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

Engine performance characteristics and evaluation of variation in the length of intake plenum

In the engine with multipoint fuel injection system using electronically controlled fuel injectors has an intake manifold in which only the air flows and, the fuel is injected into the intake valve. Since the intake manifolds transport mainly air, the supercharging effects of the variable length intake plenum will be different from carbureted engine. Engine tests have been carried out with the aim of constituting a base study to design a new variable length intake manifold plenum. The objective in this research is to study the engine performance characteristics and to evaluate the effects of the variation in the length of intake plenum. The engine test bed used for experimental work consists of a control panel, a hydraulic dynamometer and measurement instruments to measure the parameters of engine performance characteristics. The control panel is being used to perform administrative and management operating system. Besides that, the hydraulic dynamometer was used to measure the power of an engine by using a cell filled with liquid to increase its load. Thus, measurement instrument is provided in this test to measure the as brake torque, brake power, thermal efficiency and specific fuel consumption. The results showed that the variation in the plenum length causes an improvement on the engine performance characteristics especially on the fuel consumption at high load and low engine speeds which are put forward the system using for urban roads. From this experiment, it will show the behavior of engine performance

LPWAN Technologies: Emerging Application Characteristics, Requirements, and Design Considerations

Low power wide area network (LPWAN) is a promising solution for long range and low power Internet of Things (IoT) and machine to machine (M2M) communication applications. This paper focuses on defining a systematic and powerful approach of identifying the key characteristics of such applications, translating them into explicit requirements, and then deriving the associated design considerations. LPWANs are resource-constrained networks and are primarily characterized by long battery life operation, extended coverage, high capacity, and low device and deployment costs. These characteristics translate into a key set of requirements including M2M traffic management, massive capacity, energy efficiency, low power operations, extended coverage, security, and interworking. The set of corresponding design considerations is identified in terms of two categories, desired or expected ones and enhanced ones, which reflect the wide range of characteristics associated with LPWAN-based applications. Prominent design constructs include admission and user traffic management, interference management, energy saving modes of operation, lightweight media access control (MAC) protocols, accurate location identification, security coverage techniques, and flexible software re-configurability. Topological and architectural options for interconnecting LPWAN entities are discussed. The major proprietary and standards-based LPWAN technology solutions available in the marketplace are presented. These include Sigfox, LoRaWAN, Narrowband IoT (NB-IoT), and long term evolution (LTE)-M, among others. The relevance of upcoming cellular 5G technology and its complementary relationship with LPWAN technology are also discussed

Real-time wireless networks for industrial control systems

The next generation of industrial systems (Industry 4.0) will dramatically transform manyproductive sectors, integrating emerging concepts such as Internet of Things, artificialintelligence, big data, cloud robotics and virtual reality, to name a few. Most of thesetechnologies heavily rely on the availability of communication networks able to offernearly–istantaneous, secure and reliable data transfer. In the industrial sector, these tasks are nowadays mainly accomplished by wired networks, that combine the speed ofoptical fiber media with collision–free switching technology. However, driven by the pervasive deployment of mobile devices for personal com-munications in the last years, more and more industrial applications require wireless connectivity, which can bring enormous advantages in terms of cost reduction and flex-ibility. Designing timely, reliable and deterministic industrial wireless networks is a complicated task, due to the nature of the wireless channel, intrinsically error–prone andshared among all the devices transmitting on the same frequency band. In this thesis, several solutions to enhance the performance of wireless networks employed in industrial control applications are proposed. The presented approaches differ in terms of achieved performance and target applications, but they are all characterized by an improvement over existing industrial wireless solutions in terms of timeliness, reliability and determinism. When possible, an experimental validation of the designed solutions is provided. The obtained results prove that significant performance improvements are already possible, often using commercially available devices and preserving compliance to existing standards. Future research efforts, combined with the availability of new chipsets and standards, could lead to a world where wireless links effectively replace most of the existing cables in industrial environments, as it is already the case in the consumer market

Energy-efficient wireless communication schemes and real-time middleware for machine-to-machine networks

