A novel energy-safe algorithm for enhancing the battery life for IoT sensors applications

Energy safe is mandatory for all isolated IoT tools, as in long way roads, mountains, or even in smart cities. If increasing the lifetime of these tools, the rentability of the global network loop becomes more efficient. Therefore, this paper's base main is to present a new approach for saving energy inside the source nods by supervising the state of energy inside each source nod and calculating the duty cycle factor. The relationship between these parameters is based on an optimization problem formulation. In this respect, the present paper is designed to propose a new approach that deals with increasing the lifetime of the Wireless Sensors Network (WSN) attached nodes, as fixed in the application. The newly devised design rests on implementing the IEEE 802.15.4 standard beacon-enabled mode, involving a cluster tree topology. Accordingly, every subgroup is allotted to apply a specifically different duty cycle, depending on the battery's remaining energy level, which contributes to creating a wide range of functional modes. Hence, various thresholds are defined. Simulation results are proving the efficiency of the proposed approach and show the energetic benefit. The proposed flowchart has minimized the consumed energy for the WSN, which improve the battery lifetime and enhance the IoT applications robustness. Simulations and experiments have been carried out under different conditions and the results proved that the proposed method is a viable solution.publishedVersio

PluralisMAC: a generic multi-MAC framework for heterogeneous, multiservice wireless networks, applied to smart containers

Developing energy-efficient MAC protocols for lightweight wireless systems has been a challenging task for decades because of the specific requirements of various applications and the varying environments in which wireless systems are deployed. Many MAC protocols for wireless networks have been proposed, often custom-made for a specific application. It is clear that one MAC does not fit all the requirements. So, how should a MAC layer deal with an application that has several modes (each with different requirements) or with the deployment of another application during the lifetime of the system? Especially in a mobile wireless system, like Smart Monitoring of Containers, we cannot know in advance the application state (empty container versus stuffed container). Dynamic switching between different energy-efficient MAC strategies is needed. Our architecture, called PluralisMAC, contains a generic multi-MAC framework and a generic neighbour monitoring and filtering framework. To validate the real-world feasibility of our architecture, we have implemented it in TinyOS and have done experiments on the TMote Sky nodes in the w-iLab.t testbed. Experimental results show that dynamic switching between MAC strategies is possible with minimal receive chain overhead, while meeting the various application requirements (reliability and low-energy consumption)

