• When & Where: Seminars are generally (please, check the timeline and location before coming!) held on:
    • Wednesday afternoon at LINCS (14h-15h, Salle de Conseil) and
    • Thursday afternoon at Barrault (14h-15h, Amphi Saphir).
  • Contact us: if you wish to give a talk on networking, math, software or embedded-system topics, do not hesitate to contact us

[Next talks] [All talks]

22/02/2017 (@LINCS, Seminar Room)Ravi R. Mazumdar (University of Waterloo)Insensitivity of Loss Systems under Randomized SQ(d) Algorithms
01/03/2017 (@LINCS, Seminar Room)Francesco Bronzino (INRIA)Named-Object Based Services in the Future Internet Architecture
03/03/2017 (@LINCS, Seminar Room)Dusit Niyato (Nanyang Technological University, Singapore)Joint Cyber Insurance and Security-as-a-Service Provisioning in Cloud Computing
03/03/2017 (@LINCS, Seminar Room)Luigi Atzori (University of Cagliari, Italy))QoE Management for Internet Applications: Technologies and Challenges

Date:22/02/2017, 14h
Room:LINCS, Seminar Room
Speaker:Ravi R. Mazumdar (University of Waterloo)
Talk:Insensitivity of Loss Systems under Randomized SQ(d) Algorithms
Abstract:In many applications such as cloud computing, managing server farm resources etc. an incoming task or job has to be matched with an appropriate server in order to minimise the latency associated with the processing. Ideally the best choice would be to match a job to the fastest available server. However when there are thousands of servers obtaining the information on server tasks is expensive. Pioneered in the 1990's the idea of randomised sampling of a few servers was proposed by Vvedenskaya and Dobrushin in Russia and Mitzmenmacher in the US and popularised as the "power of two" schemes which basically means that sampling two servers randomly and sending the job to the "better" server (i.e. with the shortest queue, or most resources) provides most of the benefits of sampling all the servers.In the talk I will discuss multi-server loss models under power-of-d routing scheme when service time distributions are general with finite mean. Previous works on these models assume that the service times are exponentially distributed and insensitivity was suggested through simulations. Showing insensitivity to service time distributions has remained an open problem. We address this problem by considering service time distributions as Mixed-Erlang distributions that are dense in the class of general distributions on (0, infty). We derive the mean field equations (MFE) of the empirical distributions for the system and establish the existence and uniqueness of the fixed point of the MFE. Furthermore we show that the fixed point of the MFE corresponds to the fixed point obtained from the MFE corresponding to a system with exponential service times showing that the fixed point is insensitive to the distribution. We provide numerical evidence of the global asymptotic stability of the fixed point, which would then imply that the fixed point is indeed the stationary distribution. We conclude with a brief discussion of the case of the MFE with general service times showing that the MFE is now characterized by a pde whose stationary point coincides with the fixed point in the case with exponential service times.The techniques developed in this paper are applicable to study mean field limits for Markov processes on general state spaces and insensitivity properties of other queueing models.
Biography:The speaker was educated at the Indian Institute of Technology, Bombay (B.Tech, 1977), Imperial College, London (MSc, DIC, 1978) and obtained his PhD under A. V. Balakrishnan at UCLA in 1983.He is currently a University Research Chair Professor in the Dept. of ECE at the University of Waterloo,Ont., Canada where he has been since September 2004. Prior to this he was Professor of ECE at PurdueUniversity, West Lafayette, USA. He is a D.J. Gandhi Distinguished Visiting Professor at the Indian Institute of Technology, Bombay. He is a Fellow of the IEEE and the Royal Statistical Society. He is a recipient of the Best Paper Awards at INFOCOM 2006, the International Teletraffic Congress 2015, Performance 2015, and was runner-up for the Best Paper Award at INFOCOM 1998.His research interests are in modeling, control, and performance analysis of both wireline and wirelessnetworks, and in applied probability and stochastic analysis with applications to queueing, filtering, and optimization.
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Date:01/03/2017, 14h
Room:LINCS, Seminar Room
Speaker:Francesco Bronzino (INRIA)
Talk:Named-Object Based Services in the Future Internet Architecture
Abstract:After many years of constant evolution, the Internet has approached a historic inflection point where mobile platforms, applications and services are poised to replace the fixed-host/server model that has dominated the Internet since its inception. Driven by the strikingly different Internet population of mobile devices and services, new fundamental communication abstractions are required and the current IP based Internet fails to meet their requirement in a satisfying fashion. Starting from these key considerations, this talk aims to introduce the audience to a new approach to networking, that centers around the central architectural concept of Named-Object based networking and the power that lies behind it. Looking at the different architectures presented over the years, a set of new fundamental abstractions are defined, providing a comprehensive analysis of their properties and how they could be met. This study leads to the presentation of the MobilityFirst architecture in which the "narrow waist" of the protocol stack is based on Named-Objects which enable a broad range of capabilities in the network.As an example of the potential of the Named-Object abstraction, an analysis of how advanced cloud services can be supported in the proposed architecture is presented. In particular, the concept of naming is extended to natively support virtual network identifiers. It is shown that the virtual network capability can be designed by introducing the concept of a "Virtual Network Identifier (VNID)" which is managed as a Named-Object. Further, the design supports the concept of Application Specific Routing (ASR) which enables network routing decisions to be made with awareness of application parameters such as cloud server workload. Experimental results show that the new framework provides a clean and simple logic for defining and managing virtual networks while limiting the performance impact produced by the additional overhead generated by running such system. Moreover, using a prototype of the architecture deployed on a nation-wide testbed, the potential of ASR is demonstrated in a cloud service scenario.
