The recent years have witnessed a greater demand for understanding how people move in urban environments Due to the widespread usage of mobile phones, there have been several trajectory-based studies focusing on extracting the characteristics of human mobility from georeferenced mobile phone data Mobile positioning data is generally generated as scattered points in CDRs (Call Detail Records) Even though CDR data can be regarded as an inexpensive scalable source of information on human mobility, mobility studies in urban settings based on such data sources still prove to be a research challenge due to the coarseness of CDR spatial granularity Motivated by the need for transforming large-scale CDRs to movement trajectories, the present study offers a new solution which is made of two principal building blocks: (1) Developing a Bayesian-based induction method through adopting a GIS-based wave propagation model to solve the GSM-based localization problem when methods such as triangulation are not applicable due to the lack of measurements from more than one base station; (2) Reconstruction of movement trajectories from cellular location information using overlapping relations existing between observed cells as well as detection of ping-pong phenomena as auxiliary information A case study employing CDR and GPS records obtained from an experimental survey on one of the central urban zones of Tehran was conducted, which showed the effectiveness of the proposed methodology in comparison to current approaches with respect to three perspectives, including movement path exploration, individual-oriented movement features extraction, and crowd-movement modelling

From cellular positioning data to trajectories: Steps towards a more accurate mobility exploration

The Tethered balloon is new technology for telecommunication that can overcome the limitation of terrestrial system and satellite system due to demand for high capacity in telecommunication. Tethered balloon provides large coverage area with line of sight, which needs large number of base stations for coverage with terrestrial system; also reduce the delay time of the transmission compared to satellite system. Tethered balloon technology is studied in this paper for mobile communication purposes and some calculations are performed to show how path loss, coverage area and height of Tethered balloon are related. The propagation model Hata model is used.

Tethered balloon technology for telecommunication, coverage and path loss

The purpose of this paper is to show the most important technique in wireless communication networks that is an antenna radiation pattern. The antenna radiation pattern represents features of the antenna radiation shape in the space. The antenna radiation patterns used for determine the shape of cell size so that the difference cell sizes have difference antenna radiation patterns. The quality of coverage is depending on the cell size and QoS is depending on the coverage area which can provide via HAPs. Therefore, the antenna radiation pattern plays the most important role for HAPs coverage. The study focuses on the manner of cells or tier provided via HAP and the probability of services. If the distance between cells decreases, the number of cells increases that means the large number of tiers are used as well as the network performance will be affected by decreasing the distance between cells. Using steerable antenna is able to vary for providing constant coverage and improve the QoS. Since a steerable antenna is used on the HAP for allowance HAPs to be deployed in the different parts of the sky while the antennas boresight are still pointing at the desired coverage area. For each antenna pattern result is shown when Single HAP is considered in this study.

HAP antenna radiation pattern for providing coverage and service characteristics

Analysis of predicted and measured path loss over a Lagoon environment is presented. Propagation measurements were carried out at 1800 MHz, within a quarter of a year (May to August 2017) using Huawei Technologies drive test equipment. Measured data comprising of the received signal strength was taken for the initial measurements, measurements after first month, measurements after second month, and measurements after the third month. Measured path loss was compared with predictions made by free-space, log-distance, two-ray, COST 231-Hata, and Stanford University Interim (SUI) models. The COST-231 Hata model showed the most accurate performance with root mean square errors (RMSEs) of 10.03 dB, 12.38 dB, 17.59 dB, and 7.67 dB for the initial measurements, measurements after first month, measurements after second month, and measurements after third month, respectively. In order to achieve a more accurate prediction, the COST 231 Hata model was optimized using the least square algorithm. The optimized model showed improved signal prediction with RMSEs of 7.90 dB, 9.28 dB, 14.82 dB and 5.28 dB, respectively. The average RMSEs of the optimized COST 231 Hata model showed 9.32 dB compared with 11.92 dB predicted by the actual COST 231 Hata model. This accounts for about 21.81% improvements over the existing COST 231 Hata model. Therefore, the optimized COST 231-Hata model could be used to characterize radio channels in the investigated environments. Keywords: Propagation measurements, 4G LTE network, Lagoon environment, Pathloss models, Root mean squared error, Least square algorithm

