Petros Sampatakos

AQUILA: adaptive resource control for QoS using an IP-based layered architecture

Support for quality of service is an essential component of the next-generation Internet. The European research project AQUILA is committed to defining a DiffServ-based architecture for delivering on-demand QoS to requesting applications. Focal characteristics of the proposed solution are backward compatibility to the existing Internet and scalability to very large networks. To achieve such goals, AQUILA implements an overlaid distributed control layer, the resource control layer, implementing a novel mechanism for dynamic control of intradomain resources, the dynamic resource pool. On the interdomain aspects, the AQUILA architecture extends the BGRP framework for the aggregation of interdomain reservations to overcome scalability issues. This article describes the general AQUILA architecture, with a special focus on the DRP and BGRP mechanisms.

An adaptive algorithm for resource management in a differentiated services network

The Internet is widely known for lacking any kind of mechanism for the provisioning of quality of service guarantees. An overlay resource control management layer on top of a differentiated services core network is introduced for managing and adjusting the resources among network elements. This layer realises an algorithm which provides a dynamic approach for resource distribution. Our experimental results show that this algorithm can allocate network resources according to the traffic load and provide an adaptive and efficient way for re-distributing the resources among network elements.

Design of a Multi-layer Bandwidth Broker Architecture

Internet is widely known for lacking any kind of mechanism for the provisioning of Quality of Service guarantees. The Internet community concentrates its efforts on the Bandwidth Broker architecture towards this problem. This paper presents a design model of a multi-layer Bandwidth Broker architecture that introduces a Resource Control Layer, which is divided into two sub-layers. The upper one is responsible for the overall network administration, while the lower one performs per-flow policy-based admission control. The design models, the mechanisms, and algorithms adopted in this architecture will be delineated.

QMTool: an XML-based management platform for QoS-aware IP networks

Technological and human factors have contributed to the increasing complexity of the network management problem. Heterogeneity and globalization of network resources have, on one hand, increased user expectations for flexible and easy-to-use environments and, on the other, propounded entirely novel ways to face the management problem. Several research efforts recognize the need for integrated solutions to manage both network resources and services in open and global environments. Undoubtedly, these solutions should permit the coexistence of different management models and should interoperate with legacy systems. The presented management system, QoS management tool (QMTool), aspires to address the heterogeneity, complexity, and dynamic behavior of QoS-enabled IP networks by taking advantage of the optimum fit of a number of novel technologies. A layered framework architecture, including element, network management, and visualization service, is provided, and a high level of information abstraction in network configuration and monitoring is introduced mainly based on the capabilities of the Extensible Markup Language (XML). Moreover, the functional components for providing (re-)configuration, fault management monitoring, and network visualization facilities are also presented, followed by notes of implementation issues.

Network services definition and deployment in a differentiated services architecture

Next generation Internet architectures will consider the differentiated services paradigm for the provision of quality of service to the individual customer needs and applications. This paper addresses the definition and deployment of specific network services in a DiffServ environment. The proposed network services and the underlying traffic engineering methods are analyzed and simulated. Simulation outcomes prove that the fundamental principles of the network services are fulfilled.

Resource management techniques for dynamic multimedia content adaptation in heterogeneous networks

Moving towards an explosion of wireless and wired technologies coupled with an evolution of wireless terminal devices and different types of services, there is a growing need to decouple the service provision from the platform support. This need is considerably significant if we consider the influx of multi-media streaming content, the number of devices with different requirements and capabilities, the different service platforms and the uncountable number of software programs needed to be downloaded in order to present and manipulate the desired content. The architecture described in this paper presents a model for nomadic multimedia environments aiming at providing an “on-the-fly” adaptation of the delivery system. Taking advantage of the innovative capabilities offered by the current reconfigurable devices (FPGAs), the intelligent agent-based service provision and the advanced simulation techniques, it allows a hardware-independent delivery of content, where the end-devices can be reconfigured to optimally represent the multimedia content. Specifically, this paper focuses on the Simulation Server module of the architecture, which provides a dynamic and efficient approach for the optimum adjustment of the communication profile and adoption of the reconfiguration strategy, according to the user/network combination and device capabilities.

Applying the BGRP Concept for a Scalable Inter-Domain Resource Provisioning in IP Networks

Providing end-to-end QoS guarantees to mission critical applications comprises a main challenge for the today’s Internet infrastructure. The Differentiated Services architecture (DiffServ) enhanced by the Bandwidth Broker (BB) approach is a first step towards resource management. In this context, the architecture proposed in this paper realises a distributed BB architecture, in order to provide a more efficient way for managing the resources of a single domain.

Constraint-based media content delivery over heterogeneous networks and devices

Mobile and wireless technology has attained a great penetration in the market during the recent years. The need to deliver media content to a great variety of mobile and wireless devices is delineated as the indisputable future trend. This is instigated by the fact that wireless networks can now support the quality requirements of media streaming delivery, while mobile devices are able to present a variety of media content. This paper presents the Enamorado architecture that allows decoupling the development of mobile devices from advances in content formats and implements an intelligent system that selects the most appropriate content format in terms of for example device limitations, end-user preferences and current network conditions. This is particularly important, in cases which demand maximising the number of admitted users, without compromising the users quality standards. Finally, this paper presents a case study to present how the systems intelligence is applied in a real network.