121 research outputs found

    INTERVENTION of Bluetooth with WLAN and WIMAX

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    Bluetooth technology unplugs the digital peripherals and comes as cable replacement technology. IEEE 802.11 and Bluetooth are two operating in the unlicensed 2.4 GHz frequency. WiMAX is operating both licensed and unlicensed frequencies (2-11GHz). The devices equipped with IEEE 802.11 and Bluetooth are mobiles, laptops, watches and many more and in future with WiMAX. Result is the number of co-located devices may cause interference issues in the 2.4 GHz radio frequency spectrum. Bluetooth supports both voice (SCO) and data (ACL) packets. In ACL, there is retransmission of packet if it is lost while transmitting but in SCO there is no retransmission of packet. So, retransmission is big issue in Bluetooth. In this thesis, these interference issues are investigated and implement a new Bluetooth voice packet named synchronous connection-oriented with Repeated Transmission (SCORT) with WLAN interference and WiMAX interference to study the improvement in performance by using MATLAB Simulink. SCORT technique also helps in reducing co-existing interference by using HV3 type of packet in voice signal. By this technique BER does not effect at all and very minimal delay comes due to retransmission

    Adaptive Capacity Management in Bluetooth Networks

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    A Taxonomy of Self-configuring Service Discovery Systems

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    We analyze the fundamental concepts and issues in service discovery. This analysis places service discovery in the context of distributed systems by describing service discovery as a third generation naming system. We also describe the essential architectures and the functionalities in service discovery. We then proceed to show how service discovery fits into a system, by characterizing operational aspects. Subsequently, we describe how existing state of the art performs service discovery, in relation to the operational aspects and functionalities, and identify areas for improvement

    A PROTOCOL SUITE FOR WIRELESS PERSONAL AREA NETWORKS

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    A Wireless Personal Area Network (WPAN) is an ad hoc network that consists of devices that surround an individual or an object. Bluetooth® technology is especially suitable for formation of WPANs due to the pervasiveness of devices with Bluetooth® chipsets, its operation in the unlicensed Industrial, Scientific, Medical (ISM) frequency band, and its interference resilience. Bluetooth® technology has great potential to become the de facto standard for communication between heterogeneous devices in WPANs. The piconet, which is the basic Bluetooth® networking unit, utilizes a Master/Slave (MS) configuration that permits only a single master and up to seven active slave devices. This structure limitation prevents Bluetooth® devices from directly participating in larger Mobile Ad Hoc Networks (MANETs) and Wireless Personal Area Networks (WPANs). In order to build larger Bluetooth® topologies, called scatternets, individual piconets must be interconnected. Since each piconet has a unique frequency hopping sequence, piconet interconnections are done by allowing some nodes, called bridges, to participate in more than one piconet. These bridge nodes divide their time between piconets by switching between Frequency Hopping (FH) channels and synchronizing to the piconet\u27s master. In this dissertation we address scatternet formation, routing, and security to make Bluetooth® scatternet communication feasible. We define criteria for efficient scatternet topologies, describe characteristics of different scatternet topology models as well as compare and contrast their properties, classify existing scatternet formation approaches based on the aforementioned models, and propose a distributed scatternet formation algorithm that efficiently forms a scatternet topology and is resilient to node failures. We propose a hybrid routing algorithm, using a bridge link agnostic approach, that provides on-demand discovery of destination devices by their address or by the services that devices provide to their peers, by extending the Service Discovery Protocol (SDP) to scatternets. We also propose a link level security scheme that provides secure communication between adjacent piconet masters, within what we call an Extended Scatternet Neighborhood (ESN)

    Evaluation of the aggregate interference in 2.4 GHz ISM band in home, office and hospital environments

