Modeling of the Сellular Сommunication System Coverage Area Taking into Account the External Details of the Terrain

This paper proposes a new approach to estimating the contour of the coverage zone for a cellular communications base station that takes into account meaningful reflecting objects located out of the considering zone. Based on this approach, the procedure for modeling and designing the cellular system coverage area. Unlike known methods, the developed procedure considers the influence of electromagnetic wave reflection from external details of the relief, in particular essential reflecting objects located outside the considered cell. The effect of the external objects on the formation of the coverage area resulting contour is considered analytically, numerically and experimentally. The proposed solution leads to more accurate designing of the coverage area for each cell. This creates the opportunity for further development of designing techniques to more effective engineering solutions at developing and applying cellular communication systems in real situations and at various scenarios.

Evaluation of Misalignment Effect in Vehicle-to-Vehicle Visible Light Communications: Experimental Demonstration of a 75 Meters Link

The use of visible light communications technology in communication-based vehicle applications is gaining more and more interest as the research community is constantly overcoming challenge after challenge. In this context, this article addresses the issues associated with the use of Visible Light Communications (VLC) technology in Vehicle-to-Vehicle (V2V) communications, while focusing on two crucial issues. On the one hand, it aims to investigate the achievable communication distance in V2V applications while addressing the least favorable case, namely the one when a standard vehicle rear lighting system is used as a VLC emitter. On the other hand, this article investigates another highly unfavorable use case scenario, i.e., the case when two vehicles are located on adjacent lanes, rather than on the same lane. In order to evaluate the compatibility of the VLC technology with the usage in inter-vehicle communication, a VLC prototype is intensively evaluated in outdoor conditions. The experimental results show a record V2V VLC distance of 75 m, while providing a Bit Error Ratio (BER) of 10−7–10−6. The results also show that the VLC technology is able to provide V2V connectivity even in a situation where the vehicles are located on adjacent lanes, without a major impact on the link performances. Nevertheless, this situation generates an initial no-coverage zone, which is determined by the VLC receiver reception angle, whereas in some cases, vehicle misalignment can generate a BER increase that can go up to two orders of magnitude.

THE METOD OF SELECTING THE AVAILABLE SPACE VEHICLES UNDER THE TERMS OF GEOMETRICAL VISIBILITY BETWEEN THEM AND THE EARTH’S DESIGNATED AREAS

Under the warfare conditions in the east of Ukraine the problem of providing the command with space shooting information is gaining topicality. With respect to the absence of national means for solving these tasks, ordering and purchasing the space shooting information from foreign operators appears the only practical way of gaining the above information. It is noteworthy, that the market of these services is well-developed, this the problem of the reasonable formation of orders for shooting appears topical. The paper suggests a unique method for selecting available foreign space vehicles for the Earth’s remote sensing with the aim of using their target information for the benefit of the Armed Forces of Ukraine. The method is based on the advance calculations of the prognosticated coefficients of the temporal and spatial coverage of the Earth’s designated areas by the inspection zone of the space vehicles selected, comparing them with the requirements of the target information ordering customers, as well as on choosing the most appropriate options on this basis. The visibility conditions of the Earth’s designated area by the determined space vehicle at a given calendar date are formalized. Along with it the instrument of logical functions of the geometric visibility is used. Besides, the author suggests the mathematical instruments for the calculating the area of the designated territory of shooting in case of its description by the polygon of arbitrary shape with respect to the excess of this spherical polygon. The author also develops the mathematical model for determining instant shooting area on the spherical Earth by the pyramid coverage zone of the space vehicle under the in roll deviation of the sight axis of the onboard target equipment. The directions for the further research in general, and determining the physical conditions of monitoring the designated shooting areas in particular, are suggested.

Moderate geomagnetic storm condition, WAAS Alerts and real GPS positioning quality

The most significant part of the Wade Area Augmentation System (WAAS) integrity data consists of the User Differential Range Error (UDRE) and the Grid Ionospheric Vertical Error (GIVE). WAAS solutions are not completely appropriate to determine the GIVE term within the entire wade area coverage zone taking in account real irregular structure of the ionosphere. It leads to the larger confidence bounding terms and lower expected positioning availability in comparison to the reality under geomagnetic storm conditions and system outages. Thus a question arises: is the basic WAAS concept appropriate to provide the same efficiency of the integrity monitoring for both “global differential correction (i.e. clock, ephemeris etc)” and “local differential correction (i.e. ionoshrere, troposhpere and multipath)”? The aim of this paper is to compare official WAAS integrity monitoring reports and real positioning quality in US coverage zone (CONUS) and Canada area under geomagnetic storm conditions and system outages. In this research we are interested in comparison between real GPS positioning quality based on one-frequency C/A ranging mode and HAL (VAL) values which correspond to the LP, LPV and LPV200 requirements. Significant mismatch of the information between WAAS integrity data and real positioning quality was unfolded as a result of this comparison under geomagnetic storms and system outages on February, 2011 and June 22, 2015. Based on this result we think that in order to achieve high confidence of WAAS positioning availability alerts real ionospheric measurements within the wide area coverage zone must be involved instead of the WAAS GIVE values. The better way to realize this idea is to combine WAAS solutions to derive “global differential corrections” and LAAS solutions to derive “local differential corrections”.

Space Occupancy through BLE Dynamic Broadcasting

Internet of Things (IoT) merges different technologies to provide the needed infrastructure for an adequate inter-device connection and data exchange, with Bluetooth Low Energy (BLE) being one of the latest acquisitions. The use of BLE beacons offers a straightforward approach to broadcast information to any device being in the coverage zone and able to process such signal. Instead of this static solution, in this paper, we face an alternative approach that, combining both Wi-Fi and BLE beacon technologies, is able to dynamically adapt the information being broadcast depending on the particular devices in the coverage area. Taking advantage of the beacon device communications, we propose to monitor the space occupancy throughout the study area (typically inside a building) by following the beacon device data exchange. This information would be later used to improve space analysis. As a proof of concept, we have conducted an experiment inside a faculty to check the potentiality of the proposal, obtaining promising results.

Design optimization method of line-of-sight with JACK for bulldozer operator

The objective of this article is to investigate the line-of-sight (LOS) and visual areas in order to provide a lower risk of accident and a best available view for the operator of industry machine. This paper presented a method of simulating an bulldozer operation in a virtual environment for the sake of analyzing LOS of the operator during conditions of load and unload respectively. Coverage zone tool in the JACK software was utilized to calculate the percentage of visible zones from the virtual operator’s position. At the same time, the modification of design with additional cameras was proposed based on the results of LOS analysis, which significantly improved compared with original design. The results of this study proved that the modifications (with visual monitoring system) could improve visibility of bulldozer operators to some extent according to the optimization method.