PSTN network topology

A PSTN network topology is the switching network topology of a telephone network connected to the public switched telephone network (PSTN). In the United States and Canada, the Bell System network topology was the switching system hierarchy implemented and operated from the late 1940s to the 1980s for the purpose of integrating the diverse array of local telephone companies and telephone numbering plans to achieve nationwide Direct Distance Dialing (DDD) by telephone subscribers. It was the precursor of the world-wide interconnected public switched telephone network (PSTN).

Area codes 450 and 579

450 and 579450450, 579
Area codes 450 and 579 are telephone area codes in the Canadian province of Quebec, encompassing the off-island suburbs of Montreal, which is served by area codes 514 and 438. Among the cities served by area code 450 are Longueuil and Laval. The communities of Ormstown, Huntingdon, Boucherville, Varennes, Roussillon, Joliette, Saint-Hyacinthe, Granby, Chambly, Saint-Jean-sur-Richelieu and Vaudreuil-Dorion are also part of this area code.

Texts From Last Night

The texts are sent in by people who wake in the morning "to find regrettable messages sent to or from their mobile phones". The receiver then sends the allegedly discovered text into this website. The copies of the messages do not show the phone numbers, but only area codes. Since the texts are often similar to late night drunk dials, they're often graphic and sexual in nature, thus not safe for work. From a sociological perspective, the website is a "living document of twentysomething life in 2009". While TFLN has many "blackout drinking, sex, and vomit stories", there is also an extended discussion taking place about morality. The texts show how humans "interact with drugs and alcohol".

Intelligent Network

intelligent networkINIntelligent Network (IN)
It allows operators to differentiate themselves by providing value-added services in addition to the standard telecom services such as PSTN, ISDN on fixed networks, and GSM services on mobile phones or other mobile devices. The intelligence is provided by network nodes on the service layer, distinct from the switching layer of the core network, as opposed to solutions based on intelligence in the core switches or equipment. The IN nodes are typically owned by telecommunications service providers such as a telephone company or mobile phone operator. IN is supported by the Signaling System #7 (SS7) protocol between network switching centers and other network nodes owned by network operators.

Area code 770

770area code 770770; 404; 678
Currently, cell phone subscribers in the region can choose from either the 770 or 470 area code when signing up for service. When the area was originally divided in 1995, most cellphones stayed with 404, which balanced the fact that most of the landline area went to 770. Atlanta was the first city in the United States to have mandatory 10-digit dialing throughout its metro area, roughly coinciding with the 1996 Summer Olympics in Atlanta.


3-1-13113-1-1 system
This area code is also used as the area code for Sunnyvale, California (which is actually 408) in the 1983 movie WarGames during the "war dialing" sequence where the main character is searching for a video game company's modem pool. 311-555-3305 was used in a 1973 episode of "Search" Season 1, Episode 20 "Moments of Madness" as the phone number for the lair of kidnapper Ralph Byron (played by Patrick O'Neal). 3-1-1 service is generally implemented at the local level, and in some cities, it is also used for various municipal calls.

Mobile-to-mobile convergence

The term mobile to mobile calling is used in many mobile phone plans to refer to making calls to other mobile phones using the same provider's network--which is often cheaper than other calls. Mobile to mobile convergence (MMC) is a term to describe a technology used in modern computing and telephony. The term is an offshoot of fixed mobile convergence (FMC) and uses dual mode (cellular network and WiFi) phones with a special software client and an application server to connect voice calls and business applications via a VoWLAN and/or through a cellular service.

Communications in Iran

Technology start-ups in Irancommunicatione-commerce
Iran's national Internet connectivity infrastructure is based on two major networks: the public switched telephone network (PSTN) and the public data network. The PSTN provides a connection for end-users to Internet service providers (ISPs) over mostly digital lines and supports modem-based connections. The Data Communication Company of Iran (DCI), a subsidiary of TCI, operates the public data network. Iran's external Internet links use the basic Internet protocol of TCP/IP (transmission control protocol/Internet protocol) via satellite exclusively.

