| 1. |
- Tzanakaki, Anna, et al.
(författare)
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Network performance improvement in survivable WDM networks considering physical layer constraints
- 2009
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Ingår i: ICTON. - 9781424448258 ; , s. 1089-1092
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper focuses on survivable optical networks and studies in detail the network performance improvement that can be achieved when jointly considering network resilience and physical layer constraints. The protection scheme used is path-based shared protection known as backup multiplexing. In the proposed solution routing and wavelength assignment for both primary and protection paths are jointly performed considering their physical performance. Simulations comparing the proposed solution with alternative schemes aiming at maximising sharing of protection resources have shown substantial network performance improvement in terms of blocking probability reduction when jointly addressing resilience and physical layer performance requirements.
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| 2. |
- Jirattigalachote, Amornrat, et al.
(författare)
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ICBR-Diff : An Impairment Constraint Based Routing Strategy with Quality of Signal Differentiation
- 2010
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Ingår i: Journal of Networks. - : Academy Publisher. - 1796-2056. ; 5:11, s. 1279-1289
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Tidskriftsartikel (refereegranskat)abstract
- Latest advances in Wavelength Division Multiplexing (WDM) technology make it possible to build all-optical transparent networks, which are considered to be able to satisfy the rapidly growing capacity demand. However, in a transparent WDM network the optical signal transmitted from a source to a destination node might be degraded due to physical layer impairments induced by transmission through optical fibers and components. Several Impairment Constraint Based Routing (ICBR) algorithms have been proposed to consider physical layer impairments during the connection-provisioning phase in order to prevent selecting a lightpath with poor signal quality. However, these algorithms support only a single quality of transmission threshold for all connection requests, while next generation networks and the future Internet are expected to support a variety of services with potentially disparate QoS requirements. In this paper, we propose the use of bit error rate (BER) as a differentiation of service parameter for connection requests in optical WDM networks. This is achieved through the use of ICBR, whereby various BER thresholds are set depending on the QoS requirements for accepting/blocking the connection requests during the connection-provisioning phase. The evaluation results reveal that significant network performance improvement in terms of connection blocking can be achieved, compared to non-differentiated conventional routing and wavelength assignment (RWA) and ICBR algorithms.
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| 3. |
- Jirattigalachote, Amornrat, et al.
(författare)
-
Impairment aware routing with service differentiation in heterogeneous WDM networks
- 2009
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Ingår i: Network Architectures, Management, and Applications VII. - : SPIE - International Society for Optical Engineering. - 9780819480354 ; , s. 763307-
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Konferensbidrag (refereegranskat)abstract
- In transparent Wavelength Division Multiplexing (WDM) networks, the signal is transported from source to destination in the optical domain through all-optical channels, or lightpaths. A lightpath may traverse several fiber segments and optical components that in general degrade the optical signal. This effect introduces the need for considering physical layer impairments during the connection-provisioning phase. Physical layer impairments can be divided into linear and non-linear. Both types of impairments are highly dependent on the fiber characteristics, which in turn are sensitive to length, temperature and age. A close look at the fiber infrastructure of today's network operators reveals a situation where old and newly deployed fibers coexist in the network. This heterogeneous fiber plant presents a challenge. A tradeoff should be found between the QoS requirements of connection requests and the use of the available (old and new) network resources. This calls for a provisioning mechanism able to adapt to the various fiber composition scenarios. In parallel, given the need for service differentiation, the authors recently proposed an Impairment Constraint Based Routing (ICBR) algorithm, referred to as ICBR-Diff, supporting differentiation of services at the BER (Bit Error Rate) level in a network with a homogeneous fiber infrastructure. In this paper the ICBR-Diff algorithm is extended to heterogeneous network; particularly, it is evaluated in WDM networks with fiber links having varying Polarization Mode Dispersion characteristics, i.e., with old and new fiber coexisting. Simulation results show that the ICBR-Diff algorithm exhibits high adaptability in a heterogeneous fiber composition scenario. This translates into improved performance in terms of blocking probability, when compared to traditional impairment aware routing algorithms.
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| 4. |
- Jirattigalachote, Amornrat, et al.
(författare)
-
Impairment aware routing with service differentiation in heterogeneous WDM networks
- 2009
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Ingår i: 2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009. - Washington, D.C. : OSA. - 9781557528773 ; , s. 1-2
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Konferensbidrag (refereegranskat)abstract
- We evaluate an Impairment Constraint Based Routing algorithm with service differentiation (ICBR-Diff) applied in WDM networks with fiber links having varying Polarization Mode Dispersion characteristics. Simulation results show high adaptability of the ICBR-Diff approach to this heterogeneous fiber scenario when compared to conventional routing schemes.
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| 5. |
- Jirattigalachote, Amornrat, et al.
