2,137 research outputs found
A Survey on Fault Tolerance Techniques for Wireless Vehicular Networks
Future intelligent transportation systems (ITS) hold the promise of supporting the operation of safety-critical applications, such as cooperative self-driving cars. For that purpose, the communications among vehicles and with the road-side infrastructure will need to fulfil the strict real-time guarantees and challenging dependability requirements. These safety requisites are particularly important in wireless vehicular networks, where road traffic presents several threats to human life. This paper presents a systematic survey on fault tolerance techniques in the area of vehicular communications. The work provides a literature review of publications in journals and conferences proceedings, available through a set of different search databases (IEEE Xplore, Web of Science, Scopus and ScienceDirect). A systematic method, based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) Statement was conducted in order to identify the relevant papers for this survey. After that, the selected articles were analysed and categorised according to the type of redundancy, corresponding to three main groups (temporal, spatial and information redundancy). Finally, a comparison of the core features among the different solutions is presented, together with a brief discussion regarding the main drawbacks of the existing solutions, as well as the necessary steps to provide an integrated fault-tolerant approach to the future vehicular communications systems
Asynchronously Replicated Shared Workspaces for a Multi-Media Annotation Service over Internet
This paper describes a world wide collaboration system through multimedia Post-its (user generated annotations). DIANE is a service to create multimedia annotations to every application output on the computer, as well as to existing multimedia annotations. Users collaborate by registering multimedia documents and user generated annotation in shared workspaces. However, DIANE only allows effective participation in a shared workspace over a high performance network (ATM, fast Ethernet) since it deals with large multimedia object. When only slow or unreliable connections are available between a DIANE terminal and server, useful work becomes impossible. To overcome these restrictions we need to replicate DIANE servers so that users do not suffer degradation in the quality of service. We use the asynchronous replication service ODIN to replicate the shared workspaces to every interested site in a transparent way to users. ODIN provides a cost-effective object replication by building a dynamic virtual network over Internet. The topology of this virtual network optimizes the use of network resources while it satisfies the changing requirements of the users
A middleware service for fault-tolerant group communications
PhD ThesisMany distributed applications require multicast group communication services,
enabling an entity to interact with a group of other entities. Providing the reliability
and ordering guarantees required by group based applications is not a trivial task in
distributed systems where computation and communication delays might not be
known accurately. Furthermore, the approaches available to support these guarantees
are diverse. The choice of approach may significantly effect the performance of an
application and/or may not be suitable for some application types.
Nowadays, distributed applications are frequently built as a Middleware service.
The Thesis develops techniques for providing group communication support in
Middleware environments. A group communication service has been designed and
implemented in such a way as not to hinder the interoperability/portability of
applications built using it. The service provides a variety of functions that may be
tailored to suit many different types of applications.
Group communication protocols are presented that ensure reliability and ordering
guarantees. Furthermore, the reliability and ordering guarantees of such protocols
may be tailored to suit a wide variety of applications. Mechanisms that provide a
variety of approaches to inter-member and inter-group interactions that are suitable
for satisfying the requirements of many different types of applications (e.g., fault-
tolerant, collaborative) are also supported. The service can work over local and wide
area networks (Internet).Hewlett Packard laboratories
Engineering and Physical Science Research Counci
ARMADA Middleware and Communication Services
Real-time embedded systems have evolved during the past several decades from small custom-designed digital hardware to large distributed processing systems. As these systems become more complex, their interoperability, evolvability and cost-effectiveness requirements motivate the use of commercial-off-the-shelf components. This raises the challenge of constructing dependable and predictable real-time services for application developers on top of the inexpensive hardware and software components which has minimal support for timeliness and dependability guarantees. We are addressing this challenge in the ARMADA project.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48061/1/11241_2004_Article_204024.pd
Developing a distributed electronic health-record store for India
The DIGHT project is addressing the problem of building a scalable and highly available information store for the Electronic Health Records (EHRs) of the over one billion citizens of India
Introducing the new paradigm of Social Dispersed Computing: Applications, Technologies and Challenges
[EN] If last decade viewed computational services as a utility then surely
this decade has transformed computation into a commodity. Computation
is now progressively integrated into the physical networks in
a seamless way that enables cyber-physical systems (CPS) and the
Internet of Things (IoT) meet their latency requirements. Similar to
the concept of Âżplatform as a serviceÂż or Âżsoftware as a serviceÂż, both
cloudlets and fog computing have found their own use cases. Edge
devices (that we call end or user devices for disambiguation) play the
role of personal computers, dedicated to a user and to a set of correlated
applications. In this new scenario, the boundaries between
the network node, the sensor, and the actuator are blurring, driven
primarily by the computation power of IoT nodes like single board
computers and the smartphones. The bigger data generated in this
type of networks needs clever, scalable, and possibly decentralized
computing solutions that can scale independently as required. Any
node can be seen as part of a graph, with the capacity to serve as a
computing or network router node, or both. Complex applications can
possibly be distributed over this graph or network of nodes to improve
the overall performance like the amount of data processed over time.
In this paper, we identify this new computing paradigm that we call
Social Dispersed Computing, analyzing key themes in it that includes
a new outlook on its relation to agent based applications. We architect
this new paradigm by providing supportive application examples that
include next generation electrical energy distribution networks, next
generation mobility services for transportation, and applications for
distributed analysis and identification of non-recurring traffic congestion
in cities. The paper analyzes the existing computing paradigms
(e.g., cloud, fog, edge, mobile edge, social, etc.), solving the ambiguity
of their definitions; and analyzes and discusses the relevant foundational
software technologies, the remaining challenges, and research
opportunities.Garcia Valls, MS.; Dubey, A.; Botti, V. (2018). Introducing the new paradigm of Social Dispersed Computing: Applications, Technologies and Challenges. Journal of Systems Architecture. 91:83-102. https://doi.org/10.1016/j.sysarc.2018.05.007S831029
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