Availability

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In telecommunications and reliability theory, the term availability has the following meanings: The degree to which a system, subsystem, or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown, i.e. , a random, time. Simply put, availability is the proportion of time a system is in a functioning condition. (Wikipedia.org)






Conferences related to Availability

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2019 15th International Conference on the Design of Reliable Communication Networks (DRCN)

It is a forum for scientists from both industry and academy who have interest in reliability and availability of telecommunication networks, or other resilience-related topics. The aim of the conference is to bring together people from various disciplines, ranging from engineering of survivable equipment and network technologies to network management and monitoring, through methods and models for survivable and robust network design. It is a meeting for presenting excellent results and new challenges in the field of reliability and availability of communication networks and services.


2019 19th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGRID)

Cluster Computing, Grid Computing, Edge Computing, Cloud Computing, Parallel Computing, Distributed Computing


2019 21st International Conference on Advanced Communication Technology (ICACT)

With technically co-sponsored by IEEE ComSoc(Communications Society), IEEE ComSocCISTC(Communications & Information Security Technical Community), and IEEE ComSocONTC(Optical Networking Technical Community), the ICACT(International Conference onAdvanced Communications Technology) Conference has been providing an open forum forscholars, researchers, and engineers to the extensive exchange of information on newlyemerging technologies, standards, services, and applications in the area of the advancedcommunications technology. The conference official language is English. All the presentedpapers have been published in the Conference Proceedings, and posted on the ICACT Websiteand IEEE Xplore Digital Library since 2004. The honorable ICACT Out-Standing Paper Awardlist has been posted on the IEEE Xplore Digital Library also, and all the Out-Standing papersare subjected to the invited paper of the "ICACT Transactions on the Advanced Communications Technology" Journal issue by GIRI

  • 2018 20th International Conference on Advanced Communication Technology (ICACT)

    With technically co-sponsored by IEEE ComSoc(Communications Society), IEEE ComSoc CISTC(Communications & Information Security Technical Community), and IEEE ComSoc ONTC(Optical Networking Technical Community), the ICACT(International Conference on Advanced Communications Technology) Conference has been providing an open forum for scholars, researchers, and engineers to the extensive exchange of information on newly emerging technologies, standards, services, and applications in the area of the advanced communications technology. The conference official language is English. All the presented papers have been published in the Conference Proceedings, and posted on the ICACT Website and IEEE Xplore Digital Library since 2004. The honorable ICACT Out-Standing Paper Award list has been posted on the IEEE Xplore Digital Library also, and all the Out-Standing papers are subjected to the invited paper of the "ICACT Transactions on the Advanced Communications Technology" Journal issued by GIRI

  • 2017 19th International Conference on Advanced Communication Technology (ICACT)

    With technically co-sponsored by IEEE ComSoc(Communications Society), IEEE ComSoc CISTC(Communications & Information Security Technical Community), and IEEE ComSoc ONTC(Optical Networking Technical Community), the ICACT(International Conference on Advanced Communications Technology) Conference has been providing an open forum for scholars, researchers, and engineers to the extensive exchange of information on newly emerging technologies, standards, services, and applications in the area of the advanced communications technology. The conference official language is English. All the presented papers have been published in the Conference Proceedings, and posted on the ICACT Website and IEEE Xplore Digital Library since 2004. The honorable ICACT Out-Standing Paper Award list has been posted on the IEEE Xplore Digital Library also, and all the Out-Standing papers are subjected to the invited paper of the "ICACT Transactions on the Advanced Communications Technology" Journal issued by

  • 2016 18th International Conference on Advanced Communication Technology (ICACT)

    With technically co-sponsored by IEEE ComSoc(Communications Society), IEEE ComSoc CISTC(Communications & Information Security Technical Community), and IEEE ComSoc ONTC(Optical Networking Technical Community), the ICACT(International Conference on Advanced Communications Technology) Conference has been providing an open forum for scholars, researchers, and engineers to the extensive exchange of information on newly emerging technologies, standards, services, and applications in the area of the advanced communications technology. The conference official language is English. All the presented papers have been published in the Conference Proceedings, and posted on the ICACT Website and IEEE Xplore Digital Library since 2004. The honorable ICACT Out-Standing Paper Award list has been posted on the IEEE Xplore Digital Library also, and all the Out-Standing papers are subjected to the invited paper of the "ICACT Transactions on the Advanced Communications Technology" Journal issued by GiRI.