Inaccessibility in wireless sensor networks

Tese de mestrado em Engenharia Informática, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2013As redes sem fios têm sido encaradas como as redes de comunicação do futuro, fornecendo capacidades de comunicação onde os cabos não podem de ser utilizados. As tecnologias sem fio permitem flexibilidade e mobilidade na rede como também reduzir o tamanho, peso e consumo energético (SWaP) dos dispositivos de comunicação. A norma IEEE 802.15.4 foi projetada para suportar a especificação de redes de sensores sem fio (WSNs) e redes de sensores e atuadores sem fios (WSANs), e a sua utilização está a emergir em ambientes com requisitos de tempo real, tais como o industrial e aeroespacial. A camada de controlo de acesso ao meio (MAC) é o alicerce de controlo dos serviços de comunicação da rede. Distúrbios no funcionamento desta camada podem levar a rede a entrar num estado apelidado de inacessibilidade, este caracteriza-se numa falta temporária de comunicação na rede, embora não se considere que a rede falhou. Exemplos de tais perturbações são ondas electromagnéticas, falhas no circuito de dispositivos sem fios, ou até mesmo obstáculos no caminho de comunicação. Um estudo teórico anterior indica a ocorrência de inacessibilidade como fontes de atraso portanto, falhas no cumprimento de prazos que podem comprometer propriedades de confiabilidade e pontualidade de todo o sistema. Assim, este trabalho tem como objetivo validar que o estudo anterior, utilizando o simulador de rede NS-2. O simulador de rede NS-2 é uma ferramenta amplamente utilizada no suporte a simulação de redes sem fio IEEE 802.15.4. No entanto, descobrimos que não se encontra totalmente em conformidade com a norma IEEE 802.15.4. Com o intuito de efetuar a validação dos modelos de inacessibilidade, novos mecanismos devem ser introduzidos no modelo de simulação referente ao IEEE 802.15.4. Estes melhoramentos compreendem: Suporte para transmissões de tempo real, através da incorporação do mecanismo de acesso livre de contenção (CFP) e do intervalo de tempo de acesso garantido (GTS); Desenvolver as operações de gestão normalizadas não concretizadas no modulo IEEE 802.15.4 presente na versão oficial do NS-2;Adição de novos recursos necessários para a avaliação da rede em condições de erro, mais especificamente, um injetor de faltas, e um módulo de contabilização temporal e energético.Wireless networks are seen as the communication networks of the future, providing communication capabilities where cables are not able to be used. Wireless technologies enable network flexibility and mobility, and reduce size, weight, and power consumption (SWaP) of communication devices. The IEEE 802.15.4 standard was designed to support the specification of wireless sensor networks (WSNs) and wireless sensor and actuator networks (WSANs), where is emerging their utilization within environments with real time requirements, such as industrial and aerospace. The medium access control (MAC) layer is the control foundation of the network communication services. Disturbances in the MAC layer operation may lead to a network inaccessibility scenario, which consists in a temporary absence of network communication although the network is not considered failed. Examples of such disturbances are electromagnetic noise interference, glitches in the wireless device circuitry, or even obstacles in the communication path. A previous theoretical study indicates the occurrence of periods of network inaccessibility as a source of MAC transmission protocol delays which may induce application deadline misses which that compromise the dependability and timeliness properties of the whole networked system. Thus, this work aims to validate that previous study using the network simulator NS-2. The NS-2 simulator is a widely used tool supporting the simulation of IEEE 802.15.4 wireless networks. However, we discovered that its compliance to the IEEE 802.15.4 standard is imperfect. In order to perform the validation of the theoretical characterization of network inaccessibility new mechanisms need to be introduced in the IEEE 802.15.4 simulation model. These improvements comprises: the support for real-time transmissions, through the incorporation of the contention free period (CFP) and of guaranteed time slot (GTS) ; IEEE 802.15.4 standard management operations not implemented in the official NS-2 release; A flexible tool capable of re-create the inaccessibility events and simulate different error conditions on the network, which include the Fault Injector and temporal and energetic analysis tool

A Comprehensive Analysis of Literature Reported Mac and Phy Enhancements of Zigbee and its Alliances

Wireless communication is one of the most required technologies by the common man. The strength of this technology is rigorously progressing towards several novel directions in establishing personal wireless networks mounted over on low power consuming systems. The cutting-edge communication technologies like bluetooth, WIFI and ZigBee significantly play a prime role to cater the basic needs of any individual. ZigBee is one such evolutionary technology steadily getting its popularity in establishing personal wireless networks which is built on small and low-power digital radios. Zigbee defines the physical and MAC layers built on IEEE standard. This paper presents a comprehensive survey of literature reported MAC and PHY enhancements of ZigBee and its contemporary technologies with respect to performance, power consumption, scheduling, resource management and timing and address binding. The work also discusses on the areas of ZigBee MAC and PHY towards their design for specific applications

Zigbee based Wireless Sensor Network for Smart Energy Meter

Wireless sensor networks are expanding across a wide range of application scenarios. The most widely used transmitter is "ZigBee," which is used in wireless sensor networks. Based on the IEEE standard known as IEEE 802.15.4, ZigBee is an enabling low-cost technology that offers minimal energy consumption and a low data rate. It is used for remote control, medical aid, home automation, industry control, and other wireless sensor applications, in addition to wireless sensor networks and personal area network applications. This paper aims to develop a wireless sensor network and a protocol for smart energy meter applications. Our proposed system comprises a digital energy meter, a ZigBee coordinator, and a management application. A terminal alert and a cover alarm can be automatically sent to the management software by the wireless meter reading system once it has read the unit. Mistakes from Errors in leakage metering reading to manual meter reading can be avoided. This proposed system will improve efficiency by reducing labor intensity to liberate labor and force. The system setup can accommodate a large number of energy meters with sufficient hop network depth to detect a new energy meter automatically. The technology can be widely used in wireless monitoring and control applications because of its low cost, low power consumption, extended battery life, and mesh networking's ability to extend high reliability to a broader range. To connect a variety of low-power devices wirelessly, ZigBee will satisfy the rising demand. For the future generation of industrial technologies, ZigBee will be deployed.Published By: Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP) © Copyright: All rights reserved

