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The log-distance path loss model is a radio propagation model that predicts the path loss a signal encounters inside a building or densely populated areas over long distance. While the log-distance model is suitable for longer distances, the short-distance path loss model is often used for indoor environments or very short outdoor distances.
Among the most commonly used methods in the design of radio equipment such as antennas and feeds is the finite-difference time-domain method. The path loss in other frequency bands (medium wave (MW), shortwave (SW or HF), microwave (SHF)) is predicted with similar methods, though the concrete algorithms and formulas may be very different from ...
The free-space path loss (FSPL) formula derives from the Friis transmission formula. [3] This states that in a radio system consisting of a transmitting antenna transmitting radio waves to a receiving antenna, the ratio of radio wave power received P r {\displaystyle P_{r}} to the power transmitted P t {\displaystyle P_{t}} is:
The Hata model is a radio propagation model for predicting the path loss of cellular transmissions in exterior environments, valid for microwave frequencies from 150 to 1500 MHz. It is an empirical formulation based on the data from the Okumura model , and is thus also commonly referred to as the Okumura–Hata model . [ 1 ]
In the mathematical field of graph theory, the distance between two vertices in a graph is the number of edges in a shortest path (also called a graph geodesic) connecting them. This is also known as the geodesic distance or shortest-path distance. [1] Notice that there may be more than one shortest path between two vertices. [2]
where is the large-scale (log-normal) fading, is a reference distance at which the path loss is , is the path loss exponent; typically =. [ 1 ] [ 2 ] This model is particularly well-suited for measurements, whereby P L 0 {\displaystyle PL_{0}} and ν {\displaystyle \nu } are determined experimentally; d 0 {\displaystyle d_{0}} is selected for ...
where L50 is the 50th percentile (i.e., median) value of propagation path loss, LF is the free space propagation loss, A mu is the median attenuation relative to free space, G(hte) is the base station antenna height gain factor, G(hre) is the mobile antenna height gain factor, and G AREA is the gain due to the type of environment. Note that the ...
A directed walk is a finite or infinite sequence of edges directed in the same direction which joins a sequence of vertices. [2]Let G = (V, E, ϕ) be a directed graph. A finite directed walk is a sequence of edges (e 1, e 2, …, e n − 1) for which there is a sequence of vertices (v 1, v 2, …, v n) such that ϕ(e i) = (v i, v i + 1) for i = 1, 2, …, n − 1.