Glossary S-T

SIM Card (Subscriber Identity Module) A SIM card is used in GSM mobile phones to identify the user for billing and other services.

SMTP (Simple Mail Transfer Protocol) - The prevalent protocol for the transmission of e-mail on a TCP/IP network. SMTP cannot deliver e-mail directly to an inbox, so it is relied upon only to deliver e-mail to a server. A version of Post Office Protocol (POP) generally handles retrieving e-mail from a server.

SOHO (Small Office Home Office) - A term used to characterize a business run from one’s home, or any business environment with relatively few employees.

Serial A form of data processing that handles data one bit at a time, in a series. Serial processing is common to many computer peripheral devices such as keyboards and mice. Serial processing contrasts with parallel processing, which describes multiple processes happening simultaneously.

Server A server is a computer program that provides on-demand resources to other computers. Also, the term server is used to describe the computer that houses the server program.

Signal compression A technique for transmitting signals in a format that requires less bandwidth than usual.

Slamming: The practice of switching long-distance carriers without a customer’s permission or knowledge. This frequently occurs during promotional giveaways in which the fine print contains the only mention of the long-distance provider change, or in other service agreements that may or may not be directly related to long-distance service.

Sound Card A computer peripheral device for audio input and output. Sound cards contain the software necessary for audio processing and at least 2 jacks, one for a speaker output and the other for microphone input.

Sound Tube Technology Unique, patented headset technology that channels your voice through a slender metal tube to the headset’s microphone.

Speakerphone A telephone that uses a loudspeaker and an external microphone in addition to, or instead of, a traditional telephone handset. Speakerphones are excellent for simple hands-free conversations by an individual user. More advanced speakerphones, called teleconferencers, may be simultaneously used by dozens of people.

Speech Recognition A software application that understands speech as a means of data input, executes verbal commands, or converts speech into text. Most speech recognition programs are able to understand a limited vocabulary and must be 'trained' over a period of time for uncommon terms, phrases, the user’s accent, and vocal inflection. In time, speech recognition is expected to become a much more common computer interface, gradually replacing manual methods (keyboard, mouse, etc.).

Spread Spectrum A radio technology that sends radio signals over multiple channels, changing the transmission and receipt frequency at programmed intervals. This type of spread spectrum is known as frequency-hopping spread spectrum and is the prevalent method used in cordless telephones.

Streaming: The real-time transmission of sound, data, or video on the Internet. Streaming media is sent as a steady, compressed stream of data that is played as it is received. Streaming media is becoming increasingly useful as a means of obtaining sound and video without time-consuming downloads, and for point-to-point video conferencing.

Stutter Dial tone: A service provided by many phone companies that lets the user know when a message has been left in voice mail. The broken (stutter) tone is heard when you first pick up the handset, and usually lasts for a few seconds before the standard dialtone is restored.

Switch A network device that determines the pathways for a given signal or for data. 1) In telephony, the Public Switched Telephone Network (PSTN) provides circuit switching based on the data provided by the telephone number dialed and keeps a dedicated connection on that call for the duration of the transmission. 2) IP-based transmissions use packet switching. This type of switch sends small data packets to their destination over numerous pathways, where they are reassembled.

T-Carrier A digital medium originally introduced to expand the capabilities of the Bell networks’ analog telephone network. T1 lines are very commonly leased to Internet service providers (ISPs) or to businesses because of their capacity of 1.544 Mbps (the equivalent of 24 standard phone lines). T2 lines are capable of carrying 6.312 Mbps (96 standard lines) and T3, 44.736 Mbps (672 lines). Many small enterprises that do not require the full capacity of a T1 are able to lease partial T1 connections to suit their business needs.

T1 (also see T-Carrier) - A digital phone line used to carry the capacity of 24 standard telephone lines. Since it is digital and serves numerous analog applications, a T1 line employs a version of Pulse Code Modulation (PCM) and Time Division Multiplexing (TDM).

TAD (Telephone Answering Device) - Another term that describes an answering machine. A TAD may be tape-driven or, more commonly, driven by a digital chip.

TCP/IP (Transmission Control Protocol/Internet Protocol) - The underlying protocol for the Internet. There are 2 layers to the protocol: TCP, which separates data into packets for transmission; and IP, which locates and directs the packets to their destination, or IP address. Once received, packets are reassembled by TCP. TCP/IP is used with other protocols on the Internet, such as Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP) and Simple Mail Transfer Protocol (SMTP).

TDMA (Time Division Multiple Access) - A form of multiplexing used in wireless communications that divides a radio signal into separate time slots so that multiple signals may be sent on the same frequency. The time divisions are very small, and inaudible to users.

TTY/TDD (TeleTYpewriter/Telecommunications Device for the Deaf) - Solutions provided to assist hearing- or speech-impaired users to communicate on a voice telecommunications network. TTY/TDD solutions require a teletype display. The TTY user types in his or her message to a live operator who vocally relays the typed message to the person being called. Vocal responses are typed by the relay operator and sent back to the original person on the TTY device.

Telecommunications A general term used to describe any form of data transmission over a medium. Telecommunications (or telecom) includes voice, video, and text over the media of copper wire, radio frequency, cable or optical networks.

Telecommute: The use of telecommunications to permit employees to work from outside the office, usually at home. The term 'telework' is now used as often to describe remote working.

Teleconferencing: includes any technology that allows multiple users to conference simultaneously using a telephone or network connection. Teleconferencing encompasses voice, video, and data sharing.

Telephony A term used to describe the technologies of transmitting voice over electronic media. Telephony is a subset of telecommunications.

Telnet: The TCP/IP standard that permits users outside a private network to access the network as if they were directly connected to it, treating the remote user as a virtual terminal.

Traffic In telecommunications contexts, the total amount of data being moved on a network in a given time period.

Transmission Sending: a signal by wire or radio.

Triplex Adapter A jack accessory that provides 3 ports: 1 port to connect line 1 or line 2 individually, and a third port that supports both lines.

Trunk Line A communication line between 2 switching systems. For example, the communications channel between the Central Office (CO) and a Private Branch Exchange (PBX) switch, or the channel between a Local Area Network (LAN) and a T1 carrier line.

Twisted-Pair Cable Twisted-pair cable consists of at least 1 pair of copper wires. In order to reduce the occurrence of external interference, the copper wires are insulated and wound around each other. Twisted-pair cables are used for home connections to the Telephone Company (voice and data) as well as for many Local Area Network (LAN) connections as a low-cost alternative to coaxial or fiber-optic cable.

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