Showing papers by "Orange S.A. published in 2013"

Content centric m2m system

Abstract: The invention concerns a method for routing data at a first node of a network comprising at least a second node. The method comprises: - providing the first node with a database FIB storing at least one association between : o an URL component identifying a content at the first node, and o a unique identifier associated to the second node, the unique identifier being specified by the second node; - registering a content locally stored in the second node by storing in the database FIB an association between an URL component identifying the locally stored content and the unique identifier of the second node; and, upon reception from a requesting entity, by the first node, of a content request comprising a content identifier, the method further comprises: - checking in the database FIB whether the content identifier comprises the URL component, - and forwarding the content request to the second node if the content identifier comprises the URL component associated with the unique identifier of the second node.

Optimal multipath congestion control and request forwarding in Information-Centric Networks

Abstract: The evolution of the Internet into a distributed Information access system calls for a paradigm shift to enable an evolvable future network architecture. Information-Centric Networking (ICN) proposals rethink the communication model around named data, in contrast with the host-centric transport view of TCP/IP. Information retrieval is natively pull-based, driven by user requests, point-to-multipoint and intrinsically coupled with in-network caching. In this paper, we tackle the problem of joint multipath congestion control and request forwarding in ICN for the first time. We formulate it as a global optimization problem with the twofold objective of maximizing user throughput and minimizing overall network cost. We solve it via decomposition and derive a family of optimal congestion control strategies at the receiver and of distributed algorithms for dynamic request forwarding at network nodes. An experimental evaluation of our proposal is carried out in different network scenarios to assess the performance of our design and to highlight the benefits of an ICN approach.

Multipath congestion control in content-centric networks

Abstract: Data communication across the Internet has significantly changed under the pressure of massive content delivery. Content-Centric Networking (CCN) rethinks Internet communication paradigm around named data retrieval, in contrast with the host-to-host transport model of TCP/IP. Content retrieval is natively pull-based driven by user requests, point-to-multipoint and intrinsically coupled with the availability of network storage. By leveraging the key features of CCN transport, in this paper we propose for the first time a congestion control mechanism realizing efficient multipath communication over content-centric networks. Our proposal is based on a Remote Adaptive Active Queue Management (RAAQM) at the receiver that performs a per-route control of bottleneck queues along the paths. We analyze the stability of the proposed solution and assess its performance by means of CCN packet-level simulations under random and optimal route selection.

CROWD: An SDN Approach for DenseNets

Abstract: Traffic demands in mobile networks are expected to grow substantially in the next years, both in terms of total traffic volume and of bit-rate required by individual users. It is generally agreed that the only possible solution to overcome the current limitations is to deploy very dense and heterogeneous wireless networks, which we call DenseNets. However, simply scaling down existing networks by orders of magnitude, as required to fulfill traffic forecasts, is not possible because of the following constraints: i) the bottleneck would shift from the Radio Access Network (RAN) to the backhaul, ii) control overhead, especially related to mobility management, would make the network collapse, iii) operational costs of the network would be unbearable due to energy consumption and maintenance/optimisation. In this paper, Software Defined Network (SDN) for mobile networks is claimed as the paradigm shift necessary to tackle adequately the above challenges. A novel architecture is proposed, which supports DenseNets made of overlapping LTE and WLAN cells connected to the core network via a reconfigurable backhaul.

Multicriteria Optimization of Access Selection to Improve the Quality of Experience in Heterogeneous Wireless Access Networks

