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The process of creating international standards is a mystery to most people, even to the technologists who use them every day. This article describes the origins and processes of the IEEE Project 802.15 Working Group for Wireless ...
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The process of creating international standards is a mystery to most people, even to the technologists who use them every day. This article describes the origins and processes of the IEEE Project 802.15 Working Group for Wireless Personal Area Networks and their effort to bring standardization to the Bluetooth specification. The committee of experts that comprises P802.15 is chartered with codifying the physical characteristics and protocols used to construct small, low-power, ad hoc networks used for wireless interconnection of personal electronic devices.
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Low rate wireless personal area networks (LR-WPANs) offer device level wireless connectivity. They bring to light a host of new applications as well as enhance existing applications. Due to their low cost, low power consumption an...
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Low rate wireless personal area networks (LR-WPANs) offer device level wireless connectivity. They bring to light a host of new applications as well as enhance existing applications. Due to their low cost, low power consumption and self-organization features, LR-WPANs are ideal for applications such as public security, battle field monitoring, inventory tracking, as well as home and office automation. Nevertheless, one critical issue, security, needs to be solved before LR-WPANs are commonly accepted. Pursuing security in LR-WPANs is a challenging task. On one hand, wireless communications are inherently susceptible to interception and interference. On the other hand, most devices in LR-WPANs are resource-constrained and lack physical safeguards. This paper presents a systematic analysis of the threats faced by LR-WPANs with respect to the protocol stack defined by IEEE 802.15.4 and the ZigBee Alliance. Attacks are modeled and their impacts are evaluated. Some security problems within the current LR-WPAN security architecture are identified and remedies are suggested. Countermeasures of various attacks are also given.
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Bluetooth is one of the cable-replacement technologies. It uses short-range radio links to replace connecting cables. Bluetooth enables portable devices to form short-range wireless ad hoc networks. A set of Bluetooth devices shar...
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Bluetooth is one of the cable-replacement technologies. It uses short-range radio links to replace connecting cables. Bluetooth enables portable devices to form short-range wireless ad hoc networks. A set of Bluetooth devices sharing a common channel can form a personal area network called a piconet. Several piconets can also be interconnected to establish a scatternet. Zaruba, Basaghi and Chlamtac proposed a mechanism for forming a distributed scatternet called the Bluetree. The algorithm is based on selecting an arbitrary node serving as the Blueroot. The Blueroot initiates the construction of the Bluetree. Though the algorithm is very simple, there are some weak points. For example, being a tree limits its routing choices. There are also the problems of overloading on the Blueroot and the many master/slave bridges on any routing path. In this paper, we will improve the weaknesses of Bluetree by eliminating the bottleneck in the Blueroot and by reducing the number of bridges to half for almost any path. We call the new algorithm Bluegon since polygons (cycles) will be formed in the scatternet. Simulation results indicate the efficiencies of our algorithm.
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A body area network (BAN) provides connectivity and power among on-body/in-body sensors and is an attractive means for realizing the “human intranet” for health-care, medical, or multimedia applications around the human body
[1...
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A body area network (BAN) provides connectivity and power among on-body/in-body sensors and is an attractive means for realizing the “human intranet” for health-care, medical, or multimedia applications around the human body
[1]
,
[2]
. As shown in
Figure 1
, compared to a WLAN or a wireless personal area network (WPAN), it targets a much smaller range (∼2 m) with greater energy efficiency.
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In the forthcoming fourth-generation (4G) all-IP mobile communications era,apart from the cellular/mobile networks, Wireless Personal Area Networks (PANs) and Local Area Network (LAN) are expected to fulfil the "anywhere and anyti...
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In the forthcoming fourth-generation (4G) all-IP mobile communications era,apart from the cellular/mobile networks, Wireless Personal Area Networks (PANs) and Local Area Network (LAN) are expected to fulfil the "anywhere and anytime" ubiquitous services' requirement.Users will request forming "ad hoc" personal area networks to enable personal devices to autonomously inter-communicate,while Wireless LANs will enable communication with colleagues at work,at conferences,at "hot spots", at home,or on the move.In parallel,advanced sensor devices of the surrounding environment will recognize the user and provide for added value services.In order to achieve this, open standard interfaces and interoperability between devices and manufacturers are mandatory.In this paper,we describe the most important,mature Wireless PAN and LAN standards,and introduce some evolving new standards.
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This paper has focused on resolving two issues, which are to construct an antenna with wide bandwidth and an antenna that can be used for distinct wireless technologies that can operate at different frequencies. Bandwidth is the m...
