Device to Device (D2D) communication was first considered in out-band to manage energy issues in the wireless sensor networks. The primary target was to secure information about system topology for successive communication. Now the D2D communication has been legitimated in in-band by the 3rd Generation Partnership Project (3GPP). To initiate D2D communication, Device Discovery (DD) is a primary task and every D2D application benefits from DD as an end to end link maintenance and data relay when the direct path is obstructed. The DD is facing new difficulties because of the mobility of the devices over static systems, and the mobility makes it more challenging for D2D communication. For in-band D2D, DD in a single cell and multi-cell, and dense area is not legitimated properly, causing latency, inaccuracy, and energy consumption. Among extensive studies on limiting energy consumption and latency, DD is one of the essential parts concentrating on access and communication. In this paper, a comprehensive survey on DD challenges, for example single cell/multi-cell and dense area DD, energy consumption during discovery, discovery delay, and discovery security, etc., has been presented to accomplish an effective paradigm of D2D networks. In order to undertake the device (user) needs, an architecture has been projected, which promises to overwhelm the various implementation challenges of DD. The paper mainly focuses on DD taxonomy and classification with an emphasis on discovery procedures and algorithms, a summary of advances and issues, and ways for potential enhancements. For ensuring a secure DD and D2D, auspicious research directions have been proposed, based on taxonomy.
Abstract-In this paper, a secure parking reservation system using Global System for Mobile communications (GSM) technology has been performed. It helps the drivers from facing the problem that always occurs at the car park, such as time being wasted in searching for the available parking spaces and keep on circling the parking area until they found an empty parking spot. This problem usually occurs in urban areas, where number of vehicles are higher as compared to the availability of parking spaces. In this proposed system there are two modules have been developed such as parking lot monitoring and security reservation modules. For the parking lot monitoring module, the layout animation is used to display the parking lot status. In security reservation module, the users need to send SMS to reserve the parking lot and use the password provided to enter and exit the parking lot. Our main contribution is the system has more security than other previous research with the used of password to enter and exit.
This article presented a millimeter wave antenna which operated at 38 GHz for 5G mobile base station. The MIMO (Multiple Input Multiple Output) antenna consisted of 1x10 linear array configurations. The proposed antenna’s size was 88 x 98 mm^2 and printed on 1.575 mm-thick Rogers Duroid 5880 subsrate with dielectric constant of ε_r= 2.2 and loss tangent (tanδ) of 0.0009. The antenna array covered along the azimuth plane to provide the coverage to the users in omnidirection. The simulated results showed that the single element antenna had the reflection coefficient (S11) of -59 dB, less than -10 dB in the frequency range of 35.5 - 39.6 GHz. More than 4.1 GHz of impedance bandwidth was obtained. The gain of the antenna linear array was 17.8 dBi while the suppression of the side lobes was -2.7 dB. It showed a high array gain throughout the impedance bandwidth with overall of VSWR were below 1.0646. It designed using CST microwave studio.
Gas leakage in industrial area causes many health issues. Thus, to prevent such disasters happen, the atmosphere of a workplace should be regularly monitored and controlled, in order to maintain the clean air environment. However, efforts in industrial air quality control have been impeded by the lack of science-based approaches to identify and assess atmosphere air quality and level of dangerous gas. Therefore, a monitoring system for gas leakage detection needs to be developed. For the development of this system, the combustible gas sensor (MQ9) was used in order to detect the present of methane (CH4) and carbon monoxide gas (CO). This sensor will detect the concentration of the gas according to the voltage output of sensor and operated in the alarm system, autonomous control system and monitoring system by using Arduino uno as the microcontroller for the whole system. Whereas the Zigbee will send the data reading from the gas sensor to monitoring system that display on LabVIEW Graphical User Interface (GUI). Besides, user can take immediate action upon the leakage occurs, else the gas supply and the system will shut down automatically within 10 minutes to prevent the condition becoming worst.
Breast cancer is the transformation of normal cells in the breast area into a malignant tumor, which is the second largest disease as a cause of death for women. Early detection is one way to avoid significant risks in breast cancer. X-ray mammography and magnetic resonance imaging (MRI) techniques are used to detect breast cancer. However, those techniques have several limitations. Ultra-wideband (UWB) microwave imaging, approved by The Federal Communications Commission (FCC) in the United States, has promising capabilities in detecting breast cancer. Microwave imaging uses a microstrip antenna that has the advantage of convenience, potentially low cost, and is a non-ionized and safe alternative. In this paper, the ultra-wideband microstrip antenna for breast cancer detection is proposed. The antenna was designed by adding some rectangular slots on a rectangular patch to meet the UWB specifications. The antenna works well at 8.41 GHz to 10.29 GHz with directivity of 6.451 dBi and SAR value of 1.6 W / kg. The antenna was simulated with breast phantom. The tumor sizes of 6 mm and 10 mm are added to evaluate the E/H fields and current density with and without tumor. The highest E-Field value of 928.8 V / m was obtained at 10 GHz with a 10 mm tumor size. The highest H-Field value of 4.06 V / m was achieved at 10 GHz with a 6 mm tumor size. From the simulation, the E/H-field and current density are higher if there is a tumor in the breast compared to the breast without the tumor.
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