126 research outputs found

    Effects of Piconet Saturation on a Bluetooth Streaming Audio Channel

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    Bluetooth is a technology for wireless personal area networks (WPAN) that eliminates the need for cables, standardizes interfaces, and can automate many standard office processes such as sending and receiving email, synchronizing schedules, or exchanging business cards. With each workstation creating its own Bluetooth network, called a piconet, different Air Force environments have the potential, in some cases, to create more than 50 overlapping piconets, which significantly increases the potential for inter-piconet interference. This research investigates the effects of inter-piconet interference on a Bluetooth channel, streaming audio, offered at 24, 40, and 64 Kbps. It shows that as the number of overlapping piconets increases from zero to five, the effects on packet error rate are significant, climbing at times to just under 9%

    Performance Evaluation and Analysis of Effective Range and Data Throughput for Unmodified Bluetooth Communication Devices

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    The DoD and the Air Force continually seek to incorporate new technology in an effort to improve communication, work effectiveness, and efficiency. Office devices utilizing Bluetooth technology simplify device configuration and communication. They provide a means to communicate wirelessly over short distances thereby eliminating the need for different vendor specific cables and interfaces. One of the key concerns involved in incorporating new communication technology is security; the fundamental security concern of wireless communication is interception. Studies focusing on IEEE 802.11b have shown vulnerability zones around many DoD installations that reflect the ranges at which wireless communications using the 802.11b standard can be intercepted

    A design of variable transmission power control for wireless ad-hoc network

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    Includes bibliography.Wireless Ad-hoc Network has emanated to be a promising network paradigm that can handle last mile technology due to unprecedented growth of internet users. This network is promising because it extends network to remote areas such as congested environments, rural environments etc. It is known that nodes involved in Wireless Ad-hoc Network rely on battery energy as their source of power. Energy consumption has become one of the major challenges experienced in Wireless Ad-hoc Network, which must be properly tackled. This could be traced to the effect of transmission power on the nodes in the network. Transmission power largely determines the amount of energy consumed by each node in the network. Therefore, a power control technique must be adopted in order to manage and select the optimal transmission power with respect to distance. This transmission power must be sufficient to transfer information from one node to another. Literature have proposed different algorithms for power control technique in Wireless Ad-hoc Network. Some researchers looked at the power control technique in terms of minimising energy consumed from different perspectives, which include power aware routing and power control topology management. However, most of these algorithms were applied at different layers in OSI model such as physical layer, data link layer, network layer and application layer. To achieve a reduced energy consumption at each node in the network, a novel algorithm for transmission power control was designed to select optimal transmission power. The proposed algorithm was designed in such a way that it selects transmission power based on the distance between the nodes without affecting the network throughput. Graph theory is used in this research to model the network topology, and transmission power with respect to the distance

    Energy efficiency evaluation of BLE 5 technology

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    Abstract. As the demand for consumer electronic gadgets keep on growing rapidly day by day, a class of wirelessly connected digital accessories is getting to be built up. In this case, energy efficiency is considered as an essential basic necessity for a wireless communication system to be well adapted for the internet of things (IoT) application. The protocol parameters must be optimized for a given application in order to minimize power consumption. An energy model is therefore required, which can predict the energy consumption of a wireless device based on, Bluetooth low energy (BLE), e.g., for different parameter values. In this case, the BLE 5 technique can be a very effective solution. Lately, the Bluetooth 5 specifications have been introduced in order to offer remarkable improvements in comparison to the previous versions of the protocol. Bluetooth 5 coded is a new special kind of connection that comes with reliable communication features that varies in speed, range, and energy consumption aiming at providing better long-distance connections, but at a lower bit rate. Bluetooth 5 targets to improve twice the speed, four times range, and eight times the advertising in comparison to Bluetooth 4. This thesis describes the evaluation of the energy efficiency of recently specified BLE 5 technique’s coded mode. This work analyses both the analytical, and experimental performance of the energy efficiency of BLE 5 (S = 8) coded mode solution. It includes analytical modelling, Matlab programming, and real-life measurement using Nordic semiconductor nRF52840 development kit. The performance of lately revealed BLE 5 coded technique is compared to the performance of the BLE 4, which is seen today to be mostly used in case of commercial wireless devices. To improve the communication range of this low-power technique for IoT purposes, BLE 5 coded mode uses a forward error correction (FEC) method. Because of coding overhead, the packet length increases, and the throughput decreases. In this thesis, the frequency 2.4 GHz is considered. The LE Coded PHY is responsible for adding two steps into the packet transmissions, and reception. Firstly, FEC method is applied to the packet so that the receiver can make a correction of bit errors when the packet is received, and would be capable to improve the packet error rate (PER). Secondly, a pattern mapper method is applied to the packet. This FEC, and pattern mapping results in getting better sensitivity. The experimental results from this thesis show that BLE 5 technique provides better packet error rate (PER) performance, communication range performance, and received signal strength indicator (RSSI) performance than BLE 4, and BLE 5 consumes less energy than BLE 4, which was found out using analytical modelling

