Pascale Minet

• PhD + HDR
• Senior Researcher at National Institute for Research in Computer Science and Control

Data gathering systems in the Industrial IoT require an end-to-end latency as low as 1 s with coverage of a few hundred meters. The 6TiSCH standard is well suited for these types of applications. A 6TiSCH network is a multihop wireless IPv6 network which uses time-slotted channel hopping (TSCH). TSCH is a medium access mode of IEEE802.15.4 which pr...

The energy consumption of data centers (DCs) has always been increasing. It will exceed 1200 TWh in 2020. In this chapter, we determine whether resource allocation in DCs can satisfy the following three requirements: (i) give short response times, (ii) keep the data center efficient, and (iii) reduce the carbon footprint. An efficient way to reduce...

We consider a shared transportation system in an urban environment where human drivers collect vehicles that are no longer being used. Each driver, also called a platoon leader, is in charge of driving collected vehicles as a platoon to bring them back to some given location (e.g., an airport, a railway station). Platoon allocation and route planni...

The use of poor-quality links in Internet of Things (IoT) networks leads to a bad quality of experience (QoE) with long delivery delays, low reliability, short lifetime of battery-operated nodes, to name but a few. In addition, network resources, such as bandwidth and node energy, are wasted by retransmissions. An accurate estimation of link qualit...

Data Center (DC) management aims at promptly serving user requests while minimizing the energy consumed. This is achieved by turning off unnecessary servers to save energy and adapting the number of servers that are on to the time-varying and heterogeneous user requests. A great change in the number of servers on leads to a considerable management...

High accuracy air pollution monitoring in a smart city requires the deployment of a huge number of sensors in this city. One of the most appropriate wireless technologies expected to support high density deployment is LoRaWAN which belongs to the Low Power Wide Area Network (LPWAN) family and offers long communication range, multi-year battery life...

With the Internet of Things (IoT), the number of monitoring applications deployed is considerably increasing, whatever the field considered: smart city, smart agriculture, environment monitoring, air pollution monitoring, to name a few. The LoRaWAN (Long Range Wide Area Network)architecture with its long range communication, its robustness to inter...

Data Centers (DCs) need to periodically configure their servers in order to meet user demands. Since appropriate proactive management to meet demands reduces the cost, either by improving Quality of Service (QoS) or saving energy, there is a great interest in studying different proactive strategies based on predictions of the energy used to serve C...

The Internet of Things (IoT) is now experiencing its first phase of industrialization. Industrial companies are completing proofs of concept and many of them plan to invest in automation, flexibility and quality of production in their plants. Their use of a wireless network is conditioned upon its ability to meet three Key Performance Indicators (K...

Low-power wireless technologies have been applied to industrial fields not only to monitor facilities but also to control them. There is a legitimate requirement to integrate low-power wireless networks with existing IP-enabled networks such as the Internet. The 6LoWPAN standard makes this happen easily by enabling low-power wireless networks to tr...

In content delivery networks (CDNs), caches are resources that must be allocated. For that purpose, videos’ popularity knowledge helps to make efficient decisions about which videos should be cached. Thus, we must be able to anticipate future needs in terms of requested videos. To do this, we rely on the requests history. This paper focuses on pred...

In this paper, we define a cluster based scheduling algorithm for Cognitive Radio Sensor Networks. To avoid inter-clusters collision, we assign fixed channels only to nodes having one-hop neighbors out of their clusters. We denote these nodes as specific nodes. Previous studies assign distinct channels to whole neighbor clusters to avoid inter-clus...

In this paper, we propose an analysis of a slot-based protocol designed for devices of the Internet of Things (IoT). In contrast to other TDMA-based protocols, this scheme uses a random technique to access shared slots, similarly to CSMA protocols. In practice, the transmissions are scheduled in a given backoff window of slots whose duration allows...

How realistic is the connectivity in a testbed? We answer this question by gathering connectivity measurements from 11 datasets, on both testbeds and real-world deployments. We propose a 5-point checklist to assess the realism of a testbed deployment and introduce a visual tool to evaluate the connectivity characteristics of a deployment.

Which wireless technology is able to meet the requirements of space launch vehicles in terms of latency, throughput and robustness? The IEEE 802.15.4e amendment has been designed to meet such requirements. More specifically, the Time Slotted Channel Hopping (TSCH) mode has been designed for industrial automation, process control and equipment monit...

The Internet of Things enables the interconnection of smart physical and virtual objects, managed by highly developed technologies. WSN, is an essential part of this paradigm. The WSN uses smart, autonomous and usually limited capacity devices in order to sense and monitor industrial environments. However, if no authentication mechanism is deployed...

