Digital enhanced cordless telecommunications facts for kids

Kids Encyclopedia Facts

Quick facts for kids
DECT
Digital enhanced cordless telecommunications
Gigaset A165 phone with base station. In DECT terminology, the phone is the 'portable part' (PP) and the base station the 'fixed part' (FP)
Abbreviation	DECT
Organization	ETSI, DECT Forum
Domain	Cordless telephony

Digital Enhanced Cordless Telecommunications (DECT) is a special way for phones to talk to each other without wires. It's like a secret language that cordless phones use. This standard was created in Europe by a group called ETSI.

DECT became very popular in Europe, replacing older systems. It's also used in many countries in Asia, Australia, and South America. In North America (like the United States and Canada), they use a slightly different version called DECT 6.0. This means a DECT phone from Europe won't work with a DECT 6.0 base station from North America.

DECT was first designed for phones that could move between different signal areas. But it became most famous for home cordless phones. You know, the ones where you have a phone that you can carry around your house. It's also used in offices for bigger phone systems.

Besides phones, DECT technology is used in other cool gadgets. It helps baby monitors work and connects industrial sensors. There's even a special version called DECT Ultra Low Energy (DECT ULE). This version is great for smart home devices like security systems and automation.

Most DECT devices follow a common rulebook called Generic Access Profile (GAP). This means you can often use a DECT phone from one company with a DECT base station from another. They will still be able to make and receive calls. Japan has its own version called J-DECT.

Newer DECT phones use something called New Generation DECT (NG-DECT). This is also known as CAT-iq. It lets phones have more advanced features. For example, it allows for clearer sound, like "HD Voice." It also helps different brands of phones and base stations work together even better.

There's also a brand new version called DECT-2020 New Radio, or NR+. This is a super-fast way to send data. It's designed for things like the IoT and can work alongside older DECT devices.

How DECT Started
What DECT is Used For
How DECT Works
Special DECT Versions
Health and Safety
Images for kids
See also

How DECT Started

The DECT standard was created by ETSI. They started working on it in 1988, and the first rules came out in 1992. These rules explained how the wireless parts of the phones should talk to each other.

At first, DECT stood for "Digital European Cordless Telephone." But soon, they changed "Telephone" to "Telecommunications." This was to show that it could do more than just phone calls, like send data. Later, in 1995, because it was used all over the world, "European" was changed to "Enhanced."

The ITU (International Telecommunication Union) even recognized DECT as a type of 3G system. This means it's a powerful wireless technology.

The main DECT frequency band is 1880–1900 MHz. This is used in Europe and many other parts of the world. In the United States, the rules changed in 2005. This allowed DECT phones to be sold there using a slightly different frequency band (1920–1930 MHz). These special channels are just for voice calls. This helps stop interference from other wireless devices, like Wi-Fi or baby monitors.

The NG-DECT standard (CAT-iq) came out in 2007. It was made to help DECT work better with VoIP (Voice over Internet Protocol) systems. This means you can use DECT phones with internet-based phone services.

In 2011, DECT Ultra Low Energy (DECT ULE) was announced. This version uses very little power, so batteries last a long time. It's perfect for home automation and security devices. It uses the same 1.9 GHz band, so it avoids interference from things like microwave ovens.

A new way to handle sound, called LC3plus, was added to DECT in 2019. This makes voice and music sound even better. It can handle different sound qualities, from basic voice to high-quality music.

The DECT-2020 New Radio protocol came out in 2020. It's super fast, allowing data speeds up to 1.2 gigabits per second. It can use multiple antennas and has better ways to handle signals. This new protocol is great for industrial robots and professional wireless audio systems. It's also known as NR+.

What DECT is Used For

DECT was first planned for three main uses:

Home cordless phones: This is where DECT has been super successful. Most homes with a landline phone use DECT cordless phones.
Office phone systems: Many businesses use DECT for their internal phone systems. This lets employees move around the office while staying on a call.
Public access: This idea didn't work out. It was meant for large public areas, but mobile phones became much more popular.

DECT has also been used in some countries to provide phone service to homes far away. It's like a wireless "last mile" connection instead of using copper wires.

Early on, DECT was even used for wireless internet, like Olivetti's Net³ system. It was a bit like an early version of Wi-Fi. But then Wi-Fi and mobile internet (like 3G and 4G) became much faster and more common. So, DECT mainly stuck to being great for cordless phones.

How DECT Works

DECT lets a portable phone (the handset you carry) connect to a regular phone network using radio waves. A base station (the part that plugs into the wall) handles the radio connection. This base station then connects to your phone line, office phone system, or internet phone service.

