A scalable packetised radio astronomy imager

Includes bibliographical referencesModern radio astronomy telescopes the world over require digital back-ends. The complexity of these systems depends on many site-specific factors, including the number of antennas, beams and frequency channels and the bandwidth to be processed. With the increasing popularity for ever larger interferometric arrays, the processing requirements for these back-ends have increased significantly. While the techniques for building these back-ends are well understood, every installation typically still takes many years to develop as the instruments use highly specialised, custom hardware in order to cope with the demanding engineering requirements. Modern technology has enabled reprogrammable FPGA-based processing boards, together with packet-based switching techniques, to perform all the digital signal processing requirements of a modern radio telescope array. The various instruments used by radio telescopes are functionally very different, but the component operations remain remarkably similar and many share core functionalities. Generic processing platforms are thus able to share signal processing libraries and can acquire different personalities to perform different functions simply by reprogramming them and rerouting the data appropriately. Furthermore, Ethernet-based packet-switched networks are highly flexible and scalable, enabling the same instrument design to be scaled to larger installations simply by adding additional processing nodes and larger network switches. The ability of a packetised network to transfer data to arbitrary processing nodes, along with these nodes' reconfigurability, allows for unrestrained partitioning of designs and resource allocation. This thesis describes the design and construction of the first working radio astronomy imaging instrument hosted on Ethernet-interconnected re- programmable FPGA hardware. I attempt to establish an optimal packetised architecture for the most popular instruments with particular attention to the core array functions of correlation and beamforming. Emphasis is placed on requirements for South Africa's MeerKAT array. A demonstration system is constructed and deployed on the KAT-7 array, MeerKAT's prototype. This research promises reduced instrument development time, lower costs, improved reliability and closer collaboration between telescope design teams

Space Station Freedom data management system growth and evolution report

The Information Sciences Division at the NASA Ames Research Center has completed a 6-month study of portions of the Space Station Freedom Data Management System (DMS). This study looked at the present capabilities and future growth potential of the DMS, and the results are documented in this report. Issues have been raised that were discussed with the appropriate Johnson Space Center (JSC) management and Work Package-2 contractor organizations. Areas requiring additional study have been identified and suggestions for long-term upgrades have been proposed. This activity has allowed the Ames personnel to develop a rapport with the JSC civil service and contractor teams that does permit an independent check and balance technique for the DMS

Design and performance optimization of asynchronous networks-on-chip

As digital systems continue to grow in complexity, the design of conventional synchronous systems is facing unprecedented challenges. The number of transistors on individual chips is already in the multi-billion range, and a greatly increasing number of components are being integrated onto a single chip. As a consequence, modern digital designs are under strong time-to-market pressure, and there is a critical need for composable design approaches for large complex systems. In the past two decades, networks-on-chip (NoC’s) have been a highly active research area. In a NoC-based system, functional blocks are first designed individually and may run at different clock rates. These modules are then connected through a structured network for on-chip global communication. However, due to the rigidity of centrally-clocked NoC’s, there have been bottlenecks of system scalability, energy and performance, which cannot be easily solved with synchronous approaches. As a result, there has been significant recent interest in combing the notion of asynchrony with NoC designs. Since the NoC approach inherently separates the communication infrastructure, and its timing, from computational elements, it is a natural match for an asynchronous paradigm. Asynchronous NoC’s, therefore, enable a modular and extensible system composition for an ‘object-orient’ design style. The thesis aims to significantly advance the state-of-art and viability of asynchronous and globally-asynchronous locally-synchronous (GALS) networks-on-chip, to enable high-performance and low-energy systems. The proposed asynchronous NoC’s are nearly entirely based on standard cells, which eases their integration into industrial design flows. The contributions are instantiated in three different directions. First, practical acceleration techniques are proposed for optimizing the system latency, in order to break through the latency bottleneck in the memory interfaces of many on-chip parallel processors. Novel asynchronous network protocols are proposed, along with concrete NoC designs. A new concept, called ‘monitoring network’, is introduced. Monitoring networks are lightweight shadow networks used for fast-forwarding anticipated traffic information, ahead of the actual packet traffic. The routers are therefore allowed to initiate and perform arbitration and channel allocation in advance. The technique is successfully applied to two topologies which belong to two different categories – a variant mesh-of-trees (MoT) structure and a 2D-mesh topology. Considerable and stable latency improvements are observed across a wide range of traffic patterns, along with moderate throughput gains. Second, for the first time, a high-performance and low-power asynchronous NoC router is compared directly to a leading commercial synchronous counterpart in an advanced industrial technology. The asynchronous router design shows significant performance improvements, as well as area and power savings. The proposed asynchronous router integrates several advanced techniques, including a low-latency circular FIFO for buffer design, and a novel end-to-end credit-based virtual channel (VC) flow control. In addition, a semi-automated design flow is created, which uses portions of a standard synchronous tool flow. Finally, a high-performance multi-resource asynchronous arbiter design is developed. This small but important component can be directly used in existing asynchronous NoC’s for performance optimization. In addition, this standalone design promises use in opening up new NoC directions, as well as for general use in parallel systems. In the proposed arbiter design, the allocation of a resource to a client is divided into several steps. Multiple successive client-resource pairs can be selected rapidly in pipelined sequence, and the completion of the assignments can overlap in parallel. In sum, the thesis provides a set of advanced design solutions for performance optimization of asynchronous and GALS networks-on-chip. These solutions are at different levels, from network protocols, down to router- and component-level optimizations, which can be directly applied to existing basic asynchronous NoC designs to provide a leap in performance improvement

