How Cordless Telephones Work ?

We have become more mobile, not only with cell phones that allow us to communication almost anywhere but also within our own homes. It’s no longer necessary to “go answer the phone.” We can have the telephone next to us no matter where we are in the home. It’s even possible to take the phone with us when we go outside. We may still have to stay within a certain distance of the phone’s “base” but cordless telephones have given us a lot of freedom.

How do we talk on the telephone when the handset isn’t connected by the familiar coiled wire of traditional phones? To answer this question we have to understand that a cordless phone is not just a telephone. It is also a radio! In other words, new cordless phones take our voice and transmit it through the air to another receiver using radio waves at a particular frequency.

If we connect the cordless phone’s base to the wall jack as we would a traditional phone, we have established the same connection to the telephone company’s system. This base takes the incoming call through the wires in the way classic phones always have. At this point the process changes dramatically. The incoming call has to be converted to a radio signal (FM) and sent out to the handset, wherever it is. This is similar to music or talk being broadcast through the air to our receiving radio sets.

The handset can pick up this signal from the base unit if it’s within a certain distance. The FM signal is converted again, to an electrical signal. Just as with any voice or music system, the signal is converted to sound waves at the speaker. We can then hear the voice from the incoming call. In the same way, we send our voice to the handset, it is converted to radio signal, picked up at the base and sent on through the telephone system. It is possible to talk and listen almost simultaneously because the cordless phone is designed to operate on duplex frequencies – frequency pairs.

In the course of the last 30 years, specific frequencies have been assigned to cordless phones. Higher frequencies in the 1990s allowed stronger signals and more range for the handset. While early phones used very low frequencies, newer phones operate on frequencies up to 2.4 gigahertz. How do cordless telephones work? Very well, thank you!

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