Medium access and power control protocol for wireless sensor networks with directional antennas

The primary contribution of this paper lies in evaluating the potential benefits of using directional antennas in wireless sensor networks to reduce node power consumption and improve fairness and throughput. The protocol helps improve throughput and reduce energy consumption by maximising spatial reuse and with a strategy to deal with overlap between antenna patterns without any additional complexity at the sensor nodes themselves. The protocol uses packets from the hub to estimate the transmission power required by nodes, to avoid excess energy usage. The protocol is verified using RiverBed Modeler. Simulation results for fairness, throughput and node transmission energy requirement are presented, showing a reduction in average transmission power by a factor of two with respect to the protocol without power control. Good fairness is demonstrated and throughput for a 4-antenna system is 2.17 times that of a single antenna system. The antenna pattern overlap, which is often assumed negligible, is shown to have a significant effect on throughput

Medium Access Control Protocol for Wireless Sensor Networks in Harsh Environments with Directional Antennas

In this paper, we consider the application of directional antennas to the hub node of a wireless sensor network (WSN), whilst retaining an omni-directional antenna on each sensor node, thus enhancing link performance without increasing the cost, complexity or energy consumption of the sensor nodes. We propose a simple medium access control (MAC) protocol for the hub node, based on the ALOHA protocol but designed to support multiple antennas on the hub, whilst the sensors retain the original ALOHA protocol. The analysis and simulation results show a 217% increase in throughput. Further possibilities of this architecture include increased range and/or the reduced sensor power consumption

Directional antennas improve the link-connectivity of interference limited ad hoc networks

We study wireless ad hoc networks in the absence of any channel contention or transmit power control and ask how antenna directivity affects network connectivity in the interference limited regime. We answer this question by deriving closed-form expressions for the outage probability, capacity and mean node degree of the network using tools from stochastic geometry. These novel results provide valuable insights for the design of future ad hoc networks. Significantly, our results suggest that the more directional the interfering transmitters are, the less detrimental are the effects of interference to individual links. We validate our analytical results through computer simulations.Comment: 6 pages, 7 figures, conference proceedings of PIMRC'201

A Lightweight Authentication and Key Management Scheme for Wireless Sensor Networks

Security problem is one of the most popular research fields in wireless sensor networks for both the application requirement and the resource-constrained essence. An effective and lightweight Authentication and Key Management Scheme (AKMS) is proposed in this paper to solve the problem of malicious nodes occurring in the process of networking and to offer a high level of security with low cost. For the condition that the mobile sensor nodes need to be authenticated, the keys in AKMS will be dynamically generated and adopted for security protection. Even when the keys are being compromised or captured, the attackers can neither use the previous keys nor misuse the authenticated nodes to cheat. Simulation results show that the proposed scheme provides more efficient security with less energy consumption for wireless sensor networks especially with mobile sensors

Anonymat, non-traçabilité et sécurité-innocuité dans les réseaux de véhicules autonomes connectés

International audienceLes véhicules autonomes seront également « connectés », par adjonction aux systèmes bord de moyens de communication radio définis dans les standards US WAVE (ETSI ITS G5 sont les standards européens équivalents). Les communications inter-véhiculaires ont pour but de contribuer significativement à la réduction du taux d’accidents (propriété d’innocuité meilleure qu’avec la seule robotique embarquée). Les versions initiales de WAVE permettent des atteintes à la vie privée qui n’existent pas avec les véhicules à conduite humaine. Des solutions complémentaires furent donc définies (standards IEEE 1609.2, ETSI 102941) afin d’éliminer ces risques. L’ensemble comprenant WAVE et ces solutions complémentaires est noté WAVE 1.0. Des analyses rigoureuses permettent d’établir que WAVE 1.0 ne procure pas d’amélioration significative en matière d’innocuité (en sus de la robotique embarquée) et que WAVE 1.0 n’est pas satisfaisant en matière de protection de la vie privée. Les principaux risques encourus sont examinés. On développe un argumentaire en faveur de l’avènement de nouveaux standards de communications radio et optiques inter-véhiculaires—noté WAVE 2.0, fondés sur des solutions existantes qui assurent à la fois l’innocuité maximale et la discrétion absolue (l’élimination des risques examinés)

Efficient MAC Protocol for Hybrid Wireless Network with Heterogeneous Sensor Nodes

