Eleni Patouni

A framework for the deployment of self-managing and self-configuring components in autonomic environments

Over the last two decades, the advent of the Internet coupled with the diverse philosophy of networks, formed the basis for a pervasive computing environment. In the latter, the current trend is defined by the concept of autonomic computing and communications, which lies in the introduction of automated functions that enhance the intelligence of existing computing and communication systems. This concept forms a new paradigm of systems with selfware capabilities that will automatically adapt their behavior in relation to the configuration of the drastically changing environment and user preferences. In this context, this paper presents a generic architecture for the design and deployment of self-managing and self-configuring capabilities. In addition, it exploits the dynamic binding and replacement of components with autonomic capabilities. The feasibility aspects of the proposed framework are validated by means of a prototype that demonstrates the operation of plug and play solutions for an adaptable component-based protocol. Performance issues are also discussed

IEEE P1900.B: Coexistence Support for Reconfigurable, Heterogeneous Air Interfaces

This contribution presents and discusses the system concept approach which has been proposed by the European Integrated Project IST-E2R II in the IEEE P1900.B Standardization Study Group (SG); it currently is under further elaboration in the framework of the follow-up IEEE P1900.4 Working Group (WG) whose Project Authorization Request (PAR) was accepted in December 2006. This effort targets reconfigurable (typically software defined radio (SDR) based) networks and terminals in a heterogeneous wireless environment, with multi-homing capable terminals enabling the users to operate multiple wireless links simultaneously. In order to ensure backwards compatibility to legacy standards, the approach is to introduce three new building blocks into the (existing and/or evolving) heterogeneous landscape: i) A network reconfiguration management module, ii) a radio enabler and iii) a terminal reconfiguration management module. Within this paper, the key functionalities of these building blocks are detailed and discussed; it is furthermore outlined how the introduction of distributed decision-making concepts improves the efficiency of the heterogeneous system in terms of i) signaling overhead, ii) reactivity of user mobile terminals (MTs) and iii) numerical resource selection optimization complexity on the network side.

A survey of dynamically adaptable protocol stacks

The continuous development of new networking standards over the last decade has resulted in an unprecedented proliferation of interfacing technologies and their associated protocol stacks. Never before was such a wide gamut of network architectures, protocol configurations and deployment options available to network designers. Alas, this significant increase in flexibility has come at the cost of an increased complexity in network management tasks, particularly with regard to the accommodation of performance requirements. Especially in mobile settings, this is due to the greater probability of unforeseen communication contexts that renders the efficient provisioning of multiple dissimilar protocol stacks a challenging task. To address this unpredictability, several approaches based on the dynamic adaptation of protocol stacks during runtime have been proposed and investigated over the years. This article surveys major research efforts dealing with the introduction of a dynamic adaptation capacity into protocol stack subsystems. To this end, we present the respective architectures with a focus on their functional entities and their particular mode of operation. Most importantly, we elaborate on the various design approaches to adaptability and the entailed degree of coupling between protocol stack-and layer-entities and their impact on resource allocation models. Furthermore, we classify these research efforts according to a taxonomy for non-monolithic protocol stacks and discuss design trade-offs inherent in each class. We conclude the article with a summary of the key design principles for adaptable protocol stack architectures.

To Reconfigure or Not to Reconfigure: Cognitive Mechanisms for Mobile Devices Decision Making

The vast proliferation in the continuously changing telecommunications environment of Next-Generation-Networks (NGNs) poses strict requirements for the dynamic adaptation of mobile devices according to the user needs, system resources and Radio Access Technology (RAT) availability. The reconfiguration concept emerges as a paradigm that offers an effective solution to this problem. On the other hand, the operation of mobile devices offering cognitive functionalities is characterized by a significant number of parameters, many of which are contradictive and cannot be simultaneously optimized, thus constituting reconfiguration a multi-objective optimization problem. This work proposes a solution to the problem, addressing efficient decision making mechanisms to avoid the ping-pong effect of multiple reconfigurations and exploiting fuzzy logic reasoning approach for terminal reconfiguration decision, focusing on resource management and protocol configuration.

Generic architecture and mechanisms for protocol reconfiguration

The next generation of wireless mobile communications termed beyond 3G (or 4G), will be based on a heterogeneous infrastructure that comprises different wireless networks in a complementary manner. Beyond 3G will introduce reconfiguration capabilities to flexibly and dynamically (i.e., during operation) adapt the wireless protocol stacks to better meet the ever-changing service requirements. For the dynamic reconfiguration of protocol stacks during runtime operation to become a practical capability of mobile communication systems, it is necessary to establish a software architecture that functionally supports reconfiguration. In the present paper, a generic architecture and respective mechanisms to achieve protocol stack and component based protocol layer reconfiguration are proposed.