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    Abstract. In the last years, the wireless body area network (WBAN) research has grown considerably and the idea to apply WBAN to the medical and healthcare issues could materialize. A possible WBAN could exploit the ISM (industrial, scientific and medical) band, clustered around 2.4 GHz. The ISM band is just used by other communication systems and non-communication systems. These systems transmit signals, defined aggregate interference, that could hinder the WBAN communications. In this thesis, the ISM band is investigated in order to understand if the amount of interference is too high to allow implementation of a new WBAN or if the coexistence between WBAN and the other systems is still possible. The ISM band analyses are carried out using data collected in real-life measurements, in environments where a patient monitored by a WBAN could usually stay. Data was collected in an office and a home environments, situated in Florence, Italy, in “San Giuseppe” hospital located in Empoli, Italy and in Oulu University Hospital, situated in Oulu, Finland. In each location, data are collected during a week using a spectrum analyzer (SA). The information measured by the SA is the power, expressed in dBm. In this work, a spectrum occupancy evaluation (SOE) has been developed to analyze the occupancy percentage of every frequency channel of the ISM band. The occupancy value is determined by a threshold, which divides the interference samples from the noise samples. In this work, the occupancy is evaluated using both a fixed threshold and a dynamic threshold, which value directly depends on the samples’ values. The results achieved using fixed and dynamic thresholds are discussed and compared. In addition, a time domain analysis has been carried out in order to know the amplitude, the time distribution and the size of the interference contributions. The time domain results allow to predict the interference behavior, making possible the extraction of a statistical interference modelling. The final results of the analyses depend strongly on the measurement location, the time and the measurement equipment. However, in most cases, the occupancy value is below 10%. Hence, the amount of interference is not so high as to prevent the implementation of a new WBAN or to determine an added smartness to the WBAN

    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

    Message forwarding techniques in Bluetooth enabled opportunistic communication environment

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    These days, most of the mobile phones are smart enough with computer like intelligence and equipped with multiple communication technologies such as Bluetooth, wireless LAN, GPRS and GSM. Different communication medium on single device have unlocked the new horizon of communication means. Modern mobile phones are not only capable of using traditional way of communication via GSM or GPRS; but, also use wireless LANs using access points where available. Among these communication means, Bluetooth technology is very intriguing and unique in nature. Any two devices equipped with Bluetooth technology can communicate directly due to their unique IDs in the world. This is opposite to GSM or Wireless LAN technology; where devices are dependent on infrastructure of service providers and have to pay for their services. Due to continual advancement in the field of mobile technology, mobile ad-hoc network seems to be more realised than ever using Bluetooth. In traditional mobile ad-hoc networks (MANETs), before information sharing, devices have partial or full knowledge of routes to the destinations using ad-hoc routing protocols. This kind of communication can only be realised if nodes follow the certain pattern. However, in reality mobile ad-hoc networks are highly unpredictable, any node can join or leave network at any time, thus making them risky for effective communication. This issue is addressed by introducing new breed of ad-hoc networking, known as opportunistic networks. Opportunistic networking is a concept that is evolved from mobile ad-hoc networking. In opportunistic networks nodes have no prior knowledge of routes to intended destinations. Any node in the network can be used as potential forwarder with the exception of taking information one step closer to intended destination. The forwarding decision is based on the information gathered from the source node or encountering node. The opportunistic forwarding can only be achieved if message forwarding is carried out in store and forward fashion. Although, opportunistic networks are more flexible than traditional MANETs, however, due to little insight of network, it poses distinct challenges such as intermittent connectivity, variable delays, short connection duration and dynamic topology. Addressing these challenges in opportunistic network is the basis for developing new and efficient protocols for information sharing. The aim of this research is to design different routing/forwarding techniques for opportunistic networks to improve the overall message delivery at destinations while keeping the communication cost very low. Some assumptions are considered to improved directivity of message flow towards intended destinations. These assumptions exploit human social relationships analogies, approximate awareness of the location of nodes in the network and use of hybrid communication by combining several routing concept to gain maximum message directivity. Enhancement in message forwarding in opportunistic networks can be achieved by targeting key nodes that show high degree of influence, popularity or knowledge inside the network. Based on this observation, this thesis presents an improved version of Lobby Influence (LI) algorithm called as Enhanced Lobby Influence (ELI). In LI, the forwarding decision is based on two important factors, popularity of node and popularity of node’s neighbour. The forwarding decision of Enhanced Lobby Influence not only depends on the intermediate node selection criteria as defined in Lobby Influence but also based on the knowledge of previously direct message delivery of intended destination. An improvement can be observed if nodes are aware of approximate position of intended destinations by some communication means such as GPS, GSM or WLAN access points. With the knowledge of nodes position in the network, high message directivity can be achieved by using simple concepts of direction vectors. Based on this observation, this research presents another new algorithm named as Location-aware opportunistic content forwarding (LOC). Last but not least, this research presents an orthodox yet unexplored approach for efficient message forwarding in Bluetooth communication environment, named as Hybrid Content Forwarding (HCF). The new approach combines the characteristics of social centrality based forwarding techniques used in opportunistic networks with traditional MANETs protocols used in Bluetooth scatternets. Simulation results show that a significant increase in delivery radio and cost reduction during content forwarding is observed by deploying these proposed algorithms. Also, comparison with existing technique shows the efficiency of using the new schemes

