Pascal Lorenz

Université de Haute-Alsace | UHA · Institut Universitaire de Technologie de Colmar (IUT)

La dégradation de la qualité de service LoRaWAN est proportionnelle au cumule des facteurs de détérioration connues dont la congestion des passerelles. La charge utile des paquets transmis constitue un facteur impactant les indicateurs de celle-ci et en fonction d'un seuil du nombre des passerelles inversement proportionnel a un seuil des flux de d...

The advantages of LoRaWAN over conventional networks (GSM, 4G, 5G) in terms of investment and operating costs have been proven for network coverage in urban and rural areas. However, the theoretical coverage compared to the reality on the ground and the quality of service (QoS) provided remain very relative and depend on several technical factors,...

Although visible light communication (VLC) channels are more secure than radio frequency channels, the broadcast nature of VLC links renders them open to eavesdropping. As a result, VLC networks must provide security in order to safeguard the user’s data from eavesdroppers. In the literature, keyless security techniques have been developed to offer...

The Routing Protocol for Low Power and Lossy Networks (RPL) is experiencing a wave of security threats, due to the need of its utility in the Internet of Things (IoT). RPL is so far considered as one of the most utilized routing protocols in new IoT applications, which is one of the reasons the latter may lead to confronting challenges later on. In...

Wireless Sensor Networks (WSNs) are extensively used in monitoring applications such as humidity and temperature sensing in smart buildings, industrial automation, and predicting crop health. Sensor nodes are deployed in remote places to sense the data information from the environment and to transmit the sensing data to the Base Station (BS). When...

Nowadays, vehicular ad hoc networks (VANETs) have become more interesting research area. High number of safety, traffic management and even comfort applications have been developed to secure driving and make travellers satisfied. This evolution opens up a vast area of research in several fields. Specifically in the security domain, huge researches...

Wireless sensor network (WSN) represents a very important research that targets a very large number of possible applications in healthcare, smart cities, environmental monitoring, military, industrial automation and recently in smart grids. It consists of three main components: a large number of nodes, gateways and software. WSN workload needs an u...

In Wireless Sensor Networks (WSNs), the nodes mobility model determines the network functionality which strongly influences the network lifetime, coverage and the energy consumption as well. So, the mobility strategy choice is important in several critical application areas. The present paper proposes a mobility model that respects the network cove...

This chapter covers the interactions between the transport and routing protocols layers. The aim is to provide better planning and design for MANET (Mobile Ad hoc NETwork). Two previously proposed solutions are combined for a cross layer solution in order to ensure some QoS (Quality of Service) parameters. The first solution is called CL-TCP (cross...

The use of wireless sensor networks (WSNs) is growing up in the last few years. Therefore, new challenges arise every day and one of the emerging challenges in WSNs is the nodes mobility support. This feature increases the application areas of these technologies but also raises new challenges to solve. This paper proposes a new handover mechanism,...

This paper proposes a new mechanism of path selection and admission control for IPTV in IEEE 802.16j simultaneously. The proposed mechanism takes into account some constraints of Quality of Services (QoS) which are required by real-time applications, such as available bandwidth, end-to-end delay, number of hops between MR-BS and SS as well as quali...

In this paper, we evaluate and compare our scheduling strategy for various IPTV services traffic over 802.16j networks with several scheduling algorithms such as Strict Priority algorithm (SP), Weighted Round Robin (WRR), and Modified Dynamic Weighted Round Robin (MWRR). The proposed scheme adapts dynamically the scheduler operation to according qu...

In this paper, a study about wireless sensor network (WSN) deployment strategy is demonstrated and made workable for the use of multi-objective approach. The development of sensor nodes by considering multiple objectives and existence of fixed obstacles is an important optimization problem. There are two objectives in this study, connectivity and c...

SUMMARYA mobile ad hoc networks (MANET) is a decentralized, self-organizing, infrastructure-less network and adaptive gathering of independent mobile nodes. Because of the unique characteristics of MANET, the major issues to develop a routing protocol in MANET are the security aspect and the network performance. In this paper, we propose a new secu...

This paper is a study about deployment strategy for achieving coverage and connectivity as two fundamental issues in wireless sensor networks. To achieve the best deployment, a new approach based on elitist non-dominated sorting genetic algorithm (NSGA-II) is used. There are two objectives in this study, connectivity and coverage. We defined a fitn...

A mobile ad hoc network (MANET) is a wireless network with high of mobility, no fixed infrastructure and no central administration. These characteristics make MANET more vulnerable to attack. In ad hoc network, active attack i.e. DOS, and blackhole attack can easily occur. These attacks could decrease the performance of the routing protocol. We hav...

