Microwave attenuation of two-way radio according to building material and smoke in disaster environments.

Abstract

Disaster environments, such as fires, distort of two-way radio communication within buildings. This article presents an experimental study on microwave attenuation based on the smoke and wall type in a disaster environment using a two-way radio with digital mobile radio communication, widely used by firefighting crews in Korea. Furthermore, we compared the microwave attenuation of the two-way radio depending on the building materials and smoke. We then present the experimental result of the microwave characteristic corresponding to the four types of walls in a specially designed anechoic chamber (3 m × 1 m × 1 m) to analyze the microwave attenuation by the building materials, with results indicating up to 82% in 200 mm thick concrete. Moreover, we evaluated the propagation attenuation based on the four types of smoke with the same density in a container space (5.8 m × 2.8 m × 2.2 m). The results showed that the microwaves were not transmitted and significantly decreased based on the building materials at 400 MHz, which is the main cause of attenuation. It shows a property of up to 36% reduction in urethane. Although the attenuation of microwaves is not significantly large according to the fuels in smoke, fuels such as urethane, plastic, and rubber have relatively small attenuation of microwaves compared to wood, and the received power corresponding to urethane in smoke decreased the most.