Quanto: Tracking Energy in Networked Embedded Systems

We present Quanto, a network-wide time and energy profiler for embedded network devices. By combining well-defined interfaces for hardware power states, fast high-resolution energy metering, and causal tracking of programmer-defined activities, Quanto can map how energy and time are spent on nodes and across a network. Implementing Quanto on the TinyOS operating system required modifying under 350 lines of code and adding 1275 new lines. We show that being able to take finegrained energy consumption measurements as fast as reading a counter allows developers to precisely quantify the effects of low-level system implementation decisions, such as using DMA versus direct bus operations, or the effect of external interference on the power draw of a low duty-cycle radio. Finally, Quanto is lightweight enough that it has a minimal effect on system behavior: each sample takes 100 CPU cycles and 12 bytes of RAM.

• Type: Conference
• Year: 2008
• Where: OSDI
• Authors: Rodrigo Fonseca, Prabal Dutta, Philip Levis, Ion Stoica
• Keywords: Energy Consumption Measurements, Energy Profiler, Operating System, OSDI 2008, Versus Direct Bus