A Long Short-Term Memory Recurrent Neural Network Framework for Network Traffic Matrix Prediction

Network Traffic Matrix (TM) prediction is defined as the problem of estimating future network traffic from the previous and achieved network traffic data. It is widely used in network planning, resource management and network security. Long Short-Term Memory (LSTM) is a specific recurrent neural network (RNN) architecture that is well-suited to learn from experience to classify, process and predict time series with time lags of unknown size. LSTMs have been shown to model temporal sequences and their long-range dependencies more accurately than conventional RNNs. In this paper, we propose a LSTM RNN framework for predicting short and long term Traffic Matrix (TM) in large networks. By validating our framework on real-world data from GEANT network, we show that our LSTM models converge quickly and give state of the art TM prediction performance for relatively small sized models.Comment: Submitted for peer review. arXiv admin note: text overlap with arXiv:1402.1128 by other author

NeuTM: A Neural Network-based Framework for Traffic Matrix Prediction in SDN

This paper presents NeuTM, a framework for network Traffic Matrix (TM) prediction based on Long Short-Term Memory Recurrent Neural Networks (LSTM RNNs). TM prediction is defined as the problem of estimating future network traffic matrix from the previous and achieved network traffic data. It is widely used in network planning, resource management and network security. Long Short-Term Memory (LSTM) is a specific recurrent neural network (RNN) architecture that is well-suited to learn from data and classify or predict time series with time lags of unknown size. LSTMs have been shown to model long-range dependencies more accurately than conventional RNNs. NeuTM is a LSTM RNN-based framework for predicting TM in large networks. By validating our framework on real-world data from GEEANT network, we show that our model converges quickly and gives state of the art TM prediction performance.Comment: Submitted to NOMS18. arXiv admin note: substantial text overlap with arXiv:1705.0569

On the Minimization of Handover Decision Instability in Wireless Local Area Networks

This paper addresses handover decision instability which impacts negatively on both user perception and network performances. To this aim, a new technique called The HandOver Decision STAbility Technique (HODSTAT) is proposed for horizontal handover in Wireless Local Area Networks (WLAN) based on IEEE 802.11standard. HODSTAT is based on a hysteresis margin analysis that, combined with a utilitybased function, evaluates the need for the handover and determines if the handover is needed or avoided. Indeed, if a Mobile Terminal (MT) only transiently hands over to a better network, the gain from using this new network may be diminished by the handover overhead and short usage duration. The approach that we adopt throughout this article aims at reducing the minimum handover occurrence that leads to the interruption of network connectivity (this is due to the nature of handover in WLAN which is a break before make which causes additional delay and packet loss). To this end, MT rather performs a handover only if the connectivity of the current network is threatened or if the performance of a neighboring network is really better comparing the current one with a hysteresis margin. This hysteresis should make a tradeoff between handover occurrence and the necessity to change the current network of attachment. Our extensive simulation results show that our proposed algorithm outperforms other decision stability approaches for handover decision algorithm.Comment: 13 Pages, IJWM

NeuRoute: Predictive Dynamic Routing for Software-Defined Networks

This paper introduces NeuRoute, a dynamic routing framework for Software Defined Networks (SDN) entirely based on machine learning, specifically, Neural Networks. Current SDN/OpenFlow controllers use a default routing based on Dijkstra algorithm for shortest paths, and provide APIs to develop custom routing applications. NeuRoute is a controller-agnostic dynamic routing framework that (i) predicts traffic matrix in real time, (ii) uses a neural network to learn traffic characteristics and (iii) generates forwarding rules accordingly to optimize the network throughput. NeuRoute achieves the same results as the most efficient dynamic routing heuristic but in much less execution time.Comment: Accepted for CNSM 201

Limitations of OpenFlow Topology Discovery Protocol

OpenFlow Discovery Protocol (OFDP) is the de-facto protocol used by OpenFlow controllers to discover the underlying topology. In this paper, we show that OFDP has some serious security, efficiency and functionality limitations that make it non suitable for production deployments. Instead, we briefly introduce sOFTD, a new discovery protocol with a built-in security characteristics and which is more efficient than traditional OFDP.Comment: The peer reviewed version can be found here (to be published soon

Cross-layer Loss Differentiation Algorithm to Improve TCP Performances in WLANs

International audienceLoss Differentiation Algorithms (LDA) are currently used to determine the cause of packet losses with an aim of improving TCP performance over wireless networks. In this work, we propose a cross-layer solution based on two LDA in order to classify the loss origin on an 802.11 link and then to react consequently. The first LDA scheme, acting at the MAC layer, allows differentiating losses due to signal failure caused by displacement or by noise from other loss types. Moreover, in case of signal failure, it adapts the behavior of the MAC layer to avoid a costly end-to-end TCP resolution. The objective of the second LDA scheme, which acts at the TCP layer, is to distinguish a loss due to interferences from those due to congestions and to adapt consequently the TCP behavior. The efficiency of each LDA scheme and of the whole cross-layer solution are then demonstrated through simulations

Identification of nonmonotonic behaviors and stick-slip transition in liquid crystal polymers

