FreeBW-RPL: A New RPL Protocol Objective Function for Internet of Multimedia Things

Most of the current research has been restricted to scalar sensor data based IoT applications. However, today’s research and development activities rely on multimedia-based services and applications while this kind of applications has several requirements in terms of storage, bandwidth, latency, etc. Furthermore, protocols dedicated to IoT applications have proved their weakness in multimedia environments. Hence, a new paradigm called internet of multimedia things (IoMT) has been proposed to fulfill the requirements of multimedia applications. In this paradigm different multimedia things can interact and cooperate with each other over the Internet. Moreover, IETF ROLL working group standardized an IPv6 routing protocol for low-power and lossy networks (RPL for LLNs) for resource constrained devices. In this paper, we propose an enhanced version of RPL for IoMT called free bandwidth (FreeBW)-RPL in which the sensed data is essentially provided by multimedia devices. FreeBW-RPL protocol proposes a new objective function called FreeBW that takes the FreeBW calculation in the network layer. We set the QoS routing challenge as the amount of the bandwidth while selecting the routing path in order to measure the maximum FreeBW so as to deliver better performance of the multimedia applications. Simulations have been conducted over COOJA simulator. The obtained results proved that our proposal outperforms the basic ones in terms of end-to-end delay, throughput, packet delivery ratio and energy consumption and provides better performance than other protocols.

     

SparkMed: a framework for dynamic integration of multimedia medical data into distributed m-Health systems

With the advent of 4G and other long-term evolution (LTE) wireless networks, the traditional boundaries of patient record propagation are diminishing as networking technologies extend the reach of hospital infrastructure and provide on-demand mobile access to medical multimedia data. However, due to legacy and proprietary software, storage and decommissioning costs, and the price of centralization and redevelopment, it remains complex, expensive, and often unfeasible for hospitals to deploy their infrastructure for online and mobile use. This paper proposes the SparkMed data integration framework for mobile healthcare (m-Health), which significantly benefits from the enhanced network capabilities of LTE wireless technologies, by enabling a wide range of heterogeneous medical software and database systems (such as the picture archiving and communication systems, hospital information system, and reporting systems) to be dynamically integrated into a cloud-like peer-to-peer multimedia data store. Our framework allows medical data applications to share data with mobile hosts over a wireless network (such as WiFi and 3G), by binding to existing software systems and deploying them as m-Health applications. SparkMed integrates techniques from multimedia streaming, rich Internet applications (RIA), and remote procedure call (RPC) frameworks to construct a Self-managing, Pervasive Automated netwoRK for Medical Enterprise Data (SparkMed). Further, it is resilient to failure, and able to use mobile and handheld devices to maintain its network, even in the absence of dedicated server devices. We have developed a prototype of the SparkMed framework for evaluation on a radiological workflow simulation, which uses SparkMed to deploy a radiological image viewer as an m-Health application for telemedical use by radiologists and stakeholders. We have evaluated our prototype using ten devices over WiFi and 3G, verifying that our framework meets its two main objectives: 1) interactive delivery of medical multimedia data to mobile devices; and 2) attaching to non-networked medical software processes without significantly impacting their performance. Consistent response times of under 500 ms and graphical frame rates of over 5 frames per second were observed under intended usage conditions. Further, overhead measurements displayed linear scalability and low resource requirements.     

SDRAM文件结构存储控制的FPGA实现

面对不同应用场景,原始采样数据可能包含不同类型信号,而各种类型信号的处理也往往需要不同的数据帧结构。因此,需要对原始采样数据进行快速缓存,并根据数据处理的要求进行重组帧。在此使用可编程器件设计了结构化状态机对SDRAM进行读写控制,给出了一种便于FPGA实现的基于文件结构的数据缓存与重组帧方案。该方案已应用于某实际系统中,具有速度快、可靠性高的特点,并能灵活应用于其他存储系统中。     

MaSSIVE: the Mass Storage System IV Enterprise

The Mass Storage System IV Enterprise (MaSSIVE) a fourth-generation mass storage system that provides a file system service to teraflops computing systems, is described. A bitfile managed by MaSSIVE can be a complete, self-contained Unix file system specific to a particular MaSSIVE client. MaSSIVE will stage whole file systems from archival storage onto online storage devices and then provide its clients with raw block access to the staged file systems. It will comply with the IEEE Mass Storage System Reference Model, and will consist of cooperating processes distributed across a network of supermicrocomputers. The client interface to a file system will be implemented through a custom device driver that will permit I/O to MaSSIVE online storage drives. The device interface through a high-bandwidth data fabric to the storage device will use common device-controller-specific protocols. As file systems are unmounted by clients or clients disconnect from the data fabric, file systems can be migrated back to archive storage and removed from online storage     

