Techniques for ubiquitous reliable data storage

This portfolio thesis documents the work undertaken by the author under the auspices of the Engineering Doctorate (EngD) programme. The research work undertaken was completed at the sponsoring company, A2E Limited. There is a wide range of products and solutions to meet both commercial and personal electronic storage needs. This work documents research and development over a four year period into algorithms, implementations and product development for novel storage solutions for commercial and personal use. The design work and technical and business objectives were guided by the sponsoring company, A4E limited. This portfolio thesis considers the storage market at the start of the project, the commercial and technical aspects relevant to this market place and describes the development and testing of a RAID 6 algorithm in both hardware and software. The key contributions presented in this portfolio thesis include the implementation of the smallest and fastest FPGA based Reed-Solomon RAID 6 hardware accelerator. We also present the first commercial implementation of a Reed-Solomon RAID 6 intellectual property (IP) block. Both the hardware and software implementation are discussed in detail along with the supporting IP blocks and device drivers. Documentation of the product development stages and additional project work carried out to provide an understanding of product development stages and the requirements placed during such work are also examined. the results of testing and implementation are considered and the performance of the proposed solution is considered along with the commercial viability and success of the project

ClusterRAID: Architecture and Prototype of a Distributed Fault-Tolerant Mass Storage System for Clusters

During the past few years clusters built from commodity off-the-shelf (COTS) components have emerged as the predominant supercomputer architecture. Typically comprising a collection of standard PCs or workstations and an interconnection network, they have replaced the traditionally used integrated systems due to their better price/performance ratio. As paradigms shift from mere computing intensive to I/O intensive applications, mass storage solutions for cluster installations become a more and more crucial aspect of these systems. The inherent unreliability of the underlying components is one of the reasons why no system has been established as a standard storage solution for clusters yet. This thesis sets out the architecture and prototype implementation of a novel distributed mass storage system for commodity off-the-shelf clusters and addresses the issue of the unreliable constituent components. The key concept of the presented system is the conversion of the local hard disk drive of a cluster node into a reliable device while preserving the block device interface. By the deployment of sophisticated erasure-correcting codes, the system allows the adjustment of the number of tolerable failures and thus the overall reliability. In addition, the applied data layout considers the access behaviour of a broad range of applications and minimizes the number of required network transactions. Extensive measurements and functionality tests of the prototype, both stand-alone and in conjunction with local or distributed file systems, show the validity of the concept

High Speed S-band Communications System for Nanosatellites

3Cat-3 is a nanosatellite based on the 6 unit cubesat standard. Its payload is an optical multispectral imager that imposes stringent downlink requirements for a nanosatellite. This TFG is based on the experience gained in 3Cat-1 and 3Cat-2 communications systems to develop a "high speed" (goal >= 5 Mbps) downlink for nanosatellites based on the TI CC3200.In order to accomplish the objectives of the next generation of nanosatellites high-speed downlinks have to be designed. This goal faces stringent design constraints as nanosatellites are limit in power, processing capabilities and dimensions. In the quest for higher bit rates the widely used VHF band has to be replaced for higher frequency bands and the link budged margin tightened, decreasing the SNR at reception. The proposed solution uses COTS 2.4 GHz WiFi adapters as transceivers. Range limitations imposed by the default 802.11 mode of operation are bypassed by using packet forging and injection at transmission jointly with monitor mode at reception. A loss-resilient unidirectional downlink is achieved by using application-layer encoding by means of LPDC-Staircase codes. This solution has been already implemented in 3CAT-2, a 6 unit cubesat GNSS-R mission to be launched in July 2016. In addition, bursts of errors are combated by using Reed-Solomon. The system has been tested under Doppler shift and scintillation effects, and a 188Km link between Barcelona and Mallorca has been performed, showing satisfactory results

Energy-efficient wireless communication

In this chapter we present an energy-efficient highly adaptive network interface architecture and a novel data link layer protocol for wireless networks that provides Quality of Service (QoS) support for diverse traffic types. Due to the dynamic nature of wireless networks, adaptations in bandwidth scheduling and error control are necessary to achieve energy efficiency and an acceptable quality of service. In our approach we apply adaptability through all layers of the protocol stack, and provide feedback to the applications. In this way the applications can adapt the data streams, and the network protocols can adapt the communication parameters

Satellite Networks: Architectures, Applications, and Technologies

Since global satellite networks are moving to the forefront in enhancing the national and global information infrastructures due to communication satellites' unique networking characteristics, a workshop was organized to assess the progress made to date and chart the future. This workshop provided the forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. Presentations on overview, state-of-the-art in research, development, deployment and applications and future trends on satellite networks are assembled

