711 research outputs found

    Dual protocol performance using WiFi and ZigBee for industrial WLAN

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    The purpose of this thesis is to study the performance of a WNCS based on utilizing IEEE 802.15.4 and IEEE 802.11 in meeting industrial requirements as well as the extent of improvement on the network level in terms of latency and interference tolerance when using the two different protocols, namely WiFi and ZigBee, in parallel. The study evaluates the optimum performance of WNCS that utilizes only IEEE 802.15.4 protocol (which ZigBee is based on) without modifications as an alternative that is low cost and low power compared to other wireless technologies. The study also evaluates the optimum performance of WNCS that utilizes only the IEEE 802.11 protocol (WiFi) without modifications as a high bit network. OMNeT++ simulations are used to measure the end-to-end delay and packet loss from the sensors to the controller and from the controller to the actuators. It is demonstrated that the measured delay of the proposed WNCS including all types of transmission, encapsulation, de-capsulation, queuing and propagation, meet real-time control network requirements while guaranteeing correct packet reception with no packet loss. Moreover, it is shown that the demonstrated performance of the proposed WNCS operating redundantly on both networks in parallel is significantly superior to a WNCS operating on either a totally wireless ZigBee or WiFi network individually in terms of measured delay and interference tolerance. This proposed WNCS demonstrates the combined advantages of both the IEEE 802.15.4 protocol (which ZigBee is based on) without modifications being low cost and low power compared to other wireless technologies as well the advantages of the IEEE 802.11 protocol (WiFi) being increased bit rate and higher immunity to interference. All results presented in this study were based on a 95% confidence analysis

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

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    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

    Wireless Technologies for IoT in Smart Cities

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    [EN] As cities continue to grow, numerous initiatives for Smart Cities are being conducted. The concept of Smart City encompasses several concepts being governance, economy, management, infrastructure, technology and people. This means that a Smart City can have different communication needs. Wireless technologies such as WiFi, ZigBee, Bluetooth, WiMax, 4G or LTE (Long Term Evolution) have presented themselves as solutions to the communication needs of Smart City initiatives. However, as most of them employ unlicensed bands, interference and coexistence problems are increasing. In this paper, the wireless technologies available nowadays for IoT (Internet of Things) in Smart Cities are presented. Our contribution is a review of wireless technologies, their comparison and the problems that difficult coexistence among them. In order to do so, the characteristics and adequacy of wireless technologies to each domain are considered. The problems derived of over-crowded unlicensed spectrum and coexistence difficulties among each technology are discussed as well. Finally, power consumption concerns are addressed.García-García, L.; Jimenez, JM.; Abdullah, MTA.; Lloret, J. (2018). Wireless Technologies for IoT in Smart Cities. Network Protocols and Algorithms. 10(1):23-64. doi:10.5296/npa.v10i1.12798S236410

    Assessing Coexistence of IEEE 802.15.4 Networks and IEEE 802.11b/g/n Networks - A Study of Interference Effects

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    The study of the coexistence capabilities of networks based on the IEEE 802.11 and IEEE 802.15.4 standards has long been of interest to researchers owing to the individual success of these two technologies in various applications of Internet of Things (IoT). Operating in the same Industrial-Scientific-Medical (ISM) band, their coexistence does not always yield satisfactory results. The performance of a network based on IEEE 802.15.4 standard has been shown to be significantly lowered in the presence of a strong IEEE 802.11 based network (Wireless LAN) to the extent that communication based on the IEEE 802.15.4 standard can be rendered impossible in certain scenarios. This work is an effort towards analyzing interference caused by the three non-overlapping channels 1, 6 and 11 of IEEE 802.11b/g/n on the usable 2.4GHz spectrum of IEEE 802.15.4 standard. Recommendations of plausible scenarios for successful coexistence of these two networking technologies have been made. Assessment of the performance of an IEEE 802.15.4 standard based network through the Packet Delivery Ratio (PDR) on various channels of operation has yielded valuable insights. The experiments carried out in real-world environment stand as datapoints in predicting and understanding the interference behavior in real-life applications

    Coexistence and interference mitigation for WPANs and WLANs from traditional approaches to deep learning: a review

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    More and more devices, such as Bluetooth and IEEE 802.15.4 devices forming Wireless Personal Area Networks (WPANs) and IEEE 802.11 devices constituting Wireless Local Area Networks (WLANs), share the 2.4 GHz Industrial, Scientific and Medical (ISM) band in the realm of the Internet of Things (IoT) and Smart Cities. However, the coexistence of these devices could pose a real challenge—co-channel interference that would severely compromise network performances. Although the coexistence issues has been partially discussed elsewhere in some articles, there is no single review that fully summarises and compares recent research outcomes and challenges of IEEE 802.15.4 networks, Bluetooth and WLANs together. In this work, we revisit and provide a comprehensive review on the coexistence and interference mitigation for those three types of networks. We summarize the strengths and weaknesses of the current methodologies, analysis and simulation models in terms of numerous important metrics such as the packet reception ratio, latency, scalability and energy efficiency. We discover that although Bluetooth and IEEE 802.15.4 networks are both WPANs, they show quite different performances in the presence of WLANs. IEEE 802.15.4 networks are adversely impacted by WLANs, whereas WLANs are interfered by Bluetooth. When IEEE 802.15.4 networks and Bluetooth co-locate, they are unlikely to harm each other. Finally, we also discuss the future research trends and challenges especially Deep-Learning and Reinforcement-Learning-based approaches to detecting and mitigating the co-channel interference caused by WPANs and WLANs

