frames • Transmit to center Processing Center Saving battery energy !

  3. Opportunities Hardware level: performance vs. power • Sleep, idle, active Switch into lower-power sleep • Multiple frequencies/voltages (EfV2) Slow down to avoid idle Application level • Encoding and transmission slack

  4. Challenges period CPU NIC encoding encoding Potentially • Avoid CPU slack • Sleep NIC when idle transmission transmission However • Cannot avoid all slack Wait for transmission • NIC slack shorter than sleep cost (e.g., 40ms for WaveLAN)

  5. Naïve Approach period period fmax enc One frame per period • CPU: highest speed • NIC: no sleep in slack slack CPU NIC tran slack Energy: Energy:

  6. DVS Approach fmax slow down CPU • Slow down to shorten slack • But, still some slack ! fdvs enc enc CPU NIC tran Less ! Energy:

  7. Buffering Approach Why: Save both CPU and NIC energy • Avoid all CPU slack • Put idle NIC to sleep How: Buffering • Encode one frame per period Timely, no data loss • Buffer and send frames in bursts Accumulated slack > sleep cost

  8. Buffering Approach CPU Energy: Less ! NIC Energy:

  9. Experiment H263 frames Receiver (IBM ThinkPad) Sender (HP Pavilion) • Athlon CPU • DVS, implemented • WaveLan • Sleep, simulated Speed: 300 – 1000MHz Power: 0.22 – 1 Watt Trans power: 1.5 W Idle power: 1 W Sleep power: 0.1 W Sleep cost: 40 ms

  10. Results: Energy Save CPU energy by 32% - 83% Save NIC energy by 44%

  11. Results: Delay Need to buffer only1-3 frames

  12. Operating System Architecture, Hardware Coordinator Application Network Protocols Conclusion Part of the Illinois GRACE project Cross-layer adaptation • All layers are adaptive • Cooperate For energy saving http://rsim.cs.uiuc.edu/grace/

More Related