(författare)
-
Impairment Constraint Based Routing (ICBR) with service differentiation in survivable WDM networks
- 2009
-
Ingår i: European Conference on Optical Communication, ECOC. - 9781424450961 ; , s. 1-2
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Konferensbidrag (refereegranskat)abstract
- We propose and evaluate a novel survivable impairment constraint based routing (ICBR) algorithm with service differentiation at the bit error rate level. Simulations show significant improvement in connection blocking compared to conventional ICBR solutions.
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| 6. |
- Jirattigalachote, Amornrat, et al.
(författare)
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Quantifying the Benefit of BER-based Differentiated Path Provisioning in WDM Optical Networks
- 2009
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Ingår i: ICTON: 2009 11TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, VOLS 1 AND 2. - NEW YORK : IEEE. - 9781424448258 ; , s. 1097-1100
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Konferensbidrag (refereegranskat)abstract
- In this paper we propose the use of Bit Error Rate (BER) as a differentiation of service parameter for connection provisioning in optical Wavelength Division Multiplexing (WDM) networks. This is achieved through the use of Impairment Constraint Based Routing (ICBR), whereby various BER thresholds are set for accepting/blocking requests at the connection provisioning phase, depending on QoS requirements. The performance of the proposed scheme is evaluated through simulations, using dynamic traffic demands as an input at 10 Gb/s bit rate. The evaluation results reveal significant improvement in term of connection blocking, as compared to non-differentiated conventional RWA and ICBR algorithms.
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| 7. |
- Thoman, Peter, et al.
(författare)
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A taxonomy of task-based parallel programming technologies for high-performance computing
- 2018
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Ingår i: Journal of Supercomputing. - : SPRINGER. - 0920-8542 .- 1573-0484. ; 74:4, s. 1422-1434
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Tidskriftsartikel (refereegranskat)abstract
- Task-based programming models for shared memory-such as Cilk Plus and OpenMP 3-are well established and documented. However, with the increase in parallel, many-core, and heterogeneous systems, a number of research-driven projects have developed more diversified task-based support, employing various programming and runtime features. Unfortunately, despite the fact that dozens of different task-based systems exist today and are actively used for parallel and high-performance computing (HPC), no comprehensive overview or classification of task-based technologies for HPC exists. In this paper, we provide an initial task-focused taxonomy for HPC technologies, which covers both programming interfaces and runtime mechanisms. We demonstrate the usefulness of our taxonomy by classifying state-of-the-art task-based environments in use today.
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| 8. |
- Thoman, Peter, et al.
(författare)
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A Taxonomy of Task-Based Technologies for High-Performance Computing
- 2018
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Ingår i: PARALLEL PROCESSING AND APPLIED MATHEMATICS (PPAM 2017), PT II. - Cham : SPRINGER INTERNATIONAL PUBLISHING AG. - 9783319780542 ; , s. 264-274
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Konferensbidrag (refereegranskat)abstract
- Task-based programming models for shared memory - such as Cilk Plus and OpenMP 3 - are well established and documented. However, with the increase in heterogeneous, many-core and parallel systems, a number of research-driven projects have developed more diversified task-based support, employing various programming and runtime features. Unfortunately, despite the fact that dozens of different task-based systems exist today and are actively used for parallel and high-performance computing, no comprehensive overview or classification of task-based technologies for HPC exists. In this paper, we provide an initial task-focused taxonomy for HPC technologies, which covers both programming interfaces and runtime mechanisms. We demonstrate the usefulness of our taxonomy by classifying state-of-the-art task-based environments in use today.
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| 9. |
- Tzanakaki, Anna, et al.
(författare)
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Dimensioning the Future Pan-European Optical Network With Energy Efficiency Considerations
- 2011
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Ingår i: Journal of Optical Communications and Networking. - 1943-0620 .- 1943-0639. ; 3:4, s. 272-280
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Tidskriftsartikel (refereegranskat)abstract
- This paper studies the overall energy consumption of a pan-European optical transport network for three different time periods: today and in five and ten years from now. In each time period the pan-European network was dimensioned using traffic predictions based on realistic data generated by the optical networking roadmap developed in the framework of the European project Building the Future Optical Network in Europe-BONE. A wavelength routed wavelength division multiplexed optical network based on either transparent or opaque node architectures was examined considering exclusively either 10 Gbit/s or 40 Gbit/s per channel data rates. The results manifest that transparent optical networking technologies are expected to provide significant energy savings of the order of 35% to 55%. It was also shown that the migration towards higher data rates, i.e., from 10 Gbit/s to 40 Gbit/s, is assisting in improving the overall energy efficiency of the network.
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| 10. |
- Tzanakaki, Anna, et al.
(författare)
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Power considerations towards a sustainable Pan-European network
- 2011
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Ingår i: 2011 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION (OFC/NFOEC) AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE. - Washington, D.C. : OSA. ; , s. 1-3
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Konferensbidrag (refereegranskat)abstract
- Energy savings are observed and quantified in the Pan-European network using transparent optical network technology. The network was dimensioned, using realistic traffic predictions of the optical networking roadmap of the European project BONE.
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