After nearly a century of development, the application of digital radio communication walkie-talkies has become very common, from specialized fields to ordinary consumers, from military to civilian use. It is both a specialized wireless communication tool in mobile communication and a consumer tool with consumer product characteristics that can meet people's daily life needs. The walkie-talkie is a terminal device for point-to-multipoint communication, which allows many people to communicate with each other at the same time, but only one person can speak at the same time. Compared with other communication methods, the characteristics of this communication method are: instant communication, one-to-many response, economical and practical, low operating costs, no call charges, easy to use, and also has group call broadcasting, system call and confidential call functions.
In handling emergency incidents or conducting dispatch commands, its role is irreplaceable by other communication tools. Most traditional walkie-talkies use simplex analog communication methods, and some walkie-talkies use frequency division duplex analog communication methods. Digital walkie-talkies are widely used in cluster communication, but most of them are still frequency division duplex methods. The digital radio communication system of walkie-talkies and other wireless communication tools have different market positions and are difficult to replace each other.
The talking distance of the handheld device can reach 6 kilometers in a flat and unobstructed environment, but due to the influence of obstacles such as buildings and trees, the transmission of radio waves will also be affected; similarly, some external factors will also weaken the signal of the call, changing the scope of the call. When there is network support, the talking distance of digital radio communication walkie-talkies can reach several tens of kilometers. There are several factors that affect the talking distance and effect of walkie-talkies:
The higher the output power of the transmitter, the larger the coverage range of the transmission signal. The higher the receiving sensitivity of the communication machine, the farther the communication distance. The gain of the antenna, when the antenna is matched with the machine, generally, the higher the antenna height, the stronger the receiving or transmitting ability. The antenna used in handheld walkie-talkies is generally a helical antenna, which has a smaller bandwidth and gain than other types of antennas and is more susceptible to human influence.
Environmental factors mainly include the density of paths and trees, electromagnetic interference from the environment, buildings, weather conditions, and differences in terrain. These factors and other parameters directly affect the signal strength and coverage range.
Insufficient battery power. When the battery power is insufficient, the call quality will deteriorate. In severe cases, there will be noise, affecting normal communication.
The sound quality mainly depends on the pre-emphasis and de-emphasis circuits, as well as the application of advanced speech processing circuits, speech compression and expansion circuits, and low-level expansion circuits, which have good effects on fidelity speech.
The factors that affect the talking distance and effect of digital radio communication walkie-talkies are also related to the season, with better performance in summer than in winter.