@conference {Walid2016, title = {Exploiting multi-homing in hyper dense LTE small-cells deployments}, booktitle = {IEEE Wireless Communications and Networking Conference, WCNC}, volume = {2016-September}, year = {2016}, note = {cited By 0}, abstract = {It is expected that in two-Tier LTE heterogeneous networks, an extensive deployment of small cell networks (SCNs) will take place in the near future, especially in dense urban zones; hence a hyper density of SCNs randomly distributed within macro cell networks (MCNs) will emerge with many overlapping zones of neighboring SCNs. Therefore, the problems of interferences in co-channel deployment will be more complicated and then the overall throughput of downlink will substantially decrease. In order to mitigate the effect of interferences in a hyper density of SCNs scenarios, a solution based on a fully distributed algorithm for sharing time access to SCNs and multi-homing capabilities of macro cellular users is proposed to improve the overall data rate of downlink and at the same time to satisfy QoS throughput requirements of macro and home cellular users. Our tentative scheme will also reduce the signaling overhead due to the absence of coordination among small base stations (SBSs) and macro base station (MBS). Results validate our solution and show the improvement attained in a hyper density of SCNs within MCNs compared to open, closed and shared time access mechanisms based on single network selection. {\textcopyright} 2016 IEEE.}, doi = {10.1109/WCNC.2016.7565055}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84989854253\&doi=10.1109\%2fWCNC.2016.7565055\&partnerID=40\&md5=36cda03e307b208f10f73e923e3e5b77}, author = {Walid, A.a and Sabir, E.b and Kobbane, A.a and Taleb, T.c and Koutbi, M.E.a} } @article {Walid20161256, title = {Group vertical handoff management in heterogeneous networks}, journal = {Wireless Communications and Mobile Computing}, volume = {16}, number = {10}, year = {2016}, note = {cited By 0}, pages = {1256-1270}, abstract = {Traditional vertical handover schemes postulate that vertical handovers (VHOs) of users come on an individual basis. This enables users to know previously the decision already made by other users, and then the choice will be accordingly made. However, in case of group mobility, almost all VHO decisions of all users, in a given group (e.g., passengers on board a bus or a train equipped with smart phones or laptops), will be made at the same time. This concept is called group vertical handover (GVHO). When all VHO decisions of a large number of users are made at the same time, the system performance may degrade and network congestion may occur. In this paper, we propose two fully decentralized algorithms for network access selection, and that is based on the concept of congestion game to resolve the problem of network congestion in group mobility scenarios. Two learning algorithms, dubbed Sastry Algorithm and Q-Learning Algorithm, are envisioned. Each one of these algorithms helps mobile users in a group to reach the nash equilibrium in a stochastic environment. The nash equilibrium represents a fair and efficient solution according to which each mobile user is connected to a single network and has no intention to change his decision to improve his throughput. This shall help resolve the problem of network congestion caused by GVHO. Simulation results validate the proposed algorithms and show their efficiency in achieving convergence, even at a slower pace. To achieve fast convergence, we also propose a heuristic method inspired from simulated annealing and incorporated in a hybrid learning algorithm to speed up convergence time and maintain efficient solutions. The simulation results also show the adaptability of our hybrid algorithm with decreasing step size-simulated annealing (DSS-SA) for high mobility group scenario. Copyright {\textcopyright} 2015 John Wiley \& Sons, Ltd. Copyright {\textcopyright} 2015 John Wiley \& Sons, Ltd.}, doi = {10.1002/wcm.2599}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84930151466\&doi=10.1002\%2fwcm.2599\&partnerID=40\&md5=a91b7ce3e8af4694e732a00f04f01d95}, author = {Walid, A.a and Kobbane, A.a and Mabrouk, A.a and Sabir, E.b and Taleb, T.c and El Koutbi, M.a} } @conference {Walid20151168, title = {On improving network capacity for downlink and uplink of two-tier LTE-FDD networks}, booktitle = {IWCMC 2015 - 11th International Wireless Communications and Mobile Computing Conference}, year = {2015}, note = {cited By 0}, pages = {1168-1173}, abstract = {A Long Term Evolution-Frequency Division Duplexing (LTE-FDD) small cell is one of the promising solutions for improving service quality and data rate in both the uplink and downlink of home users. Small cell (e.g., femtocell, picocell, microcell) is short range, low cost and low power base station installed by the indoor consumers. However, the avoidance of interferences is still an issue that needs to be addressed for successful deployment of small base stations (SBS) within existing macro cell networks mainly in co-channel deployment. Moreover, interferences are strongly dependent on the type of access control of small cells. Closed and open access are in conflict interests for macro users and home users in the uplink and downlink. To mitigate this conflict, we propose a fully distributed algorithm based on the shared time access and executed by LTE-FDD small cells, in order to reduce the effect of interferences, improve QoS of users, and maximize the overall capacity of downlink and uplink in two-tier LTE networks when small cells are deployed randomly. Simulation results validate our algorithm and show the improvement attained in offloading macro cell and satisfying QoS requirements of home users compared to the closed and open access mechanisms in both the uplink and downlink. {\textcopyright} 2015 IEEE.