Asynchronous transfer mode

ATMasynchronous transfer modeAsynchronous Transfer Mode (ATM)
ATM is a core protocol used over the SONET/SDH backbone of the public switched telephone network (PSTN) and Integrated Services Digital Network (ISDN), but its use is declining in favour of all IP. ATM provides functionality that is similar to both circuit switching and packet switching networks: ATM uses asynchronous time-division multiplexing, and encodes data into small, fixed-sized packets (ISO-OSI frames) called cells. This differs from approaches such as the Internet Protocol or Ethernet that use variable sized packets and frames. ATM uses a connection-oriented model in which a virtual circuit must be established between two endpoints before the actual data exchange begins.

Remote concentrator

remote concentratorconcentration
In modern telephony a remote concentrator, remote concentrator unit (RCU), or remote line concentrator (RLC) is a concentrator at the lowest level in the telephone switch hierarchy. Subscribers' analogue telephone/PSTN lines are terminated on concentrators. They have three main functions, namely: * Digitize, that is, turn voice, and sometimes data, from analogue into a digital form. * Connect off-hook lines through to the local exchange — the concentration function. * Multiplex, interleaving many calls together on a single wire or optical fiber. Only a few hundred telephone lines attach to each remote concentrator.

Split plan

split plansplit
In telephony, a split plan is the practice of introducing a new area code by dividing an existing area code's territory and applying the new area code to one of the resulting divisions, replacing the existing area code within that section. Split plans are used as growth in demand for telephone numbers (due to the increase in use of pagers, fax machines, and cellular phones) require new area codes in increasingly densely populated areas.

Telecommunications in Belgium

Belgium is under a closed telephone numbering plan, but retains the trunk code, "0", for all national dialling. There were 4.668 million land telephone lines in use in Belgium in 2007, a slight decrease on the 4.769 million in use in 1997. The majority state-owned public telephone company of Belgium is Proximus. Some other or private operators exist, as Scarlet (Proximus) and Base (KPN). Mobile telephone ownership has increased by nearly one thousand percent in the period 1997-2007, from 974,494 to 10.23 million.


IPKall was a public switched telephone network to voice over IP call forwarding service. Users were able to register with the service to obtain a phone number chosen from several Washington State area codes and have all calls to that number forwarded to their Session Initiation Protocol or Inter-Asterisk eXchange uniform resource identifier, including an Asterisk server. The telephone company that provided IPKall numbers is International Telcom; they also provide a flat-rate $1/month area code 206 inbound fax service as Faxaway, a non-free voice and fax service as Kall8 (with toll-free or US local numbers) and the Kallback and KallCents discount outbound long-distance services.

Origination (telephony)

Origination in VOIP telephony refers to calls that originate in the PSTN public switched telephone network and are carried to their destination over the Internet. A VoIP call is initiated between two points, the initiation point is known as originator and the destination point is known as terminator. An Internet Telephony Service Provider (ITSP) involved in the origination of telephone calls usually offers either or both of “PC to Phone calls” and “Phone to Phone calls”. The two major business models for VoIP Originator are “Prepaid” and “Postpaid”. Hardware requirements for VoIP origination are simple.

Cable telephony

cable telephonycable telephoneDigital telephone
Cable telephony is a form of digital telephony over cable TV networks. A telephone interface installed at the customer's premises converts analog signals from the customer's in-home wiring to a digital signal, which is then sent over the cable connection to the company's switching center. The signal is then sent on to the public switched telephone network (PSTN). Cable telephone provides another revenue stream for cable television system operators and gives the consumer the convenience of a single bill for combined television, internet and telephone services. The biggest obstacle to cable telephone service is the need for nearly 100% reliable service for emergency calls.

Public land mobile network

public land mobile networkPLMNmobile phone network
Access to PLMN services is achieved by means of an air interface involving radio communications between mobile phones or other wireless enabled user equipment and land-based radio transmitters or radio base stations or even fiber optic distributed SDH network between mobile base stations and central stations via SDH equipment (ADMs) with integrated IP network services. Public Land Mobile Networks need to connect to the Public Switched Telephone Network (PSTN) in order to route calls.

Rate center

rate centerrate centre
In the North American Numbering Plan, a rate center is a geographically-specified area used for determining mileage and/or usage dependent rates in the public switched telephone network. Unlike a wire center (which is the actual physical telephone exchange building), a rate center is a regulatory construct created primarily for billing purposes.

