### Question
What is the definition of propagation model?


### Answer
The definition of **propagation model** is as follows in *47 U.S.C. § 641*:

> a mathematical formulation for the characterization of radio wave propagation as a function of frequency, distance, and other conditions

#### Citation:
  - *47 U.S.C. § 641*
  - Heading: **CHAPTER 5-WIRE OR RADIO COMMUNICATION > SUBCHAPTER VII-BROADBAND DATA**