Abstract: Wireless technology is a revolutionary advancement providing users with ubiquitous data and telephony access anywhere and anytime with no physical (PHY) connection. The currently deployed wireless networks like Wi-Fi, Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications Systems (UMTS), and Long Term Evolution (LTE) systems have different characteristics that make them complementary in terms of performance, coverage, and cost. This network variety presents an opportunity to provide better services to end users, given the advances in mobile terminals (MTs). To reach this goal, an appropriate automatic network selection (ANS) mechanism, which is able to always select the best access network, is needed. This consists of constantly monitoring any type of available access network, i.e., automatically selecting and switching to the best one, as the network that maximizes the users quality of experience, taking into account their preferences and the terminal and network conditions. ANS is a multidimensional decision-making problem that can be solved by finding an appropriate complex tradeoff between possibly conflicting criteria. In this paper, we propose an analytical model to capture the preferences of end users. Based on this model, we design an ANS mechanism that takes into account all aspects of the tradeoff between the quality of the connections, the preferences of the end users, and the cost. To highlight the benefits of our approach from the perspectives of both end users and network operators, we have implemented and tested the solution in a multitechnology simulator. Results show that the proposed solution outperforms mainstream approaches.

Voice control of applications by associating user input with action-context identifier pairs

Abstract: A method is provided for enabling or enhancing a use of voice control in a voice controlled application (VCA) via a development framework. The method includes: providing in the framework a plurality of action-context pairs—also called framework action-context pairs—usable in a memory of an application development device, which includes a processor, that serve to direct execution of the VCA, wherein the framework context defines a list of parameters related to the action and their respective value types; providing at least one of a voice recognition engine (VRE) and a natural language library to match each action-context pair with semantically related vocabulary; providing in the framework a registration mechanism that permits an association to be formed between an action-context pair and a handler in the voice controlled application. An associated development system for developing the VCA and user equipment that executes the VCA are provided as well.

Can we use flexible transponders to reduce margins

Abstract: The introduction of bit rate variable transceivers is expected to improve network reconfiguration and optimization. The different network margins are discussed along with the related strategies to reduce them.

Distributed IP mobility management from the perspective of the IETF: motivations, requirements, approaches, comparison, and challenges

Abstract: The recent explosion of mobile Internet traffic is accelerating the evolution of mobile network architectures toward flat architectures with all IP backhaul support. IP mobility support protocols are thus required to be adopted in such mobile network architectures. Accordingly, the IETF Distributed Mobility Management (DMM) working group was recently chartered to address such architectural changes with rapidly increasing mobile Internet usages. Unlike existing IP mobility support protocols, DMM protocols being considered at the IETF aim at distributing mobile Internet traffic in an optimal way while not relying on centrally deployed mobility anchors. In this article, we first discuss motivations and requirements of DMM. We then present two different possible approaches: host-based and network-based DMM approaches. Furthermore, comprehensive comparison results are provided. Finally, we discuss challenges in developments of DMM protocols.

Ergodic Control and Polyhedral Approaches to PageRank Optimization

Abstract: We study a general class of PageRank optimization problems which involve finding an optimal outlink strategy for a web site subject to design constraints. We consider both a continuous problem, in which one can choose the intensity of a link, and a discrete one, in which in each page, there are obligatory links, facultative links and forbidden links. We show that the continuous problem, as well as its discrete variant when there are no constraints coupling different pages, can both be modeled by constrained Markov decision processes with ergodic reward, in which the webmaster determines the transition probabilities of websurfers. Although the number of actions turns out to be exponential, we show that an associated polytope of transition measures has a concise representation, from which we deduce that the continuous problem is solvable in polynomial time, and that the same is true for the discrete problem when there are no coupling constraints. We also provide efficient algorithms, adapted to very large networks. Then, we investigate the qualitative features of optimal outlink strategies, and identify in particular assumptions under which there exists a “master” page to which all controlled pages should point. We report numerical results on fragments of the real web graph.

Impact of overlapping speech detection on speaker diarization for broadcast news and debates

Abstract: The overlapping speech detection systems developped by Orange and LIMSI for the ETAPE evaluation campaign on French broadcast news and debates are described. Using either cepstral features or a multi-pitch analysis, a F1-measure for overlapping speech detection up to 59.2% is reported on the TV data of the ETAPE evaluation set, where 6.7% of the speech was measured as overlapping, ranging from 1.2% in the news to 10.4% in the debates. Overlapping speech segments were excluded during the speaker diarization stage, and these segments were further labelled with the two nearest speaker labels, taking into account the temporal distance. We describe the effects of this strategy for various overlapping speech systems and we show that it improves the diarization error rate in all situations and up to 26.1% relative in our best configuration.

