Iakovos S. Venieris

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.

QoS issues in the converged 3G wireless and wired networks

The Internet evolution delineated through the last years has urged the wireless network community to support the deployment of IP multimedia services with guaranteed quality of service (QoS) in 3G wireless networks. This article copes with the interoperability between 3G wireless networks and wired next-generation IP networks, for the provision of services with an a priori known quality level over both environments. More specifically, the UMTS architecture as well as a prototypical implementation of the next-generation Internet based on DiffServ are considered. The article focuses on the mapping among the traffic classes of the two networks at the point where the networks converge, and discusses the requirements and possible solutions for their proper interworking at the signaling and user levels. Simulations prove that proper mapping among the traffic classes of each world is necessary in order to achieve the desired end-to-end traffic characteristics.

Context-aware service engineering: A survey

Context constitutes an essential part of service behaviour, especially when interaction with end-users is involved. As observed from the literature, context handling in service engineering has been during recent years a field of intense research, which has produced several interesting approaches. In this paper, we present research efforts that attempt mainly to decouple context handling from the service logic. We enumerate all context management categories, but focus on the most appropriate for service engineering, namely source code level, model-driven and message interception, taking also into account the fact that these have not been dealt with in detail in other surveys. A representative example is used to illustrate more precisely how these approaches can be used. Finally, all three categories are compared based on a number of criteria.

Mobile agent standards and available platforms

This paper examines the current status of standardization efforts concerning mobile agent technology and presents five Java-based mobile agent platforms. Standards directly relating to mobile agent technology are presented first, followed by an overview of other standardization efforts that while not directly relating to mobile agent technology, can still contribute significantly to its success. This is followed by a detailed presentation of five Java-based mobile agent platforms. The description of each platform examines its communication mechanisms, its architecture and the services that it offers to a developer. The presentation of the platforms ends with a comparative overview of their features accompanied by a brief presentation of some performance results. The paper concludes with some general remarks on the future of this technology.

End-to-end QoS specification issues in the converged all-IP wired and wireless environment

The emerging next-generation networking environment presents an IP-based core interconnecting many wireless radio access networks, providing ubiquitous access to end users through a vast variety of wireless devices. Although the IP protocol is the common denominator, the new environment brings together many different interconnecting domains, each following different QoS models, complicating the overall end-to-end QoS process. This article discusses the need to standardize an end-to-end QoS protocol. It does not, however, focus on the signaling mechanism, since there is currently a relevant ongoing activity in IETF. Instead, it concentrates on the formulation of the QoS information describing the QoS requirements of the session to be established. It presents the generic service specification framework that not only enables the QoS requirements of a specific session to be captured (like a generic QoS template), but also the QoS classes of each IP domain can be described according to it. Through the systematic specification of a domains QoS classes, an intelligent automatic mapping algorithm can be applied during an end-to-end QoS request, in order to select the most appropriate service class in each domain, as well as to extract the required traffic-related parameters to perform traffic control operations, such as admission control, policing, and scheduling.

Mobility Aware Technologies and Applications

Web Agent Supporting Transport Layer Mobility.- A Network-Aware Truncating Module for Scalable Streams Saving Bandwidth for Overused Networks.- APHIDS++: Evolution of A Programmable Hybrid Intrusion Detection System.- Challenges in Modeling and Disseminating Context Information in Ambient Networks.- A Co-designed Hardware/Software Architecture for Augmented Materials.- A Simulation Model for the Dynamic Allocation of Network Resources in a Competitive Wireless Scenario.- An Adaptive Call Admission Control to Support Mobility in Next Generation Wireless Network.- Protecting Mobile Agent Loops.- ContextWare Support for Network and Service Composition and Self-adaptation.- Fixed Mobile Convergence: 3 Words, Many Perspectives.- Analysis of Movement Detection Process for IPv6 Mobile Nodes.- A Dynamic Resource Allocation Scheme for Providing QoS in Packet-Switched Cellular Networks.- Distributed Authorization Framework for Mobile Agents.- Adaptive Content for the Mobile User: A Policy-Based Approach.- An Authorisation and Privacy Framework for Context-Aware Networks.- Widget Integration Framework for Context-Aware Middleware.- Service Deployment in Active Networks Based on a P2P System.- Mobile Agents for Testing Web Services in Next Generation Networks.- A Secure Protocol for Mobile Agents in Hostile Environment.- A Cross-Layer Approach for Publish/Subscribe in Mobile Ad Hoc Networks.- Towards Ambient Networks Management.- A Context-Aware Negotiation Model for M-Commerce.- Collection and Object Synchronization Based on Context Information.- Facilitating Context-Awareness Through Hardware Personalization Devices: The Simplicity Device.- Network Access Security Management (NASM) Model for Next Generation Mobile Telecommunication Networks.- Management of Aggregation Networks for Broadband Internet Access in Fast Moving Trains.- Design and Implementation of an Open IMS Core.- Mobility-Aware Coordination in a WLAN Hot-Spot Area.- Application-Independent Session Mobility Between User Terminals.- Using Multiple Communication Channels in a Mobile Agent Platform.- Challenges in Modelling and Using Quality of Context (QoC).- Secure and Scalable Routing Protocol for Mobile Ad-Hoc Networks.- RAPOSI: Rapidly Installable Positioning System for Indoor Environments.- Integrating a New Mobility Service into the Jade Agent Toolkit.- A New Protocol for Protecting a Mobile Agent Using a Reference Clone.- A Novel Approach Towards Autonomic Management in Context-Aware Communication Systems.- Abstraction for Privacy in Context-Aware Environments.- A Probabilistic Heuristic for Conflict Detection in Policy Based Management of Diffserv Networks.- LEA2C: Low Energy Adaptive Connectionist Clustering for Wireless Sensor Networks.

