There are different types of cordless phones that enable an individual with more mobility than talking over telephone. They use radio waves, not wires to transmit conversations from handset to a base unit. The following are the different types of cordless phones in the market:
 
2.4 GHz /900 MHz Digital Spread Spectrum Cordless: The new technology adopted in this system, separate your signals into various frequencies, to free them from interference. It has channel – scanning of spread spectrum to present best reception.
 
900 MHz Digital Cordless:   If you do not require the high quality spread spectrum phone, but still want the benefits of 900 MHz, you can go for a digital 900 MHz cordless. It was originally intended for military, but currently it is presented for common use.
 
900 MHz Analogue Cordless: This model is comparatively cheaper. It does not have digital signal enhancement, but it is sufficient for a small office.
 
46 / 49 MHz Cordless: This is a standard model in use for many years and is adequate for homes and small office.
 
Separate Data Port : If you have a home office, with a separate data port you are able to share a phone jack by plugging your computer or fax machine directly into the phone.
  
The Latest Technology: 5.8 GHz is based on the latest technology. But this model is not freely available in the market. Foremost players in the market release them to show their unique designs.  Therefore 2.4.GHz units dominate the cordless phone market.
 
5.8 GHz Digital: This is the most expensive cordless phone.
 
Difference between Analogue and Digital

The Analogue phones are noisy, susceptible to fading and interference. But digital phones are more secure and have wider range, and free from interference.
 
Range: The range of a cordless phone depends upon the environment in which it is used. Audibility will be better in places where interference from electrical and electronic equipments is less. Range also will be affected by the position of the base stations and antenna. Physical barriers such as walls or even climatic conditions can affect the range. However, choose a cordless phone in terms of its range.
 
900 MHz phones will provide improved coverage than the older model 46 / 49 MHz analogue phones. The latest 2.4 GHz phones will give you better range.
 
2.4 GHz digital phones are based on digital spread spectrum technology (DSS). The DSS handsets will indicate the frequency and spreading code.
 
Power Output: 0.001 watt for 43 – 50 MHz phones. 1 watt for DSS phones in MHz and 2.4 GHz.  And less for non DSS phones in 900 MHz band.
 
A safe Option: 43 – 50 MHz phones can be pulled out on radio scanners and 900 MHz on industrial radio scanners.  But it is impossible to listen in on DSS digitals.
 
Additional features of cordless phones:

1.      Out of range indicator
2.      High or low volume control
3.      Paging / talking from base unit to handset
4.      Dial pad and speaker phone on base unit
5.      Caller ID
 
Where to keep:   The phone can be mounted on the wall if there are children who meddle with phones or to save space on your tabletop. It may be mounted in the corridors/passage for easy accessibility to all.

Cordless telephones are electronic devices with radio frequency technology. It avoids interference problems and eavesdropping. The cordless phone is available with frequency bands, such as 1.7 MHz, 46 MHz to 47 MHz, 902 MHz to 928 MHz, 2.7 GHz.

In earlier days, analogue cordless phones were used and they used 1.7 MHz frequency band, above the AM broadcast band. It is susceptible to interference from luminous lights.

Bands of 46 MHz to 47 MHz has huge installed base of analogue models. Some of the cordless phones use audio inversion for scrambling. This model chains low-powered walkie-talkies and baby monitors that share the same frequency bands. Unscrambled models are very easily heard by virtually any radio scanner. It provides better audio frequencies with radio scanner.

Models with 902 MHz to 928 MHz band is well known for its use of shorter, non-telescoping antennas. The models cannot be heard by radio scanner with Digital Spread Spectrum (DSS). And the rest analogue models are easy to pick up as it is less crowed than 46 to 47 MHz band. In the technology of cordless telephone you can enjoy 80 channels. A model with 2.7 GHz is the latest cordless phone. To ensure privacy it is available with radio scanner to cover this band and digital spread spectrum with analogue.

When you go to shop for cordless phone, prefer to buy a new cordless phone with 900 MHz or 2.7 GHz band technology. 5.8 GHz digital spread spectrum adopted by FCC which offers improved reception, clarity, range and security over 2.4 GHz. 5.8 GHz frequency bands can incorporate the channel-scanning of spread spectrum to provide you the best response accessible in a cordless phone. 2.4 GHz technology will separate your signal into two different frequencies that makes it free of interference. Spread spectrum cordless is able to spread signal over several frequencies rather than locking onto one.

You can prefer for 900 MHz frequency band cordless phone even if you don't need a top-of-the-line spread spectrum phone. This technology provides clearer signal than 46 or 49 MHz analogue cordless phones. Buying this model you can also save some money. But cordless phone with 46 to 49 MHz frequency bands are good for home use or quiet office.

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.