EDBT 2026 Demo / reviewers in the wild / expert
Alex Galis
dblp:75/699
· DBLP profile ↗
37ranked-venue papers
0as first author
0since 2021 · last 2020
0000-0002-6551-7591ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Computer networks · 20Systems, architecture and hardware · 5Software engineering, systems software and programming languages · 3Artificial intelligence and machine learning · 1
Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.
| Computer networks
3 papers |
Software-defined and programmable networks · 45% Network optimization and economics · 22% Edge and fog computing · 15% | |
| Computer architecture, parallel and distributed computing, and storage systems
2 papers |
Cloud and datacenter computing · 84% Distributed systems · 16% |
Topics — the 9 heaviest of 12, each with the papers that count most for it
| Topic | Weight | Papers | Last | Evidence papers |
|---|---|---|---|---|
Software-defined and programmable networks › network function virtualization
service function chaining |
0.8 | 2 | 2020 | Efficient Algorithms for Delay-Aware NFV-Enabled Multicasting in Mobile Edge Clouds With Resource Sharing · IEEE Trans. Parallel Distributed Syst. 2020 Efficient NFV-Enabled Multicasting in SDNs · IEEE Trans. Commun. 2019 |
Network optimization and economics
resource allocation |
0.5 | 2 | 2020 | Efficient Algorithms for Delay-Aware NFV-Enabled Multicasting in Mobile Edge Clouds With Resource Sharing · IEEE Trans. Parallel Distributed Syst. 2020 Efficient NFV-Enabled Multicasting in SDNs · IEEE Trans. Commun. 2019 |
Software-defined and programmable networks
network function virtualization |
0.5 | 2 | 2020 | Efficient NFV-Enabled Multicasting in SDNs · IEEE Trans. Commun. 2019 Efficient Algorithms for Delay-Aware NFV-Enabled Multicasting in Mobile Edge Clouds With Resource Sharing · IEEE Trans. Parallel Distributed Syst. 2020 |
Edge and fog computing › mobile edge computing
mobile edge cloud |
0.4 | 1 | 2020 | Efficient Algorithms for Delay-Aware NFV-Enabled Multicasting in Mobile Edge Clouds With Resource Sharing · IEEE Trans. Parallel Distributed Syst. 2020 |
Routing and switching
multicast routing |
0.4 | 1 | 2019 | Efficient NFV-Enabled Multicasting in SDNs · IEEE Trans. Commun. 2019 |
Network optimization and economics
throughput maximization |
0.1 | 1 | 2019 | Efficient NFV-Enabled Multicasting in SDNs · IEEE Trans. Commun. 2019 |
Cloud and datacenter computing › resource allocation
cloud resource allocation |
0.1 | 1 | 2010 | Software architecture definition for on-demand cloud provisioning · HPDC 2010 |
Cloud and datacenter computing › resource provisioning
on-demand resource provisioning |
0.1 | 1 | 2010 | Software architecture definition for on-demand cloud provisioning · HPDC 2010 |
Distributed systems › distributed system architecture › communication architecture
virtual networks |
0.0 | 1 | 2013 | On the Selection of Management/Monitoring Nodes in Highly Dynamic Networks · IEEE Trans. Computers 2013 |
Methods — techniques the papers use, named apart from their topics
heuristic · 0.8approximation algorithm · 0.8online algorithm · 0.4competitive ratio analysis · 0.4lifespan prediction · 0.3greedy algorithm · 0.3model denotational approach · 0.1
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2020 | WIM on-demand - A modular approach for managing network slicesabstractThis paper explores and makes a case for allocating a Wide-area Infrastructure Manager (WIM) on-demand to support softwarized network slicing, as part of the full NFVI virtualised infrastructure foundation, to ensure that the connectivity attributes prescribed to network slices can be managed with flexibility and adaptability in a full end-to-end slice. We show how creating a WIM on-demand and dynamically allocating a new WIM for each network slice, rather than having one for the whole network, can be beneficial for various slicing scenarios, in a similar way that a Virtual Infrastructure Manager (VIM) on-demand has been utilized. The paper considers some of the components, abstractions, and mechanisms of WIM on-demand. Stuart Clayman, Francesco Tusa, Alex Galis, Luis M. Contreras 0001 |
NetSoft | 3 |
