État académique
Thèse en cours...
Sujet: Analyse de compétition spatiale et spatio-temporelle dans le contrôle d'accès et de puissance dans les réseaux mobiles sans fil
Direction de thèse:
Ellipse bleue: doctorant, ellipse jaune: docteur, rectangle vert: permanent, rectangle jaune: HDR. Trait vert: encadrant de thèse, trait bleu: directeur de thèse, pointillé: jury d'évaluation à mi-parcours ou jury de thèse.
Productions scientifiques
Self-similarity in urban wireless networks: Hyperfractals
International audience
We introduce a model of Poisson patterns of fixed and mobile nodes on lines designed for urban wireless networks. The pattern obeys to " Hyperfractal " rules of dimension larger than 2. The hyperfractal pattern is best suitable for capturing the traffic over the streets and highways in a city. We show that the network capacity under ad hoc routing algorithms scales much better than with the classic uniform Poisson shot model. The scaling effect depends on the hyperfractal dimensions. We show this results in two different routing models: nearest neighbor routing with no collision, minimum delay routing model assuming slotted Aloha and signal to interference ratio (SIR) capture condition, power-path loss and Rayleigh fading. The novelty of the model is that, in addition to capturing the irregularity and variability of the node configuration, it exploits self-similarity, a characteristic of urban wireless networks.
Workshop on Spatial Stochastic Models 
for Wireless Networks (SpaSWiN) https://hal.inria.fr/hal-01498987 Workshop on Spatial Stochastic Models 
for Wireless Networks (SpaSWiN), May 2017, Paris, France. 2017ARRAY(0x7fe6a74f2300) 2017-05-19
Self-similar Geometry for Ad-Hoc Wireless Networks: Hyperfractals
https://hal.inria.fr/hal-01561828 [Research Report] Nokia Bell Labs [Paris Saclay] (Nokia); Inria Paris. 2017ARRAY(0x7fe6a74e2ab0) 2017-11-07
Energy Trade-offs for end-to-end Communications in Urban Vehicular Networks exploiting an Hyperfractal Model
https://hal.inria.fr/hal-01674685 2018ARRAY(0x7fe6a74e2630) 2018-01-03
Information Dissemination in Vehicular Networks in an Urban Hyperfractal Topology
KEYWORDS: DTN; Wireless Networks; Broadcast; Fractal; Vehicular Networks; Urban networks
The goal of this paper is to increase our understanding of the fundamental performance limits of urban vehicle networks by exploiting the self-similarity and hierarchical organization of modern cities. We use an innovative model called "hyperfractal" that captures the self-similarity of the topology and vehicle locations while avoiding the extremes of regularity and randomness. We use analytical tools to derive matching theoretical upper and lower bounds for the information propagation speed of a broadcast in an urban delay tolerant network which is disconnected at all time, i.e., where end-to-end multihop paths may not exist (requiring a store-carry-and-forward routing model). We prove that the average broadcast time in a hyperfractal setup is in $\Theta(n^{1-\delta})$ where $n$ is the number of mobile nodes and where $\delta$ depends on the precise hyperfractal dimension. Furthermore, we show that the performance is due in part to an interesting self-similar phenomenon, that we denote as {\em information teleportation}, that arises as a consequence of the topology and allows an acceleration of the broadcast time. We show how our model can be validated with real cities using a fitting procedure applied to open data sets, and also how it can be extended to cities that do not follow a regular hierarchical pattern. The study also presents simulations that confirm the validity of the bounds in multiple realistic settings, including scenarios with variable speed.
https://hal.inria.fr/hal-01662286 KEYWORDS: DTN; Wireless Networks; Broadcast; Fractal; Vehicular Networks; Urban networks. 2017ARRAY(0x7fe6a7540568) 2017-12-13
Energy Savings for Virtual MISO in Fractal Sensor Networks
International audience
—We design a model of wireless terminals, i.e. transmitters and receivers, obtained from a Poisson point process with support in an embedded fractal map. The terminals form a virtual MISO (Multiple Input Single Output) system with successful reception under SNR (signal-to-noise ratio) capture condition in a single hop transmission. We show that if we omit antennas cross sections, the energy needed to broadcast a packet of information tends to zero when the density of transmitters and receivers increases. This property is a direct consequence of the fact that the support map is fractal and would not hold if the terminal distribution were Poisson uniform, as confirmed by simulations. The result becomes invalid if the cross sections overlap or if we consider a masking effect due to antennas, which would imply an extremely large density of terminals. In the case where the cross sections of the transmitters have a non-zero value, the energy has a non-zero limit which decays to zero when the cross sections tend to zero.
55th Annual Allerton Conference on Communication, Control, and Computing https://hal.archives-ouvertes.fr/hal-01591112 55th Annual Allerton Conference on Communication, Control, and Computing, Oct 2017, Urbana-Champaign, United StatesARRAY(0x7fe6a74ea118) 2017-10-03