Several research effort in recent years has shown its significant interest in the development of security measure in the routing of Mobile Ad-hoc Network (MANET). Ad-hoc On-demand Distance Vector (AODV) routing protocol has been one of the basic protocol that is modified to cope with security demands. This paper present an analytical model to evalu...

AODV routing protocol facilitates changing and simple-to-setup network environment. It helps setting up a network without sufficient infrastructure, such as in disaster area. Development of AODV protocol has gathered a worldwide research interest. However, not many researches implement AODV routing protocol in real mobile nodes and real MANET. In a...

In this chapter, the authors present an improvement to the interactions between MAC (Medium Access Control) and TCP (Transmission Control Protocol) protocols for better performance in MANET. This improvement is called IB-MAC (Improvement of Backoff algorithm of MAC protocol) and proposes a new backoff algorithm. The principle idea is to make dynami...

This paper proposes new distributed algorithms of adaptive transmit power allocation in wireless sensor networks for improving the efficiency of energy management. The proposed algorithms are based on two fundamental criteria namely: the distance between the sensor and the sink, and the distance between the sensor and its two-hop neighbours. Each s...

In this paper, we present a survey of TCP (Transmission Control Protocol) protocol for better performance in the MANET (Mobile Ad Hoc Network). After a short presentation of the main features of TCP, we give the most important problems from which TCP suffer in MANET. We present after that some approaches proposed in the literature in order to impro...

Internet protocol television (IPTV) service depends on the network quality of service (QoS) and bandwidth of the broadband service provider. IEEE 802.16j mobile multihop relay Worldwide Interoperability for Microwave Access networks have the opportunity to offer high bandwidth capacity by introducing relay stations. However, to actually satisfy QoS...

In this paper, we discuss the issue of fairness in the IEEE802.11e over wireless mesh networks. Fairness is an important factor that we have to achieve before talking about QoS. Inspired by social networks approx-imations, and to achieve fairness and provide QoS by regulating heterogeneous traffic, we extended the original IEEE802.11e protocol by i...

Time synchronization is required in wireless sensor networks in order to improve its performance. This improvement could be noticed in terms of energy, storage, computation, shared resources or bandwidth. One of the main applications in WSNs has been to decrease the energy consumption. A wireless network can save energy with this feature, but if th...

A mobile ad hoc network (MANET) is a wireless network with high of mobility, no fixed infrastructure and no central administration. These characteristics make MANET more vulnerable to attack. In ad hoc network, active attack i.e. DOS, and blackhole attack can easily occur. These attacks could decrease the performance of the routing protocol. In thi...

Energy saving is the most important feature in wireless sensor networks (WSN). An energy saving method is to perform a logical grouping of nodes and add collaboration between them. In this paper, we show a method of collaboration between groups based on the communication between neighboring groups. Using this information, the groups will be able to...

In this paper, we present an improvement for the interactions between MAC and routing protocols to better energy consumption in MANET (Mobile Ad hoc Networks) and show its incidences on the performance of the network. We propose a new approach called IMR-EE (Improvement of the Interactions between MAC and Routing protocol for Energy Efficient) whic...

One of the critical issues in Mobile Ad hoc Network (MANET) is the energy efficiency. The challenge is how to extend the limited lifetime of energy in mobile nodes. We proposed a new approach to minimise the energy consumption called EM-OLSR (Energy Efficiency in MANET by improving OLSR protocol). EM-OLSR is based on the OLSR routing protocol and a...

Electric power regulation and privatization is creating new challenges on high voltage transmission and energy distribution systems. The existing electrical infrastructures must be updated in order to meet the needs of the digital society. Smart Grid describes a next-generation electrical power system that creates an increased use of communications...

Method of forwarding executed by a node of a multi-hop access network, said node comprising a plurality of output tunnels, the method of forwarding comprising; a step of receiving a data packet of a multimedia stream, a step of processing said data packet by a scheduler, and - after said step of processing, a step of determining at least one output...

The use of electronic health (eHealth) technologies in healthcare improves the quality of health services furnished to patients. The application of these technologies helps physicians and other health professionals to pursue early detection of abnormal status on patients¿ health. Body sensor networks are a type of wireless sensor networks aimed to...

A Mobile Ad hoc Network (MANET) is a collection of terminals equipped with one or several wireless network interfaces. In this paper, we suggest an improvement of the Transmission Control Protocol (TCP), called Improvement of the Acknowledgement mechanism of TCP (IA-TCP), to better performance in MANET. IA-TCP delays the acknowledgements packets of...