Fraud Detection in Mobile Payments Utilizing Process Behavior Analysis

Abstract: Generally, fraud risk implies any intentional deception made for financial gain. In this paper, we consider this risk in the field of services which support transactions with electronic money. Specifically, we apply a tool for predictive security analysis at runtime which observes process behavior with respect to transactions within a money transfer service and tries to match it with expected behavior given by a process model. We analyze deviations from the given behavior specification for anomalies that indicate a possible misuse of the service related to money laundering activities. We evaluate the applicability of the proposed approach and provide measurements on computational and recognition performance of the tool - Predictive Security Analyser - produced using real operational and simulated logs. The goal of the experiments is to detect misuse patterns reflecting a given money laundering scheme in synthetic process behavior based on properties captured from real world transaction events.

Boiling local heat transfer enhancement in minichannels using nanofluids

Abstract: This paper reports an experimental study on nanofluid convective boiling heat transfer in parallel rectangular minichannels of 800 μm hydraulic diameter. Experiments are conducted with pure water and silver nanoparticles suspended in water base fluid. Two small volume fractions of silver nanoparticles suspended in water are tested: 0.000237% and 0.000475%. The experimental results show that the local heat transfer coefficient, local heat flux, and local wall temperature are affected by silver nanoparticle concentration in water base fluid. In addition, different correlations established for boiling flow heat transfer in minichannels or macrochannels are evaluated. It is found that the correlation of Kandlikar and Balasubramanian is the closest to the water boiling heat transfer results. The boiling local heat transfer enhancement by adding silver nanoparticles in base fluid is not uniform along the channel flow. Better performances and highest effect of nanoparticle concentration on the heat transfer are obtained at the minichannels entrance.

The relationship between specific absorption rate and temperature elevation in anatomically based human body models for plane wave exposure from 30 MHz to 6 GHz.

Abstract: According to the international safety guidelines/standard, the whole-body-averaged specific absorption rate (Poljak et al 2003 IEEE Trans. Electromagn. Compat. 45 141–5) and the peak spatial average SAR are used as metrics for human protection from whole-body and localized exposures, respectively. The IEEE standard (IEEE 2006 IEEE C95.1) indicates that the upper boundary frequency, over which the whole-body-averaged SAR is deemed to be the basic restriction, has been reduced from 6 to 3 GHz, because radio-wave energy is absorbed around the body surface when the frequency is increased. However, no quantitative discussion has been provided to support this description especially from the standpoint of temperature elevation. It is of interest to investigate the maximum temperature elevation in addition to the core temperature even for a whole-body exposure. In the present study, using anatomically based human models, we computed the SAR and the temperature elevation for a plane-wave exposure from 30 MHz to 6 GHz, taking into account the thermoregulatory response. As the primary result, we found that the ratio of the core temperature elevation to the whole-body-averaged SAR is almost frequency independent for frequencies below a few gigahertz; the ratio decreases above this frequency. At frequencies higher than a few gigahertz, core temperature elevation for the same whole-body averaged SAR becomes lower due to heat convection from the skin to air. This lower core temperature elevation is attributable to skin temperature elevation caused by the power absorption around the body surface. Then, core temperature elevation even for whole-body averaged SAR of 4 W kg−1 with the duration of 1 h was at most 0.8 °C, which is smaller than a threshold considered in the safety guidelines/standard. Further, the peak 10 g averaged SAR is correlated with the maximum body temperature elevations without extremities and pinna over the frequencies considered. These findings were confirmed for seven models, including models of a child and a pregnant female. Thus, the current basic restriction for whole-body exposure in the international guidelines is conservative. Peak spatial-averaged SAR can be used as a metric for estimating local temperature elevation even for whole-body exposure. Our computational results also support the description in the IEEE standard about the reduction of the upper applicable frequency of whole-body-averaged SAR from 6 and 3 GHz; the power density reference level is more conservative than the basic restriction limit for the whole-body averaged SAR from the standpoint of temperature elevation.