| 2020 | NEW IP Framework and Protocol for Future ApplicationsabstractIt is observed that the Internet has been slowly "fragmented" into Many Networks (ManyNets) due to both technical and commercial evolutions. The interconnection among those networks is a challenge due to their incompatible addressing mechanisms. Furthermore, emerging applications like Augmented Reality and Virtual Reality (AR/VR), holographic communications, etc. rise new requirements to the network and involve innumerable physical and virtual objects, which require more efficient and customized network services. Current Internet Protocol (IP) that aims to connect regional academic and military networks was invented half a century ago. The original IP design philosophy like fixed address length, binding machines to specific locations, and others are not sufficient anymore to tackle those challenges.In this paper, we propose a novel framework for future Internet protocol, called NEW IP, to tackle aforementioned challenges and fulfill the requirements of future applications. NEW IP inherently enables variable-length and multi-semantic network addresses, and user-definable networking. Besides the NEW IP framework, a few use cases will be illustrated to highlight the benefits it brings. Guanwen Li, Zhe Lou, Alex Galis |
NOMS | 6 |
| 2020 | Fault tolerant placement of stateful VNFs and dynamic fault recovery in cloud networks
Guochang Yuan, Zichuan Xu, Binxu Yang, Weifa Liang, Wei Koong Chai, Daphné Tuncer, Alex Galis, George Pavlou, Guowei Wu 0001 |
Comput. Networks | 7 |
| 2020 | Enabling Multicast Slices in Edge NetworksabstractTelecommunication networks are undergoing a disruptive transition toward distributed mobile edge networks with virtualized network functions (VNFs) [e.g., firewalls, intrusion detection systems (IDSs), and transcoders] within the proximity of users. This transition will enable network services, especially Internet-of-Things (IoT) applications, to be provisioned as network slices with sequences of VNFs, in order to guarantee the performance and security of their continuous data and control flows. In this article, we study the problems of delay-aware network slicing for multicasting traffic of IoT applications in edge networks. We first propose exact solutions by formulating the problems into integer linear programs (ILPs). We further devise an approximation algorithm with an approximation ratio for the problem of delay-aware network slicing for a single multicast slice, with the objective to minimize the implementation cost of the network slice subject to its delay requirement constraint. Given multiple multicast slicing requests, we also propose an efficient heuristic that admits as many user requests as possible, through exploring the impact of a nontrivial interplay of the total computing resource demand and delay requirements. We then investigate the problem of delay-oriented network slicing with given levels of delay guarantees, considering that different types of IoT applications have different levels of delay requirements, for which we propose an efficient heuristic based on reinforcement learning (RL). We finally evaluate the performance of the proposed algorithms through both simulations and implementations in a real testbed. The experimental results demonstrate that the proposed algorithms are promising. Yugen Qin, Qiufen Xia, Zichuan Xu, Pan Zhou 0001, Alex Galis, Omer F. Rana, Jiankang Ren, Guowei Wu 0001 |
IEEE Internet Things J. | 5 |
| 2020 | Efficient Algorithms for Delay-Aware NFV-Enabled Multicasting in Mobile Edge Clouds With Resource SharingabstractStringent delay requirements of many mobile applications have led to the development of mobile edge clouds, to offer low latency network services at the network edges. Most conventional network services are implemented via hardware-based network functions, including firewalls and load balancers, to guarantee service security and performance. However, implementing hardware-based network functions usually incurs both a high capital expenditure (CAPEX) and operating expenditure (OPEX). Network Function Virtualization (NFV) exhibits a potential to reduce CAPEX and OPEX significantly, by deploying software-based network functions in virtual machines (VMs) on edge-clouds. We consider a fundamental problem of NFV-enabled multicasting in a mobile edge cloud, where each multicast request has both service function chain and end-to-end delay requirements. Specifically, each multicast request requires chaining of a sequence of network functions (referred to as a service function chain) from a source to a set of destinations within specified end-to-end delay requirements. We devise an approximation algorithm with a provable approximation ratio for a single multicast request admission if its delay requirement is negligible; otherwise, we propose an efficient heuristic. Furthermore, we also consider admissions of a given set of the delay-aware NFV-enabled multicast requests, for which we devise an efficient heuristic such that the system throughput is maximized, while the implementation cost of admitted requests is minimized. We finally evaluate the performance of the proposed algorithms in a real test-bed, and experimental results show that our algorithms outperform other similar approaches reported in literature. Haozhe Ren, Zichuan Xu, Weifa Liang, Qiufen Xia, Pan Zhou 0001, Omer F. Rana, Alex Galis, Guowei Wu 0001 |
