Adaptation Process for Ad hoc Routing Protocol

International audienceBecause of several constraints in ad hoc networks, an adaptive ad hoc routing protocol is increasingly required. In this paper, we propose a synopsis of an adaptation process for an adaptive ad hoc routing protocol. Next, we put into practice the analysis of the process of adaptation to mobility by realizing an adaptive routing protocol: CSR (Cluster Source Routing) which is an extension of a widely used ad hoc routing protocol: DSR (Dynamic source Routing). Mobility and density metrics are considered to CSRDSR mode switching, it moves from a flat architecture working in DSR to a virtual hierarchical architecture. With this mode switching, CSR can enhance the scalability of the DSR routing protoco

Load balancing and lifetime maximization in WSN

Workshop Univ Kyushu-INPTStrategies that balance the energy consumption of the nodes and ensure maximum network lifetime by balancing the load are proposed and analyzed. Multiple transmission power levels are used. We studied an optimal solution for calculating the hop-by-hop traffic proportions for the particular case of nodes having just two transmission power levels, and compared the results given by the heuristics with those from the optimal analytical case

Crowd-based positioning of UAVs as Access Points

Unmanned Aerial Vehicles (UAVs) can be a cost saving and easy to deploy solution to implement a temporary network infrastructure. They can act as access points in scenarios such as emergency situations, special events, or specific area monitoring. Two main deployment families can be found in the literature. The first one, the location-based family, is based on the fundamental assumption that the network user positions are known. We do believe that this could not suit the most general scenarios. On the other hand, the location-independent family can not be as efficient as the first one. The main idea in this paper is to introduce a new crowd-based family, based on a probabilistic knowledge of user positions. We then propose a self-deployment method built on a Coulomb's law analogy where users and UAVs act as electrical charges. Short range interactions are implemented through network sensing, while long range ones use a crowd-based approach. Some numerical results are depicted, showing the performance of this self-deploying mechanism as well as a comparison with a well-known clustering algorithm

Load Balancing Techniques for Lifetime Maximizing in Wireless Sensor Networks

International audienceEnergy consumption has been the focus of many studies on Wireless Sensor Networks (WSN). It is well recognized that energy is a strictly limited resource in WSNs. This limitation constrains the operation of the sensor nodes and somehow compromises the long term network performance as well as network activities. Indeed, the purpose of all application scenarios is to have sensor nodes deployed, unattended, for several months or years.This paper presents the lifetime maximization problem in “many-to-one” and “mostly-off” wireless sensor networks. In such network pattern, all sensor nodes generate and send packets to a single sink via multi-hop transmissions. We noticed, in our previous experimental studies, that since the entire sensor data has to be forwarded to a base station via multi-hop routing, the traffic pattern is highly non-uniform, putting a high burden on the sensor nodes close to the base station.In this paper, we propose some strategies that balance the energy consumption of these nodes and ensure maximum network lifetime by balancing the traffic load as equally as possible. First, we formalize the network lifetime maximization problem then we derive an optimal load balancing solution. Subsequently, we propose a heuristic to approximate the optimal solution and we compare both optimal and heuristic solutions with most common strategies such as shortest-path and equiproportional routing. We conclude that through the results of this work, combining load balancing with transmission power control outperforms the traditional routing schemes in terms of network lifetime maximization

Performance Evaluation of Energy Efficient Policies for Ethernet Switches

International audienceEnergy efficiency has emerged as a defining scientific and engineering challenge of our time. Ethernet, as the dominant wireline technology, has been a focus of intense research and development efforts with the goal of significantly decreasing its energy consumption. In 2010 the IEEE Std 802.3az, which uses a Low Power Idle (LPI) mode to reduce the energy consumption of a link when there is no data traffic, was approved. Recently, the major manufacturers have brought to market the first switches the implement the new energy efficient standard. In this paper, we make use of the first generation of hardware that support the IEEE 802.3az to get a better understanding of the behavior of energy efficient mechanisms for ethernet. Based on measurement on DLINK switches that are IEEE 802.3az compliant, we build a power model that reflects more accurately the power used by real hardware in practice. We use the measurement-driven power model to analyze the behavior of Lazy Start, the state of the art algorithm for energy efficient ethernet, in the ns-3 simulator. Based on our analysis, we provide recommendations for improvements and potential directions for future work

