PhD graduated
Team : DELYS
Departure date : 06/30/2018

Supervision : Pierre SENS

Co-supervision : SĂ©bastien MONNET

Toward efficient dissemination of voluminous data over dense Wi-Fi Networks

We are witnessing a proliferation of mobile technologies and an increasing volume of data used by mobile applications. Devices consume thus more and more bandwidth. In this thesis, we focus on dense Wi-Fi networks during large-scale events (such as conferences). In this context, the bandwidth consumption and the interferences caused by the parallel downloads of a large volume of data by several mobile devices that are connected to the same Wi-Fi network degrade the performance of the dissemination. Device-to-Device (D2D) communication technologies such as Bluetooth or Wi-Fi Direct can be used in order to improve network performance to deliver better QoE to users.
In this thesis we propose two approaches for improving the performance of data dissemination. The first approach, more suited to a dynamic configuration, is to use point-to-point D2D connections on a flat topology for data exchange. Our evaluations show that our approach can reduce dissemination times by up to 60% compared to using Wi-Fi alone. In addition, we ensure a fair distribution of the energy load on the devices to preserve the weakest batteries in the network. We have observed that by taking into account the battery life and the bandwidth of mobile devices, the solicitation of the weakest batteries can be reduced significantly.
The second approach, more adapted to static configurations, consists in setting up hierarchical topologies by gathering mobile devices in small clusters. In each cluster, a device is chosen to relay the data that it receives from the server and forwards it to its neighbors. This approach helps to manage interference more efficiently by adjusting the signal strength in order to limit cluster reach. In this case, we observed up to 30% gains in dissemination time.
In the continuity of this thesis work, we discuss three perspectives which would be interesting to be undertaken, in particular the automatic adaptation of the dissemination to the state of the network and the simultaneous use of both topology types, flat and hierarchical.

Defence : 06/21/2018

Jury members :

M. Gabriel ANTONIU , Directeur de recherche, INRIA Rennes - Bretagne Atlantique [rapporteur]
M. Vivien QUÉMA, Professeur, Université Grenoble INP [rapporteur]
Mme. Maria POTOP-BUTUCARU, Professeur, Sorbonne Université
M. Christophe CÉRIN, Professeur, Université Paris 13 - Sorbonne Paris Cité
M. Sébastien MONNET, Professeur, Université Savoie Mont-Blanc
M. Pierre SENS, Professeur, Sorbonne Université
M. Dimitri REFAUVELET, Directeur technique, Magency

Departure date : 06/30/2018

2016-2018 Publications