Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Sensor Network Research Group University of Massachusetts, Amherst Ultra-Low Power Data Storage for Sensors Gaurav Mathur, Peter Desnoyers, Deepak Ganesan and Prashant Shenoy Motivation: Number of flash memory storage options exist for sensors NOR flash (Mica, Mica2, Telos) Multimedia cards – MMCs (RISE) NAND flash (UMass Mica2 adapter board) No comprehensive empirical comparison of the energy-efficiency of storage alternatives for sensor devices Many applications require energy-efficient, high-capacity storage Camera sensing Acoustic sensing What is the most energy-efficient storage platform for sensor devices ? How does the energy cost of storage compare to that of computation and communication ? What are the implications of an ultra-low power storage subsystem on sensor net design ? Comparison Study of Storage Technologies Toshiba Parallel NAND flash adapter Mica2 Atmel serial NOR flash TelosB STM serial NOR flash MMC adapter Compare MMC, NOR & NAND flash technology Measure active & sleep mode power consumption Implications of Low Power Storage Challenges conventional wisdom of trade-offs Computation < storage << communication Energy-efficiency of NAND flash enables ultralow power, almost infinite storage (~1 GB) High-capacity, Low-power storage impacts the following sensor application domains by supporting: Higher degree of local data archival and indexing, which supports in-network query processing Use of history for efficient network-level compression Comparison of the per byte cost of operations (in μJ) Device Mica2 NOR TelosB NOR Hitachi MMC Parallel NAND Read 0.26* 0.056* 0.144 0.004* Write 4.3* 0.127* 0.659 0.009* Erase 2.36 0.185 0.0033 0.004 Total Impact on Radio Transmission Costs 6.92 0.368 0.806 0.017 * Without ECC. Cost of performing ECC in software is approx 0.026μJ/byte Parallel NAND flash is 21 times more efficient than Telos STM flash and 407 times Mica2 Atmel flash. Comparison of computation, communication and storage costs TI MSP430 instruction Energy Ratio 0.0008 1 Toshiba NAND read 0.004 5 Toshiba CC2420 CC2420 NAND write Radio Tx Radio Rx 0.009 11 2.6 3250 2.2 2750 Storing data on NAND flash is 369 times more energy efficient than communication BMAC uses a per-packet preamble that leads to a high per-packet transmission cost Instead, store packets on NAND flash & batch transmit Can lead to a 58x reduction in communication costs ! http://sensors.cs.umass.edu/projects/essense