Model-driven development of composite context-aware web applications

Context-awareness constitutes an essential aspect of services, especially when interaction with end-users is involved. In this paper a solution for the context-aware development of web applications consisting of web services is presented. The methodology proposes a model based approach and advocates in favour of a complete separation of the web application functionality from the context adaptation at all development phases (analysis, design, implementation). In essence, context adaptation takes place on top of and is transparent to the web application business functionality. Starting from UML diagrams of independent web services and respective UML context models, our approach can produce a functional composite context-aware application. At execution level this independence is maintained through an adaptation framework based on message interception.

Simulative analysis of optimal resource allocation and routing in IBCN's

The problem of resource allocation for future integrated broadband communication networks (IBCNs) is addressed. It mainly involves resource allocation at the connection level. The resource allocation problem is decomposed into the following interdependent tasks: given that a network can accommodate the bandwidth demand of a call request, determine a route for the corresponding asynchronous transfer mode (ATM) virtual connection; and allocate bandwidth, i.e. links inside the trunks of the chosen route, to this connection according to predefined limits on bandwidth use by various service calls. Various link allocation schemes combined with routing algorithms are examined. Their performance in terms of service call blocking is evaluated using a software package developed, for that purpose. It is shown that the traditional complete sharing (CS) and complete partitioning (CP) policies are not adequate for IBCNs. Movable boundary (MB) policies are more flexible and present near-optimal performance when access of broadband service to narrowband service resources is allowed and suitable routing algorithms are dynamically applied. >

Efficient buffer management and scheduling in a combined IntServ and DiffServ architecture: a performance study

The differentiated services (DiffServ) architecture promises the provision of QoS-enabled networks by following a simple approach that eliminates scalability concerns and which can be implemented and managed in large networks. However, for end-to-end QoS an appropriate signaling scheme, like the resource reservation protocol (RSVP), should be supported. In this combined approach, signaling messages, which are generated by hosts and interpreted by edge routers, are tunneled transparently through the DiffServ core network. The treatment of the signaling messages in the DiffServ cloud is a very important issue, since long delays in their delivery or a high percentage of drops could result in unpredictable and undesirable situations. In this paper, we define a DiffServ traffic class, herein called network control traffic class, that is used by all signaling messages travelling through the DiffServ network. We provide a simulation analysis which evaluates the key properties of the new DiffServ class including priority level, link-sharing bandwidth and link-sharing structure for an hierarchical class-based resource management mechanism referred to as class-based queuing (CBQ), employed by the DiffServ core routers.

Implementing integrated and differentiated services for the Internet with ATM networks: a practical approach

This article reports on design, implementation, and preliminary experimentation of a network architecture that supports quality of service for Internet applications. It gives an overview of the various approaches toward communication networks that support application-specific degrees of QoS. Special emphasis is put on the integrated and differentiated services approaches and on combinations of them. A new architecture is described which aims to bring these concepts closer to practical realization in wide-area networks. The new architecture supports the integrated as well as differentiated services approaches in a smoothly integrated way, and uses the capabilities of an underlying ATM network to realize QoS. The enhancements to the existing network infrastructure are deliberately limited to the integration of a single new type of network element called an edge device. The potential benefits of such an architecture for various stakeholders are explained, and how the new architecture could be introduced smoothly in existing networks by small migration steps, also covering networks based on technologies other than ATM. It is shown that the approach can be scaled up to a very large QoS-aware overlay network for the Internet.