Efficient data dissemination in cooperative vehicular networks

Abstract: Vehicular networks are drawing the attention of both research community and automotive industry because they provide intelligent transportation systems as well as drivers and passengers’ assistant services. However, the industrialization of such networks faces a number of challenges, in particular, the high cost of the infrastructure to deploy. To overcome this problem, an effective solution is to rely on cooperative vehicle-to-vehicle communication to minimize the deployed infrastructure. Because a large number of cooperative vehicle-to-vehicle applications are broadcasting by nature, we proposed an efficient dissemination protocol: Road-Oriented Dissemination (ROD). ROD consists in two modules: (i) Optimized Distance Defer Transfer Module and (ii) Store-and-Forward Module. We compare our protocol with other dissemination protocols and analyze its performance by simulations, on-road tests and analytically. Performance study shows interesting results of ROD compared with the other existing solutions. ROD is able to provide a low end-to-end delay, high delivery ratios, and a minimum bandwidth usage because only a limited number of vehicles are involved in the broadcast scheme. Copyright © 2011 John Wiley & Sons, Ltd.

Dual-polarization multi-band OFDM versus single-carrier DP-QPSK for 100 Gb/s long-haul WDM transmission over legacy infrastructure.

Abstract: The transmission performance of coherent dual-polarization multi-band OFDM (DP-MB-OFDM) and QPSK (DP-QPSK) are experimentally compared for 100 Gb/s long-haul transport over legacy infrastructure combining G.652 fiber and 10 Gb/s WDM system. It is shown that DP-MB-OFDM and DP-QPSK have nearly the same performance at 100 Gb/s after transmission over a 10 × 100-km fiber line. Furthermore, the origin of performance degradations and limitations of the DP-MB-OFDM is explored numerically, as well as the impact of transmission distance and sub-band spacing.

Efficient control plane for passive optical burst switching network

Abstract: One of the main drawbacks of classical Optical Burst Switching (OBS) solutions is the loss of bursts when contentions occur. Time-domain Wavelength Interleaved Networking (TWIN) is a lossless solution with contention resolution in the edge nodes providing a simple and passive switching in the core nodes and satisfying both low-energy and efficient bandwidth use criteria. However, this solution requires an efficient control plane. In this paper, we compare three different control planes based on either centralized or distributed schemes. Moreover we use two different slot allocation strategies (contiguous or disjoint). The performances of the proposed solutions are compared in terms of total delay, jitter, queue length and bandwidth utilization. The simulation parameters are carefully chosen to take into account implementation constraints. We find that the centralized solution with contiguous slot allocation is the most efficient and it allows a throughput up to 7 Gb/s.

Synthetic logs generator for fraud detection in mobile transfer services

Abstract: Mobile payments become more and more popular and thus are very attractive targets for fraudsters. As the latter always find new ways to commit crimes and avoid detection, research in the field of fraud is always evolving. However, transactional data and feedback from existing services are lacking. This article addresses this issue by proposing a synthetic data generator. Our idea is to model the behavior of various actors to generate testing data that researchers can use to evaluate approaches for identifying fraudulent transactions. This paper presents our approach and prototype. The logs generator was evaluated by comparing the generated synthetic logs with real ones.

Multi-band OFDM Transmission with Sub-band Optical Switching

Abstract: We show here that coherent dual-polarization multi-band OFDM (DP-MB-OFDM) is a good candidate for long-haul WDM transmission and sub-wavelength optical switching. We demonstrate that optical add-drop of OFDM sub-bands as narrow as 8 GHz inside a 100 Gbps DP-MB-OFDM signal constituted of four sub-bands spaced by 12 GHz is feasible in the middle of a 10×100-km DCF-free G.652 fibre line.

