Telephone callwikipedia
A telephone call is a connection over a telephone network between the called party and the calling party.
telephone callcallphone callphone callsvoice callcallsvoice callingvoicecallingVoice Telephony

Mobile phone

mobile phonecell phonemobile
The call may use land line, mobile phone, satellite phone or any combination thereof.
A mobile phone, known as a cell phone in North America, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area.

Called party

called partycalleecall receiver
A telephone call is a connection over a telephone network between the called party and the calling party. When a telephone call has more than one called party it is referred to as a conference call.
The called party (in some contexts called the "B-Number") is a person who (or device that) answers a telephone call.

Telephone network

telephone networkNetwork engineeringtelephone
A telephone call is a connection over a telephone network between the called party and the calling party.
A telephone network is a telecommunications network used for telephone calls between two or more parties.

Conference call

conference callconference callsconference calling
When a telephone call has more than one called party it is referred to as a conference call.
A conference call is a telephone call in which someone talks to several people at the same time.

Calling party

calling partycallercall originator
A telephone call is a connection over a telephone network between the called party and the calling party.
The calling party (in some contexts called the "A-Number") is a person who (or device that) initiates a telephone call.

Telephone exchange

telephone exchangeexchangescentral office
Most telephone calls through the PSTN are set up using ISUP signalling messages or one of its variants between telephone exchanges to establish the end to end connection.
An exchange consists of electronic components and in older systems also human operators that interconnect (switch) telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers.

Hotline

hotlinehot linetelephone hotline
This is called a hot line or ringdown.
A hotline is a point-to-point communications link in which a call is automatically directed to the preselected destination without any additional action by the user when the end instrument goes off-hook.

ISDN User Part

ISUP
Most telephone calls through the PSTN are set up using ISUP signalling messages or one of its variants between telephone exchanges to establish the end to end connection.
The ISDN (Integrated Services Digital Network) User Part or ISUP is part of Signaling System No. 7 (SS7), which is used to set up telephone calls in the public switched telephone network (PSTN).

Dial tone

dial tonedial-tonestutter dial tone
Otherwise, the calling party is usually given a tone to indicate they should begin dialing the desired number.
It indicates that the exchange is working and is ready to initiate a telephone call.

Telephone number

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Fees depend on the provider of the service, the type of service being used (a call placed from a landline or wired telephone will have one rate, and a call placed from a mobile telephone will have a different rate) and the distance between the calling and the called parties.
A telephone number serves as an address for switching telephone calls using a system of destination code routing.

Switchboard operator

telephone operatorswitchboard operatoroperator
In some (now very rare) cases, if the calling party cannot dial calls directly, they will be connected to an operator who places the call for them.
With the development of computerized telephone dialing systems, many telephone calls which previously required a live operator can be placed automatically by the calling party without additional human intervention.

Alexander Graham Bell

Alexander Graham BellBellGraham Bell
The first telephone call was made on March 10, 1876 by Alexander Graham Bell.
In January 1915, Bell made the first ceremonial transcontinental telephone call.

Public switched telephone network

public switched telephone networkPSTNtelephone network
Calls may be placed through a public network (such as the Public Switched Telephone Network) provided by a commercial telephone company or a private network called a PBX.
Alerting another user of the desire to establish a telephone call was accomplished by whistling loudly into the transmitter until the other party heard the alert.

Flat rate

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In some circumstances, the caller pays a flat rate charge for the telephone connection and does not pay any additional charge for all calls made.
American telecommunications companies commonly offer a flat rate to residential customers for local telephone calls.

Rotary dial

rotary dialdialrotary telephone
The caller then rotary dials or presses buttons for the phone number needed to complete the call, and the call is routed to the phone which has that number.
It is used when initiating a telephone call to transmit the destination telephone number to a telephone exchange.

Collect call

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However, in some circumstances such as a reverse charge or collect call, the called party pays the cost of the call.
A collect call in Canada, Pakistan, and the United States, known as a reverse charge call in other parts of the English-speaking world, is a telephone call in which the calling party wants to place a call at the called party's expense.

Operator assistance

operator assistanceoperator-assistedperson-to-person
A special number can be dialed for operator assistance, which may be different for local vs. long-distance or international calls.
Operator assistance refers to a telephone call in which the calling party requires an operator to provide some form of assistance in completing the call.

Call-progress tone

call-progress tonetonesNumber unobtainable tone
Preceding, during, and after a traditional telephone call is placed, certain tones signify the progress and status of the telephone call:
In telephony, call progress tones are audible tones that provide an indication of the status of a telephone call to the user.

Ringing tone

ringback toneringing toneringback tones
Audible ringing (ringing tone, colloquially also ringback tone) is a signaling tone in telecommunication that is heard by the originator of a telephone call while the destination terminal is alerting the receiving party.

Skype

SkypeSkypingSkypes
Voice over IP technology allows calls to be made through a PC, using a service like Skype.
Voice chat allows telephone calls between pairs of users and conference calling and uses a proprietary audio codec.

Telephone phobia

Telephone phobia (telephonophobia, telephobia, phone phobia) is reluctance or fear of making or taking phone calls, literally, "fear of telephones".

Busy signal

busy signalengaged tonebusy
A busy signal (or busy tone or engaged tone) in telephony is an audible or visual signal to the calling party that indicates failure to complete the requested connection of that particular telephone call.

Call completion

There are several possible factors which can prevent a telephone call from connecting successfully:

Local call

local calllocal phone calls
Some types of calls are not charged, such as local calls (and internal calls) dialed directly by a telephone subscriber in Canada, the United States, Hong Kong, United Kingdom, Ireland or New Zealand (Residential subscribers only).