Wireless Sensor Networks (WSN) are usually used in hostile environments to collect informations. The sensors usually get their energy from batteries. It is a crucial point for the livespan of the network. Energy has to be saved for this type of networks. In WSN, routing protocols usually take care of this parameter. In this paper, we propose to use...

New communication technologies must be provided in order to improve the energy distribution. As far as we know, there is not any network protocol designed exclusively for this purpose. In this paper, we present the design and simulation of a group-based protocol to improve the energy distribution in smart grids. We will show the group-based archite...

The performance of the Wireless Sensor Networks (WSNs) is strongly affected by the limited capacity of the sensor nodes which form these networks. In fact, this limited capacity has a great influence on the lifetime of the wireless sensor networks. So an effective management of the consumed power of the nodes can increase the network lifetime. Vari...

In this article, we are presenting a series of ontology-driven mechanisms for system diagnosis. Mainly, we introduce an event ontology and concepts related to semantic tag clouds and show how to manage the activities to build an ontology-based diagnosis. We formalize these concepts in order to derive diagnosis actions and to validate the successful...

Body Area Sensor can enable healthcare monitoring in an unobtrusive way. Medical and healthcare research has been striving to find relationships between core body temperature at female genitals and certain health conditions, such as ovulation period. This paper presents a solution for intra-body temperature monitoring based on a new intra-body sens...

In this paper, we study and evaluate the overhead for a security algorithm based on clustering in MANET networks. The analysis of the communication overhead in Ad Hoc networks is an important issue because it affects the energy consumption and the limited battery life time of the mobile nodes. The algorithm partitions the network into clusters base...

Several protocols and algorithms are used for energy efficient routing in Wireless Sensor Networks (WSNs). These protocols enable not only to reduce communication latency in these networks but also to maximize the network lifetime that is directly related to energy sensors due to the constraint of the batteries. Some of these protocols use clusteri...

In an ad-hoc network, communications in the half duplex mode imply that the nodes in the Ad-Hoc network have not always fair access to the network resources. In this paper, the fair resources allocation for nodes in a double star is studied. The aim of this work is to analyse the fairness behaviour of the number of packets received by each node. A...

In a mobile wireless ad hoc network, mobile nodes cooperate to form a network without using any infrastructure such as access points or base stations. Instead, the mobile nodes forward packets for each other, allowing communication among nodes outside wireless transmission range. As the use of wireless networks increases, security in this domain be...

Actually with the increasing popularity of wireless networks, which indicate that there will be a demand for communicating devices providing high capacity communication with Quality of Service (QoS), QoS becomes an important factor in wireless networks, because it offers to the network the ability to provide services to applications with some impor...

In this paper, we address the fundamental problem of forwarding table optimization in mobile ad hoc networks and we propose a new multicast tree aggregation mechanism based on the uniqueness property of prime numbers. Instead of creating, for any new session, a new entry in the routing table, our mechanism allocates a unique identity to each sessio...

In a wireless network the communication works in half duplex mode and nodes that can interfere together. In this context, fairness is not obvious. This paper will focus on fairness in the received packets by each node. Fairness is evaluated for a static network topology called Star Network. Some simulations are used to illustrate a way to get fairn...

In the context of mobile ad hoc networks (MANETs) routing, we propose a clustering algorithm called Connectivity, Energy and Mobility driven Clustering Algorithm (CEMCA). The aim of CEMCA consists in appropriately choosing the cluster head to reduce routing overhead. In order to reduce traffic and energy consumption, the control messages are sent o...

A mobile ad hoc network (MANET) is an architecture without fixed infrastructure or centralized administration. However, when a message is transmitted in a multicast group, without any security infrastructure, it may be attacked or corrupted. In this paper we propose a new key management mechanism to support secure group multicast communications in...

The dynamic topology of ad hoc networks is an important issue on which a lot of research is carried out. Because of higher speeds of movement and networks of larger scale, the algorithms of auto-organization and clustering may be inefficient. Therefore, we propose a fully distributed clustering algorithm for mobile ad hoc networks in which the node...

Node lifetime is an important metric for communication in networks. However, node lifetime is still severely restricted by the limitations of power supply. In this paper we propose a new algorithm Save Energy and Maximize Connectivity (SEMC) that economizes the energy and keeps connectivity between the nodes. By varying the transmission range and r...

Many distributed applications build overlays on top of the Internet. Several unsolved issues at the network layer can ex-plain this trend to implement network services such as multicast, mobility, and security at the application layer. On one hand, over-lays creating basic topologies are usually limited in flexibility and scalability. On the other...