Novel Blind Equalizer for Coherent DP-BPSK Transmission Systems: Theory and Experiment

Abstract: Adaptive blind equalization based on modulus algorithm is very efficient to carry out polarization separation and inter-symbol interference compensation in a coherent dual-polarization quaternary-phase-shift-keying transmission system. Its performance is, however, very poor when coherent dual-polarization binary-phase-shift-keying (BPSK) modulation is considered. In this letter, we propose a new blind equalizer adapted to any PSK constellation and we theoretically show its convergence. Experimental BER measurements and convergence analysis are performed in a 40 Gbps coherent dual-polarization BPSK system under different physical impairments. We show that our equalizer outperforms existing blind algorithms.

A CO-OFDM System With Almost Blind Phase Noise Suppression

Abstract: We propose a high spectral efficiency coherent optical orthogonal frequency division multiplexing system utilizing a novel and almost blind phase noise compensation method. With the aid of pseudo pilots instead of pilots, laser phase noise can be suppressed effectively while the overhead of system is reduced successfully. Numerical results show that the performance of the proposed pseudo pilot-aided phase noise compensation scheme can approach that of the pilot-aided counterpart, yet achieve higher spectral efficiency even when the phase noise is severe.

Adaptive large MISO downlink with Predictor Antenna array for very fast moving vehicles

Abstract: Recently, a “Separate Receive and Training Antenna” technique has been proposed to provide energy efficient and robust wireless downlink data transmission towards antennas placed upon fast moving vehicles. Energy efficiency is attained thanks to Large Multiple Input Single Output Beamforming. Robustness to beamforming mispointing at high speed is obtained by using the recent “Predictor Antenna” concept. However, for some speeds, the Separate Receive and Training Antenna technique suffers from residual mispointing. To improve the robustness of this technique, we propose three new schemes: the “Border Switch Off Scheme”, the “Random Switch Off Scheme” and the “Polynomial Interpolation” scheme. The two first schemes dynamically mute transmit antennas selectively when the residual mispointing is too severe. The third scheme generalizes the Predictor Antenna concept and uses all antennas upon the vehicle as a Predictor Antenna Array. These schemes are here assessed over spatially correlated channels. The two first schemes reduce energy saving to slightly improve robustness, whereas the third scheme perfectly compensates all speeds up to 300 kmph with maximum energy saving, at the cost of extra complexity.

Low-cost extrapolation method for maximal LTE radio base station exposure estimation: test and validation.

Abstract: An experimental validation of a low-cost method for extrapolation and estimation of the maximal electromagnetic-field exposure from long-term evolution (LTE) radio base station installations are presented. No knowledge on downlink band occupation or service characteristics is required for the low-cost method. The method is applicable in situ. It only requires a basic spectrum analyser with appropriate field probes without the need of expensive dedicated LTE decoders. The method is validated both in laboratory and in situ, for a single-input single-output antenna LTE system and a 2×2 multiple-input multiple-output system, with low deviations in comparison with signals measured using dedicated LTE decoders.

Self-Management for Unified Heterogeneous Radio Access Networks

Abstract: The development of self-management solutions for (multi-technology, multi-layer) mobile communication networks is driven by their increasing operational complexity. Initial stand-alone SON (Self-Organizing Networks) solutions are already available, but are not sufficient to handle the networks of tomorrow. In this paper we present our approach at developing a unified management framework that integrates the existing and future advanced SON functions across several radio access technologies. The envisioned self-management system comprises (i) an integrated SON management system, in charge of policy transformation/supervision and conflict detection/handling; (ii) advanced multi-RAT/layer SON functions; and (iii) a Decision Support System providing measurement-based assistance for residual operational tasks, such as timely recommendations for targeted new site deployments.