Article de revue avec comité de lecture (2)
SAKER Louai, ELAYOUBI Salah-Eddine, COMBES Richard, CHAHED Tijani
Optimal control of wake up mechanisms of femtocells in heterogeneous networks. IEEE journal on selected areas in communications, april 2012, vol. 30, n° 3, pp. 664-672
abstract
We study, in this work, optimal sleep/wake up schemes for the base stations of network-operated femto cells deployed within macro cells for the purpose of offloading part of its traffic. Our aim is to minimize the energy consumption of the overall heterogeneous network while preserving the Quality of Service (QoS) experienced by users. We model such a system at the flow level, considering a dynamic user configuration, and derive, using Markov Decision Processes (MDPs), optimal sleep/wake up schemes based on the information on traffic load and user localization in the cell, in the cases where this information is complete, partial or delayed. Our results quantify the energy consumption and QoS perceived by the users in each of these cases and identify the tradeoffs between those two quantities. We also illustrate numerically the optimal policies in different traffic scenarios.
TARHINI Chadi, CHAHED Tijani
QoS-oriented resource allocation for streaming flows in IEEE802.16e Mobile WiMAX. Telecommunication systems, 2012
abstract
Users in OFDMA-based WiMAX are subject to Adaptive Modulation and Coding (AMC) which implies more robust and hence less frequency efficient modulation and coding for users experiencing bad radio conditions. When users are mobile, this implies lower throughput as they move away from the base station for instance. This may be acceptable for data users, but not for streaming ones which require a constant bit rate throughout the cell. We propose, in this work, a new QoS-oriented resource allocation strategy wherein streaming flows experiencing bad radio conditions are allocated more sub-carriers so as to keep their bit rate constant as they move around in the cell. The risk is however an increase in the dropping rate. To minimize the latter without increasing blocking too much, they are second subject to a state-dependent admission control scheme where the degree of acceptance depends on the density of the users in a given location. We develop an analytical model which allows us to derive some performance measures such as blocking and dropping probabilities. Our results quantify how these metrics vary with the load as well as the admission strategies.
Communication dans une conférence à comité de lecture (1)
GURKAS AYDIN Zeynep, ZAIM Abdul Halim, CHAOUCHI Hakima, ATMACA Tülin
A prediction based mobility extension for eHIP protocol. ISCIS '11 : 26th International Symposium on Computer and Information Sciences, London;Dordrecht;Heidelberg : Springer, 26-28 september 2011, London, United Kingdom, 2012, pp. 209-213, ISBN 978-1-4471-2154-1
abstract
By revealing of heterogeneous networks, importance of cooperation of different technologies and mobility management became an important issue of wireless and mobile networks. The idea of separation the role of IP addresses for location and identification of a mobile node in the network has also increased its importance. In this study, our motivation is to extend our previously proposed handover management method (early update for host identity protocol (eHIP). We propose to introduce the idea of simply employing movement prediction idea to regular eHIP and so enhancing the handover latency.