In this paper, we focus first on the time needed by a node to join a Time Slotted Channel Hopping (TSCH) network, this time is called joining time. Second, we are also interested in the network building time. Since the data generated by a sensor node remain unavailable as long as this node has not yet joined the wireless sensor network, these times...

p>The Internet of Things (IoT) has overturned the information technology world. This new phenomenon is becoming inescapable and already covers almost all fields, fromwatchmaking to automated factories. IoT simplifies our everyday life and creates value for people and businesses. Things, also called entities, are very heterogeneous, usedifferent com...

Structural health monitoring has recently been applied to aircraft and space launch vehicles (launchers), in which the number of interconnected devices is continuously increasing. Wireless sensor networks (WSNs) would certainly reduce the mass and the complexity of the wiring, yet the essential question is whether they able to meet the requirements...

A service-oriented architecture designed for the use of wireless sensors networks (WSN) in industrial applications such as the operation and maintenance of industrial installations is presented in this chapter. This architecture comprises the OCARI wireless sensor network and the OPC-UA/ROSA middleware, as well as the KASEM predictive maintenance s...

Wireless sensor networks (WSNs) have many fields of application, including industrial, environmental and military domains. Monitoring a given zone is one of the main goals of this technology. This consists in deploying sensor nodes in order to detect any event occurring in the zone and report it to the sink. We present a survey that focuses on cove...

Scheduling in an IEEE802.15.4e TSCH (6TiSCH) low-power wireless mesh network can be done in a centralized or distributed way. When using centralized scheduling, a scheduler computes a communication schedule, which then needs to be installed into the network. This can be done using standards such CoAP and CoMI, or using a custom protocol such as OCA...

TDMA (Time Division Multiple Access)) is known to be an affective method for energy saving in wireless sensor networks (WSNs). However, when any slot is exclusively reserved to one node, the TDMA-based protocols suffer from low-channel utilization and high data delivery delays. STDMA (Spatial reuse TDMA) avoids these drawbacks by allowing multiple...

In this paper, we unify the requirements of noncritical and health monitoring applications in Aircraft and Launchers. We present different challenges faced by wireless sensor networks to meet these requirements. We also propose a solution that provides an adaptive multichannel collision-free protocol for data gathering.

The IEEE 802.15.4e MAC amendment has been proposed to meet the requirements of industrial applications. Using slotted medium access with channel hopping, the MAC layer orchestrates the medium accesses of nodes according to a given schedule. Nevertheless, this amendment does not specify how this schedule is computed. The purpose of this paper is to...

In many applications such as precision agriculture (fruit tree plantation, olive groves) or environmental monitoring, wireless sensors are, very often, randomly scattered in the 3D area of interest. Such applications require full three-dimensional coverage. Undoubtedly, an initial random deployment does not achieve neither full coverage of the 3D a...

Wireless Sensor Networks (WSNs) are deployed in many fields of application. Depending on the application requirements, sensor nodes can either be mobile and autonomous or static. In both cases, they are able to cooperate together in order to monitor a given area or some given Points of Interest (PoIs). Static sensor nodes need one or several agent(...

The new IEEE 802.15.4e standard does not specify how the schedule of medium accesses followed by wireless sensors is built. That is why, we propose a distributed interference-aware joint channel and time slot assignment, called DiSCA, for a traffic-aware convergecast in multichannel wireless sensor networks (WSNs). Unlike most previous studies, we...

OCARI is a wireless sensor network designed to operate in industrial environments]. It is easy to deploy (i.e. “plug-and-play”). It is energy-efficient to support battery-operated nodes. OCARI nodes use Commercial Off-The Shelf components. OCARI provides bounded medium access delays and the energy consumption of an OCARI network is predictable. In...

Disposer d’une architecture aisée à déployer et permettant d’intégrer de manière transparente les nouveaux points de mesure dans les systèmes d’information industriels de maintenance existants représente un enjeu industriel important. En effet, cela contribue à rendre la maintenance plus accessible en termes de coût de mise en œuvre qui représente...

Communication between sensor nodes in a Wireless Sensor Network (WSN) faces energy and bandwidth constraints. The dynamic behavior over time of the wireless channels makes ephemeral the neighborhood relation between sensors. Link quality estimation is critical for many WSN applications because it drastically influences the success of transmissions....

In this article, we study the issue of delay optimization and energy efficiency in grid wireless sensor networks (WSNs). We focus on STDMA (Spatial reuse - Time Division Multiple Access) scheduling, where a predefined cycle is repeated, and where each node has fixed transmission opportunities during specific slots of the cycle (defined by colors)....

