Cordless telephone

cordless phonecordless phonescordless telephonescordlessportable phonecordless/portable phonesportable telephoneportable telephones
A cordless telephone or portable telephone is a telephone in which the handset is portable and communicates with the body of the phone by radio, instead of being attached by a cord.wikipedia
156 Related Articles

Personal Handy-phone System

PHSPersonal Access SystemXiaolingtong
Current cordless telephone standards, such as PHS and DECT, have blurred the once clear-cut line between cordless and mobile telephones by implementing cell handoff (handover); various advanced features, such as data-transfer; and even, on a limited scale, international roaming.
PHS is essentially a cordless telephone like DECT, with the capability to handover from one cell to another.

Handset

telephone handsethandset receiverreceiver
A cordless telephone or portable telephone is a telephone in which the handset is portable and communicates with the body of the phone by radio, instead of being attached by a cord.
Until the advent of the cordless telephone, the handset was usually wired to the base unit, typically by a flexible tinsel wire.

Radio

radio communicationradio communicationswireless
A cordless telephone or portable telephone is a telephone in which the handset is portable and communicates with the body of the phone by radio, instead of being attached by a cord.
Exceptions to the above rules allow the unlicensed operation by the public of low power short range transmitters in consumer products such as cell phones, cordless phones, wireless devices, walkie-talkies, citizens band radios, wireless microphones, garage door openers, and baby monitors.

George Sweigert

In 1966, George Sweigert submitted a patent application for a "full duplex wireless communications apparatus".
George H. Sweigert (1920–1999) is credited as the first inventor to patent the cordless telephone.

Digital Enhanced Cordless Telecommunications

DECTDECT 6.0DECT Standard Cipher
Current cordless telephone standards, such as PHS and DECT, have blurred the once clear-cut line between cordless and mobile telephones by implementing cell handoff (handover); various advanced features, such as data-transfer; and even, on a limited scale, international roaming. The newer 1.9 GHz band is reserved for use by phones that use the DECT standard, which should avoid interference issues that are increasingly being seen in the unlicensed 900 MHz, 2.4 GHz, and 5.8 GHz bands. There is no specific requirement for any particular transmission mode on 1.9, 2.4, and 5.8, but in practice, they have digital features such as DSSS, FHSS, and DECT. These most commonly use digital technologies like DECT, 2.4 GHz unlicensed spectrum, or 802.11a/b/g standards-based wireless LAN technology.
Digital Enhanced Cordless Telecommunications (Digital European Cordless Telecommunications), usually known by the acronym DECT, is a standard primarily used for creating cordless telephone systems.

Telephone

phonetelephonesLocal Telephone Service
A cordless telephone or portable telephone is a telephone in which the handset is portable and communicates with the body of the phone by radio, instead of being attached by a cord.

Base station

base stationsWireless base stationradio base station
The base station is connected to the telephone network through a telephone line as a corded telephone is, and also serves as a charger to charge the handset's batteries.

Baby monitor

baby monitorsbaby-monitoring devicesinfant monitor
These phones share the 49.8 MHz band (49.830 - 49.890) with some wireless baby monitors.
While these frequencies are not assigned to powerful television or radio broadcasting transmitters, interference from other wireless devices such as cordless telephones, wireless toys, computer wireless networks, radar, Smart Power Meters and microwave ovens is possible.

ISM band

ISM2.4 GHz13.56 MHz
The newer 1.9 GHz band is reserved for use by phones that use the DECT standard, which should avoid interference issues that are increasingly being seen in the unlicensed 900 MHz, 2.4 GHz, and 5.8 GHz bands.
Cordless phones, Bluetooth devices, near field communication (NFC) devices, garage door openers, baby monitors and wireless computer networks (WiFi) may all use the ISM frequencies, although these low power transmitters are not considered to be ISM devices.

Landline

Fixed linefixed-lineland line
"Plain old telephone service" (POTS) landlines are designed to transfer audio with a quality that is just adequate for the parties to understand each other.
A fixed phone line (a line that is not a mobile phone line) can be hard-wired or cordless and typically refers to the operation of wireless devices or systems in fixed locations such as homes.