IEEE Trans. Parallel Distributed Syst. | 7 |
| 2019 | NFV-Enabled Multicasting in Mobile Edge Clouds with Resource SharingabstractDriven by stringent delay requirements of mobile applications, the mobile edge cloud has emerged as a major platform to offer low latency network services from the edge of networks. Most conventional network services are implemented via hardware-based network functions, such as firewalls and load balancers, to guarantee service security and performance. However, implementing such hardware-based network functions incurs high purchase and maintenance costs. Network function virtualization (NFV) as a promising technology exhibits great potential to reduce the purchase and maintenance costs by implementing network functions as software in virtual machines (VMs). In this paper, we consider a fundamental problem of NFV-enabled multicasting in a mobile edge cloud, where each multicast request requires to process its traffic in a specified sequence of network functions (referred to as a service chain) before the traffic from a source to a set of destinations. We devise a provable approximation algorithm with an approximation ratio for the problem if requests do not have delay requirements; otherwise, we propose an efficient heuristic for it. We also evaluate the performance of the proposed algorithms against the state-of-the-art NFV-enabled multicasting algorithms, and results show that our algorithms outperform their counterparts. Zichuan Xu, Yutong Zhang 0003, Weifa Liang, Qiufen Xia, Omer F. Rana, Alex Galis, Guowei Wu 0001, Pan Zhou 0001 |
ICPP | 6 |
| 2019 | Dynamic Monitoring of Data Center SlicesabstractSlicing is a move towards segmentation of resources and deployment of NFV for the purpose of enhanced services and applications on globally shared resources. The slicing approach in this paper considers Data Center slicing and the VIM on-demand model. We focus on the monitoring of Data Center slices, showing what is needed from the monitoring perspective and how the monitoring should be done. The proposed monitoring approach is validated on a platform that supports the on-demand creation of lightweight VIM instances. Francesco Tusa, Stuart Clayman, Alex Galis |
NetSoft | 3 |
| 2019 | Efficient NFV-Enabled Multicasting in SDNsabstractMulticasting is a fundamental functionality of many network applications, including online conferencing, event monitoring, video streaming, and so on. To ensure reliable, secure, and scalable multicasting, a service chain that consists of network functions (e.g., firewalls, intrusion detection systems, and transcoders) usually is associated with each multicast request. We refer to such a multicast request with service chain requirement as an network function virtualization (NFV)-enabled multicast request. In this paper, we study NFV-enabled multicasting in a software-defined network (SDN) with an aim to maximize network throughput while minimizing the implementation cost of admitted NFV-enabled multicast requests, subject to network resource capacity, where the implementation cost of a request consists of its computing resource consumption cost in servers and its network bandwidth consumption cost when routing and processing its data packets in the network. To this end, we first formulate two NFV-enabled multicasting problems with and without resource capacity constraints and one online NFV-enabled multicasting problem. We then devise two approximation algorithms with an approximation ratio of $2M$ for the NFV-enabled multicasting problems with and without resource capacity constraints, if the number of servers for implementing the service chain of each request is no greater than a constant $M$ (≥1). We also study dynamic admissions of NFV-enabled multicast requests without the knowledge of future request arrivals with the objective to maximize the network throughput, for which we propose an efficient heuristic, and for the special case of dynamic request admissions, we devise an online algorithm with a competitive ratio of $O(\log n)$ for it when $M=1$ , where $n$ is the number of nodes in the network. We finally evaluate the performance of the proposed algorithms through experimental simulations. Experimental results demonstrate that the proposed algorithms are promising and outperform existing heuristics. Zichuan Xu, Weifa Liang, Meitian Huang, Mike Jia, Song Guo 0001, Alex Galis |
IEEE Trans. Commun. | 6 |
