Information and Computer Engineering, Ajou University, San 5 Woncheon-dong Yeongtong-gu, Suwon 443-749, Korea.
Sensors (Basel). 2010;10(1):292-312. doi: 10.3390/s100100292. Epub 2009 Dec 30.
Flash memory has become a more widespread storage medium for modern wireless devices because of its effective characteristics like non-volatility, small size, light weight, fast access speed, shock resistance, high reliability and low power consumption. Sensor nodes are highly resource constrained in terms of limited processing speed, runtime memory, persistent storage, communication bandwidth and finite energy. Therefore, for wireless sensor networks supporting sense, store, merge and send schemes, an efficient and reliable file system is highly required with consideration of sensor node constraints. In this paper, we propose a novel log structured external NAND flash memory based file system, called Proceeding to Intelligent service oriented memorY Allocation for flash based data centric Sensor devices in wireless sensor networks (PIYAS). This is the extended version of our previously proposed PIYA [1]. The main goals of the PIYAS scheme are to achieve instant mounting and reduced SRAM space by keeping memory mapping information to a very low size of and to provide high query response throughput by allocation of memory to the sensor data by network business rules. The scheme intelligently samples and stores the raw data and provides high in-network data availability by keeping the aggregate data for a longer period of time than any other scheme has done before. We propose effective garbage collection and wear-leveling schemes as well. The experimental results show that PIYAS is an optimized memory management scheme allowing high performance for wireless sensor networks.
闪存因其非易失性、小尺寸、轻重量、快速访问速度、抗震性、高可靠性和低功耗等有效特性，已成为现代无线设备更广泛使用的存储介质。传感器节点在处理速度、运行时内存、持久存储、通信带宽和有限能量等方面的资源非常有限。因此，对于支持感知、存储、合并和发送方案的无线传感器网络，需要考虑传感器节点的约束条件，设计一种高效、可靠的文件系统。在本文中，我们提出了一种新的基于日志结构的外部 NAND 闪存文件系统，称为面向基于闪存的以数据为中心的无线传感器网络中的智能服务的存储分配（PIYAS）。这是我们之前提出的 PIYA[1]的扩展版本。PIYAS 方案的主要目标是通过将内存映射信息保持在非常小的尺寸来实现即时挂载和减少 SRAM 空间，并通过根据网络业务规则将内存分配给传感器数据来提供高查询响应吞吐量。该方案通过比以前任何方案更长的时间来保存聚合数据，智能地采样和存储原始数据，并提供更高的网络内数据可用性。我们还提出了有效的垃圾收集和磨损均衡方案。实验结果表明，PIYAS 是一种优化的内存管理方案，可为无线传感器网络提供高性能。