}, doi = {10.1109/IWCMC.2015.7289248}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84949503704\&doi=10.1109\%2fIWCMC.2015.7289248\&partnerID=40\&md5=3c58a33b86b3de8e31215575eda6ba0a}, author = {Walid, A.a and Sabir, E.b and Kobbane, A.a and Taleb, T.c and El Koutbi, M.a} } @conference {Mabrouk2014672, title = {A congestion game-based routing algorithm for communicating VANETs}, booktitle = {IWCMC 2014 - 10th International Wireless Communications and Mobile Computing Conference}, year = {2014}, note = {cited By 2}, pages = {672-677}, abstract = {Vehicular Ad Hoc Network (VANET) is considered as a special application of Mobile Ad Hoc Networks (MANETs) in road traffic, which can autonomously organize networks without infrastructure. VANETs enable vehicles on the road to communicate with each other and with road infrastructure using wireless capabilities. In the last few years, extensive research has been performed to extend Internet connectivity to VANETs. Indeed, several routing protocols have been proposed to determine routes between vehicles and gateways. In this paper, we propose a routing algorithm which is based on the Congestion Game to resolve the problem of network congestion in VANET and to provide the optimal Internet access paths. The simulation results show that the proposed routing algorithm has better feasibility and effectiveness for communicating VANETs. {\textcopyright} 2014 IEEE.}, doi = {10.1109/IWCMC.2014.6906436}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908611637\&doi=10.1109\%2fIWCMC.2014.6906436\&partnerID=40\&md5=c4ef74c689e207df64ad7a4808f8c773}, author = {Mabrouk, A.a and Senhadji, M.a and Kobbane, A.a and Walid, A.a and Sabir, E.b and El Koutbi, M.a} } @conference {Walid20142817, title = {A decentralized network selection algorithm for group vertical handover in heterogeneous networks}, booktitle = {IEEE Wireless Communications and Networking Conference, WCNC}, year = {2014}, note = {cited By 5}, pages = {2817-2821}, abstract = {The traditional vertical handover schemes postulate that vertical handover of each user comes on an individual basis. This enables the users to know previously the decision already made by other users, and then the choice will be made accordingly. However, in the case of a group vertical handover, almost all the VHO decisions - which will certainly choose the best network, will be made at the same time which will lead to system performance degradation or network congestion. In this paper, we propose a totally decentralized algorithm for network selection which based on the Congestion Game to resolve the problem of network congestion in GVHO. Therefore, the proposed algorithm named Fully Decentralized Nash Learning Algorithm with incomplete information is a prediction done by each mobile in the group that helps them to reach the Nash equilibrium. Simulation results validate the algorithm and show its robustness under two scenarios. In the first one, we examine the algorithm with a fixed number of mobiles in group to evaluate the mixed strategy and the average perceived throughput of mobiles in WIMAX and HSDPA on the basis of iteration. In the second one, we examine the algorithm with different number of mobiles in group for testing the average number of iterations needed to reach the Nash equilibrium. We also compare it with the traditional vertical handover algorithm. {\textcopyright} 2014 IEEE.}, doi = {10.1109/WCNC.2014.6952895}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84912123155\&doi=10.1109\%2fWCNC.2014.6952895\&partnerID=40\&md5=35a46d7aee23563018fc6f10fc8506ab}, author = {Walid, A.a and El Kamili, M.b and Kobbane, A.a and Mabrouk, A.a and Sabir, E.c and El Koutbi, M.a} } @article {Mabrouk20141417, title = {Gateways{\textquoteright} mobility increases the capacity of communication in VANETs: Routing algorithm based on congestion game}, journal = {International Review on Computers and Software}, volume = {9}, number = {8}, year = {2014}, note = {cited By 2}, pages = {1417-1425}, abstract = {Vehicular Ad Hoc Network (VANET) is considered as a special application of Mobile Ad Hoc Networks in road traffic, which can autonomously organize networks without infrastructure. VANETs enable vehicles on the road to communicate with each other and with road infrastructure using wireless capabilities. In the last few years, extensive research provided several routing algorithms to extend Internet connectivity to VANETs through fixed gateways installed along the road. However, most of these algorithms have not been effective because of the high mobility of vehicles in the road. In this paper, we propose a routing algorithm which based both on the congestion game to resolve the problem of network congestion and on mobile gateways to resolve the problem of high mobility in VANET. Therefore, the proposed algorithm is a prediction done by each node in the network that helps them to reach the optimal route to access Internet. Simulation results validate the algorithm and show its robustness under two scenarios. In the first one, we examine the algorithm with fixed gateways installed along the road to validate the connectivity to the Internet. Whilst in the second scenario, we examine the algorithm with mobile gateways to show the effectiveness of gateways{\textquoteright} mobility on the capacity of communication and the Internet access in VANETs. {\textcopyright} 2014 Praise Worthy Prize S.r.l. - All rights reserved.}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908347271\&partnerID=40\&md5=359209fd84ed425637bce48a01410d6b}, author = {Mabrouk, A.a and Senhadji, M.b and Walid, A.a and Kobbane, A.b and El Koutbi, M.a} } @conference {Bennani201456, title = {A tax-inspired mechanism design to achieve QoS in VMIMO systems: Give to receive!}, booktitle = {IWCMC 2014 - 10th International Wireless Communications and Mobile Computing Conference}, year = {2014}, note = {cited By 0}, pages = {56-62}, abstract = {In this paper, we model a Virtual MIMO system using a game-theoretic approach. We are interested in the uplink, considering a non-coopertive game, where each user try to satisfy a quality of service. The uplink of a direct-sequence code division multiple access (DS-CDMA) data network is considered and a non-cooperative game is proposed in which users are allowed to choose their uplink receivers as well as to satisfy their quality of service. The utility function used in this framework is defined so that the throughput used by the user is divided into two components: the throughput received from cellular Network, and throughput received from Virtual MIMO System. In addition, this framework is used to study a constrained Nash equilibrium for the proposed game, and the impact of the interaction among users. {\textcopyright} 2014 IEEE.}, doi = {10.1109/IWCMC.2014.6906332}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908622993\&doi=10.1109\%2fIWCMC.2014.6906332\&partnerID=40\&md5=8f8afb3e0c78e9a74a2e145125d111ac}, author = {Bennani, H.a and Sabir, E.b and Kobbane, A.a and Walid, A.a and Ben-Othman, J.c} }