A typical DECT system for your home lets you use several cordless phones with just one phone line. You can put phones in different rooms. Extra phones usually just need a charger, not another phone jack. Many DECT phones can also work like an intercom, letting you talk between handsets.

DECT uses a specific radio frequency band, usually 1880–1900 MHz. It divides this radio space into 10 frequency channels. Then, each channel is divided into 24 time slots. This means many calls can happen at the same time without interfering with each other.

DECT is very good at avoiding interference. It usually works well even when there are other wireless devices around. This includes Wi-Fi, Bluetooth, and other cordless phones.

Technical Details

This picture shows how a DECT phone sends out short bursts of radio signals.

DECT phones use special ways to turn your voice into digital signals. They use something called G.726 ADPCM for regular calls. For clearer, "wideband" calls, they use G.722.

The most common frequencies for DECT are:

1880–1900 MHz in Europe, Asia, Australia, and New Zealand.
1920–1930 MHz (DECT 6.0) in the United States and Canada.

DECT devices are smart about finding the best channel. If a channel has too much interference, the phone can switch to a clearer one. This helps keep your calls clear.

The maximum power for DECT devices is 250 mW. But a portable phone only sends out about 10 mW on average during a call. This is because it only transmits in short bursts.

How Calls are Protected

DECT has ways to keep your calls private and secure. When you connect a new phone to a base station, they share a special secret code. This code helps them make sure they are talking to the right device.

DECT also uses encryption to scramble your voice. This makes it hard for someone to listen in on your calls. The encryption uses a 64-bit code.

However, some older DECT phones didn't always use these security features. In 2008, some experts found ways to break the encryption on older systems. Because of this, newer DECT systems (NG-DECT/CAT-iq) have much stronger security. They use a more advanced 128-bit encryption method.

The DECT Forum also has a security program. This program makes sure that new DECT devices use these stronger security features.

DECT Profiles

DECT has different "profiles" or rulebooks for how devices should work together. The most common one is the Generic Access Profile (GAP). This profile makes sure that basic phone functions work between different brands.

Other profiles exist for things like:

Connecting to office phone systems (PABXs).
Sending data, like for wireless internet (though this is less common now).
Connecting to other phone networks, like ISDN or GSM.

Special DECT Versions

DECT 6.0

DECT 6.0 is the name for DECT phones sold in North America (USA and Canada). The "6.0" doesn't mean it's a faster version. It's just a marketing name. It uses a slightly different frequency band (1.9 GHz) than DECT in Europe.

Because of these differences, DECT 6.0 phones from North America will not work in Europe. And European DECT phones will not work in North America. Using the wrong type of phone can cause problems with local mobile phone networks.

There's also a marketing term called DECT 8.0 HD. This means the phone has the newer CAT-iq 2.0 features for better sound and more options.

NG-DECT/CAT-iq

CAT-iq stands for Cordless Advanced Technology—internet and quality. It's a special certification program for DECT phones. It's based on the New Generation DECT (NG-DECT) standards.

CAT-iq adds many cool features to regular DECT phones. It makes sure phones have:

High-quality sound: This is called "HD Voice."
Better security: Stronger ways to protect your calls.
Caller ID: Showing who is calling.
Multiple lines: Handling several phone lines at once.
Advanced call features: Like call waiting, call transfer, and phonebooks.

CAT-iq helps different brands of DECT phones and base stations work together perfectly. This is especially useful for phones that connect to internet-based phone services (VoIP).

DECT-2020

DECT-2020, also known as NR+, is a very new DECT standard. It's designed to meet some of the requirements for 5G technology. It's perfect for the IoT and industrial uses.

DECT-2020 NR has many new abilities:

It works better when signals bounce off walls or objects.
It's better at resisting interference from other radio signals.
It uses the radio space more efficiently.
It can create a mesh network, where devices talk directly to each other.

This new standard is made to work alongside older DECT devices. It uses smart ways to avoid causing problems with existing DECT systems.

Health and Safety

DECT phones use UHF radio waves. These are similar to the waves used by mobile phones, Wi-Fi, and baby monitors.

In Europe, DECT phones can transmit at an average power of 10 mW. But they send out short bursts of power up to 250 mW. This is similar to some mobile phones. In North America, the average power is lower, at 4 mW.

Most studies have not found clear links between DECT phone use and health problems. However, some groups say that more research is needed to understand any long-term effects.

Images for kids

Gigaset A165 phone with base station. In DECT terminology, the phone is the 'portable part' (PP) and the base station the 'fixed part' (FP)
This picture shows how a DECT phone sends out short bursts of radio signals.