In this paper, we focus on the deployment of wireless sensor nodes in an arbitrary realistic area with an irregular shape, and with the presence of obstacles that may be opaque. Moreover, we propose a simple projection-based method that tends to minimize the number of sensor nodes needed to fully cover such an area. This method starts with the opti...

The unlicensed spectrum bands become overcrowded causing an increased level of interference for current wireless sensor nodes. Cognitive Radio Sensor Networks (CRSNs) overcome this problem by allowing sensor nodes to access opportunistically the underutilized licensed spectrum bands. The sink assigns the spectrum holes to the secondary users (SUs)....

Current Wireless Sensor Networks (WSNs) are deployed over unlicensed frequency bands that face an increased level of interference from various wireless systems. Cognitive Radio Sensor Networks (CRSNs) overcome this problem by allowing sensor nodes to access new spectrum bands to minimize interferences. In this paper, we focus on the MultiChannel Ti...

With the spectacular development in radio and MEMS technologies, having sensor nodes capable of efficiently tuning their frequency over different channels is becoming more and more straightforward. For instance, TelosB motes can communicate on multiple frequencies as specified in the 802.15.4 standard. This reality has given birth to the multichann...

The distributed virtual forces deployment algorithm provides a very good area coverage and guarantees network connectivity for a sufficient number of sensor nodes. It relies on local information between neighboring sensor nodes. However, its main drawback is node oscillations and hence a high amount of sensor node energy wasted. The grid based stra...

In this work, we study raw convergecast in multi-channel wireless sensor networks (WSNs) where the sink may be equipped with multiple radio interfaces. We propose W ave, a simple and practical distributed joint channel and time slot assignment. We evaluate the number of slots needed to complete the convergecast by simulation and compare it to the o...

In this report, we study the issue of delay optimization and energy efficiency in grid wireless sensor networks (WSNs). We focus on STDMA scheduling, where a predefined cycle is repeated, and where each node has fixed transmission opportunities during specific slots (defined by colors). We assume a STDMA algorithm that takes advantage of the regula...

Convergecast is the transmission paradigm used by data gathering applications in wireless sensor networks (WSNs). For efficiency reasons, a collision-free slotted medium access is typically used: time slots are assigned to non-conflicting transmitters. Furthermore, in any slot, only the transmitters and the corresponding receivers are awake, the ot...

A typical task in wireless sensor networks (WSNs) is to collect data from sensor nodes towards one or many sinks in a multi-hop convergecast structure. In this paper, we focus on the data gathering problem with differentiated traffic, each addressed to a specific sink in multichannel WSNs. In order to find a collision-free optimized multichannel ti...

In many applications (e.g military, environment monitoring), wireless sensors are randomly deployed in a given area. Unfortunately, this deployment is not efficient enough to ensure area coverage and network connectivity. Algorithms based on Virtual Forces are used to improve the random initial deployment. In this paper, we want to ensure coverage...

Wireless sensor networks (WSNs) are prone to node/link failures, message losses, and dynamic node joins and departures. For instance, in data gathering applications that constitute a common type of applications in WSNs, links between nodes and their parent in the data gathering tree may be broken. Protocols supporting such applications should adapt...

The goal of this paper is to present OSERENA, a distributed coloring algorithm optimized for dense wireless sensor networks (WSNs). Network density has an extremely reduced impact on the size of the messages exchanged to color the WSN. Furthermore, the number of colors used to color the network is not impacted by this optimization. We describe in t...

Extending the network lifetime is a challenging problem in wireless sensor networks. Using additional mobile agents called data collectors in order to gather data from sensor nodes and carry them to the sink, reveals a convenient solution. Intuitively, a great sensor nodes energy conservation can be achieved by single hop data gathering strategies....

Wireless sensor networks are usually randomly deployed in the monitored region. This initial deployment does neither achieve area coverage, nor ensure network connectivity. Thus, a redeployment algorithm has to be applied in order to meet these two requirements. In this paper, we overview existing centralized redeployment algorithms such as virtual...

In aerospace applications, wireless sensor networks (WSNs) collect data from sensor nodes towards a sink in a multi-hop convergecast structure. The throughput requirement of these applications is difficult to meet with a single wireless channel. That is why, in this paper, we focus on a multichannel time slot assignment that minimizes the data gath...

Graph coloring is used in wireless ad hoc and sensor networks to optimize network resources: bandwidth and energy. Nodes access the medium according to their color. It is the responsibility of the coloring algorithm to ensure that interfering nodes do not have the same color. In this paper, we focus on wireless ad hoc and sensor networks with grid...