    Trustworthy Wireless Personal Area Networks

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    In the Internet of Things (IoT), everyday objects are equipped with the ability to compute and communicate. These smart things have invaded the lives of everyday people, being constantly carried or worn on our bodies, and entering into our homes, our healthcare, and beyond. This has given rise to wireless networks of smart, connected, always-on, personal things that are constantly around us, and have unfettered access to our most personal data as well as all of the other devices that we own and encounter throughout our day. It should, therefore, come as no surprise that our personal devices and data are frequent targets of ever-present threats. Securing these devices and networks, however, is challenging. In this dissertation, we outline three critical problems in the context of Wireless Personal Area Networks (WPANs) and present our solutions to these problems. First, I present our Trusted I/O solution (BASTION-SGX) for protecting sensitive user data transferred between wirelessly connected (Bluetooth) devices. This work shows how in-transit data can be protected from privileged threats, such as a compromised OS, on commodity systems. I present insights into the Bluetooth architecture, Intel’s Software Guard Extensions (SGX), and how a Trusted I/O solution can be engineered on commodity devices equipped with SGX. Second, I present our work on AMULET and how we successfully built a wearable health hub that can run multiple health applications, provide strong security properties, and operate on a single charge for weeks or even months at a time. I present the design and evaluation of our highly efficient event-driven programming model, the design of our low-power operating system, and developer tools for profiling ultra-low-power applications at compile time. Third, I present a new approach (VIA) that helps devices at the center of WPANs (e.g., smartphones) to verify the authenticity of interactions with other devices. This work builds on past work in anomaly detection techniques and shows how these techniques can be applied to Bluetooth network traffic. Specifically, we show how to create normality models based on fine- and course-grained insights from network traffic, which can be used to verify the authenticity of future interactions

    Secure interoperation of wireless technologies

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    Tremendous emphasis has been placed on wireless technologies recently and it is expected that mobile communications will become an even bigger key driver for growth and innovation in the near future. The purpose of this paper is to study the securing, development, integration and implementation of an always on, always available, and accessible from anywhere secure wireless communication environment. Our analysis of the different wireless technologies reveals that a number of obstacles have to be managed before truly transparent wireless public data consumer offering is available. Our concern revolves around the technical development and implementation efforts of integrated wireless technologies enveloped with management processes of change and evolution. Wireless technologies have influenced our daily lives and will undoubtedly continue to play a significant role in the future. This dissertation focuses on the interoperation of wireless technologies, exploring, evaluating and presenting representations of secure, fully integrated wireless environments. The purpose is to find a cost effective, open, viable, sustainable consumer orientated high data speed offering which not only adheres to basic security requirements but surpasses it. By bringing the network to the subscriber we generate an “always-on” and “always-available” solution for data requirements fulfilling an ever increasing human demand for access to resources anywhere, anytime. A background literature of various wireless technologies, techniques and value added services is provided. An approach for the securing of critical content over wireless links in chapter seven provides a basis for access by position concepts presented in chapter eight. This secure approach to location-aware mobile access control is an essential security enhancement in the integration and interoperation models illustrated in chapter nine. These models, appropriately named SWARM 1 and SWARM 2 (System for Wireless and Roaming Mobility), illustrate different approaches to achieving a secure, fully coherent, consumer orientated, wireless data communications environment.Dissertation (MSc (Computer Science))--University of Pretoria, 2003.Computer Scienceunrestricte
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