@article { ISI:000384105900002,
	title = {Coalitional game-based behavior analysis for spectrum access in cognitive radios},
	journal = {WIRELESS COMMUNICATIONS \& MOBILE COMPUTING},
	volume = {16},
	number = {14},
	year = {2016},
	month = {OCT 10},
	pages = {1910-1921},
	abstract = {The core of cognitive radio paradigm is to introduce cognitive devices able to opportunistically access the licensed radio bands. The coexistence of licensed and unlicensed users prescribes an effective spectrum hole-detection and a non-interfering sharing of those frequencies. Collaborative resource allocation and spectrum information exchange are required but often costly in terms of energy and delay. In this paper, each secondary user (SU) can achieve spectrum sensing and data transmission through a coalitional game-based mechanism. SUs are called upon to report their sensing results to the elected coalition head, which properly decides on the channel state and the transmitter in each time slot according to a proposed algorithm. The goal of this paper is to provide a more holistic view on the spectrum and enhance the cognitive system performance through SUs behavior analysis. We formulate the problem as a coalitional game in partition form with non-transferable utility, and we investigate on the impact of both coalition formation and the combining reports costs. We discuss the Nash Equilibrium solution for our coalitional game and propose a distributed strategic learning algorithm to illustrate a concrete case of coalition formation and the SUs competitive and cooperative behaviors inter-coalitions and intra-coalitions. We show through simulations that cognitive network performances, the energy consumption and transmission delay, improve evidently with the proposed scheme. Copyright (c) 2016 John Wiley \& Sons, Ltd.},
	issn = {1530-8669},
	doi = {10.1002/wcm.2658},
	author = {Belghiti, Imane Daha and Elmachkour, Mouna and Berrada, Ismail and Kobbane, Abdellatif and Ben-Othman, Jalel}
}
@conference { ISI:000381477900169,
	title = {A Coalitional-Game-Based Incentive Mechanism for Content Caching in Heterogeneous Delay Tolerant Networks},
	booktitle = {2015 INTERNATIONAL WIRELESS COMMUNICATIONS \& MOBILE COMPUTING CONFERENCE (IWCMC)},
	series = {International Wireless Communications and Mobile Computing Conference},
	year = {2015},
	note = {11th IEEE International Wireless Communications and Mobile Computing Conference (IEEE IWCMC), Dubrovnik, CROATIA, AUG 24-25, 2015},
	pages = {987-992},
	publisher = {IEEE; IEEE Croatia Sect; Univ Dubrovnik},
	organization = {IEEE; IEEE Croatia Sect; Univ Dubrovnik},
	abstract = {In recent years, Delay Tolerant Networks (DTNs) have successfully presented as a possible extension of the Internet architecture in order to provide communication support to existing networks. However, these networks have a major issue which is the coordination among relays. In this work, we study the cooperative transmission for DTNs using coalitional game theory. We design a new incentive mechanism for heterogeneous system to induce coordination among DTN relays. In particular, we focus on the source packet dissemination to a destination using tow-hop relaying scheme, considering networks resource constraints: the relay buffer, the packet life time, and the energy consumption according to the mobile technologies. Rational mobiles are organized into separate coalition structures to meet a trade off between the source reward and the energy conservation. We discus the Nash equilibria for our game and the stable strategy state in which no mobile can get a higher payoff through changing unilaterally its coalition. Then, we use the distributed imitative Boltzmann-Gibbs learning algorithm enabling relays to learn the Nash equilibrium strategy; grand coalition. The improvement of the global system performance is examined, and a comparison between different inter-node collaboration states is presented.},
	isbn = {978-1-4799-5344-8},
	issn = {2376-6492},
	author = {Oualhaj, Omar Ait and Kobbane, Abdellatif and Elmachkour, Mouna and Sabir, Essaid and Ben-Othman, Jalel}
}
@article { ISI:000351605500008,
	title = {Data traffic-based analysis of delay and energy consumption in cognitive radio networks with and without resource reservation},
	journal = {INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS},
	volume = {28},
	number = {7},
	year = {2015},
	month = {MAY 10},
	pages = {1316-1328},
	abstract = {A new opportunistic cross-layer MAC protocol involving channel allocation and packet scheduling for cognitive radio networks is proposed. Cognitive radio allows secondary users (SUs) to exploit the available portions of the licensed spectrum bands without interfering with primary users. In particular, we consider a cognitive radio system, where SUs are equipped with two transceivers: a control transceiver and a software-defined radio transceiver. Data traffic characteristics of SUs are considered to ameliorate system performance. So, we propose a mechanism of resource reservation to improve QoS requirements that favors successful SUs to transmit data during x time slots without interfering with primary users. The key novelty of this paper is giving priority for SUs with important data traffic and which frequently solicits data channels to transmit for the remaining time of the ongoing time slot and for the next time slots directly after checking the channel availability. We develop a new analytical model to evaluate delay parameter for two scenarios with and without resource reservation and we then investigate the impact of those scenarios on the energy consumption. We show through simulations that cognitive radio performances increase noticeably with the proposed scheme. Copyright (c) 2014 John Wiley \& Sons, Ltd.},