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This paper has focused on resolving two issues, which are to construct an antenna with wide bandwidth and an antenna that can be used for distinct wireless technologies that can operate at different frequencies. Bandwidth is the most important factor in designing micro strip patch antennas. Patch antennas are inherently narrow-band, but in today's wireless communication technology, high data rates are quite common. In order to handle these high data rates, wide bandwidth is required. In this paper, a partial ground plane technique is used to enhance the bandwidth of the antenna. A square patch antenna for wide band applications operating at a frequency band of 2 to 8 GHz has been designed using CST Microwave Studio and fabricated. Measured and simulated results are compared, and they are in good agreement. The proposed antenna covers various wireless standards such as Bluetooth (2.4 GHz), WLAN (2.4, 5.1-5.8 GHz), WiMAX (2.3-5.7 GHz), and X-band satellite applications (7.1-7.76 GHz). The proposed antenna is modeled with g_l = 27.9 mm and P_l = P_w = 17 mm, exhibiting a wide bandwidth of 5.5 GHz and a fractional bandwidth of 111%. The return loss is below 10 dB for the entire frequency range.
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In recent years, interests in the application of wireless body network (WBN) have grown considerably. Wireless body sensor nodes assume deploying a stationary sensor network over a human body area. Among the well-known specificati...
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In recent years, interests in the application of wireless body network (WBN) have grown considerably. Wireless body sensor nodes assume deploying a stationary sensor network over a human body area. Among the well-known specifications, IEEE 802.15.4 originally designed for low-power, low-rate, and short-distance wireless personal area networks (WPANs) has become one of the promising candidates for interconnections between wireless sensor nodes. IEEE 802.15.4 uses a modified carrier-sense multiple access with collision avoidance (CSMA/CA) MAC protocol to access channel for transmission data; however, it suffers from inefficient channel utilization because the physical carrier sensing is only performed after the backoff period. In this paper, a rotational listening strategy (RLS) is proposed to increase the rate of successful transmission for WBN. The channel access period is logically partitioned into a number of mini-slots that are individually allocated to nodes. In this case, inefficient channel utilization and collisions can be resolved simultaneously, meanwhile retaining fairness criterion. In addition, an enhanced RLS is proposed to handle the load unbalance situation among nodes. This paper also provides a coexistence solution for the situation where there are nodes without RLS associating with an RLS-enabled WSN. Analytical and numerical simulations are both studied to evaluate the performance of RLS. Both results illustrate that RLS indeed improves transmission efficiency as well as energy consumption.
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Wireless mesh networking is a promising technology for numerous applications which appeals especially to those applications that cannot be directly supported by other wireless technologies. The commercial success of Wi-Fi and the ...
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Wireless mesh networking is a promising technology for numerous applications which appeals especially to those applications that cannot be directly supported by other wireless technologies. The commercial success of Wi-Fi and the advances in many wireless technologies have in part stimulated the development of wireless mesh networks. The persistent driving force, however, comes from the envisioned advantages of wireless mesh techniques themselves, including extended coverage, robustness, self-configuration, easy maintenance, and low cost. This article presents an overview of this emerging technology, focusing on the technical merits and related standards activities of IEEE and ZigBee that are actively applying the concept of multi-hop mesh techniques in the field of wireless networking technologies, ranging from personal area networks (PANs) to metropolitan area networks (MANs).
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Wireless Personal Area Networking (WPAN) is introduced as a new concept for next generation wireless systems. WPANs are short-range wireless systems operating in the direct surrounding of the user. A reference architecture for sho...
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Wireless Personal Area Networking (WPAN) is introduced as a new concept for next generation wireless systems. WPANs are short-range wireless systems operating in the direct surrounding of the user. A reference architecture for short-range wireless communications has been designed covering the end-to-end system design. Traditional protocol stack implementations based on layering do not function efficiently in wireless environments due to inefficiency, inflexibility and suboptimality of the functionalities in the different layers. Specifically in WPAN and other short-range wireless systems the performance benefits from a cross-layer design strategy, supporting adaptability and optimizing the use of resources over multiple layers of the protocol stack. In this paper we advocate cross-layer optimisation for WPAN systems and introduce a centralised control structure for interaction between different layers in master or leader devices. The control structure adapts the link characteristics to the channel state and user requirements. Allowing for the support of heterogeneous services, each with their own quality-of-service demands, in wireless environments.
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Mitigating inter-symbol interference (ISI) in impulse radio is one of the challenges in achieving the high data rate potential of Ultra Wideband (UWB). Available techniques such as the use of Multiband OFDM and equalizer provide a...
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Mitigating inter-symbol interference (ISI) in impulse radio is one of the challenges in achieving the high data rate potential of Ultra Wideband (UWB). Available techniques such as the use of Multiband OFDM and equalizer provide a good solution but they require complex implementation. This letter investigates and expands a newly proposed ISI reduction technique proposed in [1] named "shift window" approach. The shift window approach was not designed to combat ISI under a severe indoor wireless channel. An enhancement based on the generalization of the shift window approach is introduced for ISI reduction for wireless personal area network (WPAN). The newly proposed approach is shown to perform better under severe ISI.
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