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Bernard Cousin

Bio: Bernard Cousin is an academic researcher from University of Rennes. The author has contributed to research in topics: Multicast & Source-specific multicast. The author has an hindex of 20, co-authored 136 publications receiving 1239 citations. Previous affiliations of Bernard Cousin include Institut de Recherche en Informatique et Systèmes Aléatoires & University of Rennes 1.


Papers
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Journal ArticleDOI
TL;DR: A network-assisted approach to optimal, learning-based, and heuristic policies, such as blocking probability and average throughput, and a reinforcement learning approach is introduced to derive what to signal to mobiles.
Abstract: When several radio access technologies (e.g., HSPA, LTE, WiFi, and WiMAX) cover the same region, deciding to which one mobiles connect is known as the Radio Access Technology (RAT) selection problem. To reduce network signaling and processing load, decisions are generally delegated to mobile users. Mobile users aim to selfishly maximize their utility. However, as they do not cooperate, their decisions may lead to performance inefficiency. In this paper, to overcome this limitation, we propose a network-assisted approach. The network provides information for the mobiles to make more accurate decisions. By appropriately tuning network information, user decisions are globally expected to meet operator objectives, avoiding undesirable network states. Deriving network information is formulated as a semi-Markov decision process (SMDP), and optimal policies are computed using the Policy Iteration algorithm. Also, and since network parameters may not be easily obtained, a reinforcement learning approach is introduced to derive what to signal to mobiles. The performances of optimal, learning-based, and heuristic policies, such as blocking probability and average throughput, are analyzed. When tuning thresholds are pertinently set, our heuristic achieves performance very close to the optimal solution. Moreover, although it provides lower performance, our learning-based algorithm has the crucial advantage of requiring no prior parameterization.

89 citations

Journal ArticleDOI
TL;DR: The results show that the MC-RMSA with R-NC can effectively improve the performance of all-optical multicast in EONs to reduce the blocking probability and evaluate the heuristics in a dynamic network provisioning.
Abstract: In this paper, we study the multicast-capable routing, modulation, and spectrum assignment (MC-RMSA) schemes that consider the physical impairments from both the transmission and light splitting in elastic optical networks (EONs). Specifically, we propose to provision each multicast request with a light forest, which consists of one or more light trees to avoid the dilemma that because of the accumulated physical impairments, a relatively large light tree may have to use the lowest modulation level, and, hence, consume too many frequency slots (FS'). In order to further improve the spectral efficiency and compensate for the differential delays among the light trees, we incorporate the rateless network coding (R-NC) in the multicast system. We first formulate an integer linear programming (ILP) model to solve the problem for static network planning. Then, we propose three time-efficient heuristics that leverage the set-cover problem and utilize layered auxiliary graphs. The simulation results indicate that in both the ILP and heuristics, the MC-RMSA with R-NC can achieve better performance on the maximum index of used FS' than that without. After that we evaluate the heuristics in a dynamic network provisioning. The results show that the MC-RMSA with R-NC can effectively improve the performance of all-optical multicast in EONs to reduce the blocking probability.

64 citations

Proceedings ArticleDOI
05 Sep 2016
TL;DR: This paper proposes a stable, reliable, energy efficient routing protocol for mobile Wireless Body Area Networks that preserves the residual energy of nodes with an increase network lifetime and uses an objective model to select energy-efficient paths with stable links.
Abstract: Wireless body area network (WBAN) calls for a next generation in wireless networks. This new generation is designed to operate autonomously, to connect various medical sensors and appliances located on or inside a human body. Mobile WBANs have been designed, offering numerous practical and innovative services so that health care and quality of life can be improved. Thus, the equipment used in WBAN is usually mobile and autonomous which imposes high constraint on energy. That is, the energy efficiency must be taken into account as one of the objectives of the routing protocol designed for this type of network. Although mobile nodes may cause link breaks, most of studies ignore the link stability. In this paper, we propose a stable, reliable, energy efficient routing protocol for mobile Wireless Body Area Networks. It preserves the residual energy of nodes with an increase network lifetime. To achieve this goal, we use an objective model to select energy-efficient paths with stable links. Simulation results demonstrate that our protocol improves the state of the art in terms of energy consumption and routing overhead.

45 citations

Journal ArticleDOI
TL;DR: A comprehensive survey on Inter-Cell Interference Coordination techniques is performed, and the most suitable ICIC technique for each network scenario is identified under several parameters such as different network loads, radio conditions, and user distributions.
Abstract: LTE networks' main challenge is to efficiently use the available spectrum, and to provide satisfying quality of service for mobile users. However, using the same bandwidth among adjacent cells leads to occurrence of Inter-cell Interference especially at the cell-edge. Basic interference mitigation approaches consider bandwidth partitioning techniques between adjacent cells, such as frequency reuse of factor m schemes, to minimize cell-edge interference. Although SINR values are improved, such techniques lead to significant reduction in the maximum achievable data rate. Several improvements have been proposed to enhance the performance of frequency reuse schemes, where restrictions are made on resource blocks usage, power allocation, or both. Nevertheless, bandwidth partitioning methods still affect the maximum achievable throughput. In this proposal, we intend to perform a comprehensive survey on Inter-Cell Interference Coordination (ICIC) techniques, and we study their performance while putting into consideration various design parameters. This study is implemented throughout intensive system level simulations under several parameters such as different network loads, radio conditions, and user distributions. Simulation results show the advantages and the limitations of each technique compared to frequency reuse-1 model. Thus, we are able to identify the most suitable ICIC technique for each network scenario.