In data gathering applications which is a typical application paradigm in wireless sensor networks, sensor nodes may have different traffic demands. Assigning equal channel access to each node may lead to congestion, inefficient use of the bandwidth and decrease of the application performance. In this paper, we prove that the time slot assignment p...

Coloring is used in wireless networks to improve communication efficiency, mainly in terms of bandwidth, energy and possibly end-to-end delays. In this paper, we define the h-hop node coloring problem, with h any positive integer, adapted to two types of applications in wireless networks. We specify both general mode for general applications and st...

Wireless sensor networks (WSN) are generally randomly deployed in a given area. This initial deployment does not achieve neither area coverage, nor network connectivity. Thus, a redeployment algorithm has to be applied in order to achieve these two goals. This algorithm should meet performance criteria like saving energy and achieving stability. Ou...

Wireless sensor networks, WSNs, are an efficient way to deal with low-rate communications in confined environments such as mines or nuclear power plants because of their simplicity of deployment and low cost. In these application domains, WSNs are used to gather data from sensor nodes towards a sink in a multi-hop convergecast structure. In this pa...

Industrial applications have specific needs which require dedicated solutions. On the one hand, MEMS can be used as affordable and tailored solution while on the other hand, wireless sensor networks (WSNs) enhance the mobility and give more freedom in the design of the overall architecture. Integrating these two technologies would allow more optima...

Clustering schemes offer a practical way of providing scalability when dealing with large and dense Mobile Ad hoc Networks (MANETs). The feasibility of a clustering method can be primarily determined by the complexity of the cluster head selection. Optimizing the cluster head selection allows for the network to be more efficient by minimizing the s...

Connectivity and coverage are two crucial problems for wireless sensor networks. Several studies have focused on proposing solutions for improving and adjusting the initial deployment of a wireless sensor network to meet these two criteria. In our work, we propose a new hierarchical architecture for sensor networks that facilitates the gathering of...

Fault-tolerance is one of the main issues in Wireless Sensor Networks (WSNs) where applications require a continuous service. In this paper, we show how to use a small number of mobile robots to handle failures that may occur in the WSN. We study two strategies: Centralized Manager Strategy (CMS) and CMS with anticipation noted by CMS* to detect, r...

The goal of this research report is to present OSERENA "Optimized SchEduling RoutEr Node Activity", a distributed coloring algorithm optimized for dense wireless networks. Network density has an extremely reduced impact on the size of the messages exchanged to color the network. Furthermore, the number of colors used to color the network is not imp...

Micaz motes can communicate on multiple frequencies as specified in the 802.15.4 standard. This reality has given birth to multichannel communication paradigm in Wireless Sensor Networks (WSNs). Obviously, multichannel communication mitigates interferences, jamming and congestion, whereas it brings also challenging issues. Thus, in this paper, we a...

Graph coloring is used in wireless networks to optimize network resources: bandwidth and energy. Nodes access the medium according to their color. It is the responsibility of the coloring algorithm to ensure that interfering nodes do not have the same color. In this research report, we focus on wireless sensor networks with grid topologies. How doe...

The myriad of potential applications supported by wireless sensor networks (WSNs) has generated much interest from the research community. Various applications range from small size low industrial monitoring to large scale energy constrained environmental monitoring. In all cases, an operational network is required to fulfill the application missio...

In this article, we describe experiments with the ~ulticast protocol MOST (Multicast Overlay minimum Span­ mng Tree) on a real testbed. The testbed is a wireless multi­ hop network. with nodes running a MANET protocol, the OLSRv2 routing protocol, and with IEEE 802.11g hardware. We present our specification and implementation of MOST for OLSR:2. It...

Clustering schemes offer a practical way of providing scalability when dealing with large and dense Mobile Ad hoc Networks (MANETs). The feasibility of clustering can be determined by the complexity of the cluster head selection. Optimizing the cluster head selection allows for the network to be more efficient by minimizing the signaling overhead w...

Coloring is used in wireless networks to improve communication efficiency, mainly in terms of bandwidth, energy and possibly end-to-end delays. In this research report, we define the h-hop node coloring problem, with h any positive integer. We prove that the associated decision problem is NP-complete. We then present a 3-hop distributed coloring al...

Protocols that are to be employed in the context of the Internet of Things (IoT) have to meet a wide variety of application-specific requirements. In this report, we reflect on recent experiences, gained from several real-world deployments in which we have participated, which use low power, embedded networking devices. We discuss the lessons learne...

In wireless sensor networks, energy efficiency is mainly achieved by making nodes sleep. In this paper, we present the combination of SERENA, a new node activity scheduling algorithm based on node coloring, with TDMA/CA, a collision avoidance MAC protocol. We show that the combination of these two protocols enables substantial bandwidth and energy...