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Propagation measurements of a 4G LTE network in Lagoon environment

Modern infrastructures are becoming increasingly dependent on electronic systems, leaving them more vulnerable to electrical surges or electromagnetic interference. Electromagnetic disturbances appear in nature, e.g., lightning and solar wind; however, they may also be generated by man-made technology to maliciously damage or disturb electronic equipment. This article presents a systematic risk assessment framework for identifying possible, consequential, and plausible intentional electromagnetic interference (IEMI) attacks on an arbitrary distribution network infrastructure. In the absence of available data on IEMI occurrences, we find that a systems-based risk assessment is more useful than a probabilistic approach. We therefore modify the often applied definition of risk, i.e., a set of triplets containing scenario, probability, and consequence, to a set of quadruplets: scenario, resource requirements, plausibility, and consequence. Probability is "replaced" by resource requirements and plausibility, where the former is the minimum amount and type of equipment necessary to successfully carry out an attack scenario and the latter is a subjective assessment of the extent of the existence of attackers who possess the motivation, knowledge, and resources necessary to carry out the scenario. We apply the concept of intrusion areas and classify electromagnetic source technology according to key attributes. Worst-case scenarios are identified for different quantities of attacker resources. The most plausible and consequential of these are deemed the most important scenarios and should provide useful decision support in a countermeasures effort. Finally, an example of the proposed risk assessment framework, based on notional data, is provided on a hypothetical water distribution network.

A Systems-Based Risk Assessment Framework for Intentional Electromagnetic Interference (IEMI) on Critical Infrastructures.

The network planning is a significant step in establishment of wireless communication system. For a wireless system the primary setup takes a lot of time for process and also very expensive. Because of this reason it uses a mathematical model before the processing of the system to avoid unknown expenses. The mathematical model calculation mainly includes path loss, link budgets etc. Radio propagation is site specific and it varies substantially depending on geography, frequency at which system will operate mobile terminal speed, interface sources and other dynamic factors. To estimate the signal coverage and to achieve a high data rates, it is very important to illustrate the radio channel through important parameters and with the help of a mathematical model. In this paper we have evaluated the cell coverage area for Long Term Evolution (LTE) technology at 1800 MHz (FDD-LTE) theoretically for different transmitting antenna heights and at different transmitting power levels. This coverage area is then compared with the practical measured coverage area i.e. practical measured path loss. The signal coverage starts within the cell, by predicting the affecting parameters on the signal power level in the uplink and downlink at the practical cases. In this paper the concentration is completely on preprocess of network planning i.e. link budgeting of LTE cellular system. This investigation can also lead the radio planner to a thorough understanding of radio wave propagation for designing mobile communication system.

Cell Coverage Area and Link Budget Calculations in LTE System

This paper deals with the radio propagation models predominantly used for the 4th Generation (4G) of cellular networks generally known as Long Term Evolution (LTE). It is necessary to study the radio wave propagation models at the development level of any wireless communication network or system. A comparative analysis is made among various radio propagation prediction models to assess the appropriate prediction model which can be helpful for LTE networks in a particular environment. In the analysis part; the mean, standard deviation and root mean square value are computed. In the evaluation Free space model predicts the minimum path loss and SUI model predicts the more path loss for the given values of frequency, base station antenna heights, and Mobile equipment antenna heights and transmitted power. Ericsson, winner II, Cost-231 and ECC models are showing better results when compared with the practical data obtained in the NCR region Delhi (INDIA). Among these models Ericsson model is showing least RMSE and standard deviation. From the analysis carried out in this paper, it is observed that the Ericsson path loss model is the best model for NCR region Delhi (INDIA). To acquire more accurate results in the existed Ericsson model some modifications are given using statistical measures.

Akanksha Gupta

Papers

Cell Coverage Area and Link Budget Calculations in LTE System

Comparative analysis of propagation models in LTE networks with spline interpolation