Local call

local calllocal phone calls
In telephony, the term local call has the following meanings: * 1) Any call using a single switching center; that is, not traveling to another telephone network; * 2) A call made within a local calling area as defined by the local exchange carrier; * 3) Any call for which an additional charge, i.e., toll charge, is not billed to the calling or called party, or (depending on the country) for which this charge is reduced because it is a short-distance call (e.g. within a town or local metropolitan area). Typically, local calls have shorter numbers than long distance calls, as the area code may not be required.

Mobile Telephone Switching Office

Its subordinate BSC/RNC are responsible for assigning frequencies to each call, reassigning frequencies for handoffs, controlling handoffs so a mobile phone leaving one cell (formally known as BTS)'s coverage area, can be switched automatically to a channel in the next cell. All cellular systems have at least one MTSO which will contain at least one MSC. The MSC is responsible for switching calls to mobile units as well as to the local telephone system, recording billing data and processing data from the cell site controllers. The MSC is connected to a close telephone exchange by a trunk group. This provides an interface to the (Public Switched Telephone Network) (PSTN).


OptusCable and Wireless OptusSingTel/Optus
The long distance calling rates on offer were initially available by consumers dialing 1 before the area code and phone number. Following this, a ballot process was conducted by then regulator AUSTEL, with customers choosing their default long distance carrier. Customers who made no choice or refused to respond to the mailout campaign automatically remained as a Telstra long distance customer. Customers who remained with Telstra could dial the override code of 1456 before the area code and phone number to manually select Optus as the carrier for that single call.

Terrestrial Trunked Radio

TETRATETRA radio systemTETRA radio
TETRA terminals can act as mobile phones (cell phones), with a full-duplex direct connection to other TETRA Users or the PSTN. Emergency buttons, provided on the terminals, enable the users to transmit emergency signals, to the dispatcher, overriding any other activity taking place at the same time. The main advantages of TETRA over other technologies (such as GSM) are: * The much lower frequency used gives longer range, which in turn permits very high levels of geographic coverage with a smaller number of transmitters, thus cutting infrastructure costs. * During a voice call, the communications are not interrupted when moving to another network site.

Mass call event

mass call eventoverload the systemmillions of extra people and their calls
However, it can also apply to landline phones, in which not enough trunking telephone circuits are available into and out of any given telephone exchange or equivalent switching office at any level of the public switched telephone network (PSTN). An MCE is typically caused by a sudden disaster of some sort, such as an earthquake or explosion. One of the earliest examples was the Iroquois Theatre Fire in Chicago in 1903. The 1963 Kennedy assassination represented a mass call event for Washington, DC.

Advanced Mobile Phone System

AMPSanalogTotal Access Communication System
Martin Cooper, developed portable cellular telephony, and Mitchell was among the Motorola employees granted a patent for this work in 1973. The first call on the prototype connected, reportedly, to a wrong number. While Motorola was developing a cellular phone, from 1968-1983 Bell Labs worked out a system called Advanced Mobile Phone System (AMPS), which became the first cellular network standard in the United States. The first system was successfully deployed in Chicago, Illinois, in 1979. Motorola and others designed and built the cellular phones for this and other cellular systems.

Japanese abbreviated and contracted words

Japanese method of abbreviationabbreviationcontracted
Japanese words are spelled using characters that represent syllables (morae), rather than individual phonetic units (phonemes) as in the English alphabet. These characters are compiled into two syllabaries: hiragana and katakana. Japanese also makes extensive use of adopted Chinese characters, or kanji, which may be pronounced with one or more syllables. Therefore, when a word or phrase is abbreviated, it does not take the form of initials, but the key characters of the original phrase, such that a new word is made, often recognizably derived from the original.

Area code 913

913area code 913
The two area codes of Kansas remained constant for more than 40 years, but by the mid-1990s, the proliferation of cell phones, the growing population in the Kansas City metropolitan area (most notably Johnson County and Overland Park), and deregulation due to the Telecommunications Act of 1996, the exchanges for area code 913 were quickly being exhausted. The number supply was further limited because the entire Kansas city metropolitan area is a single LATA, meaning several numbers in area code 816, which serves the Missouri portion, weren't available for use.