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We developed and deployed a testbed based on the concept of peer aware communication (PAC), where PAC is used to refer the fully distributed and self-coordinated device-to-device (D2D) wireless networks. The testbed was originally developed for information sharing at local community by employing in-operation community buses as main components. However, strong demands rise from the local community...
This paper tackles the discovery issue in device-to-device (D2D) networks. Quick discovery is a fundamental step to realize low latency D2D communications. Assuming a synchronized superframe structure among peer devices, we propose to introduce and use common channel and group channels. Rules and procedures are defined for the purpose of enabling quick discovery. Computer simulations are performed...
The paper presents a method of antenna array pattern shaping, i.e. beamforming, for Impulse Radio Ultra-Wideband (IR-UWB) correlation beamformers. The method is based on Second Cone Programming (SOCP) and allows for several parameters of shaped pattern to be simultaneously optimized; it allows for arbitrary antenna array geometry as well as for arbitrary UWB frequency-dependent radiation pattern to...
Wireless Multi-hop Infrastructures (WMIs) enable mobile users to access the Internet through wireless multi-hop connections. Compared with conventional network infrastructures, WMIs have the low cost and flexible network deployment. The applications of WMI include smart cities, emergency responses and Internet of things. In emergency situations, WMI networks may have energy constraint. Furthermore,...
Wireless networks formed by peer devices or device-to-device communications are drawing more and more attention recently. In IEEE 802 Standardization Committee, TG15.8 was set up to develop a new standard for peer aware communication (PAC). PAC is expected to provide fast neighbor discovery, offload traffic for infrastructure-based networks, provide emergency links without fixed central control, etc...
The paper presents methodology for analyzing compliance of Impulse Radio Ultra-Wideband (IR-UWB) communications systems with regulatory limits specified by US Federal Communications Commission (FCC). First, discrete spectral component that reduce Effective Isotropic Radiated Power (EIRP) in IR-UWB spectrum are analyzed in an exemplary IRUWB system. After that, a minimal Pulse Repetition Frequency...
We designed and developed a test bed of infrastructure independent wireless network that connects end devices directly without centralized coordination. Various types of end devices are implemented and used for different scenarios. There is neither base station nor access point, so as to avoid the single-point-of-failure. The developed test bed has been deployed successfully in two real fields. It...
Wireless Multihop Infrastructures (WMIs) are promising network platforms for the applications such as smart cities, emergency responses, and outdoor events. On the other hand, the low cost maintenance and large coverage of WMIs are subject to the network dis-connectivity, which can be caused by node damage or energy depletion, especially in the emergency situations and off-grid locations. The end...
Applications of wireless communications to device-to-device and machine-to-machine attract more and more attentions. Moreover, in case that the existing infrastructures fail to work due to disaster like earthquake or other reasons, it is desirable that wireless terminals or devices within communication ranges quickly and directly form a network for information delivery. With this demand, the IEEE...
Demands for indoor-localization or indoornavigation are increasing in many fields such as a marketing, shopping related industries, and anticrime application. At present, many types of technologies of indoor-localization or indoor-navigation are proposed. Some examples are those that use ultrasonic waves, Wi-Fi, or IR-UWB. In this paper, we focus on IR-UWB technology because of its great potential...
Ultra wideband (UWB) is one of the radio technologies adopted by the IEEE 802.15.6™-2012 standard for on-body communication in body area networks (BANs). However, a number of simulation-based studies suggest the feasibility of using UWB for high data rate implant communication too. This paper presents an experimental verification of said predictions. We carried out radio transmissions of H.264/1280×720...
CdSnO3 nanopowder was prepared by chemical coprecipitation method using ammonia as precipitator and was characterized by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) methods. The gas sensing properties of Pure and Au doped CdSnO3 sensor to mustard was studied and the sensitivity to mustard and to NH3, methanol, acetone, hexane, trichloromethane, (CH3)2SO and DMMP was compared...
In this paper, results of an indoor experiment for 2.45 GHz dynamic wearable wireless body area network (WBAN) using multiport vector network analyzer is reported. Temporal changes of propagation characteristics for two human male subjects are measured for six antenna positions on-body simultaneously. Statistical characteristics and correlations between individual receiving points are reported.
Body area network (BAN) has been attracting more and more attentions, especially since BAN standardization was formally started by IEEE 802 in 2008. By enabling reliable wireless connection within body area, BAN is expected to provide an efficient way to lower disease occurrence rate and reduce medical expenditure when combining with various vital signal sensors deployed on human body. In this paper,...
The present article describes the experimental result of victim system detection by UWB wireless system to contribute for Japanese UWB regulatory discussion, in which a mitigation, including detect-and-avoid (DAA), technology implementation in the frequency range of 3.4 to 4.8 GHz is a major technical topic. A FPGA based MB-OFDM UWB receiver with 528 MHz sampling rate and 128 points FFT capability...
In most Asian and European countries, detect-and-avoid (DAA) is required at UWB low band (3.1-4.8 GHz). In Japan, we conducted evaluation experiments on the performance of DAA until March of 2010, which was a part of a three-year campaign to provide results of literature review and technical evaluation for the purpose of accomplishing Japanese UWB regulation. In this paper, experiment results on the...
A measurement campaign has been carried out in Japan to evaluate UWB technology for both aggregation characteristics and coexistence performance. Different from other previous studies, our evaluation is based on measurements with real devices. We examined both UWB low band and UWB high band, the latter has rarely been investigated by others. UWB aggregation results with real measurements are also...
Wireless body area network (WBAN) solution is an emerging technology to resolve the small area connection issues around human body, especially for the medical applications. Based on the integrated superframe structure of IEEE 802.15.4, this paper proposes a modified medium access control (MAC) protocol for WBAN with focus on the simplicity, dependability and power efficiency. Considering the support...
This paper shows channel models on path loss and power delay profile for wireless body area networks. These models were derived from measured channel transfer functions by using a vector network analyzer. The path loss models were obtained for the frequency bands of 430, 611, 953, 2450 MHz, and UWB band. A power delay profile model was given only for the UWB band because typical symbol duration of...
IEEE 802.15.4 is a current major technology for low-rate low-power wireless networks. To study the applicability of IEEE 802.15.4 over a wireless body area network (WBAN), in this paper we evaluate its three different access schemes' performance through several metrics. Considering the coexistence of contention access period (CAP) and contention-free period (CFP), we also study the mutual influences...
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