BySheridan Hurwit 2019-06-21 1362
The walkie-talkie is a mobile radio transceiver that operates within a specific range of action. The system is quite simple. With a given frequency, your walkie-talkie emits a signal within a variable radius that can range from 1 to 10km depending on the model.
This signal allows you to instantly and continuously reach your correspondents in this radius. Your messages can be heard by all users within your transmission range except for professional walkie-talkies with personal frequency.
It should be noted that the walkie-talkie operates in hall-duplex mode, whereas mobile phones operate in full-duplex mode. That is, communication is in both directions, but not simultaneously.
Communication can be between two or more users, as long as they are within the transmission range. This is where the range comes in.
You can send and receive messages only with users in your area of use. Walkie-talkies all have a range from 1 to a few kilometres.
One thing to know is that the range is also a function of the battery power. The more powerful the battery is, the greater the range of your walkie-talkie will be.
All walkie-talkies, models with or without licenses, operate on one frequency. License-free models work with public frequency ranges accessible to all users. They can be used free of charge on the PMR 446.
But professional models have a personal frequency, guaranteeing secure communication, which is assigned by the body responsible for allocating ANFR (Agence Nationale des Fréquences) licences in France. This type of frequency is rented with a monthly or annual fee.
Each transmission frequency includes 8 channels numbered from 1 to 8. All walkie-talkie models work for a given channel on the same frequency. Whatever the brand or model, communication can be done without number constraints: as long as it is on the same channel.
Most walkie-talkie models have a CTCSS (Continuous Tone Coded Squelch System) coding created to limit interference between users transmitting on the same channel. The broadcast channels are therefore associated with a code 1 to 38, which gives a total of 304 combinations.
To communicate with each other, simply set your devices to the same channel and code. Only devices set to this combination can be in contact with you. However, a PMR set to code 0 receives all messages corresponding to its channel without worrying about the code.
Some walkie-talkie models offer additional features such as secure conversations, call identification and hands-free operation. Their user guide gives you details on how it works.
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