145,591 research outputs found
Embedded dynamic programming networks for networks-on-chip
PhD ThesisRelentless technology downscaling and recent technological advancements
in three dimensional integrated circuit (3D-IC) provide a promising
prospect to realize heterogeneous system-on-chip (SoC) and homogeneous
chip multiprocessor (CMP) based on the networks-onchip
(NoCs) paradigm with augmented scalability, modularity and
performance. In many cases in such systems, scheduling and managing
communication resources are the major design and implementation
challenges instead of the computing resources. Past research
efforts were mainly focused on complex design-time or simple heuristic
run-time approaches to deal with the on-chip network resource
management with only local or partial information about the network.
This could yield poor communication resource utilizations and amortize
the benefits of the emerging technologies and design methods.
Thus, the provision for efficient run-time resource management in
large-scale on-chip systems becomes critical. This thesis proposes a
design methodology for a novel run-time resource management infrastructure
that can be realized efficiently using a distributed architecture,
which closely couples with the distributed NoC infrastructure. The
proposed infrastructure exploits the global information and status
of the network to optimize and manage the on-chip communication
resources at run-time.
There are four major contributions in this thesis. First, it presents a
novel deadlock detection method that utilizes run-time transitive closure
(TC) computation to discover the existence of deadlock-equivalence
sets, which imply loops of requests in NoCs. This detection scheme,
TC-network, guarantees the discovery of all true-deadlocks without
false alarms in contrast to state-of-the-art approximation and heuristic
approaches. Second, it investigates the advantages of implementing
future on-chip systems using three dimensional (3D) integration and
presents the design, fabrication and testing results of a TC-network
implemented in a fully stacked three-layer 3D architecture using a
through-silicon via (TSV) complementary metal-oxide semiconductor
(CMOS) technology. Testing results demonstrate the effectiveness
of such a TC-network for deadlock detection with minimal computational
delay in a large-scale network. Third, it introduces an adaptive
strategy to effectively diffuse heat throughout the three dimensional
network-on-chip (3D-NoC) geometry. This strategy employs a dynamic
programming technique to select and optimize the direction of data
manoeuvre in NoC. It leads to a tool, which is based on the accurate
HotSpot thermal model and SystemC cycle accurate model, to simulate
the thermal system and evaluate the proposed approach. Fourth, it
presents a new dynamic programming-based run-time thermal management
(DPRTM) system, including reactive and proactive schemes, to
effectively diffuse heat throughout NoC-based CMPs by routing packets
through the coolest paths, when the temperature does not exceed
chip’s thermal limit. When the thermal limit is exceeded, throttling is
employed to mitigate heat in the chip and DPRTM changes its course
to avoid throttled paths and to minimize the impact of throttling on
chip performance.
This thesis enables a new avenue to explore a novel run-time resource
management infrastructure for NoCs, in which new methodologies
and concepts are proposed to enhance the on-chip networks for
future large-scale 3D integration.Iraqi Ministry of Higher Education and Scientific Research (MOHESR)
Small-world networks, distributed hash tables and the e-resource discovery problem
Resource discovery is one of the most important underpinning problems behind producing a scalable,
robust and efficient global infrastructure for e-Science. A number of approaches to the resource discovery
and management problem have been made in various computational grid environments and prototypes
over the last decade. Computational resources and services in modern grid and cloud environments can be
modelled as an overlay network superposed on the physical network structure of the Internet and World
Wide Web. We discuss some of the main approaches to resource discovery in the context of the general
properties of such an overlay network. We present some performance data and predicted properties based
on algorithmic approaches such as distributed hash table resource discovery and management. We describe
a prototype system and use its model to explore some of the known key graph aspects of the global
resource overlay network - including small-world and scale-free properties
GRIDKIT: Pluggable overlay networks for Grid computing
A `second generation' approach to the provision of Grid middleware is now emerging which is built on service-oriented architecture and web services standards and technologies. However, advanced Grid applications have significant demands that are not addressed by present-day web services platforms. As one prime example, current platforms do not support the rich diversity of communication `interaction types' that are demanded by advanced applications (e.g. publish-subscribe, media streaming, peer-to-peer interaction). In the paper we describe the Gridkit middleware which augments the basic service-oriented architecture to address this particular deficiency. We particularly focus on the communications infrastructure support required to support multiple interaction types in a unified, principled and extensible manner-which we present in terms of the novel concept of pluggable overlay networks
Recommended from our members
Distributed simulation and the grid: Position statements
The Grid provides a new and unrivaled technology for large scale distributed simulation as it enables collaboration and the use of distributed computing resources. This panel paper presents the views of four researchers in the area of Distributed Simulation and the Grid. Together we try to identify the main research issues involved in applying Grid technology to distributed simulation and the key future challenges that need to be solved to achieve this goal. Such challenges include not only technical challenges, but also political ones such as management methodology for the Grid and the development of standards. The benefits of the Grid to end-user simulation modelers also are discussed
Heterogeneous Wireless Networks: An Analysis of Network and Service Level Diversity
Future wireless systems will be a collection of symbiotic and hierarchical networks that address different aspects of communication needs. This architectural heterogeneity constitutes a network level diversity, where wireless domains can benefit from each other's spare resources in terms of bandwidth and energy. The dissertation investigates the network diversity through particularly interesting scenarios that involve capacity-limited
multi-hop ad hoc networks and high-bandwidth wired or wireless infrastructures.
Heterogeneity and infrastructures not only exist at the level of networking technologies and architectures, but also at the level of available services in each network domain. Efficient discovery
of services across the domains and allocation of service points to individual users are beneficial for facilitating the actual communication, supplying survivable services, and better utilizing the network resources. These concepts together define the service
level diversity, which is the second topic studied in our dissertation.
In this dissertation, we first focus on a large-scale hybrid network, where a relatively resource abundant infrastructure network overlays a multi-hop wireless network. Using a random geometric random graph model and defining appropriate connectivity constraints, we derive the overall transport capacity of this hybrid network.
In the sequel, we dwell upon hybrid networks with arbitrary size and topology. We develop a Quality of Service (QoS) based framework to utilize the joint resources of the ad hoc and infrastructure tier with minimal power exposure on other symbiotic networks that operate over the same radio frequency bands. The
framework requires a cross-layer approach to adequately satisfy the system objectives and individual user demands. Since the problem is proven to be intractable, we explore sub-optimal but efficient algorithms to solve it by relying on derived performance bounds.
In the last part of the dissertation, we shift our attention from network level diversity to service level diversity. After investigating possible resource discovery mechanisms in conjunction with their applicability to multi-hop wireless environments, we present our own solution, namely Distributed Service Discovery Protocol (DSDP). DSDP enables a highly scalable, survivable, and fast resource discovery under a very dynamic network topology. It also provides the necessary architectural and signaling mechanisms to effectively implement resource allocation techniques
Distributed resource discovery using a context sensitive infrastructure
Distributed Resource Discovery in a World Wide Web environment using full-text indices will never scale. The distinct properties of WWW information (volume, rate of change, topical diversity) limits the scaleability of traditional approaches to distributed Resource Discovery. An approach combining metadata clustering and query routing can, on the other hand, be proven to scale much better. This paper presents the Content-Sensitive Infrastructure, which is a design building on these results. We also present an analytical framework for comparing scaleability of different distribution strategies
- …