Proceedings of the Fifth International Mobile Satellite Conference 1997

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial communications services. While previous International Mobile Satellite Conferences have concentrated on technical advances and the increasing worldwide commercial activities, this conference focuses on the next generation of mobile satellite services. The approximately 80 papers included here cover sessions in the following areas: networking and protocols; code division multiple access technologies; demand, economics and technology issues; current and planned systems; propagation; terminal technology; modulation and coding advances; spacecraft technology; advanced systems; and applications and experiments

Investigation of parallel programming on heterogeneous multiprocessors

Multi-core processors have become ordinary in modern commodity computers. Computationally intensive applications, like video processing, that previously only ran on specialized hardware, are now common on home computers. However, the demand for more computing power is ever-increasing, and with the introduction of high definition video, more performance is desired. As an alternative to having multiple identical processor cores, heterogeneous multiprocessors have cores with different capabilities. This allows tasks to be processed on simple cores with specialized functionality. The simplicity furthers low power consumption, small die usage, and low price. Dealing with heterogeneous cores increases the complexity of writing programs for the architecture. The reasons for this includes different capabilities of the cores, and some heterogeneous architectures do not have shared memory. Without shared memory, accessing main memory requires explicit transfers to local memory. In this thesis, we consider two architectures, the STI Cell/B.E. and Intel IXP2400, and evaluate parallelization strategies and performance for real-world problems. Our tests show promising throughput for some applications, and we propose a scheme for offloading computationally intensive parts of an existing application

AXMEDIS 2008

The AXMEDIS International Conference series aims to explore all subjects and topics related to cross-media and digital-media content production, processing, management, standards, representation, sharing, protection and rights management, to address the latest developments and future trends of the technologies and their applications, impacts and exploitation. The AXMEDIS events offer venues for exchanging concepts, requirements, prototypes, research ideas, and findings which could contribute to academic research and also benefit business and industrial communities. In the Internet as well as in the digital era, cross-media production and distribution represent key developments and innovations that are fostered by emergent technologies to ensure better value for money while optimising productivity and market coverage

Television Playout Development Towards Flexible IT-based Solutions

The purpose of this study was to update television playout system. An Estonian television and radio network operator Levira playout centre needed expansion in infrastructure to be able to accommodate larger channel count. Renewals of media asset management and automation systems were also required to handle requirements of the larger channel count and to automate processes. Television playout systems and solutions are going through big changes. These changes reflect partially new developments in the whole broadcasting industry and the way people use video, as well as changes and development in other areas of technology, especially in IT. These changes do not come without challenges with new workflows and ways of operating. These projects were to be done not only for current needs but also to be ready for the coming years. This was taken into consideration on system design and planning as well as on choosing the partners for the projects. As a result of this study, an up to date playout centre was designed with flexible IT based solutions that are easy to update and customize for varying needs of different television channels. Playout centre has room to grow and it is ready for requirements of future without need for major changes in the system.Työn tavoitteena oli television lähetyskeskuksen järjestelmän päivittäminen. Virolaisen television ja radion lähetysverkkotoimija Leviran lähetyskeskus tarvitsi laajennuksen olemassa olevaan järjestelmään, jotta se pystyisi lähettämään suuremman määrän kanavia. Myös lähetyskeskuksen medianhallinta- ja automaatiojärjestelmät täytyi päivittää tämän suuremman kanavamäärän tukemiseksi ja työnkulun tehostamiseksi. Television lähetysjärjestelmät ja ratkaisut käyvät läpi isoja muutoksia. Nämä muutokset heijastuvat osin koko televisiotoiminnan muutoksesta ja siitä, miten katsojat ylipäätään käyttävät videota ja osin informaatioteknologian (IT) kehityksestä. Se on selvää, että muutokset tuovat uusia haasteita, edellyttävät täysin uudenlaisten työnkulkujen ja ajatusmallien omaksumista. Molemmat projektit toteutettiin ottaen huomioon tämän hetken tarpeet tiedostopohjaisen työnkulun ja kasvavan kanavamäärän tuoman kapasiteettivaatimusten suhteen sekä ennen kaikkea lähivuosien mahdolliset vaatimukset muuttuvien jakelukanavien osalta. Systeemin suunnittelu ja yhteistyökumppaneiden valinta painotettiin sen mukaisesti. Toteutettuna lopputuloksena on television lähetyskeskusjärjestelmä, joka pohjautuu helposti päivitettäviin ja eri televisiokanavien vaihteleviin tarpeisiin mukautuviin IT-laitteistoihin. Järjestelmällä on tilaa kasvaa sekä kehittyä tulevaisuuteen ilman välitöntä tarvetta merkittäviin systeemitason muutoksiin