We study problems related to supporting multicast connections with Quality of Service (QoS) requirements. We investigate the problem of optimal resource allocation in the context of performance dependent costs. In thi...
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ISBN:
(纸本)0780377524
We study problems related to supporting multicast connections with Quality of Service (QoS) requirements. We investigate the problem of optimal resource allocation in the context of performance dependent costs. In this context each network element can offer several QoS guarantees, each associated with a different cost. This is a natural extension to the commonly used bi-criteria model, where each link is associated with a single delay and a single cost. This framework is simple yet strong enough to model many practical interesting networking problems. The fundamental multicast resource allocation problem under this framework is how to optimally allocate QoS requirements on the links of the multicast tree. One needs to partition the end-to-end QoS requirement along the various paths in a tree. The goal is to satisfy the end-to-end QoS requirement with minimum cost. Previous studies under this framework considered single-source multicast connections, where the End-to-end QoS requirement is specified from the source to all other multicast group members. In this paper we extend these results to the more general, and considerably harder case of multicast sessions, where the end-to-end requirement hold for every path between any two multicast group members. Our aim is to provide rigorous solutions, with proven performance guaranties, by way of algorithmic analysis. The problem under investigation is NP hard for general cost functions, thus we first present a pseudo-polynomial exact solution. From this solution we derive two efficient Ε-approximate solutions. One achieves optimal cost, but may violate the end-to-end delay requirement by a factor of (1 + Ε), and the other strictly obeys the bounds and achieves a cost within a factor of (1+Ε) of the optimum. Furthermore, we present improved results for discrete cost functions, and give a simple linear-time exact polynomial solution for a specific, and practically interesting, family of convex cost functions.
This paper presents the MASA Quality of Service (QoS) architecture. MASA stands for Mobility and Service Adaptation in Heterogeneous Mobile Networks and consists of a distributed set of autonomous entities (QoS Broker...
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ISBN:
(纸本)0889863806
This paper presents the MASA Quality of Service (QoS) architecture. MASA stands for Mobility and Service Adaptation in Heterogeneous Mobile Networks and consists of a distributed set of autonomous entities (QoS Brokers), whose interactions support end-to-end QoS for quality-aware, multi-media applications in a mobile, heterogeneous, multi-domain, multi-operator environment. We introduce our architectural design of the MASA concept on end-systems, access- and core network nodes, as well as special service nodes, like transcoders. We outline the hierarchical structure of the MASA QoS Broker with supporting QoS management subsystems. With the integration of QoS technology management and business support, MASA offers powerful new means for enhancing providers business opportunities while at the same time provides for transparent adaptive media support.
We argue that the software user, the developer, the designer and indeed the application logic itself all possess invaluable intelligence to gear how software should adapt itself to changing requirements and changing c...
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We argue that the software user, the developer, the designer and indeed the application logic itself all possess invaluable intelligence to gear how software should adapt itself to changing requirements and changing context. We present Chisel, an open framework for dynamic adaptation of services using reflection in a policy-driven, context-aware manner. The system is based on decomposing the particular aspects of a service object that do not provide its core functionality into multiple possible behaviours. As the execution environment, user context and application context change, the service object will be adapted to use different behaviours, driven by a human-readable declarative adaptation policy script. To demonstrate this framework we will provide a dynamically adaptive middleware for mobile computing. The framework will allow users and applications to make mobile-aware dynamic changes to the behaviour of various services of the middleware, and allow the addition of new unanticipated behaviours at run-time, without changing or stopping the middleware or an application that may be using it. This is achieved by implementing the behaviours as metatypes in Iguana/J, which supports non-invasive dynamic associations of metatypes to service objects without any requirement to interrupt, change or access the object's source code.
This paper introduces a formal model for the development of monitoring and control systems devoted to manage a defined class of traffic anomalies. Although a lot of sophisticated technologies have been developed over ...
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This paper introduces a formal model for the development of monitoring and control systems devoted to manage a defined class of traffic anomalies. Although a lot of sophisticated technologies have been developed over the last years, the proper detection and management of critical situations that can arise in traffic flow is still a problem. A possible solution to this problem is to provide systems for monitoring and control of traffic situation with a correlation function that creates a dynamic view of traffic situation over the space and time. In order to do this, a first order logic-based language has been developed and applied to the development of the alarm correlation module (MCA) within the context of the system for automatic monitoring of traffic (SAMOT).
This paper contributes to service level management of complex Web-based e-business environments using WBEM/CIM. Such e-business environments usually consist of Web servers and Web containers to realize client access, ...
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This paper contributes to service level management of complex Web-based e-business environments using WBEM/CIM. Such e-business environments usually consist of Web servers and Web containers to realize client access, and EJB containers or CORBA components for modeling the application business logic. Since the DMTF does not define a model providing a unified view upon such complex environments, the definition of a management information model is the core part of the work presented. Currently, the information model mainly focuses on performance aspects, like application response times, which are integral part of many SLAs. The paper also presents a framework that was developed to efficiently implement the information model. The framework increases the portability of CIM providers, which are responsible for retrieving management information, between different CIMOMs by providing an abstraction layer. In addition, the framework simplifies the development of providers by offering support for caching etc.
The paper presents the application of the multilayered multi agent situated system (MMASS) model to localization problems. In the context of multi agent system based modelling and distributed problem solving, the MMAS...
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The paper presents the application of the multilayered multi agent situated system (MMASS) model to localization problems. In the context of multi agent system based modelling and distributed problem solving, the MMASS model allows explicit representation of the environment structure where agents are situated, and provides spatial dependant agent behavior and interaction mechanisms. These aspects are of particular relevance in problems like localization, in which the representation of spatial features is unavoidable. In particular, examples of localization problems that are considered in the paper are: shopping center localization in extra-urban areas, guide placement in museums, and sign and poster positioning in cities. Moreover, the paper briefly presents the software system that has been developed for the three-dimensional (3D) simulation of virtual worlds inhabited by virtual agents. This tool has been exploited for 3D representation of the presented MMASS-based models of localization problems.
The paper presents a model that is useful for developing resource allocation algorithms for distributed real-time systems that operate in dynamic environments. Interesting aspects of the model include dynamic environm...
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作者：
Giovanni AdagioDistributed Programming Laboratory
School of Computer Science and Communication Systems Swiss Federal Institute of Technology in Lausanne (EPFL) Institute of Mathematics School of Basic Sciences Swiss Federal Institute of Technology in Lausanne (EPFL) Switzerland
This paper contributes to the characterization of synchronous models of distributed computing using topological techniques. We consider a generic synchronous model with send-omission failures and use a topological str...
This paper contributes to the characterization of synchronous models of distributed computing using topological techniques. We consider a generic synchronous model with send-omission failures and use a topological structure corresponding to a bounded number of rounds of the model. We observe some nice properties of the structure and derive from these properties necessary and sufficient conditions to solve consensus in this model.
With the rapid advent and proliferation of peer-to-peer applications, research and education communities who have high performance networks have started to search for the possibilities of being benefited from the peer...
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