| 2018 | Algorithms for Fault-Tolerant Placement of Stateful Virtualized Network FunctionsabstractTraditional network functions (NFs) such as firewalls are implemented in costly dedicated hardware. By decoupling NFs from physical devices, network function virtualization enables virtual network functions (VNF) to run in virtual machines (VMs). However, VNFs are vulnerable to various faults such as software and hardware failures. To enhance VNF fault tolerance, the deployment of backup VNFs in stand-by VM instances is necessary. In case of stateful VNFs, stand-by instances require constant state updates from active instances during its operation. This will guarantee a correct and seamless handover from failed instances to stand-by instances after failures. Nevertheless, such state updates to stand-by instances could consume significant network bandwidth resources and lead to potential admission failures for VNF requests. In this paper, we study the fault-tolerant VNF placement problem with the optimization objective of admitting as many requests as possible. In particular, the VNF placement of active/stand-by instances, the request routing paths to active instances, and state transfer paths to stand-by instances are jointly considered. We devise an efficient heuristic algorithm to solve this problem, and propose a bicriteria approximation algorithm with performance guarantees for a special case of the problem. Simulations with realistic settings show that our algorithms can significantly improve the request admission rate compared to conventional approaches. Binxu Yang, Zichuan Xu, Wei Koong Chai, Weifa Liang, Daphné Tuncer, Alex Galis, George Pavlou |
ICC | 6 |
| 2018 | Throughput optimization for admitting NFV-enabled requests in cloud networks
Zichuan Xu, Weifa Liang, Alex Galis, Yu Ma 0001, Qiufen Xia, Wenzheng Xu |
Comput. Networks | 3 |
| 2017 | Throughput maximization and resource optimization in NFV-enabled networksabstractNetwork function virtualization (NFV) has been emerging as a new paradigm to enable elastic and inexpensive network services in modern computer networks, through deploying flexible virtualized network functions (VNFs) running in virtual computing platforms. Different VNFs can be chained together to form different service chains, to meet various user data routing demands for different network services. In this paper we consider provisioning network services in an NFV-enabled network that consists of data centers for implementing VNF instances of service chains and switches. We study the throughput maximization problem with the aim to admit as many user requests as possible while minimizing the implementation cost of the requests, assuming that limited numbers of instances of each service chain have been stored in data centers. We first propose an optimal algorithm for the problem if all requests have identical packet rates; otherwise, we devise two approximation algorithms with probable approximation ratios, depending on whether the packet traffic of each request is splittable. We finally conduct experiments to evaluate the performance of the proposed algorithms by simulations. Experimental results show that the proposed algorithms achieve at least 15% more throughput than that of a greedy algorithm. Zichuan Xu, Weifa Liang, Alex Galis, Yu Ma 0001 |
ICC | 3 |
| 2017 | Approximation and Online Algorithms for NFV-Enabled Multicasting in SDNsabstractMulticasting is a fundamental functionality of networks for many applications including online conferencing, event monitoring, video streaming, and system monitoring in data centers. To ensure multicasting reliable, secure and scalable, a service chain consisting of network functions (e.g., firewalls, Intrusion Detection Systems (IDSs), and transcoders) usually is associated with each multicast request. Such a multicast request is referred to as an NFV-enabled multicast request. In this paper we study NFV-enabled multicasting in a Software-Defined Network (SDN) with the aims to minimize the implementation cost of each NFV-enabled multicast request or maximize the network throughput for a sequence of NFV-enabled requests, subject to network resource capacity constraints. We first formulate novel NFV-enabled multicasting and online NFV-enabled multicasting problems. We then devise the very first approximation algorithm with an approximation ratio of 2K for the NFV-enabled multicasting problem if the number of servers for implementing the network functions of each request is no more than a constant K (1). We also study dynamic admissions of NFV-enabled multicast requests without the knowledge of future request arrivals with the objective to maximize the network throughput, for which we propose an online algorithm with a competitive ratio of O(log n) when K = 1, where n is the number of nodes in the network. We finally evaluate the performance of the proposed algorithms through experimental simulations. Experimental results demonstrate that the proposed algorithms outperform other existing heuristics. Zichuan Xu, Weifa Liang, Meitian Huang, Mike Jia, Song Guo 0001, Alex Galis |
ICDCS | 6 |
