Papers by Piotr Rygielski
Automated Extraction of Network Traffic Models Suitable for Performance Simulation
Proceedings of the 7th ACM/SPEC on International Conference on Performance Engineering - ICPE '16, 2016
Http Dx Doi Org 10 1080 01969722 2010 520225, Sep 8, 2010
The gain of the paper is to introduce and to discuss a formal specification of computer system's ... more The gain of the paper is to introduce and to discuss a formal specification of computer system's Service Level Agreement (SLA) and its translation into structure of complex services (composed of atomic services) delivering required functionalities and non-functionalities in distributed environment. The SLA is composed of two parts specifying quantitative and qualitative requirements. The former requirements define structure of the adequate complex services as a directed graph, where potential parallelism of atomic services performance may be taken into account. The qualitative requirements are applied to select the optimal complex service realization scenario; it is based on assumption that various atomic services distinguished in the complex services structure are available in the environment in different versions and locations. Different versions of atomic services are delivering the required functionalities and satisfy non-functionalities at various levels. Various locations of atomic services means that the time and cost of atomic services delivery (communication and calculation) may vary. Proposed model of SLA translation into complex services causes that a scenario variants may be appliedamong others -to calculate upper and lower complex services' delivering times and to estimate validity of possible parallelism in complex services.
Http Dx Doi Org 10 1080 01969722 2012 678219, May 1, 2012
The paper is devoted to the problem of mobility and resource management in heterogeneous wireless... more The paper is devoted to the problem of mobility and resource management in heterogeneous wireless networks. It is assumed that in certain area covered by multiple overlapping wireless networks there is certain number of mobile clients which consume networks resources by use of the available communication services (e.g.: voice or data transmission) delivered by network providers. Moreover, it is assumed, that communication services continuity may be assured by the use of common handover techniques supporting clients mobility (e.g.: MIPv6, IEEE 802.21, etc.). The task of mobility and resources management consists of making decisions concerning the moment and the network to which particular clients should be handed over in order to optimize certain quality criterion (e.g. utilization of network resources). In this paper we show that gathering knowledge about clients movement and prediction of their future position may significantly improve the overall quality of delivered services and network resources utilization. Independent Handover [9], provides a set of mechanisms which allows to trigger higher layer media independent handover procedures based on unified set of commands and media specific events. Network layer handover is managed by mobility extensions of the IP protocol, i.e. MIPv4 [5] and MIPv6 . In order to provide service continuity and guarantee required quality of service during handovers additional modifications to mobility management protocols has been made, e.g. FMIPv6 and HMIPv6 [2]. However, a breakthrough in mobility management has been made by introduction of Media-Independent Pre-Authentication (MPA) mechanism [4], which allows for seamless and secure handovers between different administrative domains.
2011 21st International Conference on Systems Engineering, 2011
In this paper a task of resources allocation in the complex system is considered. Novelty of the ... more In this paper a task of resources allocation in the complex system is considered. Novelty of the formulated task consists of assumption that the applications assigned with resources of one machine can be migrated to another machine during system lifetime. The formulated task has been solved using proposed heuristic optimization method. Due to non-convex set of valid solutions the optimization procedure has been decomposed into two stages and forms approach similar to the relax-andround approach. Proposed decomposition approach facilitates fast algorithm convergence and guaranties that achieved solution satisfies assumed constraints.
Universal Comunication Platform for QoS-aware Delivery of Complex Services
IFIP Advances in Information and Communication Technology, 2010
The aim of this paper is to introduce a problem of e-health services quality management. The proc... more The aim of this paper is to introduce a problem of e-health services quality management. The process of delivering e-health services to users consists of two major tasks: service personalization and resources allocation. In this paper we introduce a use-cases of e-health system and distinguish services that can be offered. In order to satisfy user requirements one have to manage resources properly especially when communication conditions change (e.g. in an ambulance). An exemplary solution has been presented and conclusions for further work have been formulated.
Lecture Notes in Computer Science, 2011
The paper is devoted to the problem of mobility and resources management in heterogeneous wireles... more The paper is devoted to the problem of mobility and resources management in heterogeneous wireless networks. It is assumed that in certain area covered by multiple overlapping wireless networks there is certain number of mobile client which consume networks resources by use of available communication services (e.g.: voice or data transmission) delivered by network providers. Moreover it is assumed, that communication services continuity may be assured with use of common handover techniques supporting clients mobility (e.g: MIPv6, IEEE 802.21, etc.). The task of mobility and resources management consists of making decisions concerning the moment and the network to which particular clients should be handed over in order to optimize certain quality criterion (e.g. utilization of network resources). In this paper we show that gathering knowledge about clients movement and prediction of their future position may significantly improve the overall quality of delivered services and network resources utilization.