IEEE 802.15.4e: a Survey

Several studies have highlighted that the IEEE 802.15.4 standard presents a number of limitations such as low reliability, unbounded packet delays and no protection against interference/fading, that prevent its adoption in applications with stringent requirements in terms of reliability and latency. Recently, the IEEE has released the 802.15.4e amendment that introduces a number of enhancements/modifications to the MAC layer of the original standard in order to overcome such limitations. In this paper we provide a clear and structured overview of all the new 802.15.4e mechanisms. After a general introduction to the 802.15.4e standard, we describe the details of the main 802.15.4e MAC behavior modes, namely Time Slotted Channel Hopping (TSCH), Deterministic and Synchronous Multi-channel Extension (DSME), and Low Latency Deterministic Network (LLDN). For each of them, we provide a detailed description and highlight the main features and possible application domains. Also, we survey the current literature and summarize open research issues

On a Joint Physical Layer and Medium Access Control Sublayer Design for Efficient Wireless Sensor Networks and Applications

Wireless sensor networks (WSNs) are distributed networks comprising small sensing devices equipped with a processor, memory, power source, and often with the capability for short range wireless communication. These networks are used in various applications, and have created interest in WSN research and commercial uses, including industrial, scientific, household, military, medical and environmental domains. These initiatives have also been stimulated by the finalisation of the IEEE 802.15.4 standard, which defines the medium access control (MAC) and physical layer (PHY) for low-rate wireless personal area networks (LR-WPAN). Future applications may require large WSNs consisting of huge numbers of inexpensive wireless sensor nodes with limited resources (energy, bandwidth), operating in harsh environmental conditions. WSNs must perform reliably despite novel resource constraints including limited bandwidth, channel errors, and nodes that have limited operating energy. Improving resource utilisation and quality-of-service (QoS), in terms of reliable connectivity and energy efficiency, are major challenges in WSNs. Hence, the development of new WSN applications with severe resource constraints will require innovative solutions to overcome the above issues as well as improving the robustness of network components, and developing sustainable and cost effective implementation models. The main purpose of this research is to investigate methods for improving the performance of WSNs to maintain reliable network connectivity, scalability and energy efficiency. The study focuses on the IEEE 802.15.4 MAC/PHY layers and the carrier sense multiple access with collision avoidance (CSMA/CA) based networks. First, transmission power control (TPC) is investigated in multi and single-hop WSNs using typical hardware platform parameters via simulation and numerical analysis. A novel approach to testing TPC at the physical layer is developed, and results show that contrary to what has been reported from previous studies, in multi-hop networks TPC does not save energy. Next, the network initialization/self-configuration phase is addressed through investigation of the 802.15.4 MAC beacon interval setting and the number of associating nodes, in terms of association delay with the coordinator. The results raise doubt whether that the association energy consumption will outweigh the benefit of duty cycle power management for larger beacon intervals as the number of associating nodes increases. The third main contribution of this thesis is a new cross layer (PHY-MAC) design to improve network energy efficiency, reliability and scalability by minimising packet collisions due to hidden nodes. This is undertaken in response to findings in this thesis on the IEEE 802.15.4 MAC performance in the presence of hidden nodes. Specifically, simulation results show that it is the random backoff exponent that is of paramount importance for resolving collisions and not the number of times the channel is sensed before transmitting. However, the random backoff is ineffective in the presence of hidden nodes. The proposed design uses a new algorithm to increase the sensing coverage area, and therefore greatly reduces the chance of packet collisions due to hidden nodes. Moreover, the design uses a new dynamic transmission power control (TPC) to further reduce energy consumption and interference. The above proposed changes can smoothly coexist with the legacy 802.15.4 CSMA/CA. Finally, an improved two dimensional discrete time Markov chain model is proposed to capture the performance of the slotted 802.15.4 CSMA/CA. This model rectifies minor issues apparent in previous studies. The relationship derived for the successful transmission probability, throughput and average energy consumption, will provide better performance predictions. It will also offer greater insight into the strengths and weaknesses of the MAC operation, and possible enhancement opportunities. Overall, the work presented in this thesis provides several significant insights into WSN performance improvements with both existing protocols and newly designed protocols. Finally, some of the numerous challenges for future research are described