Modeling and Performance Evaluation of Reconfiguration Decision Making in Heterogeneous Radio Network Environments

In heterogeneous radio network environments, the incorporation of dynamic adaptation capabilities in the protocol stack of mobile devices is an important challenge. In this direction, an appropriate model of the network decision-making process for mobile device adaptation is presented. Two main adaptation alternatives are assumed: (1) handover and (2) protocol reconfiguration. We consider two classes of mobile devices, i.e., reconfigurable and autonomous; the difference between them lies on the degree by which they support the decision-making functionality. An algorithmic framework for the management of the decision-making requests for reconfiguration or handovers is proposed. This work is based on the introduced metric of user satisfaction, which is based on the network response time for serving the decision-making requests. Such a framework is important for guiding the relocation of mobile terminals to achieve offloading. Furthermore, an analytical model for the computation of the user satisfaction is introduced, based on the work by Litoiu The analysis uses multiclass queuing networks to model the requests to the network as transactions among the system entities and compute the user satisfaction and the required parameters, e.g., network response time bounds. The obtained results show how the global bounds on the asymptotic network response time and throughput per class are affected by the number and frequency of reconfiguration decision requests. The analysis quantifies how the increase in the autonomicity level of mobile devices affects the network load and how to maximize the percentage of requests handled by the network, compared with the percentage of dropped requests. Moreover, our work reveals the degree of performance deterioration caused by increasing the autonomicity level in the management of requests.

Optimisation of Radio Access Network Operation Introducing Self-x Functions: Use Cases, Algorithms, Expected Efficiency Gains

With the deployment of next generation (4G) mobile radio systems an additional radio access network is established. A variety of different Radio Access Technologies (RATs) will be operated in parallel. In this framework, the Long Term Evolution (LTE) system, specified by 3GPP, will have to co-exist with WiMAX, mobile 2G/3G networks and Wireless Local Area Networks (WLANs). To cope with this increasing diversity and complexity mechanisms for self-optimisation, self-organisation, self-healing, self-configuration (self-x) are essential to guarantee cost efficient and high quality network operation. Within the project E³ (1) self-x functionalities for different use cases and different elements of a mobile radio access network are developed. Aim of this paper is to give and overview about the interworking of different self-x functionalities and to present three exemplary use cases. I. INTRODUCTION Evolution of mobile radio networks is driven by the demand for new, high bit rate consuming applications and services. The technical answer is the development of new and more powerful radio technologies and integration into existing mobile radio networks. This leads to significantly higher complexity and heterogeneity while pressure for maintaining manageability and cost efficiency of the networks is continuously increasing. E³ answer is introduction of solutions for obtaining higher flexibility and efficiency in usage of radio, hardware and computational resources by cognition, self- organisation and self-optimisation. This paper presents the interworking of cognitive radio self-x functions in E³ environments and hereafter three exemplary self-x use cases namely Handover Parameter Optimisation, Protocol Stack Self- Configuration & Topology Self-Organisation and Knowledge- based Proactive Context Handling.

End-to-End Reconfigurability in Heterogeneous Wireless Systems - Software and Cognitive Radio Solutions enriched by Policy- and Context-based Decision Making

This paper describes the end-to-end reconfigurability (E2R II) research framework and focuses on the current status of the activities inside the consortium. E2R II is a partly funded project inside the Sixth Framework Programme of European Community. The E R II project is part of a wider program, started with the E2R I project in 2004. In this program, concepts and solutions in order to enable, manage and control the end-to-end connectivity in highly heterogeneous environments are developed, taking into account the different radio access technologies potentially active (2G/3G cellular, 4G/B3G, IEEE 802.xx, broadcast...). The key objective of the E R II project is to devise, develop, trial and showcase architectural design of reconfigurable devices and supporting system functions with the aim to offer an extensive set of operational choices to the users, application and service providers, operators, manufacturers and regulators in the context of heterogeneous systems.

Reconfigurable Wireless Communication Systems applying Distributed Decision-Making in a Heterogeneous Radio Environment

This contribution presents the system concept approach introduced by the IEEE 1900.4 Working Group (WG) and discusses inherent advantages and issues. This effort targets reconfigurable (Software Defined Radio (SDR) based) networks and terminals in a heterogeneous wireless environment, with multi-homing capable terminals which enables them to operate several wireless links simultaneously. In order to ensure backwards compatibility to legacy standards, this approach introduces three new building blocks into the (existing and/or evolving) heterogeneous landscape: i) A Network Reconfiguration Management module, ii) a Radio Enabler and iii) a Terminal Reconfiguration Management module. Within this paper, the key functionalities of these building blocks are presented and discussed; it is furthermore shown how the introduction of distributed decision-making concepts improves the efficiency of the heterogeneous system in terms of i) signaling overhead, ii) reactivity of user mobile terminals (MTs) and iii) numerical resource selection optimization complexity on the network side.

Protocol Reconfiguration Schemes for Policy-Based Equipment Management

The continuous proliferation in modern communication technologies towards a pervasive composite environment prescribes a profound shift in telecommunication management and poses new challenges, in terms of proposing key solutions for the management and support of legacy as well as emerging systems. Driven by these advances, a direct requirement lies in providing an advanced configuration system that will embrace the demands for optimal and adaptive configuration and reconfiguration of the underlying layers. This objective can be achieved by upgrading the capabilities of mobile equipment with the introduction of a configuration system that incorporates advanced features such as policy-based decision making mechanisms and protocol layer adaptation and reconfiguration procedures. This contribution exploits protocol reconfiguration schemes for policy-based equipment management as addressed in the E2R environment.