44 citations

Journal ArticleDOI
03 May 2018
TL;DR: This paper addresses the problem of energy-aware routing in SDN-based carrier-grade Ethernet networks based on turning off network nodes and links to reduce energy consumption, while respecting the rule space capacity for each Openflow switch, and maintaining an allowable maximum link utilization.
Abstract: Soft-defined networking (SDN) is a new approach that enables operators to easily manage all the network elements. In this paper, we address the problem of energy-aware routing in SDN-based carrier-grade Ethernet networks. Our approach is based on turning off network nodes and links to reduce energy consumption, while respecting the rule space capacity for each Openflow switch, and maintaining an allowable maximum link utilization. The problem of identifying the optimal set of network elements to be turned off is NP-hard. We first present an exact model based on an integer linear programming formulation for the problem. Then, we describe a set of first-fit heuristic algorithms suitable for large-sized networks. The exact and heuristic approaches are tested on SNDlib-based instances. Experimentations show the efficiency of both exact and heuristic methods for different network topologies. In particular, our heuristic algorithms are able to achieve a good balance between energy consumption, resource utilization, and network performance.

42 citations


Cited by
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Journal ArticleDOI
TL;DR: To support bursty traffic on the Internet (and especially WWW) efficiently, optical burst switching (OBS) is proposed as a way to streamline both protocols and hardware in building the future gener...
Abstract: To support bursty traffic on the Internet (and especially WWW) efficiently, optical burst switching (OBS) is proposed as a way to streamline both protocols and hardware in building the future gener...

674 citations

Book
01 Dec 1981

609 citations

Journal ArticleDOI
TL;DR: A comprehensive survey on RA in HetNets for 5G communications is provided and two potential structures for 6G communications are provided, such as a learning-based RA structure and a control- based RA structure.
Abstract: In the fifth-generation (5G) mobile communication system, various service requirements of different communication environments are expected to be satisfied. As a new evolution network structure, heterogeneous network (HetNet) has been studied in recent years. Compared with homogeneous networks, HetNets can increase the opportunity in the spatial resource reuse and improve users’ quality of service by developing small cells into the coverage of macrocells. Since there is mutual interference among different users and the limited spectrum resource in HetNets, however, efficient resource allocation (RA) algorithms are vitally important to reduce the mutual interference and achieve spectrum sharing. In this article, we provide a comprehensive survey on RA in HetNets for 5G communications. Specifically, we first introduce the definition and different network scenarios of HetNets. Second, RA models are discussed. Then, we present a classification to analyze current RA algorithms for the existing works. Finally, some challenging issues and future research trends are discussed. Accordingly, we provide two potential structures for 6G communications to solve the RA problems of the next-generation HetNets, such as a learning-based RA structure and a control-based RA structure. The goal of this article is to provide important information on HetNets, which could be used to guide the development of more efficient techniques in this research area.

321 citations

Posted Content
TL;DR: In this article, the authors provide a comprehensive tutorial on the main concepts of machine learning, in general, and artificial neural networks (ANNs), in particular, and their potential applications in wireless communications.
Abstract: Next-generation wireless networks must support ultra-reliable, low-latency communication and intelligently manage a massive number of Internet of Things (IoT) devices in real-time, within a highly dynamic environment. This need for stringent communication quality-of-service (QoS) requirements as well as mobile edge and core intelligence can only be realized by integrating fundamental notions of artificial intelligence (AI) and machine learning across the wireless infrastructure and end-user devices. In this context, this paper provides a comprehensive tutorial that introduces the main concepts of machine learning, in general, and artificial neural networks (ANNs), in particular, and their potential applications in wireless communications. For this purpose, we present a comprehensive overview on a number of key types of neural networks that include feed-forward, recurrent, spiking, and deep neural networks. For each type of neural network, we present the basic architecture and training procedure, as well as the associated challenges and opportunities. Then, we provide an in-depth overview on the variety of wireless communication problems that can be addressed using ANNs, ranging from communication using unmanned aerial vehicles to virtual reality and edge caching.For each individual application, we present the main motivation for using ANNs along with the associated challenges while also providing a detailed example for a use case scenario and outlining future works that can be addressed using ANNs. In a nutshell, this article constitutes one of the first holistic tutorials on the development of machine learning techniques tailored to the needs of future wireless networks.

265 citations