Popular Products > Electronics > Cordless Phone

A telephone that uses an antenna and radio signals to make and receive calls instead of a cord is called a cordless phone. A cordless phone consists of two main components: namely, a base station or unit that is connected to a fixed telephone line and a wireless handset that can be used anywhere in the house or garden.

The first cordless phone was invented by Teri Pall, a jazz singer, in 1965. It was a low frequency (45–50MHz) phone that covered a very limited area. George Sweigert, an American radio operator during the Second World War in Cleveland, Ohio, made advancements to this technology. Sweigert had applied for a patent in 1966 to the US Patent and Trademark Office, and he was awarded this patent in 1969. He developed the device in order to enhance communication in the battlefield while he was stationed on the South Pacific Islands.

Cordless phones were introduced into the consumer market in the 1980s. Sony was initially one of the leading manufacturers of cordless phones. However, these early phones had static problems and interfered with other signals allowing you to listen to a neighbour’s conversation. The Federal Communications Commission (FCC), a US government agency, granted permission to manufacture 900MHz frequency band phones to companies only in 1994. A frequency band of 900MHz was ideal to minimise static caused by walls, appliances and signal interference by other objects.

This move by the government triggered an upsurge in the demand and supply of cordless phones. High quality sound output was available but some phones were still prone to eavesdropping. The FCC soon allowed manufacturers to make phones with frequencies of 2.4GHz and 5.8GHz, a standard frequency band used by cordless phones today.

Some cordless phones also use the 1.9GHz band, a band reserved for voice applications, enabling them to operate in a different frequency band than Wi-Fi networks, Bluetooth, baby monitors, and other similar wireless devices. This eliminates interference with other devices.

Previously, analogue standard was used for cordless phones, but most cordless phones today work on the Digitally Enhanced Cordless Telecommunication (DECT) standard. The basic features of cordless phones include an answering machine, a speaker facility, a phonebook that can store more than a hundred numbers, an alarm and a reminder, and a caller ID and SMS facility.

Some high-end cordless phones have a VoIP (Voice over Internet Protocol) service such as Skype. They come with an Ethernet port that can be connected to a base station and your home/office Internet network. This allows you to make free and unlimited Skype-to-Skype calls anywhere in the world. Panasonic, Sony, AT&T, NetGear, British Telecom, Philips and Vtech are some of the most popular manufacturers of cordless phones.