	issn = {1074-5351},
	doi = {10.1002/dac.2764},
	author = {Elmachkour, Mouna and Kobbane, Abdellatif and Sabir, Essaid and Ben-Othman, Jalel and El Koutbi, Mohammed}
}
@conference { ISI:000366666805090,
	title = {Green Opportunistic Access for Cognitive Radio Networks: A Minority Game Approach},
	booktitle = {2014 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS (ICC)},
	series = {IEEE International Conference on Communications},
	year = {2014},
	note = {IEEE International Conference on Communications (ICC), Sydney, AUSTRALIA, JUN 10-14, 2014},
	pages = {5372-5377},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {We investigate energy conservation and system performance of decentralized resource allocation scheme in cognitive radio networks thoroughly based on secondary users competitive behavior. Indeed, the contention on data channel unoccupied by licensed user leads to a single winner, but also involves a loss of energy of all nodes. In this paper, we apply minority game (MG) to the most important phase from the opportunistic spectrum access (OSA) process: the sensing phase. We attempt to carry out a cooperation in a non-cooperative environment with no information exchange. We study the Nash equilibrium solution for pure and fully mixed strategies, and we use distributed learning algorithms enabling cognitive users to learn the Nash equilibrium. Finally, we provide numerical results to validate the proposed approach. The resource allocation based on minority game approach improves secondary users battery life and the performance of the network.},
	isbn = {978-1-4799-2003-7},
	issn = {1550-3607},
	author = {Elmachkour, Mouna and Daha, Imane and Sabir, Essaid and Kobbane, Abdellatif and Ben-Othman, Jalel},
	editor = {Jamalipour, A and Deng, DJ}
}
@conference { ISI:000371484600074,
	title = {Green opportunistic access for CRN with selfish users using Coalitional game Approach in partition form},
	booktitle = {2014 THIRD IEEE INTERNATIONAL COLLOQUIUM IN INFORMATION SCIENCE AND TECHNOLOGY (CIST{\textquoteright}14)},
	series = {Colloquium in Information Science and Technology},
	year = {2014},
	note = {3rd IEEE International Colloquium on Information Science and Technology (CIST), Tetouan, MOROCCO, OCT 20-22, 2014},
	pages = {425-429},
	publisher = {IEEE; IEEE Comp Soc; IEEE Commun Soc; IEEE Morocco Sect; IEEE Morocco Comp \& Commun Joint Chapter; UAE IEEE Student Branch; Univ Abdelmalek Essaadi; ENSA Tetouan},
	organization = {IEEE; IEEE Comp Soc; IEEE Commun Soc; IEEE Morocco Sect; IEEE Morocco Comp \& Commun Joint Chapter; UAE IEEE Student Branch; Univ Abdelmalek Essaadi; ENSA Tetouan},
	abstract = {We study energy conservation and system performance of decentralized cognitive radio network with cognitive users. Every cognitive radio (CR) user needs to sense the channel to send data, if the channel is unoccupied by a licensed user only one winner transmits its data. Hence, all other users waste their energy in sensing the licensed bands and in negotiating the resource access without managing to transmit data packets. We formulate the sensing-energy tradeoff problem for distributed cognitive radio network as a coalition formation game. Our contribution is to apply the coalitional game design to the most important phases of cognitive radio network (CRN): sensing and data transmission. The concept of coalitional game may enforce the cooperative behavior of CR users in order to improve the system performance (energy and delay..). The network is modeled using a coalitional game in partition form with non transferable utility (NTU). After forming coalitions, no CR user in those coalitions aim to change its position. Indeed, the members of this coalition will cooperate both in sensing and access phases to improve system performance. The selfish behavior becomes evident when the cognitive users are constrained to send their data in a short delay and with a minimum of energy consumption. Our proposed algorithm explains how the selfish atittude of the cognitive user leds to join the coalition that increases its individual gain, and tacitly to improve the performance of the entire system.},
	isbn = {978-1-4799-5979-2},
	issn = {2327-185X},
	author = {Belghiti, Imane Daha and Elmachkour, Mouna and Berrada, Ismail and Kobbane, Abdellatif},
	editor = {ElMohajir, M and AlAchhab, M and Chahhou, M}
}
@article { ISI:000348218400023,
	title = {The Greening of Spectrum Sensing: A Minority Game-Based Mechanism Design},
	journal = {IEEE COMMUNICATIONS MAGAZINE},
	volume = {52},
	number = {12},
	year = {2014},
	month = {DEC},
	pages = {150-156},