| 2016 | Energy-efficiency enablers and operations in software-defined environmentsabstractNew flexible network environments emerged in the last years, such as the Software-Defined Networks, the Network Function Virtualization and the various network slicing technologies. Their main goal is to satisfy and to flexibly cope with the changing requirements of both users and service / infrastructure providers with respect to the constraints of physical resources, the frequently changing network conditions, and with strategies that resolve performance bottlenecks by tuning the various performance trade-offs. Stuart Clayman, Lefteris Mamatas, Alex Galis |
NOMS | 3 |
| 2016 | Efficient management solutions for software-defined infrastructuresabstractNovel evolutions in the networking world have been proposed under the umbrella of 5G initiatives. The NFV concept is related with the building blocks for virtual networks that are characterized as highly dynamic network environments. SDN performs logically-centralized network control that is decoupled from the data plane, enabling holistic network management. Furthermore, there is a recent trend towards lightweight virtualized network devices and servers bringing significant advantages in terms of adaptability and responsiveness to the network and service environment dynamics. The above paradigms can be combined together, resulting in unprecedented flexibility in Software Defined Infrastructures (SDI) operations. Such unified environments require new efficient and distributed management facilities that are characterized by scalability, reliability, and adaptability to the dynamic conditions in terms of resource availability and changing service and infrastructure requirements. To assist the evaluation of these components, we developed a distributed facility for testing, evaluating, and experimenting with the management of these SDI environments — the Very Lightweight Software-Driven Network and Services Platform (VLSP). It exhibits the following properties: (i) it is a complete integrated management platform for SDI environments; and (ii) it is distributed and scalable, making it suitable for a wide range of topologies and network service deployments. Stuart Clayman, Lefteris Mamatas, Alex Galis |
NOMS | 3 |
| 2016 | Information Exchange Management as a Service for Network Function Virtualization EnvironmentsabstractThe Internet landscape is gradually adopting new communication paradigms characterized by flexibility and adaptability to the resource constraints and service requirements, including network function virtualization (NFV), software-defined networks, and various virtualization and network slicing technologies. These approaches need to be realized from multiple management and network entities exchanging information between each other. We propose a novel information exchange management as a service facility as an extension to ETSI's NFV management and orchestration framework, namely the virtual infrastructure information service (VIS). VIS is characterized by the following properties: 1) it exhibits the dynamic characteristics of such network paradigms; 2) it supports information flow establishment, operation, and optimization; and 3) it provides a logically centralized control of the established information flows with respect to the diverse demands of the entities exchanging information elements. Our proposal addresses the information exchange management requirements of NFV environments and is information-model agnostic. This paper includes an experimental analysis of its main functional and non-functional characteristics. Lefteris Mamatas, Stuart Clayman, Alex Galis |
IEEE Trans. Netw. Serv. Manag. | 3 |
| 2015 | NetSoft 2015 - ForewordabstractOn behalf of the Organizing and Technical Program Committees, we are pleased to welcome you to the inaugural conference on IEEE Network Softwarization (NetSoft 2015), in London, UK, April 13–17, 2015. Prosper Chemouil, George Pavlou, Raouf Boutaba, Alex Galis |
NetSoft | 4 |
| 2014 | The dynamic placement of virtual network functionsabstractThis paper addresses the problem of managing highly dynamic network and service environments, where virtual nodes and virtual links are created and destroyed depending on traffic volumes, service requests, or high-level goals such as reduction in energy consumption. This problem will be one of the main technical challenges to be faced in the evolution towards Future Networks (FN). Emerging paradigms such as Software Defined Networks (SDN) and Network Function Virtualization (NfV) are concrete steps towards infrastructures where network functions and services will be executed as applications in ensembles of virtual machines (VMs) hosted in pervasive standard hardware resources located across a network. The paper argues that in order to manage