Cross-Layer Extended Persistent Timeout Policy for SCTP and DSDV

International audienceCross layer techniques applied to various protocols stacks provide fair information sharing between OSI model layers. The performance gains have been demonstrated for many studied systems within protocols interactions. The example is illustrative of the reliable transport protocols that use retransmissions to achieve that reliability function. The performance gains of the persistent timeout policy for the management of the retransmission timeout have been produce in some recent works when applying that persistent timeout policy only to reliable transport protocol. The goal was to give an appropriate behavior in response to a bad state of the wireless channel that occurs and temporally blocks the transmission of data. The channel state is given by the 802.11 link layer through cross-layer mechanism. In this paper, the persistent policy is extended to the network layer and is applied to a stack that uses a reactive routing protocol, namely the Destination Sequenced Distance-Vector (DSDV) protocol that also generates additional periodic traffic regardless to the channel state. We are measuring the influence in terms of performance gains of the extended persistent policy because of the additional periodic signalization messages deriving from the used routing protocol. After the introduction in section I; Section II of this paper presents an overview of the Stream Control Transmission Protocol (SCTP). Section III describes the behavior of the DSDV protocol. Section IV presents the extended persistent timeout policy principle and Section V presents the simulation results used to compare the using of the traditional and the extended persistent timeout policies applied to the same protocol stack using SCTP and DSDV

Cross layer Interaction Models for SCTP and OLSR

International audienceThe evolution from wired system to the wireless environment opens a set of challenge for the improvement of the wireless system performances because of many of their weakness compared to wired networks. To achieve this goal, cross layer techniques are used to facilitate the sharing of information between the layers of the OSI model. In some precedent works, the Reverse Cross Layer (RCL) method has been proposed to facilitate the design of cross layer conceptual models. The method has the advantage to highlight the impact of each cross layer interaction on each protocol in order to update its source code and to describe the intuitive gains that can be achieve. The method may be applied to a given protocol stack or to an existent cross layer model to integrate new interactions. In this paper, we are applying the RCL method on the stack that uses the Stream Control Transport Protocol (SCTP) at the transport layer and the Optimized Link State Routing (OLSR) at the network layer. Cross layer conceptual models are produced based on new cross layer interactions that are proposed to populate the environment subsystem built with the application of the RCL method. The improvement of the environment subsystem is specified through the performance gains provide by the new interactions. The implementation of the interactions that impact the SCTP protocol is described in the Interaction Description Array. After the introduction, Section II of this paper presents an overview of the SCTP protocol. Section III is related to the overview of the OLSR protocol. Section IV is used for the application of the RCL method and the different interaction arrays it generates. Section V presents the improvement of the environment subsystem and the definition of the performance gain of each Cross Layer Atomic Action (CLAA)

RCL : A new Method for Cross-Layer Network Modelling and Simulation

International audienceThe evolution from wired network systems to wireless environments such as Ad-hoc networks enables the emerging of cross-layer systems to improve the wireless network performance. Efficient methods, that may either produce or update cross-layer conceptual models have to be considered. Those models allow an efficient organisation of the wireless systems. In our approach, a cross-layer conceptual model is composed of : cross- layer interaction models and interactions description arrays, produced by the Reverse Cross-Layer (RCL) method that we proposed. The method has been applied to a chosen protocol stack

Adaptive load control for IoT based on satellite communications

The Internet Of Things (IoT) market is growing more and more every year. Today, the number of IoT devices is estimated around 8 billion but forecasts announce 20 billion devices for 2020. Terrestrial or satellite communications systems are already deployed to answer the connectivity need. These systems rely on a Random Access CHannel (RACH) used either to send resource allocation requests or directly the useful message. Because of the number of IoT devices, the overload on the RACH is an emerging issue since it may cause a service outage. This is especially the case for IoT satellite systems because of the wide area covered by a single satellite. The Access Class Barring (ACB) is the load control mechanism used within the Narrow Band IoT. Unfortunately, no method was specified to compute the load control parameters. In this paper, in the context of a satellite IoT system, we propose a method to compute dynamically ACB based load control parameters. Thanks to our method, the load control mechanism reach excellent results regarding transmission reliability and energy consumption for various traffic scenarios

Proposal and Implementation of Encounter Data Transmission with Ultrasonic Sensor-based Active Wakeup Mechanism for Energy Efficient Sparse Wireless Sensor Network

International audienceIn this paper, we propose and implement encounter data transmission with an ultrasonic sensor-based active wakeup mechanism for sparse wireless sensor networks (SWSNs), in which sensors are placed sparsely and each sensor is unable to communicate directly. We suppose that an active wakeup mechanism will be more suitable than a low-duty-cycle mechanism for SWSNs, since the collecting node moves around randomly in the sensing field. However, it was not clear whether the collecting node can communicate with the sensor in the short passing-through period. In this paper, we propose to use an ultrasonic sensor for waking up the communication function. We also succeed in developing a real-world sensor node that wakes up only when it detects the closing of the collecting node. We evaluate the detection ratio and the average communication duration of our system in a real-world agricultural application. As a result, we confirm that our system can provide stable communication between the collecting node and the sensor for at least 20 s at 10 kmph and for 10 s at 20 kmph