Wireless phone systems
The word 'wireless' originally referred to the radiotelegraph, which transmitted telegraphic messages using radio waves in the air.
However, with the introduction of new technologies, its meaning has changed. ‘Wireless’ now commonly refers to methods of communications without wires such as mobile phone networks and wireless internet connections.
Today the term 'wireless phone system' refers to any phone system that uses radio waves. This includes mobile phone systems as well as cordless phones.
What is a cordless phone?
A cordless telephone is a combination of a telephone, and a radio transmitter and receiver.
It consists of two basic parts; a base unit attached to the telephone landline, and a mobile handset that is wirelessly connected to the base unit. The handset allows people to walk around freely within radio range of the base unit while having a conversation on the phone.
Here’s what happens when a friend calls your cordless phone:
- The base unit receives the incoming phone call as an electrical signal from the telephone wire
- It converts the signal into an FM radio signal and broadcasts it
- The handset received the FM radio signal, converts it back into an electrical signal and sends it to the speaker
- When you answer the handset transmits your voice using a second FM radio signal back to the base unit
- The base converts this into an electrical signal and sends that along the telephone wire to your friend, who hears it as your speech.
Because there are two FM radio signals used, at slightly different frequencies, both people having the conversation are able to talk and listen at the same time.