Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Standardization of Propagation Models: 800 MHz to 100 GHz -- A
  Historical Perspective   Propagation models constitute a fundamental building block of wireless
communications research. Before we build and operate real systems, we must
understand the science of radio propagation, and develop channel models that
both reflect the important propagation processes and allow a fair comparison of
different systems. In the past five decades, wireless systems have gone through
five generations, from supporting voice applications to enhanced mobile
broadband. To meet the ever increasing data rate demands of wireless systems,
frequency bands covering a wide range from 800 MHz to 100 GHz have been
allocated for use. The standardization of these systems started in the
early/mid 1980's in Europe by the European Telecommunications Standards
Institute with the advent of Global System for Mobile Communications. This
motivated the development of the first standardized propagation model by the
European Cooperation in Science and Technology (COST) 207 working group. These
standardization activities were continued and expanded for the third, fourth,
and fifth generations of COST, as well as by the Third Generation Partnership
Project, and the International Telecommunication Union. This paper presents a
historical overview of the standardized propagation models covering first to
fifth-generation systems. In particular, we discuss the evolution and
standardization of pathloss models, as well as large and small-scale fading
parameters for single antenna and multiple antenna systems. Furthermore, we
present insights into the progress of deterministic modelling across the five
generations of systems, as well as discuss more advanced modelling components
needed for the detailed simulations of millimeter-wave channels. A
comprehensive bibliography at the end of the paper will aid the interested
reader to dig deeper.

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The categories of this paper are: math-ph
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The categories of this paper are: physics
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The categories of this paper are: alg-geom
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The categories of this paper are: stat
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The categories of this paper are: hep-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: ao-sci
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The categories of this paper are: nlin
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The categories of this paper are: supr-con
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: econ
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The categories of this paper are: dg-ga
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The categories of this paper are: q-bio