Esta tesis estudia sistemas Machine-to-Machine (M2M) en los que se ejecutan tareas de manera autónoma sin, o con mínima intervención humana. Los sistemas M2M están formados por dispositivos desplegados en un entorno que recolectan información relacionada con una tarea y la envían a aplicaciones para su proceso. Las aplicaciones optimizan estas tareas y responden a los dispositivos con comandos de control. Idealmente, después de configurar las políticas de tareas, los humanos son excluidos del lazo de control. Un importante caso de uso en M2M es la automatización de la red eléctrica, también conocido como Smart Grid, que se trata en esta tesis. Muchos escenarios M2M requieren dispositivos de bajo bitrate, bajo coste y que puedan ser fácilmente desplegables y mantenidos. Una solución adecuada son los dispositivos inalámbricos, alimentados por batería y de capacidades limitadas (con reducida potencia de procesado y memoria). Un bajo mantenimiento requiere años de vida, que sólo pueden conseguirse con protocolos de comunicación altamente eficientes energéticamente. En esta tesis nos centramos principalmente en las capas MAC y de enlace (especialmente en esquemas Cooperative Automatic Repeat Request) para mejorar la eficiencia energética de los dispositivos. Proponemos y evaluamos extensiones de Cooperative MAC para varios estándares como IEEE 802.11, IEEE 802.15.4 y sus revisiones MAC. El transmisor radio de los dispositivos puede ponerse en estado de reposo cuando está inactivo, llevando a cortos periodos de activación (duty-cycle) en dispositivos de bajo bitrate, consiguiendo así un ahorro energético considerable. Dado que la capa MAC controla los estados de reposo de los transmisores radio, los esquemas de Duty-Cycle MAC son el pilar de las comunicaciones energéticamente eficientes. Por ello, en esta tesis diseñamos, analizamos y evaluamos esquemas Cooperative and Duty-Cycled ARQ (CDC-ARQ). CDC-ARQ se basa en la (re)transmisión dinámica de paquetes (dynamic packet forwarding) dependiendo del estado del canal inalámbrico. Cuantificamos las ganancias considerando enlaces inalámbricos de baja potencia con modelos realistas, que sufren efectos de apantallamiento (shadowing) desvanecimientos (fading) de canal, y presentamos las condiciones bajo las cuales CDC-ARQ consiguen mejores resultados que las técnicas estándar de forwarding. Finalmente, determinamos estrategias óptimas de selección de enlace y retransmisión para direct, multi-hop y CDC-ARQ forwarding. Los esquemas de comunicación inalámbricos energéticamente eficientes son adecuados, por ejemplo, para automatización de edificios y hogar, contribuyendo a un buen uso de la energía eléctrica en dichos escenarios. Después de considerar el entorno de dispositivos, la tesis se centra en las aplicaciones, al otro lado de los sistemas M2M. Las aplicaciones típicamente intercambian datos sobre amplias zonas con varios dispositivos remotos. Las técnicas de computación distribuida, estandarizadas e implementadas en plataformas middleware para sistemas M2M, facilitan este intercambio de datos. Los requisitos de comunicación de estas aplicaciones son diversos en términos de latencia, número de actualizaciones, número de dispositivos asociados, etc. Mientras que las soluciones middleware existentes tales como ETSI M2M satisfacen los requisitos de ciertas aplicaciones, dichas soluciones son inadecuadas para los requisitos de latencia de transmisión en tiempo real. Esta tesis propone y analiza modificaciones del ETSI M2M que mejoran el rendimiento en tiempo real. El análisis se ejemplifica con tres aplicaciones Smart Grid, una relacionada con la automatización del hogar y edificios, y las otras dos con la monitorización y control del flujo de potencia de la red eléctrica.This thesis studies emerging Machine-to-Machine (M2M) systems that execute automated tasks without, or with minimum human intervention. M2M systems consist of devices deployed in the field to collect task-related information and send it to remote applications for processing. The applications optimise the tasks and issue control commands back to the devices. Ideally, after configuring the task policies, humans are excluded from the control loop. A prominent and urgent M2M use case concentrates on the automation of the electric power grid, also known as Smart Grid, that is considered in the thesis. Many M2M scenarios require devices that are low-rate, low-cost and can be easily deployed and maintained. A fitting solution are wireless, battery-powered and resource-constrained devices (with limited processing power and memory). Low-maintenance requires years of lifetime, that can only be achieved with unprecedented energy efficiency of communication protocols. Specifically, we focus on the MAC and link layers in this thesis (especially on the Cooperative Automatic Repeat Request schemes) to improve the energy efficiency of the devices. Cooperative MAC extensions to the various standard technologies such as IEEE 802.11, IEEE 802.15.4 and its MAC amendments are proposed and evaluated. The radio transceiver of a device can be put to sleep state when inactive, yielding very low duty-cycles for low-rate devices, and thus achieving significant energy savings. Since the MAC layer controls the radio transceiver sleep states, duty-cycled MAC schemes are the cornerstone of the energy-efficient communication schemes. To that end, Cooperative and Duty-Cycled ARQ (CDC-ARQ) scheme has been designed, analysed and evaluated in this thesis. CDC-ARQ is based on dynamic packet forwarding depending on the current state of the wireless channel. The benefits are quantified by considering realistic wireless low-power links that experience shadowing and multipath fading channel effects. The conditions under which CDC-ARQ outperforms the standard forwarding techniques are presented. Finally, optimal link selection and retransmission strategies are determined for direct, multi-hop or CDC-ARQ forwarding. The studied energy-efficient wireless schemes are suitable e.g. for home and building automation which can contribute to the efficient use of the electric power in homes and buildings. After considering the device domain, the focus of this thesis turns to the applications at the other end of the M2M system. The applications typically exchange data over wide areas with many remote devices. Distributed computing techniques facilitate this data exchange, standardised and implemented in the middleware platform for M2M systems. The communication requirements of these applications are diverse in terms of data latency, update rate, number of associated devices etc. While the existing middleware solutions such as ETSI M2M fully support communication requirements of some applications, the solution is inadequate when it comes to the real-time latency constraint. Some suitable upgrades that improve the real-time performance of data exchange in ETSI M2M middleware are analysed in the thesis. The analysis is exemplified with three Smart Grid applications, one related to the home and building automation and the other two concerned with monitoring and control of the power flow in the electric grid

