Cordless telephone

cordless phonecordless phonescordlessportable phonecordless telephonescordless/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
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Personal Handy-phone System

PHSPASxiaolingtong
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 receiverphone receivers
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.

George Sweigert

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

Digital Enhanced Cordless Telecommunications

DECT DECTDECT Forum
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. 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.
Cordless telephone

Base station

base stationsbaseradio 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.
Portable phone

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
2.4 GHz (2400–2500 MHz, allocated in 1998)
Cordless phones, Bluetooth devices, near field communication (NFC) devices, garage door openers, baby monitors and wireless computer networks (WiFi) all may use the ISM frequencies, although these low power emitters are not considered ISM.

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

Direct Sequence Spread SpectrumDSSSdirect sequence
There is no specific requirement for any particular transmission mode on 900, 1.9, 2.4, and 5.8, but in practice, virtually all newer 900 MHz phones are inexpensive analog models; some digital features such as DSSS and FHSS are generally available only on the higher frequencies.
Cordless phones operating in the 900 MHz, 2.4 GHz and 5.8 GHz bands

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

a802.11a802.11a/b/g
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

any lawful deviceCarterfone DecisionCarterfone ruling
Sweigert was an active proponent for directly coupling consumer electronics to the AT&T-owned telephone lines in the late 1960s (this was banned at the time; most telephones were made by Western Electric and leased to the customer by AT&T.) 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.
Cordless telephone

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.

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 lines
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 overhand off
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 roamingnational roaming
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 operatoroperator
In specialized models, base stations are maintained by a commercial mobile network operator and users subscribe to the service.

Mains electricity

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

Duplex (telecommunications)

half-duplexfull-duplexduplex
In 1966, George Sweigert submitted a patent application for a "full duplex wireless communications appartus".

Guadalcanal

Guadalcanal IslandWest GuadalcanalGuadacanal
He was awarded in June 1969 He (see below: Patents). Sweigert, a radio operator in World War II stationed at the South Pacific Islands of Guadalcanal and Bougainville, developed the full duplex concept for untrained personnel, to improve battlefield communications for senior commanders.