these virtual infrastructures there is a need to introduce high-level systems orchestration. The paper describes an architecture based on an orchestrater that ensures the automatic placement of the virtual nodes and the allocation of network services on them, supported by a monitoring system that collects and reports on the behaviour of the resources. The orchestrater manages the creation and removal of the virtual nodes, as well as configuring, monitoring, running and stopping software on them. As a proof of these concepts, a distributed orchestrater prototype has been designed, implemented and tested with the results of different placement algorithms presented. Stuart Clayman, Elisa Maini, Alex Galis, Antonio Manzalini, Nicola Mazzocca |
NOMS | 3 |
| 2013 | Conflict free coordination of SON functions in a Unified Management Framework: Demonstration of a proof of concept prototyping platform
Nikolaos Koutsouris, Kostas Tsagkaris, Panagiotis Demestichas, Zwi Altman, Richard Combes, Pierre Peloso, Laurent Ciavaglia, Lefteris Mamatas, Stuart Clayman, Alex Galis |
IM | 10 |
| 2013 | Managing Software-Driven Networks with a unified management framework
Nikolaos Koutsouris, Kostas Tsagkaris, Panagiotis Demestichas, Lefteris Mamatas, Stuart Clayman, Alex Galis |
IM | 6 |
| 2013 | On the Selection of Management/Monitoring Nodes in Highly Dynamic NetworksabstractThis paper addresses the problem of provisioning management/monitoring nodes within highly dynamic network environments, particularly virtual networks. In a network, where nodes and links may be spontaneously created and destroyed (perhaps rapidly) there is a need for stable and responsive management and monitoring, which does not create a large load (in terms of traffic or processing) for the system. A subset of nodes has to be chosen for management/monitoring, each of which will manage a subset of the nodes in the network. A new, simple, and locally optimal greedy algorithm called Pressure is provided for choice of node position to minimize traffic. This algorithm is combined with a system for predicting the lifespan of nodes, and a tunable parameter is also given so that a system operator could express a preference for elected nodes to be chosen to reduce traffic, to be “stable,” or some compromise between these positions. The combined algorithm called PressureTime is lightweight and could be run in a distributed manner. The resulting algorithms are tested both in simulation and in a testbed environment of virtual routers. They perform well, both at reducing traffic and at choosing long lifespan nodes. Richard G. Clegg, Stuart Clayman, George Pavlou, Lefteris Mamatas, Alex Galis |
IEEE Trans. Computers | 5 |
| 2011 | Monitoring, aggregation and filtering for efficient management of virtual networks
Stuart Clayman, Richard G. Clegg, Lefteris Mamatas, George Pavlou, Alex Galis |
CNSM | 5 |
| 2010 | Platforms and Software Systems for an Autonomic InternetabstractThe current Internet does not enable easy introduction and deployment of new network technologies and services. This paper aims to progress the Future Internet (FI) by introduction of a service composition and execution environment that re-use existing components of access and core networks. This paper presents essential service-centric platforms and software systems that have been developed with the aim to create a flexible environment for an Autonomic Internet. Javier Rubio-Loyola, Antonio Astorga, Joan Serrat 0001, Wei Koong Chai, Lefteris Mamatas, Alex Galis, Stuart Clayman, Abderhaman Cheniour, Laurent Lefèvre, Olivier Mornard, Andreas Fischer 0001, Alexandru Paler, Hermann de Meer |
GLOBECOM | 6 |
| 2010 | Software architecture definition for on-demand cloud provisioningabstractCloud computing [23] is a promising paradigm for the provisioning of IT services. Cloud computing infrastructures, such as those offered by the RESERVOIR project, aim to facilitate the deployment, management and execution of services across multiple physical locations in a seamless manner. In order for service providers to meet their quality of service objectives, it is important to examine how software architectures can be described to take full advantage of the capabilities introduced by such platforms. When dealing with software systems involving numerous loosely coupled components, architectural constraints need to be made explicit to ensure continuous operation when allocating and migrating services from one host in the Cloud to another. In addition, the need for optimising resources and minimising over-provisioning requires service providers to control the dynamic adjustment of capacity throughout the entire service lifecycle. We discuss the implications for software architecture definitions of distributed applications that are to be deployed on Clouds. In particular, we identify novel primitives to support service elasticity, co-location and other requirements, propose language abstractions for these primitives and define their behavioural semantics precisely by establishing constraints on the relationship between architecture definitions and Cloud management infrastructures using a model denotational approach in order to derive appropriate service management cycles. Clovis Chapman, Wolfgang Emmerich, Fermín Galán Márquez, Stuart Clayman, Alex Galis |
