A cordless telephone is a combination of telephone and receiver which has two major parts such as base and handset. Base is able to convert the incoming call to an FM radio signal and broadcasts that signal. It is attached to the phone jack with a standard phone wire connection. Handset is able to convert the received radio signal to an electrical signal and sends that signal to the speaker. This operating on a frequency allows you to talk and listen at the same time.

As cordless telephone is an amalgamation of a radio transmitter or receiver and telephone, you have the following issues, such as range, sound quality and security. The range is the distance that the handset can be from the base. The distance can affect the sound quality, so as the radio signal it transmitted, and interfering structures. Security is an issue as radio signal goes over the open airways and they can be picked by other devices. To know more on cordless phones you need to know about radio frequency, analogue vs. digital technology and also the number of channels.

As cordless phone is a radio transmitter, it is operated at various radio frequencies set by Federal Communications Commission. It operates over three major frequency bands such as 43-50 MHz, which was common to early cordless telephones and 900 MHz which is the most common frequency for cordless phones that are used today. A 2.4 GHz or 5.8GHz cordless phone can operate at a greater distance and above frequencies that can be picked up by most radio scanners.

Analogue technology, which is common to cordless phones, is used in low-priced models. These analogue signals are more noisy or prone to interference with respect to sound quality, it can easily be picked up and interpreted by radio scanners. Digital signals provide more security and sounds clearer, it spreads spectrum DSS for cordless phones. It spreads the digital information in pieces over several frequencies between the receiver and the base.

The frequency band is subdivided into different increments or channels, which are capable of searching added increments to find a frequency pair that is clear from intrusion, to give better sound quality.