In this paper, we present a new meta-model designed for the performance modeling of network infra... more In this paper, we present a new meta-model designed for the performance modeling of network infrastructures in modern data centers. Instances of our metamodel can be automatically transformed into stochastic simulation models for performance prediction. We evaluate the approach in a case study of a road traffic monitoring system. We compare the performance prediction results against the real system and a benchmark. The presented results show that our approach, despite of introducing many modeling abstractions, delivers predictions with errors less than 32% and correctly detects bottlenecks in the modeled network.
In this work-in-progress paper, we present a new meta-model designed for the performance modeling... more In this work-in-progress paper, we present a new meta-model designed for the performance modeling of dynamic data center network infrastructures. Our approach models characteristic aspects of Cloud data centers which were not crucial in classical data centers. We present our meta-model and demonstrate its use for performance modeling and analysis through an example, including a transformation into OMNeT++ for performance simulation.
Cybernetics and Systems, 2012
The paper is devoted to the problem of mobility and resource management in heterogeneous wireless... more The paper is devoted to the problem of mobility and resource management in heterogeneous wireless networks. It is assumed that in certain area covered by multiple overlapping wireless networks there is certain number of mobile clients which consume networks resources by use of the available communication services (e.g.: voice or data transmission) delivered by network providers. Moreover, it is assumed, that communication services continuity may be assured by the use of common handover techniques supporting clients mobility (e.g.: MIPv6, IEEE 802.21, etc.). The task of mobility and resources management consists of making decisions concerning the moment and the network to which particular clients should be handed over in order to optimize certain quality criterion (e.g. utilization of network resources). In this paper we show that gathering knowledge about clients movement and prediction of their future position may significantly improve the overall quality of delivered services and network resources utilization. Independent Handover [9], provides a set of mechanisms which allows to trigger higher layer media independent handover procedures based on unified set of commands and media specific events. Network layer handover is managed by mobility extensions of the IP protocol, i.e. MIPv4 [5] and MIPv6 . In order to provide service continuity and guarantee required quality of service during handovers additional modifications to mobility management protocols has been made, e.g. FMIPv6 and HMIPv6 [2]. However, a breakthrough in mobility management has been made by introduction of Media-Independent Pre-Authentication (MPA) mechanism [4], which allows for seamless and secure handovers between different administrative domains.
Cybernetics and Systems, 2010
The gain of the paper is to introduce and to discuss a formal specification of computer system's ... more The gain of the paper is to introduce and to discuss a formal specification of computer system's Service Level Agreement (SLA) and its translation into structure of complex services (composed of atomic services) delivering required functionalities and non-functionalities in distributed environment. The SLA is composed of two parts specifying quantitative and qualitative requirements. The former requirements define structure of the adequate complex services as a directed graph, where potential parallelism of atomic services performance may be taken into account. The qualitative requirements are applied to select the optimal complex service realization scenario; it is based on assumption that various atomic services distinguished in the complex services structure are available in the environment in different versions and locations. Different versions of atomic services are delivering the required functionalities and satisfy non-functionalities at various levels. Various locations of atomic services means that the time and cost of atomic services delivery (communication and calculation) may vary. Proposed model of SLA translation into complex services causes that a scenario variants may be appliedamong others -to calculate upper and lower complex services' delivering times and to estimate validity of possible parallelism in complex services.
Handover: A Tool for Optimization of Wireless Networks
... Paweł Swiatek, Piotr Rygielski and Adam Grzech Institute of Computer Science Wroclaw Universi... more ... Paweł Swiatek, Piotr Rygielski and Adam Grzech Institute of Computer Science Wroclaw University of Technology Wybrzeze Wyspianskiego 27 50-370 ... of assignment of M users to N networks for which each user receives requested network capacity: fam (uam ,ram ) ≥ usrm(c ...
Resources Management and Services Personalization in Future Internet Applications
QoS-aware Complex Service Composition in SOA-Based Systems
Wireless Network Management Through Network-Enforced Handover
IMPROVING QoS GUARANTIES VIA ADAPTIVE PACKET SCHEDULING
Adaptive packet scheduling for requests delay guaranties in packet-switched computer communication network
ABSTRACT
Graph-fold: an efficient method for complex service execution plan optimization
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Papers by Piotr Rygielski