Joint hardware-software leakage minimization approach for the register file of VLIW embedded architectures

New applications demand very high processing power when run on embedded systems. Very Long Instruction Word (VLIW) architectures have emerged as a promising alternative to provide such processing capabilities under the given energy budget. However, in this new VLIW-based architectures, the register file is a very critical contributor to the overall power consumption and new approaches have to be proposed to reduce its power while preserving system performance. In this paper, we propose a novel joint hardware-software approach that reduces the leakage energy in the register files of these embedded VLIW architectures. This approach relies upon an energy-aware register assignment method and a hardware support that creates sub-banks in the global register file that can be switched on/off at run time. Our results indicate energy savings in the register file, after considering the overhead of the added extra hardware, up to 50% for modern multimedia embedded applications without performance degradation. We illustrate this approach using real-life applications running on these processors. We also illustrate the tradeoff between the area overhead vs. the gains in the leakage energy for the different strategies.     

一种新的网络对象存储设备研究

Internet的飞速发展对于存储系统的可扩展性提出了很高的要求,也带来了由数据模型与存储模型的不一致问题引起的服务器性能瓶颈现象.针对这些情况,本文提出了网络对象附属存储设备(NAOSD)的概念,其利用设备处理器的能力直接支持结构化数据存储.这一设计减少了存储系统中数据服务器的负载,增加了系统吞吐量.同时,研究了该设备原型在集群环境中的应用,提出了数据/元数据统一存储与查询式数据定位机制.分析表明,这些机制能够较显著地提高系统扩展性——数据访问时间随系统规模的扩大呈对数增长,优于传统的映射定位机制.我们已经模拟实现了NAOSD,并在性能比较测试中取得了较好的效果.     

Research on data load balancing technology of massive storage systems for wearable devices

Because of the limited memory of the increasing amount of information in current wearable devices, the processing capacity of the servers in the storage system can not keep up with the speed of information growth, resulting in low load balancing, long load balancing time and data processing delay. Therefore, a data load balancing technology is applied to the massive storage systems of wearable devices in this paper. We first analyze the object-oriented load balancing method, and formally describe the dynamic load balancing issues, taking the load balancing as a mapping problem. Then, the task of assigning each data node and the request of the corresponding data node’s actual processing capacity are completed. Different data is allocated to the corresponding data storage node to complete the calculation of the comprehensive weight of the data storage node. According to the load information of each data storage node collected by the scheduler in the storage system, the load weight of the current data storage node is calculated and distributed. The data load balancing of the massive storage system for wearable devices is realized. The experimental results show that the average time of load balancing using this method is 1.75 ?h, which is much lower than the traditional methods. The results show the data load balancing technology of the massive storage system of wearable devices has the advantages of short data load balancing time, high load balancing, strong data processing capability, short processing time and obvious application.     

基于索引的文件备份方案

针对数据备份服务器上存在大量相同文件冗余的问题,提出了一种新的基于索引的文件备份方案,其核心是用二维链表形式对备份文件建立索引,并对相同的文件只存储一个副本,从而消除重复文件的冗余,达到节省存储空间的目的。该方案包括以下几个部分:相同文件的识别、文件的存储、文件夹的处理、文件备份过程和备份的更新.理论分析和实验表明,该方案较传统方法节省了存储空间,但备份过程中的系统负载和时间消耗有所增加.     

Rabb et: Using Layout-Aware Backup for RAID Reconstruction

Once a disk of storage system is failed, RAID mechanism will reconstruct to keep the reliability. The reconstruction leads to a sharp deterioration in I/O performance of RAID, and the storage system cannot pro-vide high performance service for the applications. The Multi-TB disk capacity and high load of the application make the reconstruction last for a very long time. This paper proposes Rabbet, a method accelerating RAID re-construction using data of backup. Rabbet includes a new RAID reconstruction frame, a RAID layout-aware map-ping mechanism for backup, and a reconstruction algo-rithm. The result of experiments shows that, comparing to the classic DOR methods Rabbet shortens the RAID5 reconstruction process to 13.9%–42.8% and decreases the average response time for applications during reconstruc-tion by 3.2%–14.6%. Rabbet also improves the reliability of storage systems.     