The Fifth NASA Symposium on VLSI Design

The fifth annual NASA Symposium on VLSI Design had 13 sessions including Radiation Effects, Architectures, Mixed Signal, Design Techniques, Fault Testing, Synthesis, Signal Processing, and other Featured Presentations. The symposium provides insights into developments in VLSI and digital systems which can be used to increase data systems performance. The presentations share insights into next generation advances that will serve as a basis for future VLSI design

Feasibility of wireless mesh for LTE-Advanced small cell access backhaul

Mobiilidatan määrä on muutaman viime vuoden aikana kasvanut voimakkaasti ja nykyiset ennustukset arvioivat eksponentiaalista kasvukäyrää tulevien vuosien aikana. Matkapuhelinjärjestelmät ovat kehittyneet nopeasti tämän trendin ohjaamana. Neljännen sukupolven matkapuhelinverkkostandardien myötä, uudet innovaatiot kuten heterogeeniset verkkoratkaisut tarjoavat ratkaisun nykyisiin skaalautuvuus- ja kapasiteettiongelmiin. Joitain ilmeisiä ongelmakohtiakin kuitenkin esiintyy kuten heterogeenisten verkkojen runkokytkennän toteuttaminen. Yksi lupaavimmista tavoista toteuttaa heterogeenisten verkkojen runkokytkentä on langaton ja itseorganisoituva mesh-verkko. Tämän opinnäytetyön tavoitteena on varmistaa ja testata Nokia Siemens Networksin kehittämän mesh-runkokytkentäverkkokonseptin toteutettavuutta ja toiminnallisuutta soveltuvan validointijärjestelmän avulla. Kaiken kaikkiaan validointijärjestelmä ja sen päälle toteutettu mesh-protokolla toimivat moitteettomasti koko kehitys- ja testausprosessin ajan. Konseptin eri ominaisuudet ja mekanismit todistettiin täysin toteutettaviksi ja toimiviksi. Muutamalla lisäominaisuudella ja konseptiparannuksella mesh-konsepti tarjoaa houkuttelevan ja innovatiivisen ratkaisun heterogeenisten verkkojen runkokytkentään tulevaisuudessa.Mobile traffic demands and volumes are increasing and will dramatically keep increasing in the future. Along with this, mobile networks have evolved to better match this growth. Fourth generation cellular network standard introduced a set of new innovations for mobile communications, including support for heterogeneous network deployments. Heterogeneous networking is the likely answer for future mobile data capacity shortage but also poses some challenges, the most evident being how to implement the backhauling. One of the most promising heterogeneous network backhaul solutions is a meshed radio system with self-organizing features. The main scope of this master's thesis is the verification of functionality and feasibility of a wireless mesh backhaul concept developed by Nokia Siemens Networks through a proof-of-concept system. All in all, the wireless mesh proof-of-concept system performed strongly throughout the development and testing process. The different functionalities were proven to work successfully together. With further development and enhancement, the system concept displays extreme potential for a state-of-the-art heterogeneous network backhaul technology

Third International Symposium on Space Mission Operations and Ground Data Systems, part 1

Under the theme of 'Opportunities in Ground Data Systems for High Efficiency Operations of Space Missions,' the SpaceOps '94 symposium included presentations of more than 150 technical papers spanning five topic areas: Mission Management, Operations, Data Management, System Development, and Systems Engineering. The papers focus on improvements in the efficiency, effectiveness, productivity, and quality of data acquisition, ground systems, and mission operations. New technology, techniques, methods, and human systems are discussed. Accomplishments are also reported in the application of information systems to improve data retrieval, reporting, and archiving; the management of human factors; the use of telescience and teleoperations; and the design and implementation of logistics support for mission operations