	abstract = {Cognitive radio technology allows the reuse of the underutilized frequency spectrum on an opportunistic and non-interfering basis by means of introducing, besides the legitimate primary users of the spectrum, a new kind of users called cognitive or secondary users. Thus, reliable spectrum sensing is critical to dynamically detect available licensed frequency bands and mitigate the primary signals, but it remains realistically difficult to carry out. In fact, although distributed collaborative sensing has turned out to be fruitful for the cognitive radio environment, its accuracy is often affected by the selfish and autonomous behavior of users. In this article, we model distributed spectrum sensing and channel allocation as a non-cooperative game, and apply the minority game to bring forth and study the cooperative behavior of users. The novelty brought by our study consists of alleviating the number of users contending for primary channels by giving them the opportunity to choose between the two, either sensing the channel or being inactive during the time slot. To address the trade-off faced by the SUs, we evaluate the performance of two secondary systems in a green communications context: energy consumption and transmission delay.},
	issn = {0163-6804},
	author = {Elmachkour, Mouna and Sabir, Essaid and Kobbane, Abdellatif and Ben-Othman, Jalel and El Koutbi, Mohammed}
}
@conference { ISI:000346142800015,
	title = {Modeling and Evaluating a Cloudlet-based Architecture for Mobile Cloud Computing},
	booktitle = {2014 9TH INTERNATIONAL CONFERENCE ON INTELLIGENT SYSTEMS: THEORIES AND APPLICATIONS (SITA{\textquoteright}14)},
	year = {2014},
	note = {9th International Conference on Intelligent Systems - Theories and Applications (SITA), Inst Natl Postes \& Telecommunicat, Rabat, MOROCCO, MAY 07-08, 2014},
	publisher = {IEEE; IEEE Morocco},
	organization = {IEEE; IEEE Morocco},
	abstract = {With the rising popularity of Internet-enabled mobile devices, users are increasingly demanding better quality of service (QoS). However, the resources of these devices and their connectivity levels remain insufficient, even though they are improving, for offering acceptable levels of QoS to users. Cloud computing infrastructures offer large and scalable resources that allow shifting the physical location of computation and storage to the cloud. Nevertheless, the integration of mobile computing with cloud computing would not guarantee adequate levels of service for mobile users. It rather delivers scalability at the cost of higher delay and higher power consumption on the mobile device. Instead, using local resources based on users geographical locations has the potential to improve the performance and QoS for mobile users. In this paper, we present and study a centralized architecture that relies on the concept of local clouds, cloudlets, to leverage the geographical proximity of resources to mobile users and offer them a better user experience. We use a continuous time Markov-chain (CTMC) to model the different nodes of the architecture: user nodes, cloudlets, and the main cloud. We estimate the delay incurred in the proposed architecture by simulating search engine queries generated by mobile users using the CTMC state models. Initial simulation results show that the usage of a cloudlet-based architecture especially centralized architecture has an efficient gains in terms of latency delay and synchronisation mechanisms.},
	isbn = {978-1-4799-3566-6},
	author = {Routaib, Hayat and Elmachkour, Mouna and Sabir, Essaid and Badidi, Elarbi and Elkoutbi, Mohammed}
}
@conference { ISI:000312146500012,
	title = {New Insights from a Delay Analysis for Cognitive Radio Networks with and without Reservation},
	booktitle = {2012 8TH INTERNATIONAL WIRELESS COMMUNICATIONS AND MOBILE COMPUTING CONFERENCE (IWCMC)},
	series = {International Wireless Communications and Mobile Computing Conference},
	year = {2012},
	note = {8th IEEE International Wireless Communications and Mobile Computing Conference (IWCMC), Limassol, CYPRUS, AUG 27-31, 2012},
	pages = {65-70},
	publisher = {IEEE; IEEE Cyprus Sect; Frederick Univ},
	organization = {IEEE; IEEE Cyprus Sect; Frederick Univ},
	abstract = {In wireless communication systems, the delay remains a crucial factor. In this work, we focus on the design of a new opportunistic cross-layer MAC protocol involving channels allocation and packet scheduling for cognitive networks in order to optimize system performance. Cognitive radio provides the opportunity for secondary users (unlicensed users) to use available portions of the licensed spectrum bands without interfering with primary users (licensed users). We consider that each secondary user is equipped with two transceivers. The role of the first transceiver is to obtain and exchange channels information on the control channel. The second transceiver is devoted to periodically detect and dynamically use the available data channels. The paper deals with channel allocation considering traffic characteristics of secondary users. So, we propose a mechanism of resource reservation to improve Quality of Service (QoS) requirements that favors successful secondary users to transmit data during x time slots without interfering with primary users. We develop a new analytical model, while taking into account the backoff mechanism. We analyze delay parameter for two scenarios with and without resource reservation. We show through simulations that our approach guarantees an optimal response delay.},
	isbn = {978-1-4577-1379-8},
	issn = {2376-6492},
	author = {Elmachkour, Mouna and Kobbane, Abdellatif and Sabir, Essaid and El Koutbi, Mohammed}
}
