Concept
Roaming
Related concepts (16)
Mobile telephony
Mobile telephony is the provision of telephone services to mobile phones rather than fixed-location phones (landline phones). Telephony is supposed to specifically point to a voice-only service or connection, though sometimes the line may blur. Modern mobile phones connect to a terrestrial cellular network of base stations (cell sites), whereas satellite phones connect to orbiting satellites. Both networks are interconnected to the public switched telephone network (PSTN) to allow any phone in the world to be dialed.
AT&T Mobility
AT&T Mobility LLC, also known as AT&T Wireless and marketed as simply AT&T, is an American telecommunications company. It is a wholly owned subsidiary of AT&T Inc. and provides wireless services in the United States. AT&T Mobility is the largest wireless carrier in the United States, with 217.4 million subscribers at the end of Q4 2022. The company is headquartered in Brookhaven, Georgia. Originally known as Cingular Wireless (a joint venture between SBC Communications and BellSouth) from 2000 to 2007, the company acquired the old AT&T Wireless in 2004; SBC later acquired the original AT&T and adopted its name.
Network switching subsystem
Network switching subsystem (NSS) (or GSM core network) is the component of a GSM system that carries out call out and mobility management functions for mobile phones roaming on the network of base stations. It is owned and deployed by mobile phone operators and allows mobile devices to communicate with each other and telephones in the wider public switched telephone network (PSTN). The architecture contains specific features and functions which are needed because the phones are not fixed in one location.
Cellular network
A cellular network or mobile network is a telecommunications network where the link to and from end nodes is wireless and the network is distributed over land areas called cells, each served by at least one fixed-location transceiver (typically three cell sites or base transceiver stations). These base stations provide the cell with the network coverage which can be used for transmission of voice, data, and other types of content.
Mobile phone
A mobile phone (or cellphone) 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, as opposed to a fixed-location phone (landline phone). The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). Modern mobile telephone services use a cellular network architecture and therefore mobile telephones are called cellphones (or "cell phones") in North America.
Mobile phone operator
A mobile phone operator, wireless provider, or carrier is a mobile telecommunications company that provides wireless Internet GSM services for mobile device users. The operator gives a SIM card to the customer who inserts it into the mobile device to gain access to the service. There are two types of mobile operators: a mobile network operator (MNO) which owns the underlying network and spectrum assets required to run the service. a mobile virtual network operator (MVNO) which buys wholesale service from an MNO and sells on to its own customers.
T-Mobile US
T-Mobile US, Inc. is an American wireless network operator headquartered in Overland Park, Kansas, and Bellevue, Washington, U.S. Its largest shareholder is multinational telecommunications company Deutsche Telekom AG, which , holds a 53.3% majority stake in the company. T-Mobile US is the third-largest wireless carrier in the United States, with 113.6 million subscribers at the end of Q4 2022. The company was founded in 1994 by John W. Stanton of the Western Wireless Corporation as VoiceStream Wireless.
SIM card
A SIM card (full form: Subscriber Identity Module or Subscriber Identification Module) is an integrated circuit (IC) intended to store securely the international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and laptops). Technically the actual physical card is known as a universal integrated circuit card (UICC); this smart card is usually made of PVC with embedded contacts and semiconductors, with the SIM as its primary component.
UMTS
The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the International Telecommunication Union IMT-2000 standard set and compares with the CDMA2000 standard set for networks based on the competing cdmaOne technology. UMTS uses wideband code-division multiple access (W-CDMA) radio access technology to offer greater spectral efficiency and bandwidth to mobile network operators.
SMS
Short Message/Messaging Service, commonly abbreviated as SMS, is a text messaging service component of most telephone, Internet and mobile device systems. It uses standardized communication protocols that let mobile devices exchange short text messages. An intermediary service can facilitate a text-to-voice conversion to be sent to landlines. SMS technology originated from radio telegraphy in radio memo pagers that used standardized phone protocols. These were defined in 1986 as part of the Global System for Mobile Communications (GSM) series of standards.