  • 2015 17th International Conference on Advanced Communication Technology (ICACT)

    With technically co-sponsored by IEEE ComSoc(Communications Society), IEEE ComSoc CISTC(Communications & Information Security Technical Community), and IEEE ComSoc ONTC(Optical Networking Technical Community), the ICACT(International Conference on Advanced Communications Technology) Conference has been providing an open forum for scholars, researchers, and engineers to the extensive exchange of information on newly emerging technologies, standards, services, and applications in the area of the advanced communications technology. The conference official language is English. All the presented papers have been published in the Conference Proceedings, and posted on the ICACT Website and IEEE Xplore Digital Library since 2004. The honorable ICACT Out-Standing Paper Award list has been posted on the IEEE Xplore Digital Library also, and all the Out-Standing papers are subjected to the invited paper of the "ICACT Transactions on the Advanced Communications Technology" Journal issued by GiRI.

  • 2014 16th International Conference on Advanced Communication Technology (ICACT)

    Technology, service, architecture, strategy, and policy in newly emerging system, standard, service, and variety of application on the area of telecommunications. ICACT 2014 provides an open forum for scholar, researcher, engineer, policy maker, network planner, and service provider in the advanced communication technologies.

  • 2013 15th International Conference on Advanced Communication Technology (ICACT)

    Technology, standard, service, architecture, strategy, and policy in newly emerging systems and a variety of applications in the area of communications. ICACT2013 provides an open forum for scholar, researcher, engineer, policy maker, network planner, and service provider in the advanced communications technologies.

  • 2012 14th International Conference on Advanced Communication Technology (ICACT)

    Technology, service, architecture, strategy, and policy in newly emerging systems, standards, service, and a variety of applications in the area of telecommunicatons. ICACT 2012 provides an open forum for scholars, researchers, engineers, policy makers, network planners, and service providers in the advanced communication technologies.

  • 2011 13th International Conference on Advanced Communication Technology (ICACT)

    International Conference on Advanced Communication Technology (ICACT) provides an open forum for researchers, engineers, policy, network planners, and service providers in the advanced communication technologies. Extensive exchange of information will be provided on newly emerging systems, standards, services, and variety of applications on the area of telecommunications.

  • 2010 12th International Conference on Advanced Communication Technology (ICACT)

    ICACT is an annual conference providing an open forum for researchers, engineers, network planners, and service providers in telecommunications. Extensive exchange of information will be provided on newly emerging systems, standards, services, and variety of applications in the area of telecommunications.

  • 2009 11th International Conference on Advanced Communication Technology (ICACT)

    ICACT is an annual conference providing an open forum for researchers, engineers, network planners, and service providers in telecommunications. Extensive exchange of information will be provided on newly emerging systems, standards, services, and variety of applications in the area of telecommunications.

  • 2008 10th International Conference Advanced Communication Technology (ICACT)

  • 2007 9th International Conference Advanced Communication Technology (ICACT)

  • 2006 8th International Conference Advanced Communication Technology (ICACT)

  • 2005 7th International Conference Advanced Communication Technology (ICACT)

  • 2004 6th International Conference Advanced Communication Technology (ICACT)


2019 34th IEEE/ACM International Conference on Automated Software Engineering (ASE)

The IEEE/ACM Automated Software Engineering (ASE) Conference series is the premier research forum for automated software engineering. Each year, it brings together researchers and practitioners from academia and industry to discuss foundations, techniques and tools for automating the analysis, design, implementation, testing, and maintenance of large software systems.


2019 42nd International Convention on Information and Communication Technology, Electronics and Microelectronics (MIPRO)

Computer in Technical Systems, Intelligent Systems, Distributed Computing and VisualizationSystems, Communication Systems, Information Systems Security, Digital Economy, Computersin Education, Microelectronics, Electronic Technology, Education


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Periodicals related to Availability

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Automation Science and Engineering, IEEE Transactions on

The IEEE Transactions on Automation Sciences and Engineering (T-ASE) publishes fundamental papers on Automation, emphasizing scientific results that advance efficiency, quality, productivity, and reliability. T-ASE encourages interdisciplinary approaches from computer science, control systems, electrical engineering, mathematics, mechanical engineering, operations research, and other fields. We welcome results relevant to industries such as agriculture, biotechnology, healthcare, home automation, maintenance, manufacturing, pharmaceuticals, retail, ...