HPDC | 5 |
| 2010 | Towards an Information Management Overlay for emerging networksabstractThere has recently been an increasing research interest in network management infrastructures that autonomously adapt to the dynamics of the environment. In this paper, we present an information management platform, called the Information Management Overlay (IMO), which is an infrastructure that regulates information flow based on the properties and the state of the network environment. We discuss the design, implementation and optimization issues of this platform and we investigate experimentally how the IMO can adapt to different settings and optimization requirements. Lefteris Mamatas, Stuart Clayman, Marinos Charalambides, Alex Galis, George Pavlou |
NOMS | 4 |
| 2010 | QoS-Aware Service Selection Algorithms for Pervasive Service Composition in Mobile Wireless Environments
Kun Yang 0001, Alex Galis, Hsiao-Hwa Chen |
Mob. Networks Appl. | 2 |
| 2009 | Service Coalitions for Future Internet ServicesabstractThis paper proposes an algorithm that enables the support for a service market place in which service providers can negotiate and form coalitions in a self-centred approach. We present the main features of the algorithm and evaluate the proposed solution under different technical aspects including social network topology, scalability and convergence to optimal results. Javier Rubio-Loyola, Carlos Mérida-Campos, Steven Willmott, Antonio Astorga, Joan Serrat 0001, Alex Galis |
ICC | 6 |
| 2009 | RESERVOIR: Management technologies and requirements for next generation Service Oriented InfrastructuresabstractRESERVOIR project is developing an advanced system and service management approach that will serve as the infrastructure for cloud computing and communications and future Internet of services by creative coupling of service virtualization, grid computing, networking and service management techniques. This paper presents work in progress for the integration and management of such systems into a new generation of managed service infrastructure. Benny Rochwerger, Alex Galis, Eliezer Levy, Juan A. Cáceres, David Breitgand, Yaron Wolfsthal, Ignacio Martín Llorente, Mark Wusthoff, Rubén S. Montero, Erik Elmroth |
Integrated Network Management | 2 |
| 2008 | Stochastic maintenance of overlays in structured P2P systems
Peter Kersch, Róbert Szabó, Lawrence Cheng, Kerry Jean, Alex Galis |
Comput. Commun. | 5 |
| 2007 | Secure Bootstrapping of Distributed Hash Tables in Dynamic Wireless NetworksabstractExisting research work on Distributed Hash Tables (DHTs) assume that, prior to actually establishing a DHT, large number potential member nodes would come together at one point and at one place, and would all agree on the characteristics of the DHT to-be-established. This paper presents DHT bootstrapping, which is a novel approach to enable secure, efficient and scalable deployment of DHTs in wireless networks, in particular in wireless networks with time-varying topology. Our solution is not restricted to a particular type of DHT implementation. Lawrence Cheng, Kerry Jean, Roel Ocampo, Alex Galis, Peter Kersch, Róbert Szabó |
ICC | 4 |
| 2007 | Self-Management of Context-Aware Overlay Ambient NetworksabstractAmbient networks (ANs) are dynamically changing and heterogeneous as they consist of potentially large numbers of independent, heterogeneous mobile nodes, with spontaneous topologies that can logically interact with each other to share a common control space, known as the ambient control space. ANs are also flexible i.e. they can compose and decompose dynamically and automatically, for supporting the deployment of cross-domain (new) services. Thus, the AN architecture must be sophisticatedly designed to support such high level of dynamicity, heterogeneity and flexibility. We advocate the use of service specific overlay networks in ANs, that are created on-demand according to specific service requirements, to deliver, and to automatically adapt services to the dynamically changing user and network context. This paper presents a self-management approach to create, configure, adapt, contextualise, and finally teardown service specific overlay networks. Bertrand Mathieu, Alex Galis, Lawrence Cheng, Kerry Jean, Roel Ocampo, Marcus Brunner, Martin Stiemerling, Marco Cassini |