Performance enhancements for single hop and multi-hop meshed high data rate wireless personal area networks

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The High Data Rate (HDR) Wireless Personal Area Networks (WPANs) typically have a limited operating range and are intended to support demanding multi-media applications at high data rates. In order to extend the communication range, HDR WPANs can operate in a wireless mesh configuration (i.e. enable multiple WPAN clusters) to communicate in a multi-hop fashion. HDR WPANs face several research challenges and some of the open key issues are limited capacity, optimum resource allocation to requesting devices and maintaining Quality of Service (QoS) for real time multimedia flows. Although, there have been some scheduling algorithms proposed for HDR WPANs, the main objective is to maintain the QoS in most cases whereas efficient and fair utilization of network capacity is still largely open for research. This thesis mainly intends to resolve the issues related to capacity of HDR WPANs such as admission control, fair allocation of Channel Time Allocations (CTAs), improvement in capacity through transmission power control, and efficient utilization of time by each flow. A technique which re-orders the time slots to reduce queuing delay for meshed WPANs is also proposed and evaluated. The first contribution aims to improve peer-to-peer connectivity in case of two or more independent piconet devices by proposing an inter-PAN communication framework that is augmented by an admission control strategy to handle the cases when the superframe capacity is congested. The queued devices are prioritized by proposing a parameter called the Rejection Ratio. The second contribution consists of a resource allocation framework for meshed WPANs. The main objectives are to reduce the control traffic due to high volume of channel time reservation requests and introduce an element of fairness in the channel time allocated to requesting devices. The objectives are achieved by using traffic prediction techniques and an estimated backoff procedure to reduce control traffic, and define different policies based on offered traffic for fair allocation of channel time. The centralized scheme uses traffic prediction techniques to use the proposed concept of bulk reservations. Based on the bulk reservations and resource allocation policies, the overall overhead is reduced while an element of fairness is shown to be maintained for certain scenarios. In the third contribution, the concepts of Time Efficiency and CTA switching are introduced to improve communication efficiency and utilization of superframe capacity in meshed WPANs. Two metrics known as Switched Time Slot (STS) and Switched Time Slot with Re-ordering (STS-R) are proposed which aim to achieve the purpose. The final contribution proposes and evaluates a technique called CTA overlappnig to improve capacity in single hop and meshed WPANs using tramission power control. Extensive simulation studies are performed to analyze and to evaluate the proposed techniques. Simulation results demonstrate significant improvements in meshed WPANs performance in terms of capacity utilization, improvement in fairness index for CTA allocation by upto 62% in some cases, reduction in control traffic overhead by upto 70% and reduction in delay for real time flows by more than 10% in some cases