Communications Magazine, IEEE

IEEE Communications Magazine was the number three most-cited journal in telecommunications and the number eighteen cited journal in electrical and electronics engineering in 2004, according to the annual Journal Citation Report (2004 edition) published by the Institute for Scientific Information. Read more at http://www.ieee.org/products/citations.html. This magazine covers all areas of communications such as lightwave telecommunications, high-speed data communications, personal communications ...


Communications, IEEE Transactions on

Telephone, telegraphy, facsimile, and point-to-point television, by electromagnetic propagation, including radio; wire; aerial, underground, coaxial, and submarine cables; waveguides, communication satellites, and lasers; in marine, aeronautical, space and fixed station services; repeaters, radio relaying, signal storage, and regeneration; telecommunication error detection and correction; multiplexing and carrier techniques; communication switching systems; data communications; and communication theory. In addition to the above, ...


Computational Biology and Bioinformatics, IEEE/ACM Transactions on

Specific topics of interest include, but are not limited to, sequence analysis, comparison and alignment methods; motif, gene and signal recognition; molecular evolution; phylogenetics and phylogenomics; determination or prediction of the structure of RNA and Protein in two and three dimensions; DNA twisting and folding; gene expression and gene regulatory networks; deduction of metabolic pathways; micro-array design and analysis; proteomics; ...


Computer

Computer, the flagship publication of the IEEE Computer Society, publishes peer-reviewed technical content that covers all aspects of computer science, computer engineering, technology, and applications. Computer is a resource that practitioners, researchers, and managers can rely on to provide timely information about current research developments, trends, best practices, and changes in the profession.


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Most published Xplore authors for Availability

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Xplore Articles related to Availability

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Availability requirement for a fault-management server in high-availability communication systems

IEEE Transactions on Reliability, 2003

This paper investigates the availability requirement for the fault management server in high-availability communication systems. This study shows that the availability of the fault management server does not need to be 99.999% in order to guarantee a 99.999% system availability, as long as the fail-safe ratio (the probability that the failure of the fault management server does not bring down ...


Instantaneous availability and interval availability for systems with time-varying failure rate: stair-step approximation

Proceedings 2001 Pacific Rim International Symposium on Dependable Computing, 2001

Because of the fast pace of information technology, an electronic product may be in the field for just a couple of years. Therefore, instantaneous availability and interval availability during its operational lifetime are more important metrics than the steady-state availability. The paper presents a stair-step approximation to the instantaneous availability and interval availability for systems with time-varying failure rates. The ...


Calculating the system steady-state availability as a function of subsystem steady-state availability

IEEE SOUTHEASTCON 2014, 2014

The number of large complex applications requiring highly availability is increasing. A divide an conquer approach is used to construct these types of systems where subsystems are designed and built independently of one another. This practice is very common for large government projects such as the space shuttle, air traffic control system, and most complex military systems. Oftentimes, the manufacturer ...


A New Approach to Analysis of Interval Availability

2008 Third International Conference on Availability, Reliability and Security, 2008

This paper gives a novel and useful representation of interval availability over a time period [0, T] for a 2-state continuous time Markov chain (2-CTMC) model. The representation is in terms of an order statistic of a binomially distributed random rank in a random sample of Poisson size from a distribution uniform on the interval [0,1]. This representation is then ...


High availability support for the design of stateful networking equipments

First International Conference on Availability, Reliability and Security (ARES'06), 2006

The availability of some critical equipment like gateways, firewalls and proxies must be guaranteed in operational networks. In early equipments, the routing and filtering decisions were based on the packet information, nowadays this static approach is not longer safe. Existing high availability (HA) solutions do not cover all the aspects to ensure availability of advanced settings that are being deployed ...


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Educational Resources on Availability

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IEEE-USA E-Books

  • Availability requirement for a fault-management server in high-availability communication systems

    This paper investigates the availability requirement for the fault management server in high-availability communication systems. This study shows that the availability of the fault management server does not need to be 99.999% in order to guarantee a 99.999% system availability, as long as the fail-safe ratio (the probability that the failure of the fault management server does not bring down the system) and the fault coverage ratio (probability that the failure in the system can be detected and recovered by the fault management server) are sufficiently high. Tradeoffs can be made among the availability of the fault management server, the fail-safe ratio, and the fault coverage ratio to optimize system availability. A cost-effective design for the fault management server is proposed.