International audienceThe recent identification of shear-induced phases in the isotropic melts of liquid crystal polymers shows that these materials are expected to display original nonlinear behaviors. We have investigated the flow behavior of a nematic sidechain polymer above its isotropic-nematic transition temperature. Nonlinear rheology and bire-fringence measurements indicate the appearance, above a critical shear rate, of the shear-induced isotropic-nematic phase transition. The rheological behavior of this induced phase is characterized by undamped time-periodic shear stress oscillations. These sustained oscillations are interpreted in terms of a stick-slip mechanism alternating high-friction static state and low-friction kinetic state. PACS number͑s͒: 83.80.Xz, 47.20.Hw, 83.50.Ax, 64.70.Md Polymers are non-Newtonian fluids ͓1͔ whereas liquid crystals do not behave as simple fluids close to phase transitions ͓2͔. When these two complex fluids are coupled to form a melt of sidechain liquid crystal polymers ͑SCLCPs͒, the resulting rheological behavior is expected to be peculiar. The very first flow studies ͓3͔ have indeed indicated that SCLCP melts display strong nonlinear behaviors above the isotropic-nematic transition temperature (T NI). This behavior looks similar to the well-studied shear-induced behavior of giant micelle solutions which display a shear-induced IN transition above T NI ͓4,5͔. The SCLCP shear-induced transition was revealed by flow birefringence and via the existence of a stress plateau in the stress versus shear rate curve. The stress plateau can be explained by entering an unstable flow region; above a critical shear rate, the region is characterized by a decreasing stress with increasing shear rate. The system is then supposed to phase separate into homogeneous bands ͑shear banding͒ to maintain the imposed shear rate ͓5͔. The existence of such nonequilibrium states opens the question of identification of the coupling parameters associated with the critical shear rate. Clearly, the shear induced SCLCP critical times are not associated with the lifetime of the pretransi-tional fluctuations, suggesting a coupling with slower time scales which could be rather consistent with the existence of macroscopic heterogeneities as proposed by Collin et al. ͓6͔. The shear-induced phase conformation of the polymer main chain was also determined using small angle neutron scattering. For a LC polymer characterized in the equilibrium nem-atic phase by a perpendicular main chain/mesogen coupling ͑oblate conformation͒, we observed that the initially perpendicular coupling is inverted in the shear-induced nematic phase to a parallel coupling with the main-chain conforma-tion becoming prolate ͓3͔. This structural rearrangement can be proposed as a working hypothesis to explain the appearance of shear-induced transitions in SCLCP isotropic melts. The purpose of the present paper is to analyze the flow behavior produced above T NI by a SCLCP whose main-chain conformation is already prolate in the equilibrium nematic phase ͓7͔. The experimental techniques used are nonlinear rheology and flow birefringence. A nonequilibrium phase compatible with shear-banding is identified together with the observation of a second nonlinear behavior corresponding to an oscillating regime. The SCLCP chosen, PA 4-CN, is characterized as a prolate nematic polymer ͓7͔. The monomers have been synthesized at the Laboratoire Lé on Brillouin and polymerized by Poly-merExpert via controlled radical polymerization. The polymer described here corresponds to a molecular weight of M W ϭ85 800 and a polydispersity index of Iϭ1.1. This molecular weight corresponds to a nonentangled polymer and no rubbery plateau was found in viscoelastic measurements. This PA 4-CN presents the following succession of me-sophases: Tg-30 °C-N-116 °C-I and corresponds to the formul

VNR Algorithm: A Greedy Approach For Virtual Networks Reconfigurations

6 pagesInternational audienceIn this paper we address the problem of virtual network reconfiguration. In our previous work on virtual network embedding strategies, we found that most virtual network rejections were caused by bottlenecked substrate links while peak resource use is equal to 18%. These observations lead us to propose a new greedy Virtual Network Reconfiguration algorithm, VNR. The main aim of our proposal is to 'tidy up' substrate network in order to minimise the number of overloaded substrate links, while also reducing the cost of reconfiguration. We compare our proposal with the related reconfiguration strategy VNA-Periodic, both of them are incorporated in the best existing embedding strategies VNE-AC and VNE-Greedy in terms of rejection rate. The results obtained show that VNR outperforms VNA-Periodic. Indeed, our research shows that the performances of VNR do not depend on the virtual network embedding strategy. Moreover, VNR minimises the rejection rate of virtual network requests by at least ' 83% while the cost of reconfiguration is lower than with VNA-Periodic

Creation of Virtual Wi-Fi Access Point and Secured Wi-Fi Pairing, through NFC

The growing ubiquity of Wi-Fi networks combined with the integration of low-cost Wi-Fi chipsets in all devices makes Wi-Fi as the wireless technology the most used for accessing to internet [1]. This means that the development of a Wi-Fi strategy has become an imperative for almost all operators worldwide. In this context, APs (Access Points) have to become as secure as cellular networks. Furthermore, authentication process between a mobile device and an access point has to be automated, without user constraining configuration. For reaching this purpose, client must have different credentials depending on authentication method. Our goal is to create an architecture that is both ergonomic and flexible in order to meet the need for connection and client mobility. We use NFC technology as a radio channel for starting communication with the network. The communication initiation will instantiate a virtual Wi-Fi AP and distribute all policies and access certificates for an authentication based on EAP-TLS (it could be extended to any EAP method for 802.1X standard). The end result of our new topology is to allow access to services through a virtual Wi-Fi AP with an enterprise-grade in a public hotspot