一种能耗优化的RAID小写预读方法

视频监控、备份、归档等应用产生海量存储数据，导致存储能耗急剧增加.S-RAID采用局部并行数据布局，可显著降低该类应用的存储能耗.为使更多磁盘待机节能，S-RAID通常执行"小写"操作，写操作时会额外引入等量的读操作，会显著降低性能.现有预读机制主要发生在文件级，无法感知RAID级小写引发的读旧数据、旧校验数据等读操作，因此不会也无法预读该类数据.为此，提出一种面向S-RAID的RAID级小写预读算法，由小写操作触发并在RAID级执行预读，根据S-RAID的数据布局方式，大粒度异步预读小写需要的旧数据、旧校验数据，有效减少I/O数和寻道数，提高磁盘的利用率.该方法可显著提高S-RAID的写性能，并且不依赖于任何额外硬件，具有更高的可用性.     

Networked multimedia: the Medusa environment

The Medusa project at Olivetti Research aims to provide a networked multimedia environment in which many streams of multimedia data, perhaps thousands, are active simultaneously. Medusa uses a peer-to-peer architecture to control networked multimedia devices. In the software model presented to the applications programmer, active objects called modules represent cameras, displays, format converters, and so on. Data flows from module to module through connections between them, with proxy modules to restrict access for security reasons. The Medusa project is based on hardware that is a collection of asynchronous transfer mode (ATM) direct peripherals, including cameras, audio systems, multimedia storage servers, LCD displays, and televisions, as well as ATM networked workstations     

A joint signal processing and cryptographic approach to multimedia encryption.

In recent years, there has been an increasing trend for multimedia applications to use delegate service providers for content distribution, archiving, search, and retrieval. These delegate services have brought new challenges to the protection of multimedia content confidentiality. This paper discusses the importance and feasibility of applying a joint signal processing and cryptographic approach to multimedia encryption, in order to address the access control issues unique to multimedia applications. We propose two atomic encryption operations that can preserve standard compliance and are friendly to delegate processing. Quantitative analysis for these operations is presented to demonstrate that a good tradeoff can be made between security and bitrate overhead. In assisting the design and evaluation of media security systems, we also propose a set of multimedia-oriented security scores to quantify the security against approximation attacks and to complement the existing notion of generic data security. Using video as an example, we present a systematic study on how to strategically integrate different atomic operations to build a video encryption system. The resulting system can provide superior performance over both generic encryption and its simple adaptation to video in terms of a joint consideration of security, bitrate overhead, and friendliness to delegate processing.     

Clustering hypervisors to minimize failures in mobile cloud computing

Resource virtualization has become one of the key super‐power mobile computing architecture technologies. As mobile devices and multimedia traffic have increased dramatically, the load on mobile cloud computing systems has become heavier. Under such conditions, mobile cloud system reliability becomes a challenging task. In this paper, we propose a new model using a naive Bayes classifier for hypervisor failure prediction and prevention in mobile cloud computing. We exploit real‐time monitoring data in combination with historical maintenance data, which achieves higher accuracy in failure prediction and early failure‐risk detection. After detecting hypervisors at risk, we perform live migration of virtual servers within a cluster, which decreases the load and prevents failures in the cloud. We performed a simulation for verification. According to the experimental results, our proposed model shows good accuracy in failure prediction and the possibility of decreasing downtime in a hypervisor service. Copyright © 2017 John Wiley & Sons, Ltd.     

DJFS: Providing Highly Reliable and High‐Performance File System with Small‐Sized NVRAM

File systems and applications try to implement their own update protocols to guarantee data consistency, which is one of the most crucial aspects of computing systems. However, we found that the storage devices are substantially under‐utilized when preserving data consistency because they generate massive storage write traffic with many disk cache flush operations and force‐unit‐access (FUA) commands. In this paper, we present DJFS (Delta‐Journaling File System) that provides both a high level of performance and data consistency for different applications. We made three technical contributions to achieve our goal. First, to remove all storage accesses with disk cache flush operations and FUA commands, DJFS uses small‐sized NVRAM for a file system journal. Second, to reduce the access latency and space requirements of NVRAM, DJFS attempts to journal compress the differences in the modified blocks. Finally, to relieve explicit checkpointing overhead, DJFS aggressively reflects the checkpoint transactions to file system area in the unit of the specified region. Our evaluation on TPC‐C SQLite benchmark shows that, using our novel optimization schemes, DJFS outperforms Ext4 by up to 64.2 times with only 128 MB of NVRAM.     