Although several Directional Medium Access Control (DMAC) protocols have been designed for use with homogeneous networks, it can take a substantial amount of time to change sensor nodes that are equipped with an omnidirectional antenna for sensor nodes with a directional antenna. Thus, we require a novel MAC protocol for use with an intermediate wireless network that consists of heterogeneous sensor nodes equipped with either an omnidirectional antenna or a directional antenna. The MAC protocols that have been designed for use in homogeneous networks are not suitable for use in a hybrid network due to deaf, hidden, and exposed nodes. Therefore, we propose a MAC protocol that exploits the characteristics of a directional antenna and can also work efficiently with omnidirectional nodes in a hybrid network. In order to address the deaf, hidden, and exposed node problems, we define RTS/CTS for the neighbor (RTSN/CTSN) and Neighbor Information (NIP) packets. The performance of the proposed MAC protocol is evaluated through a numerical analysis using a Markov model. In addition, the analytical results of the MAC protocol are verified through an OPNET simulation

MAC Protocols for Wireless Mesh Networks with Multi-beam Antennas: A Survey

Multi-beam antenna technologies have provided lots of promising solutions to many current challenges faced in wireless mesh networks. The antenna can establish several beamformings simultaneously and initiate concurrent transmissions or receptions using multiple beams, thereby increasing the overall throughput of the network transmission. Multi-beam antenna has the ability to increase the spatial reuse, extend the transmission range, improve the transmission reliability, as well as save the power consumption. Traditional Medium Access Control (MAC) protocols for wireless network largely relied on the IEEE 802.11 Distributed Coordination Function(DCF) mechanism, however, IEEE 802.11 DCF cannot take the advantages of these unique capabilities provided by multi-beam antennas. This paper surveys the MAC protocols for wireless mesh networks with multi-beam antennas. The paper first discusses some basic information in designing multi-beam antenna system and MAC protocols, and then presents the main challenges for the MAC protocols in wireless mesh networks compared with the traditional MAC protocols. A qualitative comparison of the existing MAC protocols is provided to highlight their novel features, which provides a reference for designing the new MAC protocols. To provide some insights on future research, several open issues of MAC protocols are discussed for wireless mesh networks using multi-beam antennas.Comment: 22 pages, 6 figures, Future of Information and Communication Conference (FICC) 2019, https://doi.org/10.1007/978-3-030-12388-8_

Controle de potência de transmissão proporcional-integral para redes wirelesshart

As redes de sensores sem fio (wsns) têm ganhado cada vez mais espaço no monitoramento e controle de processos na indústria. Dentro destas redes, os dispositivos são alimentados por baterias, e a comunicação é feita por radiofrequência. Por conta disto, os rádios dos dispositivos são responsáveis por consumir boa parte da energia armazenada nas suas baterias, e a comunicação dos dispositivos está sujeita à interferência provinda de outras redes e do maquinário industrial. Para sanar estes problemas podem ser empregadas técnicas de controle de potência de transmissão (cpt). Existem diversas técnicas de cpt na literatura, visando os mais diversos objetivos, desde economia de energia e redução de interferência, até controle da topologia da rede. Este trabalho apresenta uma proposta de emprego de (cpt) em uma rede de sensores sem fio através da utilização de controladores proporcionais-integrais (pi). Juntamente com a técnica proposta, são apresentados um procedimento para projeto dos controladores e alguns algoritmos desenvolvidos para o caso ideal e para os casos com saturação dos níveis de potência disponíveis. Este trabalho se diferencia dos trabalhos encontrados na literatura por apresentar uma técnica de controle linear e que depende apenas de informações já disponíveis em cada dispositivo cuja potência será ajustada. Deste modo, esta técnica pode ser empregada em conjunto com protocolos industriais mais restritivos quanto às informações que podem ser trocadas nas mensagens. Além disso, esta técnica reduz ainda mais o consumo e a interferência por evitar transmissões desnecessárias. A proposta apresentada foi validada através de simulações e de um experimento com dispositivos WirelessHART reais, apresentando bons resultados e provando que é possível controlar a potência sem a necessidade das informações extras.Wireless sensor networks (wsns) are being increasingly adopted in monitor and control tasks in the industry. The devices within these networks are battery-powered, and they communicate through radio frequency. Therefore the radios of the devices account for the most of the consumption of the energy stored in the batteries, and the devices’ communication is subject to interference from other networks and industrial machinery. Transmission power control (tpc) techniques can be employed to cope with these problems. There are several tpc techniques in the literature, aiming at a wide range of objectives, from energy saving and interference reduction, to network topology control. This work presents the proposal of a (tpc) technique in a wireless sensor network that works by employing proportional-integral (pi) controllers. Besides the technique itself, a procedure is presented to design the controllers along some algorithms developed to the ideal case, and the case when there is saturation in the available power levels. This work, unlike the other works found in the literature, presents a linear technique that depends only on information that is already available in each device whose power needs to be adjusted. Therefore, the proposed technique can be employed together with more restrictive industrial protocols that limit the information that can be exchanged in the messages. Besides, it further reduces the power consumption and the interference by avoiding unnecessary transmissions. The proposal was validated through simulations and an experiment using real WirelessHART devices, presenting good results and proving that it is possible to adjust the transmission power without necessarily using the extra information