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Date:03/03/2017, 11h
Room:LINCS, Seminar Room
Speaker:Dusit Niyato (Nanyang Technological University, Singapore)
Talk:Joint Cyber Insurance and Security-as-a-Service Provisioning in Cloud Computing
Abstract:As computing services are increasingly cloud-based, corporations are investing in cloud-based security measures. The Security-as-a-Service (SECaaS) paradigm allows customers to outsource security to the cloud, through the payment of a subscription fee. However, no security system is bulletproof, and even one successful attack can result in the loss of data and revenue worth millions of dollars. To guard against this eventuality, customers may also purchase cyber insurance to receive recompense in the case of loss. To achieve cost effectiveness, it is necessary to balance provisioning of security and insurance, even when future costs and risks are uncertain. This presentation introduces a stochastic optimization model to optimally provision security and insurance services in the cloud. Since the model is a mixed integer problem, we also introduce a partial Lagrange multiplier algorithm that takes advantage of the total unimodularity property to find the solution in polynomial time. We show the effectiveness of these techniques using numerical results based on real attack data to demonstrate a realistic testing environment, and find that security and insurance are interdependent.
Biography:Dusit Niyato is currently an associate professor in the School of Computer Science and Engineering, at the Nanyang Technological University, Singapore. He received B.E. from King Mongkuk’s Institute of Technology Ladkrabang (KMITL), Thailand in 1999 and Ph.D. in Electrical and Computer Engineering from the University of Manitoba, Canada in 2008. He has published more than 300 technical papers in the area of wireless and mobile networking and authored the books "Resource Management in Multi-Tier Cellular Wireless Networks", "Game Theory in Wireless and Communication Networks: Theory, Models, and Applications" and "Dynamic Spectrum Access and Management in Cognitive Radio Networks". He won the Best Young Researcher Award of IEEE Communications Society (ComSoc) Asia Pacific (AP) and The 2011 IEEE Communications Society Fred W. Ellersick Prize Paper Award. He is a distinguished lecturer of the IEEE Communications Society. His works have received more than 13,000 citations (Google Scholar).Currently, he serves as an area editor of IEEE Transactions on Wireless Communications (Radio Management and Multiple Access), an associate editor of IEEE Transactions on Communications, an editor of IEEE Communications Surveys and Tutorials (COMST), and IEEE Transactions on Cognitive Communications and Networking (TCCN). He was a guest editor of IEEE Journal on Selected Areas on Communications, special issue on Cognitive Radio Networking & Communications, and Recent Advances in Heterogeneous Cellular Networks. He is a Fellow of IEEE.
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Date:03/03/2017, 10h
Room:LINCS, Seminar Room
Speaker:Luigi Atzori (University of Cagliari, Italy))
Talk:QoE Management for Internet Applications: Technologies and Challenges
Abstract:The talk starts by presenting the current approaches for a QoE-aware service management in the Internet, i.e., application oriented or network management, which are mostly characterized by the tools available by the stakeholders implementing the process and also by their own interests. Then, the current limits and issues of these approaches are highlighted, together with the current directions of development in the field. These are mostly characterized by a strong evolution towards the virtualization of the services through the introduction of the SDN and NFV paradigms. These allow for a more flexible management of the services with a better control of the QoE and for a potential stronger cooperation among the different actors involved in the service provisioning chain.
Biography:Luigi Atzori (SM'09) is Associate Professor at the Department of Electrical and Electronic Engineering at the University of Cagliari (Italy), where he leads the laboratory of Multimedia and Communications with around 15 affiliates (http://mclab.diee.unica.it). L. Atzori research interests are in multimedia communications and computer networking (wireless and wireline), with emphasis on multimedia QoE, multimedia streaming, NGN service management, service management in wireless sensor networks, architecture and services in the Internet of Things. He is the coordinator of the Marie Curie Initial Training Network on QoE for multimedia services (http://qoenet-itn.eu), which involves ten European Institutions in Europe and one in South Korea. He has been the editor for the ACM/Springer Wireless Networks Journal and guest editor for many journals, including the IEEE Communications Magazine, the Springer Monet and the Elsevier Signal Processing: Image Communications Journals. He is member of the steering committee for the IEEE Trans. on Multimedia, member of the editorial board of the IEEE IoT, the Elsevier Ad Hoc Networks and the Elsevier Digital Communications and Networks journals. He served as a technical program chair for various international conferences and workshops. He served as a reviewer and panelist for many funding agencies, including H2020, FP7, Cost and Italian MIUR.
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