一种基于纠删码的分布式存储容灾的设计与实现

在广域的文件存储系统中,每一个节点的可用性是至关重要的,这就需要在该系统中引入一定的冗余来提高每个存储节点的可用性以对存储的数据起到保护的作用。传统的冗余方式是完全复制,但随着副本个数的增加,该机制在存储空间上的浪费暴露无遗,而且在一定程度上这对整个系统性能的提高几乎没有帮助。本丈提出一种基于纠删码的分布式网络容灾模型,在空间冗余度和性能上均优于传统的存储模型。     

海量存储系统评测体系的研究

随着信息化建设的逐步深入,对计算机系统的两大能力,即运算和存储能力的要求越来越高,尤其是存储能力.主要研究了基于SAN存储网络的海量存储系统的评测体系.评测体系主要从性能、能耗、功能、可用性、可靠性5个方面,典型应用、存储系统软件、信息组织核心系统、存储网络、存储设备、存储器件6个层次构建.从每个角度都提出了具体的指标...     

A Novel Multimedia Streaming Scheme for N-Screen Services in Wireless USB Networks

Ultra wideband (UWB) technology has emerged as a solution for the wireless interface between medical sensors and a personal server in future telemedicine systems. Wireless universal serial bus (USB) is the USB technology merged with UWB technology. Wireless USB can be applied to wireless personal area network applications as well as personal area network applications like wired USB. In case of n-screen service applications, data traffics must broadcast to the adjacent devices However, the current wireless USB is designed to support the communication through the point-to-point connection between the host and the device only. This policy increases delay and energy consumption of wireless host and devices significantly. Therefore, in this paper, we propose a novel multimedia streaming scheme for n-screen service in wireless USB networks. The simulation results show that proposed protocol can enhance the throughput and delay performance and improve energy efficiency by minimizing the multimedia data delivery process.     

A generic platform for scalable access to multimedia-on-demandsystems

Access to multimedia servers is commonly done according to a client/server model where the end user at the client host retrieves multimedia objects from a multimedia server. In a distributed environment, a number of end users may need to access a number of multimedia servers through one or several communication networks. Such a scenario reveals the requirement for a distributed access platform. In addition, the demand for multimedia information is increasing beyond the capabilities of high performance storage devices. Therefore, load distribution and scalability issues must be addressed while designing and implementing the distributed access platform. This paper introduces a scalable access platform (SAP) for managing user access to multimedia-on-demand systems while optimizing resource utilization. The platform is generic and capable of integrating heterogeneous multimedia servers. SAP operation combines static replication and dynamic load distribution policies. It provides run time redirecting of client requests to multimedia servers according to the workload information dynamically collected in the system. To support multimedia-on-demand systems with differing quality-of-service (QoS) requirements, the platform also takes into account, as part of the access process, user QoS requirements and cost constraints. This paper also presents an application of the generic platform implementing a scalable movie-on-demand system, called SMoD. Performance evaluation based on simulation shows that in many cases SMoD can reduce the blocking probability of user requests, and thus can support more users than classical video-on-demand (VoD) systems. It also shows that the load is better distributed across the video servers of the system     

Software architecture for integration of video services in theEtherphone system

Software mechanisms that make use of analog transmission and storage of video for computer-controlled video communication and file storage are described. The authors extended the Etherphone voice management system to support video conferencing and file storage. The software mechanisms for conference management consist of a central connection manager, and video and user interface agents running on client workstations. A conferencing architecture that supports multiplicity in the number of conferences and media is presented. The video file server stores and retrieves full-motion video information within conferences. It uses optical disks to store video frames and builds a high-level file and directory interface. The user interface to the directory interface is a multimedia document editor that permits video annotations to be freely interspersed with text. The performance of the system, which spans multiple media networks, has been highly satisfactory     

Indoor Power Harvesting Using Photovoltaic Cells for Low-Power Applications

Utilization of low-power indoor devices such as remote sensors, supervisory and alarm systems, distributed controls, and data transfer system is on steady rise. Due to remote and distributed nature of these systems, it is attractive to avoid using electrical wiring to supply power to them. Primary batteries have been used for this application for many years, but they require regular maintenance at usually hard to access places. This paper provides a complete analysis of a photovoltaic (PV) harvesting system for indoor low-power applications. The characteristics of a target load, PV cell, and power conditioning circuit are discussed. Different choices of energy storage are also explained. Implementation and test results of the system are presented, which highlights the practical issues and limitations of the system.