Direct-sequence spread spectrum

DSSSDirect Sequence Spread SpectrumDS-CDMA
There is no specific requirement for any particular transmission mode on 1.9, 2.4, and 5.8, but in practice, they have digital features such as DSSS, FHSS, and DECT.

IEEE 802.11

802.11802.11b/g/n802.11b/g
These most commonly use digital technologies like DECT, 2.4 GHz unlicensed spectrum, or 802.11a/b/g standards-based wireless LAN technology.
Because of this choice of frequency band, 802.11b/g/n equipment may occasionally suffer interference in the 2.4 GHz band from microwave ovens, cordless telephones, and Bluetooth devices etc. 802.11b and 802.11g control their interference and susceptibility to interference by using direct-sequence spread spectrum (DSSS) and orthogonal frequency-division multiplexing (OFDM) signaling methods, respectively.

Antenna (radio)

antennaantennasradio antenna
Practical influences on quality and range are signal strength, antenna quality, the method of modulation used, and interference, which varies locally.
An example of a low-gain antenna is the whip antenna found on portable radios and cordless phones.

IEEE 802.11a-1999

a802.11aIEEE 802.11a
It is also possible for a cordless phone to interfere with the 802.11a wireless standard, as the 802.11a standard can be configured to operate in the 5.8 GHz range.
The increased number of usable channels (4 to 8 times as many in FCC countries) and the near absence of other interfering systems (microwave ovens, cordless phones, baby monitors) give 802.11a significant aggregate bandwidth and reliability advantages over 802.11b/g.

Radio scanner

scannerpolice scannerscanners
Many analog phone signals are easily picked up by radio scanners, allowing anyone within range to listen in on conversations (though this is illegal in many countries).
There are Canadian and European unblocked versions available, but these are illegal to import into the U.S. Frequencies used by early cordless phones at 43.720–44.480 MHz, 46.610–46.930 MHz, and 902.000–906.000 MHz can be picked up by many scanners.

Carterfone

Carterfone decisionCarterphoneCarterphone decision
The Carterfone coupler, a crude device for interconnecting a two-way radio with the telephone, led to the reversal of the Federal Communications Commission ban on direct coupling of consumer equipment to phone lines (known as the landmark Carterfone decision) on June 26, 1968.

Telephone network

Network engineeringtelephonefixed and mobile networks
The base station is connected to the telephone network through a telephone line as a corded telephone is, and also serves as a charger to charge the handset's batteries.

Telephone line

phone linelinetelephone cable
The base station is connected to the telephone network through a telephone line as a corded telephone is, and also serves as a charger to charge the handset's batteries.

Rechargeable battery

rechargeablerechargeable batteriesstorage batteries
The base station is connected to the telephone network through a telephone line as a corded telephone is, and also serves as a charger to charge the handset's batteries.

Handover

handoffhanded offhanded over
Current cordless telephone standards, such as PHS and DECT, have blurred the once clear-cut line between cordless and mobile telephones by implementing cell handoff (handover); various advanced features, such as data-transfer; and even, on a limited scale, international roaming.

Roaming

roaminternational roamingroaming charges
Current cordless telephone standards, such as PHS and DECT, have blurred the once clear-cut line between cordless and mobile telephones by implementing cell handoff (handover); various advanced features, such as data-transfer; and even, on a limited scale, international roaming.

Mobile network operator

wireless carriernetwork operatorMNO
In specialized models, base stations are maintained by a commercial mobile network operator and users subscribe to the service.

Mains electricity

mainsmains powerelectricity supply
Unlike a corded telephone, a cordless telephone needs mains electricity to power the base station.

Mobile Telephone Service

MTSLimited capacity Mobile Telephone Service for automobilesMobile Service
The first, MTS, or Mobile Telephone Service went into service in 1946.

Improved Mobile Telephone Service

IMTSIMTS frequenciesIMTS, or Improved Mobile Telephone Service
The second generation radio telephone, or IMTS, or Improved Mobile Telephone Service became active in 1964.