Providing guaranteed quality of service (QoS) in wireless networks is a key issue for deploying multimedia applications. To support such a QoS, an arduous problem concerning how to find a feasible end to end path to satisfy multiple QoS constraints should be studied. In general, multi-constrained path selection, with or without optimization, is an...

Summary Nowadays, the cross-layer design approach is the most relevant concept in mobile ad hoc networks which is adopted to solve several open issues. It aims to overcome ad hoc networks performance problems by allowing protocols belonging to different layers to cooperate and share network status information while still maintaining separated layer...

Power conservation is a crucial problem in mobile ad hoc wireless networks knowing that, each mobile node has a limited amount of energy concentrated in a battery. The main objective of our paper is to use a variable transmission range in order to save some energy and to keep the connectivity of the network. Our algorithm is implemented at the data...

This paper investigates the influence of control packet (setup message) processing time and optical cross-connect (OXC) configuration time on the performance of optical burst switched (OBS) mesh networks with degree-four topologies. The performance analysis considers five resource reservation protocols, just-in-time (JIT), JumpStart, JIT<sup>+ </su...

Today, the original IEEE 802.11 standard has several problems in providing Quality of Service in MANETs. A single FIFO queue is used in best effort manner and it does not support QoS. The upcoming IEEE 802.11e was drafted to overcome these drawbacks. In this paper we describe a new multiple queuing system with an adaptive scheduling taking into acc...

Currently, mobile ad hoc networks (MANETs) lack load-balancing capabilities, and thus, they fail to provide good performance especially in the case of a large volume of traffic. Ad hoc networks lack also service differentiation. However, in these wireless environments, where channel conditions are variable and bandwidth is scarce, the differentiate...

This paper discusses performance implications of meshing degree (or nodal degree) for optical burst switching (OBS) mesh networks using one-way resource reservation protocols. The analysis is focused on the following topologies: rings, chordal rings with nodal degrees ranging from three to six, mesh-torus, NSFNET, ARPANET and the European Optical N...

This paper discusses the influence of setup message processing time and optical switch configuration time on the performance of IP over optical burst switched mesh networks using one-way resource reservation protocols. It is shown that the network performance is almost independent of the optical switch configuration time for values smaller than 0.1...

In this paper, we present a performance assessment of one-way resource reservation protocols in optical burst switched (OBS) mesh networks. The performance analysis considers five resource reservation protocols, Just-In-Time (JIT), JumpStart, JIT+, Just-Enough-Time (JET) and Horizon, and focuses on the following topologies: rings, degree-three chor...

In this paper, we present a new leader election algorithm for mobile ad hoc networks, in order to handle arbitrary topology changes and group self-organizing or self-stabilising. Our proposed leader election algorithm ensures that eventually nodes of a communication system network can form a group. Within this group start nodes trigger the leader e...

The lack of resources in routers will become a crucial issue with the deployment of state storing protocols. In particular, single or any source multicast protocols will most probably take over large amounts of resources for maintaining multicast tree information. The aim of this paper is to study the possibility and benefit of using multiple short...

A growing number of network applications create virtual networks called overlays on top of the Internet. Because advanced communication modes such as multicast have not been able to be successfully deployed at the network layer, they are now being implemented at the application layer thus creating such virtual networks. However these overlays requi...

This paper discusses performance implications of meshing degree (or nodal degree) for optical burst switching (OBS) mesh networks using signaling protocols with one-way reservation schemes. The analysis is focused on the following topologies: rings, chordal rings with nodal degrees ranging from three to six, mesh-torus, NSFNET, ARPANET and the Euro...

Many multicast applications, such as video-on-demand and video conferencing, desire quality of service (QoS) support from an underlying network. The differentiated services (DiffServ) approach will bring benefits for theses applications. However, difficulties arise while integrating native IP multicasting with DiffServ, such as multicast group stat...

This paper investigates the role of nodal degree (meshing degree) in optical burst switching (OBS) mesh networks using signaling protocols with one-way reservation schemes. The analysis is focused on the following topologies: rings, degree-three chordal rings, degree-four chordal rings, degree-five chordal rings, mesh-torus, NSFNET, ARPANET and the...

Currently, the emergence of nomadic applications has raised intense research interest in providing quality of service (QoS) in mobile ad hoc networks (MANETs). An ad hoc network can be considered as an autonomous distributed system that consists of a set of identical mobile nodes that move independently and freely. Each node uses wireless links to...