    Co-existence of wireless communication systems in ISM bands: An analytical study

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    Ph.DDOCTOR OF PHILOSOPH

    Wireless personal area networks and free-space optical links

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    This thesis is concerned with the link layer design of indoor (IrDA) and outdoor infrared links, as well as the performance of the higher layers of two major Wireless Personal Area Network (WPAN) technologies: IrDA and Bluetooth. Recent advancesin wireless technology have made it possible to put networking technology into small portable devices. During the past few years, WPAN technologies have been the subject of a tremendous growth both in research and development. Although many studies have been conducted on wireless links to address different issues on physical and link layers, wireless communications are still characterised by high error rates becauseof the frequently changing medium. On the other hand, performance studies of the higher layers are also very important. In this thesis, for the first time, a comprehensivestudy of the interactions betweenthe higher and the lower protocol layers of IrDA and Bluetooth has been carried out to improve the overall system performance. Mathematical models for the link layers are introduced for the infrared systems: infrared data association (IrDA) and free space optics (FSO). A model for the IrDA (indoor infrared) link layer is developed by considering the presence of bit errors. Based on this model, the effect of propagation delay on the link through put is investigated. An optimization study is also carried out to maximize the link throughput. FSO (outdoor infrared) links are often characterized by high speed and long link distance. A mathematical model for the FSO link layer is also developed. Significant improvement of the link throughput is achieved by optimizing the link parameters. Based on the link layer model, the performance of the IrDA higher layers (transport, session and application layers) is investigated. First, a mathematical model of TinyTP (transport protocol) is elaborated and subsequently verified by simulations. The effects of multiple connections and available buffer size are investigated. The throughput at the TinyTP level is optimized for different buffer sizes. Subsequently, the session layer, including Object Exchange (OBEX) and IrDA Burst (IrBurst) protocols, is studied and modelled. The derived mathematical model is verified by simulation results. A set of protocol parameters and hardware selection guidelines is proposed to optimize the overall system performance while also keeping the hardware requirementto a minimum. Finally, two rapidly developing IrDA applications, IrDA financial messaging(IrFM) and IrDA simple connection (IrSC), are studied. IrFM is investigated by comparison to other digital payment technologies, while the performance of IrSC is compared in two different technical approaches. In order to improve the throughput and minimize the transmission delay for the Bluetooth data applications, a systematic analysis is carried out for the Bluetooth Logical Link Control and Adaptation Layer Protocol (L2CAP). L2CAP is layered above the Bluetooth link layer (Baseband) and is essential to Bluetooth data applications. A simple and intuitive mathematical model is developed to derive simple equations for the L2CAP throughput and the average packet delay. The derived throughput equation, which is validated by simulations, takes into account bit errors as well as packet retry limits. Finally, a number of easy-to-implement performance enhancement schemes are proposed, including the optimum use of the protocol parameters

    Performance evaluation of bluetooth low energy for high data rate body area networks

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    Bluetooth Low Energy (BLE) is a promising wireless network technology, in the context of body area network (BAN) applications, to provide the required quality of service (QoS) support concerning the communication between sensor nodes placed on a user’s body and a personal device, such as a smartphone. Most previous BLE performance studies in the literature have focused primarily in networks with a single slave (point-to-point link) or traffic scenarios with relatively low data rate. However, many BAN sensors generate high data rate traffic, and several sensor nodes (slaves) may be actively sending data in the same BAN. Therefore, this work focuses on the evaluation of the suitability of BLE mainly under these conditions. Results show that, for the same traffic, the BLE protocol presents lower energy consumption and supports more sensor nodes than an alternative IEEE 802.15.4-based protocol. This study also identifies and characterizes some implementation constraints on the tested platforms that impose limits on the achievable performance.This work has been supported by FCT (Fundação para a Ciência e Tecnologia) in the scope of the projects UID/EEA/04436/2013 and UID/CTM/50025/2013, and by FEDER funds through the COMPETE 2020 Programme

    Mobile Ad hoc Networking: Imperatives and Challenges

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    Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, "ad-hoc" network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, e.g., disaster recovery environments. Ad hoc networking concept is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad hoc paradigm. Recently, the introduction of new technologies such as the Bluetooth, IEEE 802.11 and Hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent evolutions have been generating a renewed and growing interest in the research and development of MANET. This paper attempts to provide a comprehensive overview of this dynamic field. It first explains the important role that mobile ad hoc networks play in the evolution of future wireless technologies. Then, it reviews the latest research activities in these areas, including a summary of MANET\u27s characteristics, capabilities, applications, and design constraints. The paper concludes by presenting a set of challenges and problems requiring further research in the future
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