@conference { ISI:000380509200017,
	title = {A New Optimal Hybrid Spectrum Access in Cognitive Radio: Overlay-Underlay Mode},
	booktitle = {2015 INTERNATIONAL CONFERENCE ON WIRELESS NETWORKS AND MOBILE COMMUNICATIONS (WINCOM)},
	year = {2015},
	note = {International conference on wireless networks and mobile communications, Marrakech, MOROCCO, OCT 20-23, 2015},
	pages = {92-98},
	abstract = {In this paper, we propose a hybrid cognitive radio (CR) system where underlay and overlay CR approaches are combined under SIRN constraints. This new access type allows to optimize the spectrum sensing time with throughput improvement. Our proposed access type is based on a merger of these two modes depending on the number of secondary users (SU) in the Underlay Mode and on the access probabilities for these two modes. The number of all users in the Underlay access mode should not exceed a certain number of users. When a new SU arrives and if the number of SUs in Underlay mode is already equal to the predifined max number, the SU decides to switch to the Overlay mode to access the canal using this method. The SU states will be modeled with a Markov chain, the aim of this work is attempting to show that this new method allows to increase the throughput of the SU with energy optimization. The exact outage probability of secondary system is also derived for this model. Simulation results show that the performance, especiallay the throughput can be significantly increased by the proposed hybrid system.},
	isbn = {978-1-4673-8224-3},
	author = {Gmira, Sara and Kobbane, Abdellatif and Sabir, Essaid}
}
@conference { ISI:000351846000018,
	title = {A new Cross layer Architecture for Service Differentiation in Wireless Sensor Networks},
	booktitle = {2013 IEEE MALAYSIA INTERNATIONAL CONFERENCE ON COMMUNICATIONS (MICC)},
	year = {2013},
	note = {IEEE 11th Malaysia International Conference on Communications (MICC), Kuala Lumpur, MALAYSIA, NOV 26-28, 2013},
	pages = {92-97},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {This paper describes a new cross-layer architecture that supports service differentiation in Wireless Sensor Networks (WSN). In WSNs, sensor nodes are supposed to communicate using a random access method. We propose a mathematical model that combines parameters form network and MAC layers. We aim to estimate and to enhance the throughput of multi-hop WSNs and the stability of the forwarding queues used for real-time and best-effort traffic. We suppose in this paper that we have one single sink in the WSN and we study the impact of the probability of transmitting (real-time and best-effort traffic), density of sensor and hop count on the end-to-end throughput.},
	isbn = {978-1-4799-1532-3},
	author = {Loutfi, Ahmed and Mohamed, Senhadji and Sabir, Essaid and Kobbane, Abdellatif and El Koutbi, 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}
}
