How does a cordless phone work?
In a cordless phone, the base is connected to the phone jack using a phone wire. The base equipment gets the signals (incoming call) via phone line, changes them to radio signals and relays them in a specific frequency range.
The handset receives the signals and covert them into electric signal and transmit them to the speaker. The speaker converts the electric signals into sound that you can hear.
Likewise, when you speak, the voice signals are converted by the base into electric signals which are transmitted over the phone line. The duplex frequency of the cordless phone allows both the incoming and outgoing voice signals to be transmitted over the line simultaneously so that you can speak and listen at the same time.
Cordless phones come with many features that resemble a standard telephone. However, the radio transmitter in a cordless phone is a major feature that you may not find in a standard telephone. In addition, the various cordless phone models come with different set of features which are explained below:
The major features like range, sound quality and security often differ from one model to another. The range indicates the maximum distance between base and the handset that allows you to use the unit comfortably. While the distance affects the sound quality, other factors like interferences like wireless devices and walls can also impact the reception of sound signals. Since you talk wirelessly, the security feature of cordless phones is also equally important as the sound signals can be intercepted by other cordless phone devices, radio scanners etc.
Radio Frequencies (RF)
There are three RF standards approved by the Federal Communications Commission (FCC) for cordless phone usage. The older 43-50 MHz is no longer used for reasons of poor sound quality and short range problems. The 900 MHz Radio Frequency range is widely used in cordless phones and provides better sound clarity and greater range. However, these signals can be intercepted by devices like radio scanners so this range is not a good option if the security is an important issue for you.
The 2.4 GHz and 5.8 GHZ cordless phones not only provide the best sound quality and longer range but also offer the best security as the signals of these bands can not be easily picked up by radio scanners or other interceptors.
Analog/Digital Technology
Analog signal processing is susceptible to interferences and also offers poor sound quality. Although cordless phones that use this technology are cheaper, the analog signals can be easily intercepted by radio scanners.
Digital phone signals provide better sound quality and are more secure as well. The new digital spread spectrum (DSS) technology transmits sound signals in various frequencies and gives the best protection to your phone conversations.
Channels
The high end cordless phones come with up to 100 channels at a frequency range of 2.4 or 5.8 GHz. This feature helps the base unit to process the sound signals more efficiently and gives you clearer and better sound quality. The 900 MHz cordless phones usually have 20 to 50 channels while the higher frequency band cordless phones come with channels between 60 and 100.