  • Instantaneous availability and interval availability for systems with time-varying failure rate: stair-step approximation

    Because of the fast pace of information technology, an electronic product may be in the field for just a couple of years. Therefore, instantaneous availability and interval availability during its operational lifetime are more important metrics than the steady-state availability. The paper presents a stair-step approximation to the instantaneous availability and interval availability for systems with time-varying failure rates. The precision of the stair-step approximation is discussed. Numerical results for the systems with Weibull failure rate reveal that the steady-state availability may give an optimistic (pessimistic) evaluation to the systems with decreasing (increasing) failure rate.

  • Calculating the system steady-state availability as a function of subsystem steady-state availability

    The number of large complex applications requiring highly availability is increasing. A divide an conquer approach is used to construct these types of systems where subsystems are designed and built independently of one another. This practice is very common for large government projects such as the space shuttle, air traffic control system, and most complex military systems. Oftentimes, the manufacturer of the subsystem must show a certain level of steady-state availability has been achieved during the design/build phase of the subsystem. The overall builder of the complex system must integrate the subsystems together to produce the required functionality and also demonstrate that the system steady-state availability meets or exceeds a certain threshold. This estimation of system availability (A<sub>sssys</sub>)is greatly simplified if the known subsystem availability values (A<sub>sssubi</sub>) could be used to calculate system availability. Oftentimes, the subsystem manufacturer does not provide the subsystem failure rate and/or repair rate. Thus, the only the subsystem availability is on hand to assist in the calculation of system level availability. This paper presents a novel technique for calculating A<sub>sssys</sub> as a function of n subsystem availabilities {A<sub>sssub1</sub>, A<sub>sssub2</sub>,...,A<sub>sssubn</sub>}.

  • A New Approach to Analysis of Interval Availability

    This paper gives a novel and useful representation of interval availability over a time period [0, T] for a 2-state continuous time Markov chain (2-CTMC) model. The representation is in terms of an order statistic of a binomially distributed random rank in a random sample of Poisson size from a distribution uniform on the interval [0,1]. This representation is then used to obtain the variance of interval availability for the 2-CTMC model. It is proposed to judge the fluctuations in interval availability by considering the derived coefficient of variation. Both the order statistic representation and the variance of interval availability constitute new contributions to the availability literature.

  • High availability support for the design of stateful networking equipments

    The availability of some critical equipment like gateways, firewalls and proxies must be guaranteed in operational networks. In early equipments, the routing and filtering decisions were based on the packet information, nowadays this static approach is not longer safe. Existing high availability (HA) solutions do not cover all the aspects to ensure availability of advanced settings that are being deployed these days. Some important issues like the reduction of the downtime and the need for failure detection in such scenarios must be studied. This paper describes the implementation of high available stateful network equipments: these systems apply policies based on the state of the connections, such information is gathered in runtime by means of packet inspection. This work specifically focuses on Linux systems and firewalls because the IT industry trusts more and more OpenSource solutions to deploy critical services because of its quality and the access to the source code. We propose the SNE library (stateful network equipment), which is an add-on to current HA protocols, to solve the existing limitations. In this paper, we describe the proposed architecture and we detail a set problematic scenarios supported by our library, as well as first experiments and the evaluation.

  • Maximizing the Availability of Replicated Services in Widely Distributed Systems Considering Network Availability

    Availability is an important issue in distributed environments that promise to provide quality of services and thus the mechanisms to improve data or service availability is critical to ensure such quality of service. Replication schemes have been widely used to improve data or service availability. In addition to the number of replicas, the location of the replicas also impacts the data availability. In this paper, we consider the impact of node and network link failures on the availability of replicated data and services. Efficient replica allocation algorithms with runtime of O(K|V|<sup>2</sup>) are developed to improve data availability, where K is the predetermined number of replica and |V| is the number of nodes in the system. Experimental studies have been conducted to evaluate how effective the proposed replica allocation algorithms on improving the availability of replicated data or services. The results show that the two proposed solutions are effective on enhancing system availability, especially when the number of replicas is small.