    Development and Flight Testing of a Wireless Avionics Network Based on the IEEE 802.11 Protocols

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    This report describes the development and flight testing of the IEEE 802.11 protocol-based Wireless Flight Management System (WFMS) using low cost Commercial-Off-The-Shelf (COTS) equipment and software. The unlicensed spectrum allocation in the 2.4 GHz and 5 GHz bands by the FCC has encouraged the industry to develop new standards for short-range communication that are commercially viable. This has resulted in new short-range communication technologies like Bluetooth and the Wireless Local Area Network (WLAN). The new modulation techniques developed for wireless communication support wired equivalent data rates. The commercial success of these technologies and their wide market adaptation has resulted in reduced costs for the devices that support these technologies. Applications of wireless technology in aerospace engineering are vast, including development, testing, manufacturing, prognostics health management, ground support equipment and active control. The high data rates offered by technologies like WLAN (IEEE 802.11 a/b/g) are sufficient to implement critical and essential data applications of avionics systems. A wireless avionics network based on IEEE 802.11a/b/g protocols will reduce the complexity and cost of installation and maintenance of the avionics system when compared to the existing wired system. The proposed WFMS imitates the flight management system of any commercial aircraft in terms of functionality. It utilizes a radio frequency for the transmission of the sensor data to the Cockpit Display Unit (CDU) and the Flight Management Computer (FMC). WFMS consists of a FMC, data acquisition node, sensor node and a user interface node. The FMC and the data acquisition nodes are built using PC/104 standard modules. The sensor node consists of an Attitude and Heading Reference System (AHRS) and a GPS integrated with a serial device server. The user interface node is installed with moving map software which receives data from the AHRS and GPS to display flight information including topographic maps, attitude, heading, velocity, et cetera. This thesis demonstrates the performance evaluation of the WFMS both on the ground and in flight, and its advantages over a wired system. This thesis focuses on the evaluation of IEEE 802.11a/b/g protocols for avionics application. Efforts taken to calibrate the available bandwidth of the WLAN network at different operating conditions and varying ranges using different network analysis tools are explained briefly. Considerable research on issues like electromagnetic interference and network security critical to the development of a wireless network for avionics has also been done. This report covers different aspects of the implementation of wireless technology for aircraft systems. This work is a successful starting point for the new fly-by-wireless concept with extensions to active wireless flight control

    Utilizing ZigBee Technology for More Resource-efficient Wireless Networking

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    Wireless networks have been an essential part of communication in our daily life. Targeted at different applications, a variety of wireless networks have emerged. Due to constrained resources for wireless communications, challenges arise but are not fully addressed. Featured by low cost and low power, ZigBee technology has been developed for years. As the ZigBee technology becomes more and more mature, low-cost embedded ZigBee interfaces have been available off the shelf and their sizes are becoming smaller and smaller. It will not be surprising to see the ZigBee interface commonly embedded in mobile devices in the near future. Motivated by this trend, we propose to leverage the ZigBee technology to improve existing wireless networks. In this dissertation, we classify wireless networks into three categories (i.e., infrastructure-based, infrastructure-less and hybrid networks), and investigate each with a representative network. Practical schemes are designed with the major objective of improving resource efficiency for wireless networking through utilizing ZigBee technology. Extensive simulation and experiment results have demonstrated that network performance can be improved significantly in terms of energy efficiency, throughput, packet delivery delay, etc., by adopting our proposed schemes

    Low-Power Wireless for the Internet of Things: Standards and Applications: Internet of Things, IEEE 802.15.4, Bluetooth, Physical layer, Medium Access Control,coexistence, mesh networking, cyber-physical systems, WSN, M2M

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    International audienceThe proliferation of embedded systems, wireless technologies, and Internet protocols have enabled the Internet of Things (IoT) to bridge the gap between the virtual and physical world through enabling the monitoring and actuation of the physical world controlled by data processing systems. Wireless technologies, despite their offered convenience, flexibility, low cost, and mobility pose unique challenges such as fading, interference, energy, and security, which must be carefully addressed when using resource-constrained IoT devices. To this end, the efforts of the research community have led to the standardization of several wireless technologies for various types of application domains depending on factors such as reliability, latency, scalability, and energy efficiency. In this paper, we first overview these standard wireless technologies, and we specifically study the MAC and physical layer technologies proposed to address the requirements and challenges of wireless communications. Furthermore, we explain the use of these standards in various application domains, such as smart homes, smart healthcare, industrial automation, and smart cities, and discuss their suitability in satisfying the requirements of these applications. In addition to proposing guidelines to weigh the pros and cons of each standard for an application at hand, we also examine what new strategies can be exploited to overcome existing challenges and support emerging IoT applications
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