Integrated Network Management | 3 |
| 2005 | Implicit Flow QoS Signaling Using Semantic-Rich Context Tags
Roel Ocampo, Alex Galis, Hermann de Meer, Chris Todd |
IWQoS | 2 |
| 2003 | Functional Evaluation of an Integrated IP over WDM
Joan Serrat 0001, Eduardo Grampín, Lampros Raptis, Fotis Karayannis, Kostas Vaxevanakis, Dimitris Chronis, Harris Katopodis, Gerard Hoekstra, Willem A. Romijn, Alex Galis, Eugene Kozlovski |
Integrated Network Management | 10 |
| 2003 | Rule-Driven Mobile Intelligent Agents for Real-Time Configuration of IP Networks
Kun Yang 0001, Alex Galis, Dayou Liu |
KES | 2 |
| 2003 | Network-centric context-aware service over integrated WLAN and GPRS networksabstractIn order to bring together the higher speed of WLAN and the wider coverage of GPRS, solution from service's perspective is necessary. And this kind of integrated service should be context-aware in order to automatically adapt itself to the changing environment. This paper proposes to explore the applicability of using network-centric context-aware service to integrate WLAN and GPRS network environments. Starting from typical scenario description and requirement analysis, a policy-based context model is presented, which takes into account the real implementation of context-aware service in the underlying networks. A context-aware service scenario called modern professor is explored to exemplify this methodology based on the policy-based context-aware service system architecture. Kun Yang 0001, Alex Galis, Joan Serrat 0001, Kerry Jean, Nikolaos Vardalachos |
PIMRC | 2 |
| 2002 | SNAP based resource control for active networksabstractThis paper proposes a new efficient mechanism for controlling and managing the resources within and around the active nodes: routers and switches that have a legacy SNMP management system. Existing system such as ABLE has an out-of- band management capability, which is insufficient for managing data flow as the flow progresses through the network. This paper proposes the use of the combined approach of SNAP and SNMP as an efficient network resource management mechanism on the FAIN active nodes. It has an in-band management approach in which each data flow will negotiate its next hop before it goes there; or it can create IPSec tunnels and modify routing table entries for the data flow. Walter Eaves, Lawrence Cheng, Alex Galis, Thomas Becker 0005, Toshiaki Suzuki, Spyros G. Denazis, Chiho Kitahara |
GLOBECOM | 3 |
| 2002 | IP over WDM networks: a policy-based management approachabstractThis paper describes the policy-based management architecture devised for management of IP over WDM networks and is part of the work carried out in the IST Project WINMAN, whose aim is to develop and validate an open and flexible integrated management system for this type of networks. The IETF has been working in the policy based management area, through two of its groups, in order to provide the means for managing IP based networks, offering some QoS guarantees. At the same time hybrid networks such as those placing IP directly over WDM are emerging as the solution to the increasing need for bandwidth. Management of such networks in an integrated fashion is a large research area. We are interested in integrating the policy management paradigm for managing integrated networks, such as IP over WDM networks. Nikolaos Vardalachos, Alex Galis, Eduardo Grampín, Joan Serrat 0001 |
NOMS | 2 |
| 2001 | Integrated Management for IP end-to-end Transport Services over WDM NetwroksabstractThis paper outlines the initial architectural results of WINMAN, an European research and development project started in July 2000, whose aim is to offer an integrated network management solution for the provisioning and maintenance of IP over WDM end-to-end transport services derived from service level agreements (SLAs). Management requirements for IP over WDM have been identified and a two-tier architecture has been conceived for the system that is intended for proof concept of the WINMAN solution. The first layer contains the technology dependent managers, that is one for the IP technology and another manager for the WDM. These two management systems will interact with existing network element management systems the southbound WINMAN interface. On top of this layer there is a second interface whose purpose is the integration of the above mentioned management systems. This system will be in turn integrated in different experimental test beds and fully tested in real life conditions. Joan Serrat 0001, Alex Galis, Nadia Katsanou, Lampros Raptis, Fotis Karayannis, Polina Bayvel, W. Verhoef, Harold C. H. Balemans, Eduardo Grampín, Dimitris Chronis, Bruno Mayersohn, Daniel Josef, Chris Todd |
Integrated Network Management | 2 |