  • Estimation and analysis of time-varying availability under the drive of mission scenarios

    The dynamic characteristics and the estimation method of operational availability under general mission scenarios are researched. Though the simulation method can be used to study the time-varying operational availability, it has shortage in finding and analyzing the inherent law of operational availability. According to definition, the operational availability can be derived by the supply availability and achievable availability, and so the transformation character of operational availability can be derived on the research of supply availability and maintenance availability. In order to solve this problem, the authors study the characteristics of supply availability and maintenance availability on the requirements of mission scenarios. The dynamic characteristics of operational availability are derived and the estimation method of time-varying availability is given. Further, the time of operational availability reaching stationary value is obtained. Once the problem is solved, a profit comparison is also made between the analytical method described in this paper and the simulation method to observe whether the analytical approach incorporates mission scenarios in the time-availability. Experiments show that the model works well, and so the feasibility and rationality of the analytical method are validated. This result establishes good base for further research in relative problems.

  • Availability improvement of ship's optical communication network

    The paper presents the heuristic approach to availability analysis of optical communication networks connecting ship's systems. The availabilities of individual components have been calculated, as the basis for the entire system availability evaluation. Several network availability structures and protection scenarios are presented and the availability evaluated. Based on the analysis, the possibility for improving ship's communication system availability has been proposed, contributing to the overall availability improvement of ship's systems.

  • Analysis and optimization of service availability in a HA cluster with load-dependent machine availability

    Calculations of service availability of a high-availability (HA) cluster are usually based on the assumption of load- independent machine availabilities. In this paper, we study the issues and show how the service availabilities can be calculated under the assumption that machine availabilities are load dependent. We present a Markov chain analysis to derive the steady-state service availabilities of a load-dependent machine availability HA cluster. We show that with a load-dependent machine availability, the attained service availability is now policy dependent. After formulating the problem as a Markov decision process, we proceed to determine the optimal policy to achieve the maximum service availabilities by using the method of policy iteration. Two greedy assignment algorithms are studied: least load and first derivative length (FDL) based, where least load corresponds to some load balancing algorithms. We carry out the analysis and simulations on two cases of load profiles: In the first profile, a single machine has the capacity to host all services in the HA cluster; in the second profile, a single machine does not have enough capacity to host all services. We show that the service availabilities achieved under the first load profile are the same, whereas the service availabilities achieved under the second load profile are different. Since the service availabilities achieved are different in the second load profile, we proceed to investigate how the distribution of service availabilities across the services can be controlled by adjusting the rewards vector.

  • On Availability Comparison of Reservation Modes for Multi-state Air Conditioning Systems Using Markov Approach

    In this paper we compare different reservation modes of Air conditioning systems for apartments, offices or cooling rooms that have a specific regime of temperature/humidity conditions. In the first reservation mode the required temperature and humidity conditions are provided by two cooling chillers (conditioners) with reserved chiller staying in cold reserve. In the second mode the reserved chiller orders from rented firm. Markov Models are built for comparison analysis of possible operation modes. The model takes into consideration the important factors such as cooling generators output, failure and repair rate, availability, time of supply of rented chiller. A numerical example is presented to illustrate the described approach.



Standards related to Availability

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IEEE Application Guide for Distributed Digital Control and Monitoring for Power Plants


IEEE Loss Evaluation Guide for Power Transformers and Reactors


IEEE Recommended Practice for Communications-Based Train Control (CBTC) System Design and Functional Allocations

This recommended practice establishes a preferred system design and functional allocation for CBTC systems.


IEEE Standard Definitions for Use in Reporting Electric Generating Unit Reliability, Availability, and Productivity

This document standardizes terminology and indexes for reporting electric generating unit reliability, availability, and productivity performance measures while recognizing the power industry’s needs, including marketplace competition. This standard also includes equations for equivalent demand forced outage rate (EFORd), newly identified outage states, discussion of commercial availability, energy weighted equations for group performance indexes, definitions of outside management control (OMC), pooling ...


IEEE Standard Dictionary of Measures of the Software Aspects of Dependability

This standard specifies and classifies measures of the software aspects of dependability. It is an expansion of the scope of the existing standard; the revision includes the following aspects of dependability: reliability, availability, and maintainability of software. The applicability of this standard is any software system; in particular, it applies to mission critical systems, where high reliability, availability, and maintainability ...


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