Application priority framework for fixed mobile converged communication networks

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The current prospects in wired and wireless access networks, it is becoming increasingly important to address potential convergence in order to offer integrated broadband services. These systems will need to offer higher data transmission capacities and long battery life, which is the catalyst for an everincreasing variety of air interface technologies targeting local area to wide area connectivity. Current integrated industrial networks do not offer application aware context delivery and enhanced services for optimised networks. Application aware services provide value-added functionality to business applications by capturing, integrating, and consolidating intelligence about users and their endpoint devices from various points in the network. This thesis mainly intends to resolve the issues related to ubiquitous application aware service, fair allocation of radio access, reduced energy consumption and improved capacity. A technique that measures and evaluates the data rate demand to reduce application response time and queuing delay for multi radio interfaces is proposed. The technique overcomes the challenges of network integration, requiring no user intervention, saving battery life and selecting the radio access connection for the application requested by the end user. This study is split in two parts. The first contribution identifies some constraints of the services towards the application layer in terms of e.g. data rate and signal strength. The objectives are achieved by application controlled handover (ACH) mechanism in order to maintain acceptable data rate for real-time application services. It also looks into the impact of the radio link on the application and identifies elements and parameters like wireless link quality and handover that will influence the application type. It also identifies some enhanced traditional mechanisms such as distance controlled multihop and mesh topology required in order to support energy efficient multimedia applications. The second contribution unfolds an intelligent application priority assignment mechanism (IAPAM) for medical applications using wireless sensor networks. IAPAM proposes and evaluates a technique based on prioritising multiple virtual queues for the critical nature of medical data to improve instant transmission. Various mobility patterns (directed, controlled and random waypoint) has been investigated and compared by simulating IAPAM enabled mobile BWSN. The following topics have been studied, modelled, simulated and discussed in this thesis: 1. Application Controlled Handover (ACH) for multi radios over fibre 2. Power Controlled Scheme for mesh multi radios over fibre using ACH 3. IAPAM for Biomedical Wireless Sensor Networks (BWSN) and impact of mobility over IAPAM enabled BWSN. Extensive simulation studies are performed to analyze and to evaluate the proposed techniques. Simulation results demonstrate significant improvements in multi radios over fibre performance in terms of application response delay and power consumption by upto 75% and 15 % respectively, reduction in traffic loss by upto 53% and reduction in delay for real time application by more than 25% in some cases

On the Use of LoRaWAN for Indoor Industrial IoT Applications

Low-Power Wide-Area Networks (LPWANs) have recently emerged as appealing communication systems in the context of the Internet of Things (IoT). Particularly, they proved effective in typical IoT applications such as environmental monitoring and smart metering. Such networks, however, have a great potential also in the industrial scenario and, hence, in the context of the Industrial Internet of Things (IIoT), which represents a dramatically growing field of application. In this paper we focus on a specific LPWAN, namely, LoRaWAN, and provide an assessment of its performance for typical IIoT employments such as those represented by indoor industrial monitoring applications. In detail, after a general description of LoRaWAN, we discuss how to set some of its parameters in order to achieve the best performance in the considered industrial scenario. Subsequently we present the outcomes of a performance assessment, based on realistic simulations, aimed at evaluating the behavior of LoRaWAN for industrial monitoring applications. Moreover, the paper proposes a comparison with the IEEE 802.15.4 network protocol, which is often adopted in similar application contexts. The obtained results confirm that LoRaWAN can be considered as a strongly viable opportunity, since it is able to provide high reliability and timeliness, while ensuring very low energy consumption